US4521441A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Plasma enhanced diffusion process
Assignee: Motorola Solutions Inc
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Filing: 1983-12-19
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Granted: 1985-06-04
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Expires: 2003-12-19
Abstract
Abstract A process is disclosed for doping a semiconductor substrate which achieves a lower sheet resistivity than is otherwise obtainable. A spin-on dopant material is applied to the surface of the semiconductor substrate and subsequently heated to drive off solvents contained in the dopant material. The layer of spin-on dopant material is then plasma treated, preferably in an oxygen plasma, to enhance the diffusion properties of the spin-on material. The substrate and dopant material are then heated to an elevated temperature to accomplish the desired depth of diffusion.
Inventors
- 👤 Dervin L. Flowers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:11
CPC Classifications
H; H10; H10P; H10P32/00; H10P32/10; H10P32/14; H10P32/1408; H10P32/141; H10P32/17; H10P32/171
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
52 words
A process for doping a semiconductor substrate which comprises the steps of: applying spin-on dopant material to said substrate; heating said material to a first temperature; plasma treating said material to enhance the conductivity of diffused regions formed therefrom; and heating said substrate to a second temperature higher than said first temperature.
Claim 2
Dependent Claim
52 words
A process for doping a semiconductor substrate which comprises the steps of: applying spin-on dopant material to said substrate; heating said material to a first temperature; plasma treating said material to enhance the conductivity of diffused regions formed therefrom; and heating said substrate to a second temperature higher than said first temperature.
Claim 3
Dependent Claim
19 words
The process of claim 1 wherein said step of plasma treating comprises placing said material in an oxygen plasma.
Claim 4
Dependent Claim
16 words
The process of claim 2 wherein said step of plasma treating is continued for 15-45 minutes.
Claim 5
Dependent Claim
21 words
The process of claim 1 wherein said spin-on material is applied in a layer having a thickness of about 400-3000 Å.
Claim 6
Dependent Claim
25 words
The process of claim 1 wherein said dopant material comprises a conductivity determining impurity selected from the group consisting of phosphorous, arsenic, antimony, and boron.
Claim 7
Dependent Claim
18 words
The process of claim 1 wherein said first temperature is between about 150° C. and about 400° C.
Claim 8
Dependent Claim
15 words
The process of claim 1 wherein said second temperature is about 850° C. or greater.
Claim 9
Dependent Claim
41 words
The process of claim 1 wherein said step of heating said substrate and material to a second temperature comprises the steps of: heating to about 800° C.; ramping said temperature upward to said second temperature; and then ramping said temperature downward.
Claim 10
Dependent Claim
16 words
The process of claim 6 wherein said heating to a first temperature is done in air.
Claim 11
Dependent Claim
21 words
The process of claim 6 wherein said heating to a first temperature is done in an ambient comprising N 2 .
Claim 12
Dependent Claim
24 words
The process of claim 10 wherein said heating to a first temperature is done in an ambient comprising N 2 and O 2 .
Claim 13
Dependent Claim
14 words
The process of claim 1 further comprising the step of patterning said dopant material.
Claim 14
Dependent Claim
72 words
A process for doping a semiconductor substrate which comprises the steps of: providing a patterned masking layer on said substrate; applying a layer of spin-on dopant material overlying said masking layer and said substrate; heating said dopant material to a temperature of about 150° C.-400° C.; exposing said dopant material to an oxygen plasma; and heating said dopant material to a temperature of 850°-1200° C. to diffuse said dopant into said substrate.
Claim 15
Dependent Claim
72 words
A process for doping a semiconductor substrate which comprises the steps of: providing a patterned masking layer on said substrate; applying a layer of spin-on dopant material overlying said masking layer and said substrate; heating said dopant material to a temperature of about 150° C.-400° C.; exposing said dopant material to an oxygen plasma; and heating said dopant material to a temperature of 850°-1200° C. to diffuse said dopant into said substrate.
Claim 16
Dependent Claim
21 words
The process of claim 13 further comprising the step of forming a capping layer overlying said layer of spin-on dopant material.
Claim 17
Dependent Claim
84 words
A process for doping a semiconductor substrate which comprises the steps of: forming a patterned diffusion mask on the surface of said substrate, said mask having apertures therein to expose selected portions of said substrate; forming a layer of spin-on dopant material overlying said mask and extending into said apertures to contact said selected portions of said substate; heating said layer to about 150°-400° C.; exposing said layer to a plasma comprising oxygen; and heating said layer to a temperature of about 850°-1200° C.
Claim 18
Dependent Claim
84 words
A process for doping a semiconductor substrate which comprises the steps of: forming a patterned diffusion mask on the surface of said substrate, said mask having apertures therein to expose selected portions of said substrate; forming a layer of spin-on dopant material overlying said mask and extending into said apertures to contact said selected portions of said substate; heating said layer to about 150°-400° C.; exposing said layer to a plasma comprising oxygen; and heating said layer to a temperature of about 850°-1200° C.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-06-03 | 1988-12-03 | 1989-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-06-03 | 1992-12-03 | 1993-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-06-03 | 1996-12-03 | 1997-06-04 | $7700.00 | Window Closed / Lapsed |