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Patent US5932919A successfully refreshed from Google Patents.
US5932919A
Expired / Lapsed
US
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MOSFETs with improved short channel effects
Assignee: Mosaid Technologies Inc
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Filing: 1997-05-14
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Granted: 1999-08-03
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Expires: 2017-05-14
Abstract
Abstract In the manufacture of CMOS devices, the n+ gate is partially counterdoped with boron to produce a modified p-type FET that has improved short channel effects, reduced gate induced drain leakage and gate oxide fields for improved reliability. A doped polysilicon layer is formed over a silicon or silicon oxide substrate, and is counterdoped with boron to a level of about 1×10 13 /cm 2 to 5×10 16 /cm 2 to adjust the work function but without changing the essentially n-type character of the gate electrode. This single counterdoping step achieves improved results for sub-micron devices at low cost. For CMOS device manufacturing, the alternating n-type and p-type devices are made in similar manner but reversing the n-type and p-type dopants.
Inventors
- 👤 Udo Schwalke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:27
CPC Classifications
H; H10; H10D; H10D64/00; H10D64/60; H10D64/66; H10D64/661; H10D64/662; H10D64/663; H10D84/00; H10D84/01; H10D84/0123; H10D84/0126; H10D84/0165; H10D84/0172; H10D84/0177; H10D84/02; H10D84/03; H10D84/038; H10D84/80; H10D84/82; H10D84/83; H10D84/85; H10D84/856; H10D84/859; H10D84/8312; H10D84/83135
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
47 words
In an n+ gate of a p-type metal oxide semiconductor field effect transistor, the improvement comprising an n+ gate partially and uniformly counter doped with boron without changing the electrical character of the n+ gate so as to reduce the threshold voltage and improve short channel effects.
Claim 2
Dependent Claim
47 words
In an n+ gate of a p-type metal oxide semiconductor field effect transistor, the improvement comprising an n+ gate partially and uniformly counter doped with boron without changing the electrical character of the n+ gate so as to reduce the threshold voltage and improve short channel effects.
Claim 3
Dependent Claim
29 words
A field effect transistor according to claim 1 wherein the counterdoping of the gate is from about 1×10 13 cm 2 to about 5×10 16 cm 2 of boron.
Claim 4
Dependent Claim
34 words
A field effect transistor according to claim 2 wherein the n + ions are present in the gate at a level of about 1×10 20 cm 3 to about 1×10 21 cm 3 .
Claim 5
Dependent Claim
14 words
A field effect transistor according to claim 1 wherein said gate comprises polycide layers.
Claim 6
Dependent Claim
47 words
In a p+ gate of an n-type metal oxide semiconductor field effect transistor, the improvement comprising a p+ gate partially and uniformly counterdoped with n+ ions without changing the electrical character of the p+ gate so as to reduce the threshold voltage and improve short channel effects.
Claim 7
Dependent Claim
47 words
In a p+ gate of an n-type metal oxide semiconductor field effect transistor, the improvement comprising a p+ gate partially and uniformly counterdoped with n+ ions without changing the electrical character of the p+ gate so as to reduce the threshold voltage and improve short channel effects.
Claim 8
Dependent Claim
14 words
A field effect transistor according to claim 5 wherein said gate comprises polycide layers.
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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) | 2002-08-02 | 2003-02-01 | 2003-08-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2006-08-02 | 2007-02-01 | 2007-08-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2010-08-02 | 2011-02-01 | 2011-08-03 | $7700.00 | Window Closed / Lapsed |