Flying mobile on-board ellipsometer, polarimeter, reflectometer and the like systems

• US 7,277,171 B1
• Filed: 04/14/2005
• Issued: 10/02/2007
• Est. Priority Date: 01/16/2001
• 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, Johs, Blaine D., Welch, James D., Woollam, John A., Goeden, Christopher A.
• Primary Examiner(s): Pham; Hoa Q.
• Application Number:
  US11/105,852
• Time in Patent Office: 901 Days
• Field of Search: 356364-369, 250/225
• US Class Current: 356/369
• CPC Class Codes: G01N 2021/151 Gas blown
• CPC Class Codes: G01N 2021/212 Arrangement with total internal reflection
• CPC Class Codes: G01N 2021/214 Variangle incidence arrangement
• CPC Class Codes: G01N 21/21 Polarisation-affecting properties G01N21/19 takes precedence
• CPC Class Codes: G01N 21/55 Specular reflectivity
• CPC Class Codes: G01N 2201/021 Special mounting in general
• CPC Class Codes: G01N 2201/0693 Battery powered circuitry

Abstract

A substantially self-contained “on-board” material system investigation system functionally mounted on a three dimensional locational system to enable positioning at desired locations on, and distances from, the surface of a large sample, including the capability to easily and conveniently change the angle-of-incidence of a beam of electromagnetic radiation onto a sample surface.

Claims

1. A system selected from the group consisting of:

reflectometer;

rotating analyzer ellipsometer;

rotating polarizer ellipsometer;

rotating compensator ellipsometer;

modulation element ellipsometer;

Mueller Matrix measuring system;

functionally mounted to a two dimension location means for positioning said selected system at points in a two dimensional plane which is, in use, oriented substantially parallel to but offset from, the plane of a surface of a sample;

said selected system comprising on-board;

source means for providing a beam of electromagnetic radiation; and

data detector means for detecting electromagnetic radiation;

such that in use said selected system is located near the surface of said sample and a beam of electromagnetic radiation provided by said source means is caused to interact therewith and enter said data detector means;

said selected system further comprising means for adjusting the location thereof at desired third dimension offset locations with respect to points in said plane of the surface of said sample; and

said selected system further comprising means for controlling the location of the source means and data detector means in said two dimension plane;

said selected system further comprising at least one electromagnetic beam intercepting angle-of-incidence changing system comprising elements which are easily functionally entered into the locus of the electromagnetic beam on both sides of said sample system, which at least one electromagnetic beam intercepting angle-of-incidence changing system serves to direct said electromagnetic beam onto substantially the same spot on the sample system as is the case where the said at least one electromagnetic beam intercepting angle-of-incidence changing system is not functionally present, but at an angle-of-incidence which is different than that when said at least one electromagnetic beam intercepting angle-of-incidence changing system is not functionally present, said at least one electromagnetic beam intercepting angle-of-incidence changing system not effecting, or requiring change of, the locus of the electromagnetic beams outside said at least one electromagnetic beam intercepting angle-of-incidence changing system, on either side of said means for supporting a sample system.

2. A system as in claim 1, which further comprises attached cable means for at least one selection from the group consisting of:

providing electrical power; and

transmitting data from said data detector means.

3. A system as in claim 1, which further comprises an on-board battery source of electric power.

4. A system as in claim 1, which further comprises an on-board wireless transmitter for transmitting data from said data detector means.

5. A system as in claim 1, in which the:

reflectometer;

rotating analyzer ellipsometer;

rotating polarizer ellipsometer;

rotating compensator ellipsometer;

modulation element ellipsometer;

Mueller Matrix measuring system;

is spectroscopic in that it operates at a multiplicity of wavelengths.

6. A system as in claim 1, in which said system is 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.

7. A system as in claim 1, in which said selected system further comprises means for flowing purging gas onto said sample at a location thereon at which electromagnetic radiation of UV and/or IR wavelengths is caused to impinge.

8. A system as in claim 1, in which said at least one electromagnetic beam intercepting angle-of-incidence changing system comprises, on each side of said means for supporting a sample system, at least one selection from the groups consisting of:

multiple angle prism(s); and

a system of mirrors;

said at least one electromagnetic beam intercepting angle-of-incidence changing system being slidably mounted to a guide element such that the functional presence thereof in the pathway of the locus of the electromagnetic beams on both sides of said means for supporting a sample system is effected by physical sliding motion of said at least one electromagnetic beam intercepting angle-of-incidence changing system along said guide element.

9. A system as in claim 1, in which said at least one electromagnetic beam intercepting angle-of-incidence changing system comprises a first multiangle prism on the incident side of said means for supporting a sample system and a second multiangle prism thereafter, said first and second multiangle prisms each having a first and a second side, each said multiangle prism presenting with first and second inner surfaces associated with said first and second sides, respectively, the first and second side of each multiangle prism having means for changing the properties of inner surface thereof from essentially transmissive to essentially reflective, each said multiangle prism being oriented such that an electromagnetic beam entering thereinto encounters the first or second inner surface thereof and either passes therethrough and progresses on to contact a sample system placed on said means for supporting a sample system, or reflects from said first or second inner surface thereof and then from said second or first inner surface thereof, respectively, and then progresses on to contact a sample system placed on said means for supporting a sample system.

10. A system as in claim 9, which further comprises at least one shutter door which can be opened to let the electromagnetic beam pass, or closed to block its passage, said at least one shutter door being positioned in the electromagnetic beam locus selected from the group consisting of:

defined by passage through said first or second side of said first multiangle prism; and

defined by reflection from said first or second side of said first multiangle prism;

said at least one shutter door being positioned between at least one selection from the group consisting of;

said first multiangle prism and the means for supporting a sample system; and

said means for supporting a sample system and said second multiangle prism.

11. A system as in claim 1, in which said at least one electromagnetic beam intercepting angle-of-incidence changing system comprises, on first and second sides of said means for supporting a sample system, first and second beam splitters, respectively, which first and second beam splitters each pass approximately half, and reflect approximately half of a beam of electromagnetic radiation caused to be incident thereupon at an oblique angle to a surface thereof;

said at least one electromagnetic beam intercepting angle-of-incidence changing system further comprising a first reflective means positioned to intercept the approximately half of the electromagnetic beam which reflects from said first beam splitter on the incident side of said means for supporting a sample system and direct it toward said means for supporting a sample system; and

also further comprising a second reflective means positioned after said means for supporting a sample system to intercept an electromagnetic beam which reflects from a sample system placed on said means for supporting a sample system and direct it toward the second beam splitter;

said material system investigating system further comprising at least one shutter door which can be opened to let the electromagnetic beam pass, or closed to block its passage, said at least one shutter door being positioned in the pathway of the electromagnetic beam between which progresses along a locus selected from the group consisting of;

defined by passage through said first beam splitter; and

defined by reflection from said first beam splitter;

on either side of said means for supporting a sample system.

12. A system as in claim 1, which includes at least two multiple angle prisms, one being present on one side of said sample system, and the other thereof being present on the other side of said sample system.

13. A system as in claim 1, which includes focusing optic positioned to focus a beam of electromagnetic radiation onto a sample system.

14. A system as in claim 1, which includes means for adjusting the orientation of at least one electromagnetic beam intercepting angle-of-incidence changing system, optionally in simultaneous combination which includes focusing optics positioned to focus a beam of electromagnetic radiation onto a sample system and recollimate the beam of electromagnetic radiation which reflects from said sample system.

15. A system as in claim 1, in which the at least one electromagnetic beam intercepting angle-of-incidence changing system comprises, on at least one side selected from the group consisting of:

said first and;

said second;

sides of said means for supporting a sample system, at least one system of mirrors, said at least one system of mirrors being comprised of;

a means for changing the propagation direction of an initial beam of electromagnetic radiation without significantly changing the phase angle between orthogonal components thereof, said means comprising two pairs of reflecting mirrors oriented so that said initial beam of electromagnetic radiation reflects from a first reflecting means in the first pair of reflecting means to a second reflecting means in said first pair of reflecting means, in a first plane; and

such that the beam of electromagnetic radiation which reflects from the second reflecting means in said first pair of reflecting means reflects from the first reflecting means in said second pair of reflecting means to said second reflecting means in said second pair of reflecting means, in a second plane which is essentially orthogonal to said first plane;

such that the direction of propagation of the beam of electromagnetic radiation reflected from the second reflecting means in said second pair of reflecting means is different from the propagation direction of the initial beam of electromagnetic radiation;

the basis of operation being that changes entered between the orthogonal components by the first pair of reflective means is canceled by that entered by the second pair of reflective means.

16. An system for application in investigating a sample system with electromagnetic radiation, sequentially comprising:

a. a source of a beam electromagnetic radiation;

b. a polarizer element;

c. optionally a compensator element;

d. additional element(s);

e. a sample system;

f. additional element(s);

g. optionally a compensator element;

h. an Analyzer element; and

i. a Detector System;

wherein said additional component(s) in d. and f. each comprise at least one electromagnetic beam intercepting angle-of-incidence changing system element which can be easily entered into the locus of the electromagnetic beam on both sides of said sample system, which at least one electromagnetic beam intercepting angle-of-incidence changing system elements serves to direct said electromagnetic beam onto substantially the same spot on the sample system as is the case where the said at least one electromagnetic beam intercepting angle-of-incidence changing system elements are not present, but at an angle-of-incidence which is different than that when said at least one electromagnetic beam intercepting angle-of-incidence changing system is not present, said at least one electromagnetic beam intercepting angle-of-incidence changing system elements not effecting, or requiring change of, the locus of the electromagnetic beams outside said at least one electromagnetic beam intercepting angle-of-incidence changing system elements, on either side thereof, hence does not require multiple sources and detectors or change of position of at least one selection from the group consisting of;

said source of electromagnetic radiation; and

said detector thereof;

to effect change said angle-of-incidence;

said material system investigating system being functionally mounted to a two dimension location means for positioning said selected system at points in an two dimensional plane which is, in use, oriented substantially parallel to but offset from, the plane of a surface of said sample system;

such that in use said selected system is located near the surface of said sample and a beam of electromagnetic radiation provided by said source means is caused to interact therewith and enter said data detector means;

said selected system further comprising means for adjusting the location thereof at desired third dimension offset locations with respect to points in said plane of the surface of said sample; and

said selected system further comprising means for controlling the location of the source means and data detector means in said two dimension plane.

17. A system as in claim 16, in which each electromagnetic beam intercepting angle-of-incidence changing system is a selection from the group consisting of:

multiangle prisms; and

a plurality of mirrors.

18. A system selected from the group consisting of:

reflectometer;

rotating analyzer ellipsometer;

rotating polarizer ellipsometer;

rotating compensator ellipsometer;

modulation element ellipsometer;

Mueller Matrix measuring system;

functionally mounted to a two dimension location means for positioning said selected system at points in a two dimensional plane which is, in use, oriented substantially parallel to but offset from, the plane of a surface of a sample;

said selected system comprising on-board;

source means for providing a beam of electromagnetic radiation; and

data detector means for detecting electromagnetic radiation;

such that in use said selected system is located near the surface of said sample and a beam of electromagnetic radiation provided by said source means is caused to interact therewith and enter said data detector means;

said selected system further comprising means for adjusting the location thereof at desired third dimension offset locations with respect to points in said plane of the surface of said sample; and

said selected system further comprising means for controlling the location of the source means and data detector means in said two dimension plane;

said selected system further comprising a means for setting the angle of incidence of a beam of electromagnetic radiation comprising, as viewed in elevation, first and second arms pivotally interconnected to one another at an upper aspect thereof by a first pivot means, said first and second arms projecting downward and to the left and right of said first pivot means;

distal ends of said first and second arms being pivotally affixed to third and forth arms, said third and forth arms being pivotally interconnected to one another by a second pivot means at a lower aspect thereof, said third and forth arms being projected upward and to the left and right of said second pivot means at said lower aspect thereof;

there being at least two substantially downward projecting arms pivotally affixed to each of said third and forth arms, distal ends of which are pivotally affixed to fifth and sixth arms which are not interconnected to one another, but project upward to the left and right, respectively;

there being affixed to one of said fifth and sixth arms a source of a beam of electromagnetic radiation, and to the other of said sixth and fifth arms a detector of said beam of electromagnetic radiation;

there further being a sample located such that a beam of electromagnetic radiation produced by said source of a beam of electromagnetic radiation reflects from an upper surface of said sample and enters said detector of said beam of electromagnetic radiation;

such that in use when the first pivot means at which said first and second arms are interconnected is caused to be vertically raised or lowered, the angle of incidence at which the beam of electric radiation approaches said sample surface is changed, but the location at which it interacts with said sample surface remains substantially unchanged.

19. A system selected from the group consisting of:

reflectometer;

rotating analyzer ellipsometer;

rotating polarizer ellipsometer;

rotating compensator ellipsometer;

modulation element ellipsometer;

Mueller Matrix measuring system;

functionally mounted to a two dimension location means for positioning said selected system at points in a two dimensional plane which is, in use, oriented substantially parallel to but offset from, the plane of a surface of a sample;

said selected system comprising on-board;

source means for providing a beam of electromagnetic radiation; and

data detector means for detecting electromagnetic radiation;

such that in use said selected system is located near the surface of said sample and a beam of electromagnetic radiation provided by said source means is caused to interact therewith and enter said data detector means;

said selected system further comprising means for adjusting the location thereof at desired third dimension offset locations with respect to points in said plane of the surface of said sample; and

said selected system further comprising means for controlling the location of the source means and data detector means in said two dimension plane;

said system further comprising one electromagnetic beam intercepting angle-of-incidence changing system comprising elements which are easily functionally entered into the locus of the electromagnetic beam on one side of said sample system, which one electromagnetic beam intercepting angle-of-incidence changing system serves to direct said electromagnetic beam to, or receive said electromagnetic beam from substantially the same spot on the sample system as is the case where the said one electromagnetic beam intercepting angle-of-incidence changing system is not functionally present.