US6800563B2
Expired / Lapsed
US
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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 10:26
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.
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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) | 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 |