US6018186A
Expired / Lapsed
US
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Three-dimensional, deep-trench, high-density read-only memory (ROM) and its manufacturing method
Assignee: United Microelectronics Corp
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Filing: 1997-08-20
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Granted: 2000-01-25
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Expires: 2017-08-20
Abstract
Abstract A three-dimensional, deep-trench, high-density ROM and its manufacturing method are provided. The ROM device comprises a silicon substrate having a plurality of parallel trenches above it surface, wherein, between every two adjacent trenches, there is a higher region. During programming of the ROM device, deeper trenches are formed to define the OFF-state non-conducting memory cells, so that misalignment problems that lead to transistor cell leakage are prevented. The ROM device provides reduced breakdown of the source/drain regions as well.
Inventors
- 👤 Chen-Chung Hsu
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 08:33
CPC Classifications
H; H10; H10B; H10B20/00; H10B20/27; H10B20/30; H10B20/36
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
163 words
A three-dimensional, high-density ROM, comprising: a plurality of parallel bit lines formed in a silicon substrate, each of the bit lines having a depth substantially equal to the depth of the other bit lines; a plurality of word lines running perpendicular to and above the bit lines; and a plurality of memory cells, each memory cell being formed at a junction of two adjacent bit lines and a portion of one of the word lines and having a channel region, the channel region having a depth and containing gate oxide and polysilicon, the plurality of memory cells including a plurality of non-conducting memory cells and a plurality of conducting memory cells, the channel region of the conducting memory cells having a depth substantially equal to the depth of the plurality of bit lines, the channel region of the non-conducting memory cells having a depth greater than the depth of the channel region of the conducting memory cells and penetrating through the bit lines.
Claim 2
Dependent Claim
163 words
A three-dimensional, high-density ROM, comprising: a plurality of parallel bit lines formed in a silicon substrate, each of the bit lines having a depth substantially equal to the depth of the other bit lines; a plurality of word lines running perpendicular to and above the bit lines; and a plurality of memory cells, each memory cell being formed at a junction of two adjacent bit lines and a portion of one of the word lines and having a channel region, the channel region having a depth and containing gate oxide and polysilicon, the plurality of memory cells including a plurality of non-conducting memory cells and a plurality of conducting memory cells, the channel region of the conducting memory cells having a depth substantially equal to the depth of the plurality of bit lines, the channel region of the non-conducting memory cells having a depth greater than the depth of the channel region of the conducting memory cells and penetrating through the bit lines.
Claim 3
Dependent Claim
17 words
A ROM according to claim 1, wherein a channel region of each conducting memory cell is arc-shaped.
Claim 4
Dependent Claim
19 words
A ROM according to claim 1, wherein arsenic is used as a dopant to form the plurality bit lines.
Claim 5
Dependent Claim
24 words
A ROM according to claim 1, wherein each of the plurality of word lines comprises a gate oxide layer and an impurity-doped polysilicon layer.
Claim 6
Dependent Claim
16 words
A ROM according to claim 4, wherein the gate oxide layer is a silicon dioxide layer.
Claim 7
Dependent Claim
22 words
A ROM according to claim 4, wherein the thickness of the gate oxide layer is between approximately 100 Å to 250 Å.
References Cited (Backward Citations)
US5329148A
Cited
US5214303A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2003-01-24 | 2003-07-26 | 2004-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2007-01-24 | 2007-07-26 | 2008-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2011-01-24 | 2011-07-26 | 2012-01-25 | $7700.00 | Window Closed / Lapsed |