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US5324685A
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Method for fabricating a multilayer epitaxial structure
Assignee: Arris Technology Inc
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Filing: 1993-02-09
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Granted: 1994-06-28
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Expires: 2013-02-09
Abstract
Abstract An all epitaxial process performed entirely in a CVD reactor is employed to grow heavily doped layer on lightly doped layer on a heavily doped substrate, eliminating the need for separate diffusion, even for high impurity concentrations. The process starts with a heavily doped silicon substrate of carrier concentration typically greater than 1×10 19 per cm 3 . To minimize outdiffusion, the substrate is "capped" by growing very thin and heavily doped silicon layers which are depleted by hydrogen purges. A first epitaxial layer is grown over the "capped" substrate. This layer is relatively lightly doped, having a resistivity of more than 200 ohm.cm. A second epitaxial layer is then grown over the first epitaxial layer. The second epitaxial layer has a polarity opposite to that of the substrate and is heavily doped to a resistivity of less than 0.005 ohm cm.
Inventors
- 👤 Reinhold Hirtz
- 👤 Gregory Zakaluk
- 👤 Joseph Chan
- 👤 Dennis Garbis
- 👤 Lawrence Laterza
- 👤 Ali Salih
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:15
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/15; Y; Y10; Y10S; Y10S438/00; Y10S438/902
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
109 words
An all epitaxial method for fabricating a multilayer structure for a semiconductor in CVD reactor chamber comprising: a) forming a substrate of a polarity of heavily doped silicon; b) growing a first silicon cap layer over the substrate; c) purging the chamber after the first cap layer is grown; d) growing a second silicon cap layer; e) purging the chamber after the second silicon cap layer is grown; f) growing a lightly doped first epitaxial layer above the second capped layer; and g) growing a heavily doped second epitaxial layer above the first epitaxial layer, the second epitaxial layer having a polarity opposite to the polarity of the substrate.
Claim 2
Dependent Claim
109 words
An all epitaxial method for fabricating a multilayer structure for a semiconductor in CVD reactor chamber comprising: a) forming a substrate of a polarity of heavily doped silicon; b) growing a first silicon cap layer over the substrate; c) purging the chamber after the first cap layer is grown; d) growing a second silicon cap layer; e) purging the chamber after the second silicon cap layer is grown; f) growing a lightly doped first epitaxial layer above the second capped layer; and g) growing a heavily doped second epitaxial layer above the first epitaxial layer, the second epitaxial layer having a polarity opposite to the polarity of the substrate.
Claim 3
Dependent Claim
28 words
The method of claim 1 wherein the step of forming the substrate comprises forming a substrate of a material with a resistivity of less than 0.0035 ohm cm.
Claim 4
Dependent Claim
31 words
The method of claim 1 wherein the step of forming the substrate comprises forming the substrate of a material with a resistivity in the range of 0.001 to 0.002 ohm cm.
Claim 5
Dependent Claim
40 words
The method of claim 1 wherein the step of forming the cap layer comprises the step of heating the substrate in an atmosphere containing a source of silicon obtained from a group of compounds consisting of trichlorosilane, chlorosilane and silicone.
Claim 6
Dependent Claim
42 words
The method of claim 1 wherein the step of growing the first epitaxial layer comprises the step of growing the first epitaxial layer in a chemical vapor deposition reactor in a hydrogen ambient at a temperature between 1000° C. and 1200° C.
Claim 7
Dependent Claim
35 words
The method of claim 1 wherein the step of growing the first epitaxial layer comprises the step of growing a layer in a chemical deposition reactor with a resistivity of less than 200 ohm cm.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein the step of growing the first epitaxial layer comprises the step of growing the layer in a chemical deposition reactor with a resistivity of less than 50 ohm cm.
Claim 9
Dependent Claim
34 words
The method of claim 1 wherein the step of growing the first epitaxial layer comprises the step of growing a layer in a chemical deposition reactor with a thickness of 5 to 100 microns.
Claim 10
Dependent Claim
53 words
The method of claim 1 wherein the step of growing the second epitaxial layer comprises the step of growing the second epitaxial layer on the first epitaxial layer in a chemical vapor deposition reactor in a gas environment which is the source of dopant selected from the group of arsenic, phosphorus and antimony.
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) | 1997-06-27 | 1997-12-27 | 1998-06-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-06-27 | 2001-12-27 | 2002-06-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-06-27 | 2005-12-27 | 2006-06-28 | $7700.00 | Window Closed / Lapsed |