Patent US4890147A successfully refreshed from Google Patents.
US4890147A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Through-field implant isolated devices and method
Assignee: Texas Instruments Inc
•
Filing: 1987-04-15
•
Granted: 1989-12-26
•
Expires: 2007-04-15
Abstract
Abstract Preferred embodiments include channel stop implants for CMOS devices by through field boron implants (152) after the field oxide (144, 145) has been grown and with the implant depth determined by the thin portions of the field oxide (145). Junction (154) breakdown is preserved by channeling the implant (152) to penetrate far below the junctions (154).
Inventors
- 👤 Clarence W. Teng
- 👤 Roger A. Haken
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 14:23
CPC Classifications
H; H10; H10P; H10P30/00; H10P30/20; H10P30/202; H10P30/204; H10P30/21; H10P30/212; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/0125; H10W10/0126; H10W10/10; H10W10/13
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
106 words
An integrated semiconductor circuit comprising: a semiconductor substrate; a first and a second field oxide region extending a first and a second distance, respectively, into said semiconductor substrate, wherein said first distance is less than said second distance; a device region in said semiconductor substrate separating said first and second field oxide regions; a substantially continuous layer of dopant extending through said first and second field oxide regions and through said substrate beneath said device region, wherein said layer of dopant has a peak concentration of dopant which is located substantially at said first distance into said substrate in said first and second field oxide regions.
Claim 2
Dependent Claim
106 words
An integrated semiconductor circuit comprising: a semiconductor substrate; a first and a second field oxide region extending a first and a second distance, respectively, into said semiconductor substrate, wherein said first distance is less than said second distance; a device region in said semiconductor substrate separating said first and second field oxide regions; a substantially continuous layer of dopant extending through said first and second field oxide regions and through said substrate beneath said device region, wherein said layer of dopant has a peak concentration of dopant which is located substantially at said first distance into said substrate in said first and second field oxide regions.
Claim 3
Dependent Claim
36 words
The circuit of claim 1 wherein said peak concentration of dopant below said device region is located substantially at a range equal to a mean range obtained by on-axis implantation of said dopant in said substrate.
Claim 4
Dependent Claim
17 words
The circuit of claim 1 wherein said substrate is <100> crystalline silicon and said dopant is boron.
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) | 1992-12-25 | 1993-06-26 | 1993-12-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-12-25 | 1997-06-26 | 1997-12-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-12-25 | 2001-06-26 | 2001-12-26 | $7700.00 | Window Closed / Lapsed |