US5045911A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lateral PNP transistor and method for forming same
Assignee: International Business Machines Corp
•
Filing: 1990-10-30
•
Granted: 1991-09-03
•
Expires: 2010-10-30
Abstract
Abstract A process of forming a lateral PNP transistor includes the steps of: providing a chip of semiconductor material including an isolated N- device region; implanting N dopant material at a relatively low power and low dosage into a selected implant region of the device region; implanting N dopant material at a relatively higher power and higher dosage into the implant region; and forming emitter and collector regions in the device region such that an intrinsic base region is defined between the collector and emitter regions in the implant region.
Inventors
- 👤 Peter A. Habitz
- 👤 Chang-Ming Hsieh
- 👤 Yi-Shiou Huang
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 23:50
CPC Classifications
H; H10; H10D; H10D10/00; H10D10/01; H10D10/061; H10D62/00; H10D62/10; H10D62/17; H10D62/177; H10D62/184; H10W; H10W10/00; H10W10/01; H10W10/031; H10W10/30
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
121 words
A lateral PNP transistor, comprising: a body of semiconductor material including an electrically isolated N- device region; an N implant region formed in said device region; an emitter region of opposite conductivity type to said device region formed in the surface of said N implant region; and a collector region of same conductivity type as said emitter region formed in the surface of said device region at least partially within said N implant region; said emitter and collector regions spaced to define a base region therebetween in said N implant region; said N implant region having a relatively higher dopant concentration proximate the bottom of said emitter region and a relatively lower dopant concentration proximate the surface of said base region.
Claim 2
Dependent Claim
121 words
A lateral PNP transistor, comprising: a body of semiconductor material including an electrically isolated N- device region; an N implant region formed in said device region; an emitter region of opposite conductivity type to said device region formed in the surface of said N implant region; and a collector region of same conductivity type as said emitter region formed in the surface of said device region at least partially within said N implant region; said emitter and collector regions spaced to define a base region therebetween in said N implant region; said N implant region having a relatively higher dopant concentration proximate the bottom of said emitter region and a relatively lower dopant concentration proximate the surface of said base region.
Claim 3
Dependent Claim
17 words
A transistor in accordance with claim 1 wherein said emitter region is entirely in said implant region.
Claim 4
Dependent Claim
34 words
A transistor in accordance with claim 1 and further including: a P substrate underlying said device region; and an N+ buried subcollector region in the surface of said P substrate underlying said device region.
Claim 5
Dependent Claim
27 words
A transistor in accordance with claim 3 and further including an N+ reach-through region extending from the surface of said body to said N+ buried subcollector region.
Claim 6
Dependent Claim
41 words
A transistor in accordance with claim 4 wherein said implant region is deepest proximate the portion of said device region opposite said reach-through region and tapers off to the surface of said device region a predetermined distance from said reach-through region.
Claim 7
Dependent Claim
15 words
A transistor in accordance with claim 1 wherein said body comprises a silicon semiconductor material.
Claim 8
Dependent Claim
24 words
A transistor in accordance with claim 1 wherein said device region is selected to have a concentration of about 1×10 16 atoms/cm 3 .
Claim 9
Dependent Claim
87 words
A transistor in accordance with claim 7 wherein: the ions used to dope said implant region are phosphorus ions; and said implant region formed by a two step ion implanting process, including a first implanting step selected to have a dosage in the range of about 2×10 11 -3×10 12 atoms/cm 2 and an energy of about 100 Kev, and a second implanting step selected to have a dosage in the range of about 1×10 12 -2×10 13 atoms/cm 2 and an energy of about 350 Kev.
Claim 10
Dependent Claim
41 words
A transistor in accordance with claim 1 wherein the concentration in said implant region proximate the surface of said base region is selected sufficient to inhibit an emitter-collector punch-through breakdown of about 2 volts at 1 nanoamp/micron of emitter surface length.
Claim 11
Dependent Claim
36 words
A transistor in accordance with claim 2 wherein the concentration in said implant region proximate the bottom of said emitter region is selected to be equal to or greater than about 7×10 16 atoms/cm 3 .
References Cited (Backward Citations)
US4045251A
Cited
US4005451A
Cited
US4332627A
Cited
US4283236A
Cited
US4390890A
Cited
US4546536A
Cited
US4510676A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-09-02 | 1995-03-04 | 1995-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-09-02 | 1999-03-04 | 1999-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-09-02 | 2003-03-04 | 2003-09-03 | $7700.00 | Window Closed / Lapsed |