Inspection method of photo mask for use in manufacturing semiconductor device

• US 20020192578A1
• Filed: 04/25/2002
• Published: 12/19/2002
• Est. Priority Date: 04/26/2001
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Tanaka, Satoshi, Inoue, Soichi
• Granted Patent: US 6,990,225 B2
• Time in Patent Office: Days
• US Class Current: 430/30
• CPC Class Codes: G01N 21/956 Inspecting patterns on the surface of objects contactless testing of electronic circuits G01R31/308; testing currency G07D; manufacturing processes per se of semiconductor devices implementing a measuring step H01L22/10
• CPC Class Codes: G03F 1/84 Inspecting
• CPC Class Codes: G03F 7/705 Modelling or simulating from physical phenomena up to complete wafer processes or whole workflow in wafer productions
• CPC Class Codes: G03F 7/706 Aberration measurement
• CPC Class Codes: G06T 2207/30148 Semiconductor; IC; Wafer
• CPC Class Codes: G06T 7/0002 Inspection of images, e.g. flaw detection
• CPC Class Codes: G06T 7/001 using an image reference approach

Abstract

An inspection method of a mask pattern for exposure comprises using substantially the same inspection wavelength as an exposure wavelength for use in the exposure apparatus and using a detection optical system of the inspection apparatus having a numerical aperture larger than a numerical aperture of a projection optical system of the exposure apparatus to prepare image data of the mask pattern for exposure using the detection optical system and reconstructing low-ordered diffracted light distribution obtained from the mask pattern for exposure by using the image data based on information of the detection optical system. The inspection method comprises using transfer simulation in the projection optical system of the exposure apparatus to obtain an image intensity distribution obtained on a wafer from the low-ordered diffracted light distribution and judging acceptance/rejection of inspection based on the obtained image intensity distribution.

Claims

1. An inspection method of a mask pattern for exposure for use in an exposure apparatus for manufacturing a semiconductor device, comprising:

using substantially the same inspection wavelength as an exposure wavelength for use in said exposure apparatus and using a detection optical system of said inspection apparatus having a numerical aperture larger than a numerical aperture of a projection optical system of said exposure apparatus to prepare image data of said mask pattern for exposure using the detection optical system;

reconstructing a low-ordered diffracted light distribution obtained from said mask pattern for exposure by using the image data based on information of said detection optical system;

using transfer simulation in said projection optical system of said exposure apparatus to obtain an image intensity distribution obtained on a wafer from the low-ordered diffracted light distribution; and

judging acceptance/rejection of inspection based on said obtained image intensity distribution.

2. The inspection method of the mask pattern for exposure according to claim 1, further comprising:

setting said inspection wavelength (λ

ins) in a range in which optical characteristics during the use of said exposure wavelength (λ

) and optical characteristics during the use of said inspection wavelength do not change.

3. The inspection method of the mask pattern for exposure according to claim 2, further comprising:

using said inspection wavelength (λ

ins) which has the range of the following equation (1) with respect to said exposure wavelength (λ

);

0.9λ

≦

λ

ins≦

1.1λ

 

 

(1).

4. The inspection method of the mask pattern for exposure according to claim 1, further comprising:

preparing said image data of said mask pattern for exposure so that a pixel distance (D) converted on the mask to be inspected of the image data satisfies at least a condition of the following equation (2);

D≦

λ

ins/(2(1+σ

ins)NAins) 

 

(2),

in which λ

ins denotes said inspection wavelength, NAins denotes an objective side numerical aperture of said detection optical system, and σ

ins denotes a coherence factor of said detection optical system.

5. The inspection method of the mask pattern for exposure according to claim 1, wherein obtaining said low-ordered diffracted light distribution comprises:

using only the diffracted light distribution present in the range of the following equations (3), (4) as said low-ordered diffracted light distribution (m(f,g)) of the mask pattern;

−

(1+σ

)NA/λ

≦

f≦

(1+σ

)NA/λ

 

 

(3); and

−

(1+σ

)NA/λ

≦

g ≦

(1+σ

)NA/λ

 

 

(4),

in which σ

denotes a coherence factor of said exposure apparatus, NA denotes a projection optical system numerical aperture of said exposure apparatus, λ

denotes said exposure wavelength, and f, g denote a projection optical system pupil coordinate of said exposure apparatus.

6. The inspection method of the mask pattern for exposure according to claim 5, wherein obtaining said diffracted light distribution of said mask pattern for exposure comprises:

perturbing an initial value (m0(f,g)) of the diffracted light distribution obtained from a design value of said mask pattern for exposure and obtaining a value of m(f,g) so as to minimize the value of R obtained by the following equation (5);

7. The inspection method of the mask pattern for exposure according to claim 5, further comprising:

obtaining said diffracted light distribution (m(f,g)) of said mask pattern for exposure from data (I(x,y)) obtained by correcting said obtained image data in a light intensity distribution in a detection apparatus surface of said detection optical system so as to minimize the value of R determined by the following equation (6);

8. The inspection method of the mask pattern for exposure according to claim 1, wherein performing said acceptance/rejection judgment of said inspection comprises:

assuming a predetermined focusing precision or an exposure amount dispersion during exposure;

obtaining a processed shape obtained on the wafer under the conditions; and

judging whether a dimension precision satisfies a predetermined reference.

9. A photo mask for exposure which is formed using the inspection method of the mask pattern for exposure according to claim 1.

10. A semiconductor device which is manufactured using a photo mask for exposure formed using the inspection method of the mask pattern for exposure according to claim 1 in a manufacturing process.