发明名称 |
INSPECTION METHOD AND INSPECTION APPARATUS |
摘要 |
An inspection method and apparatus comprising, a step of reflecting linearly-polarized light having a predetermined wavelength using an non-polarizing beam splitter after transmitting the linearly-polarized light through a half-wave plate, irradiating a sample with the linearly-polarized light having a polarization plane of a predetermined angle, causing the light reflected by the sample to be incident to an image capturing sensor through a lens, the non-polarizing beam splitter, and an analyzer, and acquiring an optical image of a pattern formed on the sample; acquiring a plurality of optical images by changing an angle of the analyzer or the half-wave plate, and obtaining an angle of the analyzer or the half-wave plate such that a value of (σ/√A) becomes a minimum; and a step of inspecting whether a defect of the pattern exists, wherein the pattern is a repetitive pattern having a period at a resolution limit or less. |
申请公布号 |
US2014232849(A1) |
申请公布日期 |
2014.08.21 |
申请号 |
US201414177546 |
申请日期 |
2014.02.11 |
申请人 |
NuFlare Technology, Inc. |
发明人 |
OGAWA Riki;Hirono Masatoshi |
分类号 |
G06T7/00 |
主分类号 |
G06T7/00 |
代理机构 |
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代理人 |
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主权项 |
1. An inspection method comprising:
a step of reflecting linearly-polarized light having a predetermined wavelength emitted from a light source using an non-polarizing beam splitter after transmitting the linearly-polarized light through a half-wave plate, irradiating a sample that is an inspection target with the linearly-polarized light having a polarization plane of a predetermined angle, causing the light reflected by the sample to be incident to an image capturing sensor through a lens, the non-polarizing beam splitter, and an analyzer, in this order, and acquiring an optical image of a pattern formed on the sample; a step of acquiring a plurality of optical images by changing an angle of the analyzer or the half-wave plate, and obtaining an angle of the analyzer or the half-wave plate such that a value of (σ/√A), which is obtained from a standard deviation σ of a gray level and an average gray level A in the optical images, becomes a minimum; and a step of inspecting whether a defect of the pattern exists with respect to the optical image that is acquired at the angle of the analyzer or the half-wave plate at which the value of (σ/√A) becomes the minimum, wherein the pattern is a repetitive pattern having a period at a resolution limit or less, the resolution limit being defined by a wavelength of the light source and a numerical aperture of the lens. |
地址 |
Yokohama JP |