Surface Inspecting Method

Patent metadata

Field	Value
Publication number	US-2016153915-A1
Application number	US-201514955635-A
Country	US
Kind code	A1
Filing date	Dec 1, 2015
Priority date	Dec 2, 2014
Publication date	Jun 2, 2016
Grant date	—

Abstract

A surface inspecting method includes: irradiating an incident light beam of a first polarized state on a target object, the incident light beam comprising parallel light and having a cross-sectional area: measuring a second polarized state of a reflected light beam reflected from the target object; and performing inspection on an entire area of the target object on which the incident light beam is irradiated, based on a variation between the first polarized state and the second polarized state.

First claim

What is claimed is:

1 . A surface inspecting method comprising:
irradiating an incident light beam of a first polarized state on a target object, the incident light beam comprising parallel light and having a cross-sectional area: measuring a second polarized state of a reflected light beam reflected from the target object; and performing an inspection on an entire area of the target object on which the incident light beam is irradiated, based on a variation between the first polarized state and the second polarized state.

2 . The surface inspecting method of claim 1 , wherein the target object comprises a pattern, and
the performing of the inspection comprises: calculating physical quantities of an imaginary thin film indicating a same polarized state as the second polarized state with respect to the incident light beam; and calculating physical quantities of the target object from the physical quantities of the imaginary thin film by using a relationship in which a height of the pattern is proportional to a thickness of the imaginary thin film and a width of the pattern is proportional to a value acquired by dividing a materials mixing ratio of the imaginary thin film by the height of the pattern.

3 . The surface inspecting method of claim 2 , wherein the calculating of the physical quantities of the imaginary thin film comprises:
providing a theoretical model having substantially a same shape as the imaginary thin film and comparing a theoretical result of the theoretical model with a result measured with respect to the target object; adjusting a parameter of the theoretical model and acquiring a condition in which the theoretical result matches the measured result; and calculating the physical quantities of the imaginary thin film using the condition.

4 . The surface inspecting method of claim 3 , further comprising outputting, in an image form, a difference between a theoretical spectrum indicating a theoretical result with respect to a plurality of wavelength ranges of the theoretical model and a measurement spectrum indicting a result measured with respect to the plurality of wavelength ranges in the target object; and
detecting defects of the target object.

5 . The surface inspecting method of claim 2 , wherein the target object comprises a plurality of patterns that are periodically formed.

6 . The surface inspecting method of claim 1 , wherein the measuring of the second polarized state comprises:
irradiating a plurality of light beams having different wavelength ranges on the target object in time series; and measuring a plurality of light beams reflected from the target object in time series.

7 . The surface inspecting method of claim 1 , wherein the surface inspecting method is performed with respect to each of a plurality of wavelength ranges, and
the surface inspecting method further comprises outputting, in an image form, a polarization spectrum indicating each second polarized state according to the plurality of wavelength ranges after the inspection.

8 . The surface inspecting method of claim 1 , wherein the performing of the inspection comprises:
providing a theoretical model having substantially a same shape as the target object and comparing a theoretical result of the theoretical model with respect to a polarized state and a result measured with respect to the target object; adjusting a parameter of the theoretical model such that the theoretical result matches the measured result; and irradiating incident light beams having various incidence angles on the theoretical model and the target object and calculating the flatness of the surface of the target object according to a difference between polarized states of reflected light beams reflected from the theoretical model and the target object.

9 . The surface inspecting method of claim 1 , wherein the performing of the inspection comprises:
dividing a polarization spectrum for each element region with respect to the target object by using a designed pattern of the target object; and measuring a specific defect tendency for each element region from a distribution tendency of the polarization spectrum divided for each element region.

10 . The surface inspecting method of claim 1 , wherein the measuring is performed by a detector, and a sub-pixel means that a pixel region capable of being maximally resolved by the detector is divided into at least two regions, and
the surface inspecting method further comprises, after the inspection, moving a stage supporting the target object by the sub-pixel.

11 . A surface inspecting method comprising:
irradiating an incident light beam of a first polarized state on a first inspection region, and primarily measuring a second polarized state of a reflected light beam reflected from the first inspection region; moving a stage supporting a target object by a sub-pixel such that the incident light beam is irradiated on a second inspection region overlapping the first inspection region by an area of at least one sub-pixel; and irradiating an incident light beam of a third polarized state on the second inspection region, and secondarily measuring a fourth polarized state of a reflected light beam reflected from the second inspection region, wherein a sub-pixel is smaller than a pixel region, and the pixel region is a region that is capable of being maximally resolved by a detector.

12 . The surface inspecting method of claim 11 , wherein the incident light beam is a parallel light beam having a cross-sectional area, and
the incident light beam is irradiated on the entire first inspection region in the primarily measuring and is irradiated on the entire second inspection region in the secondarily measuring.

13 . The surface inspecting method of claim 11 , further comprising synthesizing overlapped regions of a first image of the second polarized state with respect to the first inspection region and a second image of the third polarized state with respect to the second inspection region.

14 . The surface inspecting method of claim 11 , wherein the moving and the secondarily measuring are repeated twice or more.

15 . The surface inspecting method of claim 11 , wherein the stage is movable in at least one of a vertical direction and a horizontal direction by at least one sub-pixel.

16 . A surface inspecting method comprising:
irradiating an incident light beam of a first polarized state on a first inspection region, and primarily measuring a second polarized state of a reflected light beam reflected from the first inspection region with a detector; and irradiating an incident light beam of a third polarized state on a second inspection region, and secondarily measuring a fourth polarized state of a reflected light beam reflected from the second inspection region with the detector, wherein the second inspection region is offset from the first inspection region by less than a pixel of the detector, and the pixel of the detector is a region that is capable of being maximally resolved by a detector.

17 . The surface inspecting method of claim 16 , wherein the first and second inspection regions are offset by moving a stage supporting a target object by a sub-pixel such that the incident light beam is irradiated on a second inspection region overlapping the first inspection region by an area of at least one sub-pixel.

18 . The surface inspecting method of claim 16 , wherein the incident light beam is a parallel light beam having a cross-sectional area, and
the incident light beam is irradiated on

Assignees

• Samsung Electronics Co Ltd

Inventors

• Ko Kang-Woong
• Ryu Sung-Yoon
• Sohn Young-Hoon
• Song Gil-Woo
• Ahn Tae-Heung
• Jeon Hyoung-Jo
• Han Sang-Kyeong
• Horie Masahiro
• Ko Woo-Seok
• Yang Yu-Sin
• Lee Sang-Kil
• Jeon Byeong-Hwan

Classifications

• G01N21/21

  Polarisation-affecting properties (G01N21/19 takes precedence) · CPC title

• G01N2021/8848

  Polarisation of light · CPC title

• G01N21/8806 Primary

  Specially adapted optical and illumination features · CPC title

• G01N21/9501

  Semiconductor wafers (manufacturing processes per se of semiconductor devices implementing a measuring step H10P74/20) · CPC title

• G01N2021/213

  Spectrometric ellipsometry · CPC title