Patent US4526468A successfully refreshed from Google Patents.
US4526468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for determining the phase of phase transformable light scattering material
Assignee: Tencor Instruments Inc
•
Filing: 1983-06-30
•
Granted: 1985-07-02
•
Expires: 2003-06-30
Abstract
Abstract A method of determining the crystalline or structural quality of phase transformable material such as silicon uses light scattering. The material is exposed to a beam of light of a selected wavelength. Scattered light having an intensity above a threshold is detected to provide a signal which is used to control the intensity of a display beam of a visual display device. The threshold is varied to thereby vary the display beam intensity so as to provide the minimum intensity of display beam which yields a full display. The value of the thusly adjusted threshold intensity is used as a direct measure of the structural quality of the material. The light scattering process is used to determine the phase of deposited material. A layer of silicon material annealed from as-deposited amorphous phase material is easily and quickly distinguished from material as-deposited crystalline phase material and subsequently annealed.
Inventors
- 👤 Edgar F. Steigmeier
- 👤 Heinrich Auderset
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 12:04
CPC Classifications
G; G01; G01N; G01N21/00; G01N21/84; G01N21/88; G01N21/95; G01N21/9501; G01N21/17; G01N21/47; G01N21/4738; G01N21/59; G01N21/5907; G01N2021/5915; G01N2021/5938; G01N2201/00; G01N2201/10; G01N2201/108; G01N2201/1087
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
177 words
A method for determining the phase of a deposited material having a property of absorbing light to a given penetration depth, said material being capable of being deposited in either of two predetermined phases, comprising the steps of: (a) depositing one of said two phases of said material on a surface; (b) exposing one or more regions of said material to a beam of light of a selected wavelength; (c) detecting light having an intensity greater than a threshold intensity scattered from the exposed material to provide an electrical signal proportional to the intensity of scattered light detected above said threshold intensity; (d) applying the electrical signal to a visual display device to control the intensity of the display beam of the device; and (e) varying said threshold intensity to thereby vary the intensity of the display beam so as to provide the minimum intensity of display beam which yields a full display of the exposed material, wherein the value of the threshold intensity is a direct measure of the phase in which said material was deposited.
Claim 2
Independent Claim
177 words
A method for determining the phase of a deposited material having a property of absorbing light to a given penetration depth, said material being capable of being deposited in either of two predetermined phases, comprising the steps of: (a) depositing one of said two phases of said material on a surface; (b) exposing one or more regions of said material to a beam of light of a selected wavelength; (c) detecting light having an intensity greater than a threshold intensity scattered from the exposed material to provide an electrical signal proportional to the intensity of scattered light detected above said threshold intensity; (d) applying the electrical signal to a visual display device to control the intensity of the display beam of the device; and (e) varying said threshold intensity to thereby vary the intensity of the display beam so as to provide the minimum intensity of display beam which yields a full display of the exposed material, wherein the value of the threshold intensity is a direct measure of the phase in which said material was deposited.
Claim 3
Dependent Claim
45 words
The method of claim 1 comprising depositing said material at a first relatively low temperature, and, following said depositing step, annealing said material at a relatively high temperature, whereby the phase of said material as-deposited prior to annealing is determined by said value of intensity.
Claim 4
Dependent Claim
36 words
The method of claim 1 comprising depositing said material by low pressure chemical vapor deposition (LPCVD) of silicon in either an amorphous phase at 560° to 580° C. or crystalline phase at 600° to 620° C.
Claim 5
Dependent Claim
22 words
The method of claim 1 comprising depositing said material selected from the group consisting of chalcogenides and alloys of tellurium and selenium.
Claim 6
Dependent Claim
25 words
The method of claim 1 comprising depositing said material from the chalcogenides group consisting essentially of tellurium and selenium and binary or ternary alloys thereof.
Claim 7
Dependent Claim
23 words
The method of claim 1, wherein the light exposing step comprises scanning the light beam of a selected surface portion of the material.
Claim 8
Dependent Claim
29 words
The method of claim 1, wherein the light exposing step comprises exposing the material to a plurality of selected spatially separated beams incident on the surface of the material.
Claim 9
Dependent Claim
22 words
The method of claim 1, wherein the wavelength of said light is selected from a wavelength within the range of 2,600-5,200 angstroms.
Claim 10
Dependent Claim
22 words
The method of claim 1 comprising depositing said material as a layer of amorphous silicon on a layer of single crystal silicon.
Claim 11
Dependent Claim
33 words
The method of claim 1 comprising depositing said material as a layer of polycrystalline silicon on a layer of single crystal silicon and annealing said polycrystalline layer prior to steps (b) to (e).
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-01 | 1988-12-31 | 1989-07-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-01 | 1992-12-31 | 1993-07-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-01 | 1996-12-31 | 1997-07-02 | $7700.00 | Window Closed / Lapsed |