US5466627A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stacked capacitor process using BPSG precipitates
Assignee: United Microelectronics Corp
•
Filing: 1994-03-18
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Granted: 1995-11-14
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Expires: 2014-03-18
Abstract
Abstract A MOST capacitor for use in a DRAM is formed by using BPSG precipitates after densification as a mask for etching a BPSG layer to form BPSG islands. The BPSG islands are then used as a mask for etching a polysilicon layer to form pillars in the polysilicon layer.
Inventors
- 👤 Water Lur
- 👤 Jenn-Tarng Lin
- 👤 Hsiaw-Sheng Chin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:56
CPC Classifications
H; H10; H10B; H10B12/00; H10B12/01; H10B12/02; H10B12/03; H10B12/033; H10B12/30; H10B12/31; H10B12/318; Y; Y10; Y10S; Y10S438/00; Y10S438/942; Y10S438/947
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
114 words
A method for making a capacitor for use in a DRAM cell comprising the steps of a) forming a conductive polysilicon layer on a silicon substrate, b) forming a glass layer on the polysilicon layer containing a precipitable material, c) treating the glass layer so that said precipitable material is precipitated out of the glass layer to form precipitates thereon, d) using the precipitates as a mask, etching the glass layer to form glass islands, e) using the glass islands as a mask, etching the polysilicon layer to from a plurality of pillars, f) depositing a dielectric layer on the etched polysilicon layer, and g) depositing a second polysilicon layer on the dielectric layer.
Claim 2
Independent Claim
114 words
A method for making a capacitor for use in a DRAM cell comprising the steps of a) forming a conductive polysilicon layer on a silicon substrate, b) forming a glass layer on the polysilicon layer containing a precipitable material, c) treating the glass layer so that said precipitable material is precipitated out of the glass layer to form precipitates thereon, d) using the precipitates as a mask, etching the glass layer to form glass islands, e) using the glass islands as a mask, etching the polysilicon layer to from a plurality of pillars, f) depositing a dielectric layer on the etched polysilicon layer, and g) depositing a second polysilicon layer on the dielectric layer.
Claim 3
Dependent Claim
10 words
The method of claim 1 wherein said glass is BPSG.
Claim 4
Dependent Claim
16 words
The method claim 1 wherein said islands have a size in the range of 0.05-0.2 microns.
Claim 5
Dependent Claim
19 words
The method of claim 1 wherein said treating step comprises thermally treating the glass layer to form said precipitates.
Claim 6
Dependent Claim
21 words
The method of claim 1 wherein said treating step comprises thermally densifying said glass layer at a temperature of 800°-1000° C.
Claim 7
Dependent Claim
26 words
The method of claim 1 wherein said treating step comprises thermally densifying said glass layer to form an SiO 2 structure containing residual soluble precipitable material.
References Cited (Backward Citations)
US4859622A
Cited
JPH02308551A
Cited
JPH03266460A
Cited
US5304828A
Cited
US5332696A
Cited
US5232876A
Cited
US5169803A
Cited
US5158905A
Cited
US5164881A
Cited
US5256587A
Cited
US5134086A
Cited
US5234857A
Cited
US5182232A
Cited
US5112773A
Cited
US5313100A
Cited
US5068199A
Cited
US5110752A
Cited
US5227322A
Cited
US5213992A
Cited
US5342800A
Cited
US5302540A
Cited
US5350707A
Cited
US5244842A
Cited
US5405801A
Cited
US5204280A
Cited
US5254503A
Cited
US5308786A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1998-11-13 | 1999-05-15 | 1999-11-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-11-13 | 2003-05-15 | 2003-11-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-11-13 | 2007-05-15 | 2007-11-14 | $7700.00 | Window Closed / Lapsed |