Spectroscopic ellipsometer and polarimeter systems

• US 7,336,361 B1
• Filed: 10/25/2005
• Issued: 02/26/2008
• Est. Priority Date: 09/20/1995
• Status: Expired due to Term

• Current Assignee: J.A. Woollam Co., Inc.
• Original Assignee: J.A. Woollam Co., Inc.
• Inventors: Liphardt, Martin M., He, Ping, Hale, Jeffrey S., Herzinger, Craig M., Johs, Blaine D., Green, Steven E., Woollam, John A.
• Primary Examiner(s): Chowdhury; Tarifur
• Assistant Examiner(s): Akanbi; Isiaka O
• Application Number:
  US11/256,891
• Time in Patent Office: 854 Days
• Field of Search: 356/369, 356399-402, 356/153
• US Class Current: 356/369
• CPC Class Codes: G01J 4/00 Measuring polarisation of light
• CPC Class Codes: G01N 2021/213 Spectrometric ellipsometry
• CPC Class Codes: G01N 21/211 Ellipsometry optical thickness measurement G01B11/06

Abstract

A spectroscopic ellipsometer or polarimeter system having a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and a detector system which comprises a multiplicity of detector elements, there being apertures before the stage for supporting a material system, and thereafter, the system further having at least one multi-element lens and optionally being present in an environmental control chamber.

Claims

1. A spectroscopic rotating compensator material system investigation system comprising a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and at least one detector system which contains a multiplicity of detector elements, said spectroscopic rotating compensator material system investigation system further comprising at least one compensator(s) positioned at a location selected from the group consisting of:

before said stage for supporting a material system;

after said stage for supporting a material system; and

both before and after said stage for supporting a material system;

such that when said spectroscopic rotating compensator material system investigation system is used to investigate a material system present on said stage for supporting a material system, said analyzer and polarizer are maintained essentially fixed in position and at least one of said at least one compensator(s) is caused to continuously rotate while a polychromatic beam of electromagnetic radiation produced by said source of a polychromatic beam of electromagnetic radiation is caused to pass through said polarizer and said compensator(s), said polychromatic beam of electromagnetic radiation being also caused to interact with said material system, pass through said analyzer and interact with said dispersive optics such that a multiplicity of essentially single wavelengths are caused to simultaneously enter a corresponding multiplicity of detector elements in said at least one detector system;

said spectroscopic rotating compensator material system investigation system being further characterized by the presence of at least one multi-element lens positioned before and/or after said stage for supporting a material system.

2. A spectroscopic rotating compensator material system investigation system as in claim 1, in which said at least one multi-element lens is characterized by a selection from the group consisting of:

a) said at least one multi-element lens comprises;

two sequentially oriented elements, one of said two sequentially oriented elements being of a shape and orientation which individually diverges a beam of electromagnetic radiation caused to pass therethrough, and the other being of a shape and orientation which individually converges a beam of electromagnetic radiation caused to pass therethrough, there being a region between said at least two elements such that, in use, a beam of electromagnetic radiation sequentially passes through one of said at least two elements, then said region therebetween, and then the other of said at least two elements before emerging as an effectively converged, focused, beam of electromagnetic radiation;

b) said at least one multi-element lens comprises;

a sequential combination of a bi-convex element and a bi-concave element;

c) said at least one multi-element lens comprises;

a sequential combination of a bi-concave element and a bi-convex element;

d) said at least one multi-element lens comprises;

a sequential combination of a bi-convex element and a plano-concave element with said concave side of said plano-concave element adjacent to said bi-convex element;

e) said at least one multi-element lens comprises;

a sequential combination of a bi-convex element and a plano-concave element with said essentially flat side of said plano-concave element being adjacent to said bi-convex element;

f) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a bi-convex element with said essentially flat side of said plano-concave element adjacent to said bi-concave element;

g) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and bi-convex element with said concave side of said plano-concave element adjacent to said bi-convex element;

h) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element and a bi-concave element with said essentially flat side of said plano-convex element adjacent to said bi-concave element;

i) said at least one multi-element lens comprises;

a sequential combination of a bi-concave element with a plano-convex element with said convex side of said plano-convex element adjacent to said bi-concave element;

j) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a plano-convex element with the essentially flat side of said plano-concave element being adjacent to the convex side of the plano-convex element;

k) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a plano-convex element with the essentially flat side of said planoconcave element being adjacent to the flat side of said plano-convex element;

l) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element and a plano-concave element with the essentially flat side of said plano-convex element and the essentially flat side of said plano-concave element being adjacent to one another;

m) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a plano-convex element with the concave side of said plano-concave element being adjacent to the convex side of the plano-convex element;

n) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element bi-concave element with said convex side of said plano-convex element adjacent to said bi-concave element;

o) said at least one multi-element lens comprises;

a sequential combination of a bi-concave element and a plano-convex element with said essentially flat side of said plano-convex element adjacent to said bi-concave element;

p) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element and a plano-concave element with said convex side of said plano-convex element adjacent to the concave side of the plano-concave element;

q) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a plano-convex element with said essentially flat side of said plano-concave element being adjacent to the essentially convex side of the plano-convex element;

r) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element and a plano-concave element with said convex side of said plano-convex element being adjacent to the essentially flat side of the plano-concave element;

s) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element with a plano-convex element with the essentially flat side of said plano-convex element being adjacent to the concave side of said plano-concave element;

t) said at least one multi-element lens comprises;

at least one of the input and output lenses comprises at least two sequentially oriented elements, and is characterized by being a selection from the group consisting of;

a sequential combination of a converging element and a diverging element;

a sequential combination of a diverging element and a converging element;

a sequential combination of a converging element, a diverging element, a converging element and a diverging element;

a sequential combination of a converging element, a diverging element, a diverging element and a converging element;

a sequential combination of a diverging element, a converging element, a diverging element and a converging element;

a sequential combination of a diverging element, a converging element, a converging element and a diverging element;

includes a miniscus lens; and

includes an aspherical lens;

u) said at least one multi-element lens comprises;

two elements with a region therebetween, wherein said region between said at least two elements has the optical properties of a selection from the group consisting of;

a void region; and

a functional equivalent to a void region;

v) said at least one multi-element lens comprises;

at least two elements which are made from different materials independently selected from the group consisting of;

CaF₂;

BaF₂;

LiF;

MgF₂;

fused silica;

a void region;

a gas filled region;

a liquid filled region; and

a functional equivalent to a void region;

and wherein each of said at least two elements are individually selected to be made of different materials;

w) said at least one multi-element lens is characterized by at least one selection from the group consisting of;

a) the focal length is between forty and forty-one millimeters over a range of wavelengths of at least two-hundred to seven-hundred nanometers;

b) the focal length varies by less than five (5%) percent over a range of wavelengths of between two-hundred and five-hundred nanometers; and

c) the spot diameter at the focal length is less than seventy-five microns over a range of wavelengths of at least two-hundred to seven-hundred nanometers;

x) said at least one multi-element lens comprises;

an element made of a selection from the group consisting of;

CaF₂; and

fused silica;

y) at least one thereof;

is made of two elements, one of said elements being made of Fused Silica and the other of CaF₂;

z) said at least one multi-element lens comprises;

a converging element selected from the group consisting of;

a positive miniscus;

an asymmetric convex;

and/or a diverging element selected from the group consisting of;

a negative miniscus;

an asymmetric concave;

said selected at least one multi-element lens being characterized in that it demonstrates at least some birefringence.

3. A spectroscopic rotating compensator material system investigation system as in claim 1, in which said at least one multi-element lens comprises three lenses present in a tube, each thereof being precisely located with respect to one another and secured in said position by cement which is entered into said holes through the wall of said tube when an acceptable effect on said beam of electromagnetic radiation is achieved.

4. A spectroscopic rotating compensator material system investigation system as in claim 1, in which said at least one multi-element lens is comprised of two calcium fluoride lenses disposed on opposite sides of a fused silica lens, or two fused silica lenses disposed on opposite sides of a calcium fluoride lens, and is characterized by at least one selection from the group consisting of:

a) the focal length is between forty and forty-one millimeters over a range of wavelengths of at least two-hundred to seven-hundred nanometers;

b) the focal length varies by less than five (5%) percent over a range of wavelengths of between two-hundred and five-hundred nanometers; and

c) the spot diameter at the focal length is less than seventy-five microns over a range of wavelengths of at least two-hundred to seven-hundred nanometers.

5. A spectroscopic rotating compensator material system investigation system as in claim 1, in which said at least one multi-element lens is comprised of two calcium fluoride lenses disposed on opposite sides of a fused silica lens, said multi-element lens being characterized in that it demonstrates at least some birefringence.

6. A spectroscopic rotating compensator material system investigation system as in claim 1, in which said at least one multi-element lens is comprised of a calcium fluoride lens with two fused silica lenses disposed on opposite sides thereof of, said multi-element lens being characterized in that it demonstrates at least some birefringence.

7. A spectroscopic rotating compensator material system investigation system as in claim 1 in which the rotating compensator is of a type selected from the group consisting of:

Berek-type with optical axis essentially perpendicular to a surface thereof;

non-Berek-type with an optical axis essentially parallel to a surface thereof;

zero-order wave plate;

zero-order waveplate constructed from two multiple order waveplates;

a sequential plurality of zero-order waveplates, each constructed each from a plurality of multiple order waveplates;

rhomb;

polymer;

achromatic crystal; and

pseudo-achromatic;

and in which said compensator provides retardance within a range of thirty (30.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) minimum wavelength is less than/equal to one-hundred-ninety (190) and maximum wavelength greater than/equal to seventeen-hundred (1700) nanometers;

b) minimum wavelength is less than/equal to two-hundred-twenty (220) and maximum wavelength MAXW greater than/equal to one-thousand (1000) nanometers;

c) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) range where (MAXW)/(MINW) is at least four-and-one-half (4.5);

or said compensator provides retardance within a range of seventy-five (75.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) between one-hundred-ninety (190) and seven-hundred-fifty (750) nanometers;

b) between two-hundred-forty-five (245) and nine-hundred (900) nanometers;

c) between three-hundred-eighty (380) and seventeen-hundred (1700) nanometers;

d) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) wherein the ratio of (MAXW)/(MINW) is at least one-and-eight-tenths.

8. A spectroscopic rotating compensator material system investigation system as in claim 1 which is characterized by a mathematical model comprising calibration parameters, at least one of which is a member of the group consisting of:

effective polarizer azimuthal angle orientation (Ps);

present material system PSI (Ψ

), as a function of angle of incidence and a thickness;

present material system DELTA (Δ

), as a function of angle of incidence and a thickness;

compensator azimuthal angle orientation (C_s);

matrix components of said compensator;

analyzer azimuthal angle orientation (A_s); and

detector element image persistence (x_n) and read-out (p_n) nonidealities;

which mathematical model is effectively a transfer function which enables calculation of electromagnetic beam magnitude as a function of wavelength detected by a detector element (DE), given magnitude as a function of wavelength provided by said source of polychromatic beam of electromagnetic radiation (EPCLB);

said calibration parameter(s) selected from the group consisting of;

effective polarizer azimuthal angle orientation (Ps);

present material system PSI (Ψ

), as a function of angle of Incidence and a thickness;

present material system DELTA (Δ

), as a function of angle of incidence and a thickness;

compensator azimuthal angle orientation;

matrix components of said compensator (C_s) as a function of wavelength;

analyzer azimuthal angle orientation (A_s); and

detector element image persistence (x_n) and read-out (p_n) nonidealities;

being, in use, evaluated by performance of a mathematical regression of said mathematical model onto at least one, multi-dimensional, data set(s), said at least one, multi-dimensional, data set(s) being magnitude values vs. wavelength and a at least one parameter selected from the group consisting of;

angle-of-incidence of said polychromatic beam of electromagnetic radiation with respect to a present material system (MS); and

effective or actual azimuthal angle rotation of one element selected from the group consisting of;

said polarizer (P); and

said analyzer (A);

obtained over time, while said compensator (C) is caused to continuously rotate;

said at least one, multi-dimensional, data set(s) each being normalized to a selection from the group consisting of;

a data set D.C. component;

a data set A.C. component;

a parameter derived from a combinations of a data set D.C. component and a data set A.C. component.

9. A spectroscopic rotating compensator material system investigation system as in claim 1 which further comprises an environmental control chamber in which is present said spectroscopic rotating compensator material system investigation system, said environmental control chamber is characterized by a selection from the group consisting of:

it comprises at least one chamber region in which is present polarization state generator comprising component(s) prior to said material system, said material system, and polarization state detector comprising component(s) after said material system;

it comprises at least three chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system, in the second of which is present the material system and in the third of which is present polarization state detector comprising component(s) after said material system;

it comprises at least two chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system and said material system, and in the second of which is present polarization state detector comprising component(s) after said material system;

it comprises at least two chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system, and in the second of which is present polarization state detector comprising component(s) after said material system and said material system.

10. A spectroscopic ellipsometer or polarimeter system as in claim 1 in which the multiplicity of detector elements are arranged in a selection from the group consisting of:

one-dimensional array;

two-dimensional array; and

three-dimensional array.

11. A spectroscopic rotating compensator material system investigation system comprising a source of a polychromatic beam of electromagnetic radiation, a polarizer, a stage for supporting a material system, an analyzer, a dispersive optics and at least one detector system which contains a multiplicity of detector elements, said spectroscopic rotating compensator material system investigation system further comprising at least one pseudo-achromatic compensator(s) positioned at a location selected from the group consisting of:

before said stage for supporting a material system;

after said stage for supporting a material system; and

both before and after said stage for supporting a material system;

there being in the path of a polychromatic beam of electromagnetic radiation, provided by said source thereof, at least four apertures between said source of polychromatic beam of electromagnetic radiation and said stage for supporting a material system, and at least three apertures between said stage for supporting a material system and said at least one detector system;

said spectroscopic rotating compensator material system investigation system being further characterized in that it further comprises at least one multi-element lens in the pathway of said polychromatic beam of electromagnetic radiation;

such that when said spectroscopic rotating compensator material system investigation system is used to investigate a material system present on said stage for supporting a material system, said analyzer and polarizer are maintained essentially fixed in position and at least one of said at least one compensator(s) is caused to continuously rotate while a polychromatic beam of electromagnetic radiation produced by said source of a polychromatic beam of electromagnetic radiation is caused to pass through said polarizer and said at least one compensator(s) and said at least four apertures between said source of polychromatic beam of electromagnetic radiation and said stage for supporting a material system, said polychromatic beam of electromagnetic radiation being also caused to interact with a material system on said stage for supporting a material system, pass through said analyzer and said at least three apertures between said stage for supporting a material system, and interact with said dispersive optics such that a multiplicity of essentially single wavelengths are caused to simultaneously enter a corresponding multiplicity of detector elements in said at least one detector system;

said polychromatic beam of electromagnetic radiation also being caused to pass through said at least one multi-element lens.

12. A spectroscopic rotating compensator material system investigation system as in claim 11, in which said at least one multi-element lens is characterized by a selection from the group consisting of:

a) said at least one multi-element lens comprises;

two sequentially oriented elements, one of said two sequentially oriented elements being of a shape and orientation which individually diverges a beam of electromagnetic radiation caused to pass therethrough, and the other being of a shape and orientation which individually converges a beam of electromagnetic radiation caused to pass therethrough, there being a region between said at least two elements such that, in use, a beam of electromagnetic radiation sequentially passes through one of said at least two elements, then said region therebetween, and then the other of said at least two elements before emerging as an effectively converged, focused, beam of electromagnetic radiation;

b) said at least one multi-element lens comprises;

a sequential combination of a bi-convex element and a bi-concave element;

c) said at least one multi-element lens comprises;

a sequential combination of a bi-concave element and a bi-convex element;

d) said at least one multi-element lens comprises;

a sequential combination of a bi-convex element and a plano-concave element with said concave side of said plano-concave element adjacent to said bi-convex element;

e) said at least one multi-element lens comprises;

a sequential combination of a bi-convex element and a plano-concave element with said essentially flat side of said plano-concave element being adjacent to said bi-convex element;

f) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a bi-convex element with said essentially flat side of said plano-concave element adjacent to said bi-concave element;

g) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and bi-convex element with said concave side of said plano-concave element adjacent to said bi-convex element;

h) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element and a bi-concave element with said essentially flat side of said plano-convex element adjacent to said bi-concave element;

i) said at least one multi-element lens comprises;

a sequential combination of a bi-concave element with a plano-convex element with said convex side of said plano-convex element adjacent to said bi-concave element;

j) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a plano-convex element with the essentially flat side of said plano-concave element being adjacent to the convex side of the plano-convex element;

k) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a plano-convex element with the essentially flat side of said planoconcave element being adjacent to the flat side of said plano-convex element;

l) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element and a plano-concave element with the essentially flat side of said plano-convex element and the essentially flat side of said plano-concave element being adjacent to one another;

m) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a plano-convex element with the concave side of said plano-concave element being adjacent to the convex side of the plano-convex element;

n) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element bi-concave element with said convex side of said plano-convex element adjacent to said bi-concave element;

o) said at least one multi-element lens comprises;

a sequential combination of a bi-concave element and a plano-convex element with said essentially flat side of said plano-convex element adjacent to said bi-concave element;

p) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element and a plano-concave element with said convex side of said plano-convex element adjacent to the concave side of the plano-concave element;

q) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element and a plano-convex element with said essentially flat side of said plano-concave element being adjacent to the essentially convex side of the plano-convex element;

r) said at least one multi-element lens comprises;

a sequential combination of a plano-convex element and a plano-concave element with said convex side of said plano-convex element being adjacent to the essentially flat side of the plano-concave element;

s) said at least one multi-element lens comprises;

a sequential combination of a plano-concave element with a plano-convex element with the essentially flat side of said plano-convex element being adjacent to the concave side of said plano-concave element;

t) said at least one multi-element lens comprises;

at least one of the input and output lenses comprises at least two sequentially oriented elements, and is characterized by being a selection from the group consisting of;

a sequential combination of a converging element and a diverging element;

a sequential combination of a diverging element and a converging element;

a sequential combination of a converging element, a diverging element, a converging element and a diverging element;

a sequential combination of a converging element, a diverging element, a diverging element and a converging element;

a sequential combination of a diverging element, a converging element, a diverging element and a converging element;

a sequential combination of a diverging element, a converging element, a converging element and a diverging element;

includes a miniscus lens; and

includes an aspherical lens;

u) said at least one multi-element lens comprises;

two elements with a region therebetween, wherein said region between said at least two elements has the optical properties of a selection from the group consisting of;

a void region; and

a functional equivalent to a void region;

v) said at least one multi-element lens comprises;

at least two elements which are made from different materials independently selected from the group consisting of;

CaF₂;

BaF₂;

LiF;

MgF₂;

fused silica;

a void region;

a gas filled region;

a liquid filled region; and

a functional equivalent to a void region;

and wherein each of said at least two elements are individually selected to be made of different materials;

w) said at least one multi-element lens is characterized by at least one selection from the group consisting of;

a) the focal length is between forty and forty-one millimeters over a range of wavelengths of at least two-hundred to seven-hundred nanometers;

b) the focal length varies by less than five (5%) percent over a range of wavelengths of between two-hundred and five-hundred nanometers; and

c) the spot diameter at the focal length is less than seventy-five microns over a range of wavelengths of at least two-hundred to seven-hundred nanometers;

x) said at least one multi-element lens comprises;

an element made of a selection from the group consisting of;

CaF₂; and

fused silica;

y) at least one thereof;

is made of two elements, one of said elements being made of Fused Silica and the other of CaF₂;

z) said at least one multi-element lens comprises;

a converging element selected from the group consisting of;

a positive miniscus;

an asymmetric convex;

and/or a diverging element selected from the group consisting of;

a negative miniscus;

an asymmetric concave;

said selected at least one multi-element lens being characterized in that it demonstrates at least some birefringence.

13. A spectroscopic rotating compensator material system investigation system as in claim 11, in which said at least one multi-element lens comprises three lenses present in said tube, each thereof being precisely located with respect to one another and secured in said position by cement which is entered into said holes through the wall of said tube when an acceptable effect on said beam of electromagnetic radiation is achieved.

14. A spectroscopic rotating compensator material system investigation system as in claim 11, in which said at least one multi-element lens is comprised of two calcium fluoride lenses disposed on opposite sides of a fused silica lens, or two fused silica lenses disposed on opposite sides of a calcium fluoride lens, and is characterized by at least one selection from the group consisting of:

a) the focal length is between forty and forty-one millimeters over a range of wavelengths of at least two-hundred to seven-hundred nanometers;

b) the focal length varies by less than five (5%) percent over a range of wavelengths of between two-hundred and five-hundred nanometers; and

c) the spot diameter at the focal length is less than seventy-five microns over a range of wavelengths of at least two-hundred to seven-hundred nanometers.

15. A spectroscopic rotating compensator material system investigation system as in claim 11, in which said at least one multi-element lens is comprised of two calcium fluoride lenses disposed on opposite sides of a fused silica lens, said multi-element lens being characterized in that it demonstrates at least some birefringence.

16. A spectroscopic rotating compensator material system investigation system as in claim 11, in which said at least one multi-element lens is comprised of a calcium fluoride lens with two fused silica lenses disposed on opposite sides thereof of, said multi-element lens being characterized in that it demonstrates at least some birefringence.

17. A spectroscopic rotating compensator material system investigation system as in claim 11, in which the rotating compensator comprises a selection from the group consisting of:

comprised of a combination of at least two zero-order waveplates, said zero-order waveplates and having their respective fast axes rotated to a position offset from zero or ninety degrees with respect to one another;

comprised of a combination of at least a first and a second effective zero-order wave plate, said first effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, and said second effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another;

the fast axes of the multiple order waveplates in said second effective zero-order wave plate being rotated to a position at a nominal forty-five degrees to the fast axes of the multiple order waveplates and in said first effective zero-order waveplate;

comprised of a combination of at least a first and a second effective zero-order wave plate, said first effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, and said second effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another;

the fast axes of the multiple order waveplates in said second effective zero-order wave plate being rotated to a position away from zero or ninety degrees with respect to the fast axes of the multiple order waveplates and in said first effective zero-order waveplate; and

comprised of a combination of at least one zero-order waveplate and at least one effective zero-order waveplate, said effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, the fast axes of the multiple order waveplates in said effective zero-order wave plate being rotated to a position away from zero or ninety degrees with respect to the fast axis of the zero-order waveplate;

Berek-type with optical axis essentially perpendicular to a surface thereof;

non-Berek-type with an optical axis essentially parallel to a surface thereof;

zero-order wave plate;

zero-order waveplate constructed from two multiple order waveplates;

a sequential plurality of zero-order waveplates, each constructed each from a plurality of multiple order waveplates;

rhomb;

polymer;

achromatic crystal; and

pseudo-achromatic;

and in which said compensator provides retardance within a range of thirty (30.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) minimum wavelength is less than/equal to one-hundred-ninety (190) and maximum wavelength greater than/equal to seventeen-hundred (1700) nanometers;

b) minimum wavelength is less than/equal to two-hundred-twenty (220) and maximum wavelength MAXW greater than/equal to one-thousand (1000) nanometers;

c) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) range where (MAXW)/(MINW) is at least four-and-one-half (4.5);

or said compensator provides retardance within a range of seventy-five (75.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) between one-hundred-ninety (190) and seven-hundred-fifty (750) nanometers;

b) between two-hundred-forty-five (245) and nine-hundred (900) nanometers;

c) between three-hundred-eighty (380) and seventeen-hundred (1700) nanometers;

d) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) wherein the ratio of (MAXW)/(MINW) is at least one-and-eight-tenths.

18. A spectroscopic rotating compensator material system investigation system as in claim 11 which is characterized by a mathematical model comprising calibration parameters, at least one of which is a member of the group consisting of:

effective polarizer azimuthal angle orientation (Ps);

present material system PSI (Ψ

), as a function of angle of incidence and a thickness;

present material system DELTA (Δ

), as a function of angle of incidence and a thickness;

compensator azimuthal angle orientation (C_s);

matrix components of said compensator;

analyzer azimuthal angle orientation (A_s); and

detector element image persistence (x_n) and read-out (p_n) nonidealities;

which mathematical model is effectively a transfer function which enables calculation of electromagnetic beam magnitude as a function of wavelength detected by a detector element (DE), given magnitude as a function of wavelength provided by said source of polychromatic beam of electromagnetic radiation (EPCLB);

said calibration parameter(s) selected from the group consisting of;

effective polarizer azimuthal angle orientation (Ps);

present material system PSI (Ψ

), as a function of angle of incidence and a thickness;

present material system DELTA (Δ

), as a function of angle of incidence and a thickness;

compensator azimuthal angle orientation;

matrix components of said compensator (C_s) as a function of wavelength;

analyzer azimuthal angle orientation (A_s); and

detector element image persistence (x_n) and read-out (p_n) nonidealities;

being, in use, evaluated by performance of a mathematical regression of said mathematical model onto at least one, multi-dimensional, data set(s), said at least one, multi-dimensional, data set(s) being magnitude values vs. wavelength and a at least one parameter selected from the group consisting of;

angle-of-incidence of said polychromatic beam of electromagnetic radiation with respect to a present material system (MS); and

effective or actual azimuthal angle rotation of one element selected from the group consisting of;

said polarizer (P); and

said analyzer (A);

obtained over time, while said compensator (C) is caused to continuously rotate;

said at least one, multi-dimensional, data set(s) each being normalized to a selection from the group consisting of;

a data set D.C. component;

a data set A.C. component;

a parameter derived from a combinations of a data set D.C. component and a data set A.C. component.

19. A spectroscopic rotating compensator material system investigation system as in claim 11 which further comprises an environmental control chamber in which is present said spectroscopic rotating compensator material system investigation system, said environmental control chamber is characterized by a selection from the group consisting of:

it comprises at least one chamber region in which is present polarization state generator comprising component(s) prior to said material system, said material system, and polarization state detector comprising component(s) after said material system;

it comprises at least three chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system, in the second of which is present the material system and in the third of which is present polarization state detector comprising component(s) after said material system;

it comprises at least two chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system and said material system, and in the second of which is present polarization state detector comprising component(s) after said material system;

it comprises at least two chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system, and in the second of which is present polarization state detector comprising component(s) after said material system and said material system.

20. A spectroscopic ellipsometer or polarimeter system as in claim 11 in which the multiplicity of detector elements are arranged in a selection from the group consisting of:

one-dimensional array;

two-dimensional array; and

three-dimensional array.

21. A spectroscopic rotating compensator material system investigation system comprising a source of a polychromatic beam of electromagnetic radiation, a first aperture, a second aperture, a fixed polarizer, a rotating compensator, a third aperture, a forth aperture, a first substantially achromatic lens, a fifth aperture, a stage for supporting a material system, a sixth aperture, a second substantially achromatic lens, a seventh aperture, an eighth aperture, a fixed analyzer, a ninth aperture, a third substantially achromatic lens, an optical fiber and at least one detector system which comprises a dispersive element and a multiplicity of detector elements, there further being a UV filter present between said source of a polychromatic beam of electromagnetic radiation and said stage for supporting a material system;

such that when said spectroscopic rotating compensator material system investigation system is used to investigate a material system present on said stage for supporting a material system, said fixed analyzer and fixed polarizer are maintained essentially fixed in position and said rotating compensator is caused to continuously rotate while a polychromatic beam of electromagnetic radiation produced by said source of a polychromatic beam of electromagnetic radiation is sequentially caused to pass through said first aperture, second aperture, fixed polarizer, rotating compensator, third aperture, forth aperture, first substantially achromatic lens, fifth aperture, said polychromatic beam of electromagnetic radiation also passing through said UV filter, then interact with a material system placed on said stage for supporting a material system, then sequentially pass through said sixth aperture, second substantially achromatic lens, seventh aperture, eighth aperture, fixed analyzer, ninth aperture, third substantially achromatic lens, enter said optical fiber and therevia enter said detector system;

at least one of said first, second and third substantially achromatic lenses being characterized in that it comprises at least two elements which are made from different materials independently selected from the group consisting of;

CaF₂;

BaF₂;

LiF;

MgF₂;

fused silica;

a void region;

a gas filled region;

a liquid filled region; and

a functional equivalent to a void region.

22. A spectroscopic rotating compensator material system investigation system as in claim 21 in which the rotating compensator comprises a selection from the group consisting of:

comprised of a combination of at least two zero-order waveplates, said zero-order waveplates and having their respective fast axes rotated to a position offset from zero or ninety degrees with respect to one another;

comprised of a combination of at least a first and a second effective zero-order wave plate, said first effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, and said second effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another;

the fast axes of the multiple order waveplates in said second effective zero-order wave plate being rotated to a position at a nominal forty-five degrees to the fast axes of the multiple order waveplates and in said first effective zero-order waveplate;

comprised of a combination of at least a first and a second effective zero-order wave plate, said first effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, and said second effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another;

the fast axes of the multiple order waveplates in said second effective zero-order wave plate being rotated to a position away from zero or ninety degrees with respect to the fast axes of the multiple order waveplates and in said first effective zero-order waveplate; and

comprised of a combination of at least one zero-order waveplate and at least one effective zero-order waveplate, said effective zero-order wave plate being comprised of two multiple order waveplates which are combined with the fast axes thereof oriented at a nominal ninety degrees to one another, the fast axes of the multiple order waveplates in said effective zero-order wave plate being rotated to a position away from zero or ninety degrees with respect to the fast axis of the zero-order waveplate;

Berek-type with optical axis essentially perpendicular to a surface thereof;

non-Berek-type with an optical axis essentially parallel to a surface thereof;

zero-order wave plate;

zero-order waveplate constructed from two multiple order waveplates;

a sequential plurality of zero-order waveplates, each constructed each from a plurality of multiple order waveplates;

rhomb;

polymer;

achromatic crystal; and

pseudo-achromatic;

and in which said compensator provides retardance within a range of thirty (30.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) minimum wavelength is less than/equal to one-hundred-ninety (190) and maximum wavelength greater than/equal to seventeen-hundred (1700) nanometers;

b) minimum wavelength is less than/equal to two-hundred-twenty (220) and maximum wavelength MAXW greater than/equal to one-thousand (1000) nanometers;

c) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) range where (MAXW)/(MINW) is at least four-and-one-half (4.5);

or said compensator provides retardance within a range of seventy-five (75.0) to less than one-hundred-thirty-five (135) degrees over a range of wavelengths defined by a selection from the group consisting of;

a) between one-hundred-ninety (190) and seven-hundred-fifty (750) nanometers;

b) between two-hundred-forty-five (245) and nine-hundred (900) nanometers;

c) between three-hundred-eighty (380) and seventeen-hundred (1700) nanometers;

d) within a range of wavelengths defined by a maximum wavelength (MAXW) and a minimum wavelength (MINW) wherein the ratio of (MAXW)/(MINW) is at least one-and-eight-tenths.

23. A spectroscopic rotating compensator material system investigation system as in claim 21, in which:

said first aperture is a pin-hole, through which a portion of the polychromatic beam of electromagnetic radiation passes, with a nominal internal diameter of between 100 and 600 microns;

said second aperture through which a portion of the polychromatic beam of electromagnetic radiation passes, has a nominal internal diameter has a nominal internal diameter of 3 to 3.5 millimeters;

said third aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 3.5 millimeters;

said forth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 3.75 millimeters;

said fifth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 4.8 millimeters;

said sixth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 4.8 millimeters;

said seventh aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 3.75 millimeters;

an eighth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has a nominal internal diameter of 3.5 millimeters;

said ninth aperture, through which a portion of the polychromatic beam of electromagnetic radiation passes, has an internal diameter has an adjustable internal diameter.

24. A spectroscopic rotating compensator material system investigation system as in claim 21 which is characterized by a mathematical model comprising calibration parameters, at least one of which is a member of the group consisting of:

effective polarizer azimuthal angle orientation (Ps);

present material system PSI (ψ

), as a function of angle of incidence and a thickness;

present material system DELTA (Δ

), as a function of angle of incidence and a thickness;

compensator azimuthal angle orientation (C_s);

matrix components of said compensator;

analyzer azimuthal angle orientation (A_s); and

detector element image persistence (x_n) and read-out (p_n) nonidealities;

which mathematical model is effectively a transfer function which enables calculation of electromagnetic beam magnitude as a function of wavelength detected by a detector element (DE), given magnitude as a function of wavelength provided by said source of polychromatic beam of electromagnetic radiation (EPCLB);

said calibration parameter(s) selected from the group consisting of;

effective polarizer azimuthal angle orientation (Ps);

present material system PSI (Ψ

), as a function of angle of incidence and a thickness;

present material system DELTA (Δ

), as a function of angle of incidence and a thickness;

compensator azimuthal angle orientation;

matrix components of said compensator (C_s) as a function of wavelength;

analyzer azimuthal angle orientation (A_s); and

detector element image persistence (x_n) and read-out (p_n) nonidealities;

being, in use, evaluated by performance of a mathematical regression of said mathematical model onto at least one, multi-dimensional, data set(s), said at least one, multi-dimensional, data set(s) being magnitude values vs. wavelength and a at least one parameter selected from the group consisting of;

angle-of-incidence of said polychromatic beam of electromagnetic radiation with respect to a present material system (MS); and

effective or actual azimuthal angle rotation of one element selected from the group consisting of;

said polarizer (P); and

said analyzer (A);

obtained over time, while said compensator (C) is caused to continuously rotate;

said at least one, multi-dimensional, data set(s) each being normalized to a selection from the group consisting of;

a data set D.C. component;

a data set A.C. component;

a parameter derived from a combinations of a data set D.C. component and a data set A.C. component.

25. A spectroscopic rotating compensator material system investigation system as in claim 21 which further comprises an environmental control chamber in which is present said spectroscopic rotating compensator material system investigation system, said environmental control chamber is characterized by a selection from the group consisting of:

it comprises at least one chamber region in which is present polarization state generator comprising component(s) prior to said material system, said material system, and polarization state detector comprising component(s) after said material system;

it comprises at least three chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system, in the second of which is present the material system and in the third of which is present polarization state detector comprising component(s) after said material system;

it comprises at least two chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system and said material system, and in the second of which is present polarization state detector comprising component(s) after said material system;

it comprises at least two chamber regions, in one of which is present polarization state generator comprising component(s) prior to said material system, and in the second of which is present polarization state detector comprising component(s) after said material system and said material system.

26. A spectroscopic ellipsometer or polarimeter system as in claim 21 in which the multiplicity of detector elements are arranged in a selection from the group consisting of:

one-dimensional array;

two-dimensional array; and

three-dimensional array.