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US6800563B2
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Forming tapered lower electrode phase-change memories
Assignee: Ovonyx Memory Technology LLC
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Filing: 2001-10-11
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Granted: 2004-10-05
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Expires: 2021-10-11
Abstract
Abstract A phase-change memory may have a tapered lower electrode coated with an insulator. The coated, tapered electrode acts as a mask for a self-aligned trench etch to electrically separate adjacent wordlines. In some embodiments, the tapered lower electrode may be formed over a plurality of doped regions, and isotropic etching may be used to taper the electrode as well as part of the underlying doped regions.
Inventors
- 👤 Daniel Xu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 10:37
CPC Classifications
H; H10; H10B; H10B63/00; H10B63/20; H10N; H10N70/00; H10N70/011; H10N70/20; H10N70/231; H10N70/801; H10N70/821; H10N70/826; H10N70/841; H10N70/8413; H10N70/8418; H10N70/881; H10N70/882; H10N70/8828; G; G11; G11C; G11C2213/00; G11C2213/50; G11C2213/52; G11C2213/70; G11C2213/72
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
53 words
A method of forming a phase-change memory cell comprising: forming a tapered electrode for a phase-change memory cell over a substrate; forming junctions below said tapered electrode; forming a plurality of layers of different doping levels in said substrate; and forming a trench in said layers using the tapered electrode as a mask.
Claim 2
Independent Claim
53 words
A method of forming a phase-change memory cell comprising: forming a tapered electrode for a phase-change memory cell over a substrate; forming junctions below said tapered electrode; forming a plurality of layers of different doping levels in said substrate; and forming a trench in said layers using the tapered electrode as a mask.
Claim 3
Dependent Claim
13 words
The method of claim 1 including covering said tapered electrode with an insulator.
Claim 4
Dependent Claim
24 words
The method of claim 1 including covering said electrode with an insulator and forming a pair of trenches using said electrode as a mask.
Claim 5
Dependent Claim
13 words
The method of claim 1 including self-aligning the trench to the tapered electrode.
Claim 6
Dependent Claim
13 words
The method of claim 1 including forming a tapered electrode by isotropically etching.
Claim 7
Dependent Claim
12 words
The method of claim 1 including forming said layers by ion implantation.
Claim 8
Dependent Claim
20 words
The method of claim 1 including etching said layers using the same isotropic etch used to form said tapered electrode.
Claim 9
Dependent Claim
15 words
The method of claim 7 including forming a tapered substrate portion below said tapered electrode.
Claim 10
Dependent Claim
16 words
The method of claim 8 including forming a conical-shaped substrate portion covered by said tapered electrode.
Claim 11
Dependent Claim
22 words
The method of claim 8 including covering said tapered substrate portion with an insulator and anisotropic etching said covered tapered substrate portion.
References Cited (Backward Citations)
US4085498A
Cited
US4599705A
Cited
US4474623A
Cited
US4845533A
Cited
USRE37259E1
Cited
US6014400A
Cited
US6150253A
Cited
US6407004B1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2007-10-05 | 2008-04-05 | 2008-10-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2011-10-05 | 2012-04-05 | 2012-10-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2015-10-05 | 2016-04-05 | 2016-10-05 | $7700.00 | Window Closed / Lapsed |