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US3875416A
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Methods and apparatus for the production of semiconductor devices by electron-beam patterning and devices produced thereby
Assignee: Texas Instruments Inc
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Filing: 1974-02-11
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Granted: 1975-04-01
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Expires: 1994-02-11
Abstract
Abstract This specification describes the method and apparatus for the exposure of sensitive resists by the use of closely scanned rasters described by a focussed electron beam. Variation in the line width is used to produce different raster shapes as required. A succession of similar rasters can be described spaced over a semiconductor wafer for the purpose of producing the patterning required for the production of a plurality of similar semiconductor devices on the single wafer. A technique for aligning the wafer with the scan of the electron beam is described using markers distributed over the surface of the wafer there being one marker for each small raster to be described by the beam from the wafer; one alignment system using a cathode-ray tube display of the images of the reference marker magnified and placed closed together on the screen so that errors in alignment can readily be detected.
Inventors
- 👤 Denis Frank Spicer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 12:47
CPC Classifications
H; H10; H10P; H10P76/00; H10P76/20; H10P76/204; H10P76/2045; H01; H01J; H01J37/00; H01J37/30; H01J37/304; H01J37/3045; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/946
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
231 words
A method for selectively exposing an electron bombardment sensitive material on a substrate surface using an electron beam apparatus having a predetermined optical field, wherein said sensitive material includes a plurality of areas respectively corresponding to said optical field of said electron beam apparatus, and means for stepping said electron beam to successively expose said plurality of areas such that each exposed area is aligned relative to a reference pattern, including the steps of: 1. forming adjacent a surface of said electron beam sensitive material an alignment marker pattern associated with said areas and corresponding to said reference pattern, 2. sequentially step scanning in a uninterrupted sequence the said alignment pattern associated with a selected one of said areas to generate data signals corresponding to said alignment marker pattern and indicating positional errors of said alignment marker pattern relative to said reference alignment pattern, 3. adjusting the relative positions of the scanning path of said electron beam and said substrate in response to said data signals to precisely align said alignment marker pattern and said reference alignment pattern, 4. and then without moving said substrate step scanning said electron beam over selected portions of predetermined sub-areas within said aligned one area in an uninterrupted sequence to selectively expose said portions in each sub-area whereby said exposed portions of said sub-areas have precisely predetermined positional relationships relative to said reference alignment pattern.
Claim 2
Independent Claim
231 words
A method for selectively exposing an electron bombardment sensitive material on a substrate surface using an electron beam apparatus having a predetermined optical field, wherein said sensitive material includes a plurality of areas respectively corresponding to said optical field of said electron beam apparatus, and means for stepping said electron beam to successively expose said plurality of areas such that each exposed area is aligned relative to a reference pattern, including the steps of: 1. forming adjacent a surface of said electron beam sensitive material an alignment marker pattern associated with said areas and corresponding to said reference pattern, 2. sequentially step scanning in a uninterrupted sequence the said alignment pattern associated with a selected one of said areas to generate data signals corresponding to said alignment marker pattern and indicating positional errors of said alignment marker pattern relative to said reference alignment pattern, 3. adjusting the relative positions of the scanning path of said electron beam and said substrate in response to said data signals to precisely align said alignment marker pattern and said reference alignment pattern, 4. and then without moving said substrate step scanning said electron beam over selected portions of predetermined sub-areas within said aligned one area in an uninterrupted sequence to selectively expose said portions in each sub-area whereby said exposed portions of said sub-areas have precisely predetermined positional relationships relative to said reference alignment pattern.
Claim 3
Dependent Claim
44 words
sequentially step scanning in a uninterrupted sequence the said alignment pattern associated with a selected one of said areas to generate data signals corresponding to said alignment marker pattern and indicating positional errors of said alignment marker pattern relative to said reference alignment pattern,
Claim 4
Dependent Claim
44 words
sequentially step scanning in a uninterrupted sequence the said alignment pattern associated with a selected one of said areas to generate data signals corresponding to said alignment marker pattern and indicating positional errors of said alignment marker pattern relative to said reference alignment pattern,
Claim 5
Dependent Claim
28 words
The method according to claim 1, wherein the alignment marker pattern comprises indentations in said substrate surface and a coating of insulating material overlies the alignment marker pattern.
Claim 6
Dependent Claim
68 words
The method according to claim 1, and including: a. generating a magnified display responsive to the data signals indicating positional errors of the alignment marker pattern relative to the said reference alignment pattern, and b. adjusting the relative positions of the scanning path of the electron beam and the substrate in response to the said display to precisely align said alignment marker pattern and said reference alignment pattern.
Claim 7
Dependent Claim
33 words
adjusting the relative positions of the scanning path of said electron beam and said substrate in response to said data signals to precisely align said alignment marker pattern and said reference alignment pattern,
Claim 8
Dependent Claim
33 words
adjusting the relative positions of the scanning path of said electron beam and said substrate in response to said data signals to precisely align said alignment marker pattern and said reference alignment pattern,
Claim 9
Dependent Claim
52 words
and then without moving said substrate step scanning said electron beam over selected portions of predetermined sub-areas within said aligned one area in an uninterrupted sequence to selectively expose said portions in each sub-area whereby said exposed portions of said sub-areas have precisely predetermined positional relationships relative to said reference alignment pattern.
Claim 10
Dependent Claim
52 words
and then without moving said substrate step scanning said electron beam over selected portions of predetermined sub-areas within said aligned one area in an uninterrupted sequence to selectively expose said portions in each sub-area whereby said exposed portions of said sub-areas have precisely predetermined positional relationships relative to said reference alignment pattern.
Claim 11
Dependent Claim
35 words
A method according to claim 1, wherein said step of generating said data signals comprises generating a video signal responsive to secondary electron emission from the substrate due to impact of the electron beam thereon.
Claim 12
Dependent Claim
37 words
A method according to claim 1, wherein each said step of scanning with an electron beam comprises: a. focussing the beam on the sensitive material, and b. scanning a closely spaced raster with the focussed electron beam.
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) | 1978-03-31 | 1978-09-30 | 1979-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-31 | 1982-09-30 | 1983-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-31 | 1986-09-30 | 1987-04-01 | $7700.00 | Window Closed / Lapsed |