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CN-122003594-A - Optical thin film analyzer free from influence of back reflection of substrate and analysis method using the same

CN122003594ACN 122003594 ACN122003594 ACN 122003594ACN-122003594-A

Abstract

The present invention relates to an optical thin film analysis device that is not affected by reflection on the back surface of a substrate and an analysis method using the same, and more particularly, to an optical thin film analysis device that can measure the thickness of a thin film and refractive index and extinction coefficient as optical constants simultaneously by an optical method without being affected by reflection on the back surface of a substrate and an analysis method using the same, and to an optical thin film analysis device that improves spatial resolution and measurement accuracy by solving the problem of reflection on the back surface of a substrate while measuring the thickness and optical constants of a thin film and an analysis method using the same.

Inventors

  • ZHENG CHANGSHUI

Assignees

  • 郑昌水

Dates

Publication Date
20260508
Application Date
20240923
Priority Date
20231031

Claims (16)

  1. 1. An optical thin film analysis device that is not affected by back reflection of a substrate, comprising: A light source emitting a light beam; A substrate coated with a thin film through which a light beam emitted from the light source is transmitted; A multiple beam splitter positioned between the light source and the substrate and splitting a transmitted beam transmitted through the substrate into a plurality of beams; A beam pitch expander for expanding a pitch of the multiple beams separated into a plurality of multiple beams; a beam filter transmitting a portion of the beam expanded by the beam pitch expander and reflecting the remaining portion; a beam deviation compensator for compensating a deviation of the beam transmitted or reflected by the beam filter, and And the light-transmitting type light detector receives the light beam with the deviation compensated by the light beam deviation compensator.
  2. 2. An optical thin film analysis device that is not affected by back reflection of a substrate, comprising: A light source emitting a light beam; A substrate coated with a thin film through which a light beam emitted from the light source is transmitted; A multiple beam splitter positioned between the light source and the substrate and splitting a transmitted beam transmitted through the substrate into a plurality of beams; a beam filter for transmitting a part of the multiple beams separated into a plurality of multiple beams and reflecting the remaining part; a beam deviation compensator for compensating a deviation of the beam transmitted or reflected by the beam filter, and And the light-transmitting type light detector receives the light beam with the deviation compensated by the light beam deviation compensator.
  3. 3. An optical thin film analysis device that is not affected by back reflection of a substrate, comprising: A light source emitting a light beam; A substrate coated with a thin film through which a light beam emitted from the light source is transmitted; A multiple beam splitter positioned between the light source and the substrate and splitting a transmitted beam transmitted through the substrate into a plurality of beams; A beam pitch expander for expanding a pitch of the multiple beams separated into a plurality of multiple beams; A beam filter for transmitting a part of the beam expanded by the beam pitch expander and reflecting the remaining part, and And a light-transmitting type photodetector for receiving the light beam transmitted or reflected by the light beam filter.
  4. 4. An optical thin film analysis device that is not affected by back reflection of a substrate, comprising: A light source emitting a light beam; A substrate coated with a thin film through which a light beam emitted from the light source is transmitted; A multiple beam splitter positioned between the light source and the substrate and splitting a transmitted beam transmitted through the substrate into a plurality of beams; A beam filter for transmitting a part of the multiple beams separated into a plurality of multiple beams and reflecting the remaining part, and And a light-transmitting type photodetector for receiving the light beam transmitted or reflected by the light beam filter.
  5. 5. An optical thin film analysis device that is not affected by back reflection of a substrate, comprising: A light source emitting a light beam; A substrate coated with a thin film through which a light beam emitted from the light source is transmitted; A multiple beam splitter positioned between the light source and the substrate and splitting a transmitted beam transmitted through the substrate into a plurality of beams; A beam deviation compensator for compensating for deviation and separation of the multiple beams separated into a plurality of multiple beams, and And a light-transmitting type photodetector for receiving the light beam whose deviation and separation are compensated by the light beam deviation compensator.
  6. 6. The optical thin film analysis apparatus as claimed in any one of claims 1 to 5, wherein the optical thin film analysis apparatus is not affected by back reflection of the substrate, The light source is of a short wavelength or a multiple wavelength, and polarized light of a light beam of the light source is either one of s-polarized light and p-polarized light or variable directions of the s-polarized light and the p-polarized light.
  7. 7. The optical thin film analysis apparatus as claimed in any one of claims 1 to 5, wherein the optical thin film analysis apparatus is not affected by back reflection of the substrate, When a light beam before transmitting the substrate from the light source is defined as an incident light beam, a light beam after transmitting the substrate is defined as a transmitted light beam, and a light beam after being reflected by the substrate is defined as a reflected light beam, the substrate is rotated by a substrate holder, and a rotation axis of the substrate is rotated with reference to a direction perpendicular to a plane formed by the incident light beam, the reflected light beam, and the transmitted light beam.
  8. 8. The optical thin film analysis apparatus as claimed in any one of claims 1 to 5, wherein the optical thin film analysis apparatus is not affected by back reflection of the substrate, The multiple beam splitter is a convex lens.
  9. 9. An optical thin film analysis apparatus not affected by back reflection of a substrate according to claim 1 or 3, The beam pitch expander is a prism-based beam expander or a pair of lens-based beam expander.
  10. 10. The optical thin film analysis apparatus as claimed in any one of claims 1 to 4, wherein the optical thin film analysis apparatus is not affected by back reflection of the substrate, The beam filter is a shielding screen or mirror.
  11. 11. The optical thin film analysis apparatus as claimed in any one of claims 1, 2 and 5, wherein the optical thin film analysis apparatus is not affected by back reflection of the substrate, The beam deviation compensator is a convex lens.
  12. 12. An optical thin film analysis method free from the influence of back reflection of a substrate, comprising: A first step of emitting a light beam by a light source; A second step of transmitting the light beam emitted in the first step through a multiple beam splitter; a third step of dividing the light beam transmitted through the multiple beam splitter into multiple light beams by transmitting the substrate coated with the thin film; A fourth step of causing the multiple light beams of the third step to transmit the beam pitch expander so as to expand the beam pitch; A fifth step of transmitting a part of the light beam expanded in the fourth step through a beam filter and reflecting the remaining part; A sixth step of making the transmitted beam or the reflected beam in the fifth step pass through a beam deviation compensator to compensate for the beam deviation, and A seventh step of receiving, by the photodetector, the light beam whose deviation was compensated in the sixth step.
  13. 13. An optical thin film analysis method free from the influence of back reflection of a substrate, comprising: A first step of emitting a light beam by a light source; A second step of transmitting the light beam emitted in the first step through a multiple beam splitter; a third step of dividing the light beam transmitted through the multiple beam splitter into multiple light beams by transmitting the substrate coated with the thin film; A fourth step of transmitting a part of the multiple light beams of the third step through a light beam filter and reflecting the remaining part; A fifth step of making the transmitted beam or the reflected beam in the fourth step pass through a beam deviation compensator to compensate for the beam deviation, and And a sixth step of receiving, by the photodetector, the light beam whose deviation was compensated in the fifth step.
  14. 14. An optical thin film analysis method free from the influence of back reflection of a substrate, comprising: A first step of emitting a light beam by a light source; A second step of transmitting the light beam emitted in the first step through a multiple beam splitter; a third step of dividing the light beam transmitted through the multiple beam splitter into multiple light beams by transmitting the substrate coated with the thin film; A fourth step of causing the multiple light beams of the third step to transmit the beam pitch expander so as to expand the beam pitch; A fifth step of transmitting a part of the light beam expanded in the fourth step through a beam filter and reflecting the remaining part, and A sixth step of receiving, by the photodetector, the light beam transmitted or the reflected light beam in the fifth step.
  15. 15. An optical thin film analysis method free from the influence of back reflection of a substrate, comprising: A first step of emitting a light beam by a light source; A second step of transmitting the light beam emitted in the first step through a multiple beam splitter; a third step of dividing the light beam transmitted through the multiple beam splitter into multiple light beams by transmitting the substrate coated with the thin film; A fourth step of transmitting a part of the multiple light beams of the third step through a light beam filter and reflecting the remaining part, and And a fifth step of receiving, by the photodetector, the light beam transmitted or the reflected light beam in the fourth step.
  16. 16. An optical thin film analysis method free from the influence of back reflection of a substrate, comprising: A first step of emitting a light beam by a light source; A second step of transmitting the light beam emitted in the first step through a multiple beam splitter; a third step of dividing the light beam transmitted through the multiple beam splitter into multiple light beams by transmitting the substrate coated with the thin film; A fourth step of making the multiple light beams of the third step pass through a light beam deviation compensator to compensate for deviation and separation of the light beams, and And a fifth step of receiving, by the photodetector, the light beam whose deviation was compensated in the fourth step.

Description

Optical thin film analyzer free from influence of back reflection of substrate and analysis method using the same Technical Field The present invention relates to an optical thin film analysis device that is not affected by reflection on the back surface of a substrate and an analysis method using the same, and more particularly, to an optical thin film analysis device that can measure the thickness of a thin film and refractive index and extinction coefficient as optical constants simultaneously by an optical method without being affected by reflection on the back surface of a substrate and an analysis method using the same, and to an optical thin film analysis device that improves spatial resolution and measurement accuracy by solving the problem of reflection on the back surface of a substrate while measuring the thickness and optical constants of a thin film and an analysis method using the same. Background Since various research materials are fabricated in the form of thin film samples on a substrate, thickness measurement of the thin film samples is a very important task in material research. It is well known that methods of optically measuring the thickness of a film sample employ non-contact/non-destructive methods and are therefore very useful. In addition, when the use of the material is in the optical field, it is also necessary to measure refractive index and extinction coefficient together as optical constants, and thus an optical thin film analysis method is very important. On the other hand, as the optical thin film analysis methods, there are an elliptical polarized light method (ellipsometry, refer to non-patent document 1), a spectral reflectance analysis method (spectroscopic REFLECTANCE ANALYSIS, refer to non-patent document 2), a spectral transmittance analysis method (spectroscopic transmission analysis, refer to non-patent document 2), and a non-spectral transmittance analysis method (nonspectroscopic transmission analysis, refer to non-patent document 3). However, in the case where the substrate of the thin film is not thick (in reality, most of the thin film samples are in this case), reflection of the beam (beam) on the back surface of the substrate becomes a great problem in the optical thin film analysis method. Fig. 1 is a schematic diagram showing a portion of a light beam transmitted through a substrate 40, and the remaining portion reflected by the substrate 40. As shown in fig. 1, a portion of the incident light beam 10 is split into a light beam 20-1 reflected at a specific region 50R-1 of the front surface of the substrate 40 and a transmitted light beam. Here, the transmitted light beam is split into a light beam reflected again at the back surface of the substrate 40 and a transmitted light beam 30-1. Here, the reflected light beam is split into a light beam reflected again at one region 50R-2 of the front surface of the substrate 40 and a transmitted light beam 20-2. Here, the reflected light beam is split into a light beam reflected again at the back surface of the substrate 40 and a transmitted light beam 30-2. Here, the reflected light beam is split into a light beam reflected again at one region 50R-3 of the front surface of the substrate 40 and a transmitted light beam 20-3. The reflected beam is split into a beam that is reflected again at the back side of the substrate 40 and a transmitted beam 30-3. Here, the reflected light beam continues to repeat reflection from the front and back surfaces of the substrate 40. Thus, the reflected beam 20 is composed of multiple beams 20-1, 20-2, 20-3, etc., and the transmitted beam 30 is composed of multiple beams 30-1, 30-2, 30-3, etc. The spacing delta between multiple beams can be expressed as delta = 2d scosθitanθs (where sin theta i=nssinθs). Wherein n s、ds、θi、θs represents the refractive index of the substrate 40, the thickness of the substrate 40, the incident angle, and the refraction angle on the substrate 40, respectively. Fig. 2 shows the variation of the pitch of the light beam multiply reflected from the substrate 40 with respect to the angle of incidence of the light beam on the substrate 40. Fig. 2 shows a case of a glass substrate having a refractive index=1.5. As can be seen from fig. 2, in the case of a thin glass substrate of "refractive index=1.5, thickness=1 mm", the numerical range of the beam pitch is 0mm to 0.76mm, with very small values. Due to this small beam spacing, the multiple reflected beams of the substrate spatially overlap. Therefore, when the multiple reflected light beams of the substrate are spatially overlapped, the light beams interfere with each other. The interference of the multiple reflected light beams of the substrate may cause errors in the analysis operation of the thin film 50, thereby making it difficult to obtain accurate measurement values. In addition, if there is reflection of the back surface of the substrate 40, not only the specific region (region to be analyzed) 50R-1 o