US3901744A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making semiconductor devices
Assignee: International Standard Electric Corp
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Filing: 1974-01-24
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Granted: 1975-08-26
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Expires: 1994-01-24
Abstract
Abstract A method of making a semiconductor device avoids the problems of excessive liquid phase epitaxial growth at the edges of a slice which can interfere with processing in a sliding boat technique. A layer of refractory masking material is deposited on the front and back surfaces of the substrate slice. The central area of the front surface is then etched to leave the protective layer on the sides, edges and back. This prevents the undesired growth at the sides during the subsequent steps of growing semiconductor layers on the substrate. The slice is placed in a recess in a graphite boat having a sliding portion containing melts which contact the slice to grow first and second semiconductor layers. The central area of the back masking layer and substrate are then etched away to expose the first layer.
Inventors
- 👤 Derek E Bolger
- 👤 Martin Pion
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 19:29
CPC Classifications
H; H10; H10P; H10P50/00; H10P50/60; H10P50/64; H10P50/642; H10P50/646; H01; H01J; H01J9/00; H01J9/02; H01J9/12; H10P14/00; H10P14/20; H10P14/26; H10P14/263; H10P14/27; H10P14/271; H10P14/29; H10P14/2901; H10P14/2907; H10P14/2911; H10P14/32; H10P14/3202; H10P14/3214; H10P14/3221; H10P14/34; H10P14/3402; H10P14/3414; H10P14/3421; H10P95/00; Y; Y10; Y10S; Y10S438/00; Y10S438/928; Y10S438/977
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
123 words
A METHOD OF MANUFACTURE OF A SEMICONDUCTOR DEVICE FROM A SLICE OF SEMICONDUCTIVE MATERIAL INCLUDING THE STEP OF COATING THE SLICE WITH A LAYER OF REFRACTORY MASING MATERIAL COVERING THE TWO OPPOSITE FACES AND THE SIDES OF THE SLICE, THE STEP OF ETCHING AWAY A CENTRAL REGION OF SAID REFACTORY MASKING MATERIAL ON ONE OF SAID FACES TO EXXPOSE SAID CENTRAL REGION OF SAID ONE FACE AND LEAVE A PERIPHERAL GEGION, THE STEP OF DEPOSITING FIRST AND SECOND SEMICONDUCTOR LAYERS IN SAID EXPOSED CENTRAL REGION OF SAID ONE FACE BY LIQUID PHASE EPITAXY, EPITOXIAL GROWTH AT THE SIDES AND PERIPHERAL EDGES OF THE SLICE BEING PREVENTED BY THE MASKING MATERIAL, AND THE STEP OF ETCHING AWAY CENTRAL REGIONS OF SAID REFACTORY MASKING MATE-
Claim 2
Independent Claim
123 words
A METHOD OF MANUFACTURE OF A SEMICONDUCTOR DEVICE FROM A SLICE OF SEMICONDUCTIVE MATERIAL INCLUDING THE STEP OF COATING THE SLICE WITH A LAYER OF REFRACTORY MASING MATERIAL COVERING THE TWO OPPOSITE FACES AND THE SIDES OF THE SLICE, THE STEP OF ETCHING AWAY A CENTRAL REGION OF SAID REFACTORY MASKING MATERIAL ON ONE OF SAID FACES TO EXXPOSE SAID CENTRAL REGION OF SAID ONE FACE AND LEAVE A PERIPHERAL GEGION, THE STEP OF DEPOSITING FIRST AND SECOND SEMICONDUCTOR LAYERS IN SAID EXPOSED CENTRAL REGION OF SAID ONE FACE BY LIQUID PHASE EPITAXY, EPITOXIAL GROWTH AT THE SIDES AND PERIPHERAL EDGES OF THE SLICE BEING PREVENTED BY THE MASKING MATERIAL, AND THE STEP OF ETCHING AWAY CENTRAL REGIONS OF SAID REFACTORY MASKING MATE-
Claim 3
Dependent Claim
49 words
The method of claim 1 wherein one face of said slice is coated with a first layer of said refractory masking material and the opposite face is coated with a second layer of said refractory masking material to overlap a peripheral portion of said first layer of masking material.
Claim 4
Dependent Claim
44 words
The method as claimed in claim 1 wherein said step of depositing layers includes growing a first layer of one semiconductor material in said central region of said one face followed by a second layer of another semiconductor material upon the first semiconductor layer.
Claim 5
Dependent Claim
15 words
The method as claimed in claim 3 wherein the material of the slice is GaAs.
Claim 6
Dependent Claim
26 words
The method as claimed in claim 4 wherein said first semiconductor layer is of gallium aluminum arsenide and said second semiconductor layer is of gallium arsenide.
Claim 7
Dependent Claim
16 words
The method as claimed in claim 3 wherein the layer of refractory masking material is silica.
Claim 8
Dependent Claim
16 words
The method as claimed in claim 3 wherein the layer of refractory material is silicon nitride.
Claim 9
Dependent Claim
24 words
The method as claimed in claim 3 wherein the layer of refractory material is silica and including a second refractory layer of silicon nitride.
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) | 1978-08-25 | 1979-02-24 | 1979-08-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-08-25 | 1983-02-24 | 1983-08-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-08-25 | 1987-02-24 | 1987-08-26 | $7700.00 | Window Closed / Lapsed |