US4945069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Organic space holder for trench processing
Assignee: Texas Instruments Inc
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Filing: 1988-12-16
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Granted: 1990-07-31
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Expires: 2008-12-16
Abstract
Abstract A void (60) is created in a semiconductor substrate (52) by forming a cavity which is subsequently filled with an organic polymer (66). The organic polymer is masked and etched to form a spacer. A dielectric (70) fills the portions of the cavity where the organic polymer was etched away. The organic polymer is subsequently etched leaving a void.
Inventors
- 👤 Duane E. Carter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:59
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/038; H10B12/0383; H10P; H10P76/00; H10P76/20; H10W; H10W10/00; H10W10/01; H10W10/011; H10W10/012; H10W10/041; H10W10/10; H10W10/13; H10W10/40; H10W20/00; H10W20/01; H10W20/021
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
78 words
A method of forming a trench-transistor comprising the steps of: forming a trench in a semiconductor substrate; forming a conducting region within a bottom portion of said trench defining a cavity in the upper portion of said trench; forming a spacer region of an organic material within said cavity; forming a dielectric region about said organic spacer region within said cavity; removing said organic spacer region to create a void; and forming a conducting layer within said void.
Claim 2
Independent Claim
78 words
A method of forming a trench-transistor comprising the steps of: forming a trench in a semiconductor substrate; forming a conducting region within a bottom portion of said trench defining a cavity in the upper portion of said trench; forming a spacer region of an organic material within said cavity; forming a dielectric region about said organic spacer region within said cavity; removing said organic spacer region to create a void; and forming a conducting layer within said void.
Claim 3
Dependent Claim
26 words
The method of claim 1 further comprising the step of forming a protective layer over the walls of said cavity prior to forming said spacer region.
Claim 4
Dependent Claim
13 words
The method of claim 2 wherein said protective layer comprises a nitride layer.
Claim 5
Dependent Claim
44 words
The method of claim 2 further comprising the step of, after removing said spacer region, anisotropically etching the portion of said protective layer which was protected by said spacer region to leave a portion of said protective layer on the sidewall of said cavity.
Claim 6
Dependent Claim
54 words
The method of claim 1 wherein said step of forming said spacer region comprises the steps of: forming a layer of organic material to fill said cavity; planarizing said organic material to a level substantially planar to the upper surface of said substrate; and removing a portion of said organic material within said cavity.
Claim 7
Dependent Claim
11 words
The method of claim 1 wherein said spacer region comprises polyimide.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein said step of forming a conducting region comprises the step of forming a doped polysilicon layer within said cavity and separated from the walls thereof by a dielectric layer.
Claim 9
Dependent Claim
13 words
The method of claim 1 wherein said dielectric region comprises conformally deposited oxide.
Claim 10
Dependent Claim
25 words
The method of claim 8 and further comprising the step of forming a glass region to fill any voids left by said conformal oxide layer.
Claim 11
Dependent Claim
22 words
The method of claim 1 and further comprising the step of planarizing said dielectric region to expose portions of said spacer region.
Claim 12
Dependent Claim
16 words
The method of claim 1 further comprising the step of forming doped regions adjacent said trench.
Claim 13
Independent Claim
69 words
A method for fabrication of a device, comprising the steps of: providing a substrate with a cavity formed therein; filling said cavity with a first material; forming an etch mask partially covering said first material; etching said first material where not protected by said etch mask; filling the portion of said first material removed by said etching with a second material; and removing the remainder of said first material.
Claim 14
Independent Claim
69 words
A method for fabrication of a device, comprising the steps of: providing a substrate with a cavity formed therein; filling said cavity with a first material; forming an etch mask partially covering said first material; etching said first material where not protected by said etch mask; filling the portion of said first material removed by said etching with a second material; and removing the remainder of said first material.
Claim 15
Dependent Claim
12 words
A method as in claim 12 wherein said first material comprises polyimide.
Claim 16
Dependent Claim
13 words
A method as in claim 12 wherein said second material comprises silicon dioxide.
Claim 17
Dependent Claim
12 words
A method as in claim 12 wherein said substrate comprises crystalline silicon.
Claim 18
Dependent Claim
12 words
A method as in claim 12 wherein said etching is anistropic etching.
References Cited (Backward Citations)
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JPS61102751A
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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) | 1993-07-30 | 1994-01-29 | 1994-07-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-07-30 | 1998-01-29 | 1998-07-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-07-30 | 2002-01-29 | 2002-07-31 | $7700.00 | Window Closed / Lapsed |