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US4983226A Expired / Lapsed US ⏱️ 0.0 years remaining

Defect free trench isolation devices and method of fabrication

Assignee: Texas Instruments Inc
•
Filing: 1990-03-15
•
Granted: 1991-01-08
•
Expires: 2010-03-15
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Abstract

Abstract The specification discloses an isolation trench (36) formed in a semiconductor body. A stress relief layer (38) of oxide is formed on the interior walls of the trench (36), the layer (38) being sufficiently thin to prevent stressing of the lower corners of the trench (36). A masking layer (40) of nitride is formed over the layer (38). An isolation body (42) of oxide or polysilicon then refills the remainder of the trench and a cap oxide (43) and layer (44) of field oxide is formed over the semiconductor body and the filled trench.

Inventors

  • 👤 William R. Hunter
  • 👤 Christopher Slawinski
  • 👤 Clarence W. Teng

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-29 07:54
CPC Classifications
H; H10; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/014; H10W10/041; H10W10/10; H10W10/13; H10W10/17; H10W10/40; Y; Y10; Y10S; Y10S148/00; Y10S148/05

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 99 words
An isolation trench in a semiconductor body comprising: a trench formed in the semiconductor body; a layer of insulating material on the interior walls of said trench, said layer of insulating material being sufficiently thin to prevent stressing of the corners of said trench; a masking layer formed adjacent said layer of insulating material; a dialectric layer of insulating material formed adjacent said masking layer; a second masking layer adjacent said dielectric layer; and an isolation body filling the remaining area of said trench; and a layer of field oxide formed over the semiconductor body and the filled trench.
Claim 2
Dependent Claim 99 words
An isolation trench in a semiconductor body comprising: a trench formed in the semiconductor body; a layer of insulating material on the interior walls of said trench, said layer of insulating material being sufficiently thin to prevent stressing of the corners of said trench; a masking layer formed adjacent said layer of insulating material; a dialectric layer of insulating material formed adjacent said masking layer; a second masking layer adjacent said dielectric layer; and an isolation body filling the remaining area of said trench; and a layer of field oxide formed over the semiconductor body and the filled trench.
Claim 3
Dependent Claim 13 words
The isolation trench of claim 1 wherein said isolation body comprises silicon oxide.
Claim 4
Dependent Claim 12 words
The isolation trench of claim 1 wherein said isolation body comprises polysilicon.
Claim 5
Dependent Claim 15 words
The isolation trench of claim 1 wherein said layer of insulating material comprises silicon oxide.
Claim 6
Dependent Claim 12 words
The isolation trench of claim 1 wherein said masking layer comprises nitride.
Claim 7
Dependent Claim 24 words
The isolation trench of claim 1 wherein said layer of insulating material has a thickness in the range of 200 Å to 450 Å.
Claim 8
Dependent Claim 20 words
The isolation trench of claim 1 wherein said masking layer has a thickness of from 300 Å to 600 Å.
Claim 9
Dependent Claim 18 words
The isolation trench of claim 1 wherein said field oxide is formed at a temperature above 1000° C.

References Cited (Backward Citations)

US3500139A Cited
US4079506A Cited
US4396460A Cited
US4563227A Cited
JPS58153349A Cited
JPS58200575A Cited
US4582565A Cited
US4528047A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-01-07 1994-07-09 1995-01-08 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-01-07 1998-07-09 1999-01-08 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-01-07 2002-07-09 2003-01-08 $7700.00 Window Closed / Lapsed

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