Patent US4575743A successfully refreshed from Google Patents.
US4575743A
Expired / Lapsed
US
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Double layer ROM integrated circuit
Assignee: Suwa Seikosha KK
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Filing: 1983-04-26
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Granted: 1986-03-11
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Expires: 2003-04-26
Abstract
Abstract A first ROM is comprised of a transistor matrix. The polycrystalline silicon forming the gates of the transistors of the first ROM and another polycrystalline silicon region are arranged in a matrix, and diodes are formed by PN junctions at the crossing points. Thus, a second ROM is comprised of a diode matrix. The two ROMS are formed in layers on one common plane and each ROM can retain different information, independently of each other.
Inventors
- 👤 Masami Hashimoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:07
CPC Classifications
H; H10; H10B; H10B20/00
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
85 words
A double layer ROM integrated circuit comprising: a first ROM formed of a matrix of transistors, the source, drain and gate electrodes of the transistors being formed of one of P-type and N-type polycrystalline silicon; and a second ROM formed of a matrix of diodes, the diodes being formed by a junction between P-type and N-type polycrystalline silicon regions, the gate electrodes of the transistors in the first ROM being one of the polycrystalline silicon regions forming each of the diodes in the second ROM.
Claim 2
Dependent Claim
85 words
A double layer ROM integrated circuit comprising: a first ROM formed of a matrix of transistors, the source, drain and gate electrodes of the transistors being formed of one of P-type and N-type polycrystalline silicon; and a second ROM formed of a matrix of diodes, the diodes being formed by a junction between P-type and N-type polycrystalline silicon regions, the gate electrodes of the transistors in the first ROM being one of the polycrystalline silicon regions forming each of the diodes in the second ROM.
Claim 3
Dependent Claim
25 words
The double layer ROM of claim 1 wherein the first ROM is formed of P-channel transistors, the gate electrodes being formed of P-type polycrystalline silicon.
Claim 4
Dependent Claim
35 words
The double layer ROM of claim 2 wherein the diodes of the second ROM are formed by the junctions between the P-type polycrystalline silicon gates of the first ROM transistors and N-type polycrystalline silicon regions.
Claim 5
Dependent Claim
26 words
The double layer ROM of claim 1 wherein the diode matrix forming the second ROM is formed on top of the transistors forming the first ROM.
Claim 6
Dependent Claim
30 words
The double layer ROM of claim 1 wherein each of the diodes forming the second ROM is formed on the gate of one of the transistors forming the first ROM.
Claim 7
Dependent Claim
26 words
The double layer ROM of claim 2 wherein the diode matrix forming the second ROM is formed on top of the transistors forming the first ROM.
Claim 8
Dependent Claim
26 words
The double layer ROM of claim 3 wherein the diode matrix forming the second ROM is formed on top of the transistors forming the first ROM.
Claim 9
Dependent Claim
30 words
The double layer ROM of claim 2 wherein each of the diodes forming the second ROM is formed on the gate of one of the transistors forming the first ROM.
Claim 10
Dependent Claim
30 words
The double layer ROM of claim 3 wherein each of the diodes forming the second ROM is formed on the gate of one of the transistors forming the first ROM.
Claim 11
Dependent Claim
25 words
The double layer ROM of claim 1 wherein the first ROM is formed of N-channel transistors, the gate electrodes being formed of N-type polycrystalline silicon.
Claim 12
Dependent Claim
25 words
The double layer ROM of claim 1 wherein the first ROM is formed of P-channel transistors, the gate electrodes being formed of N-type polycrystalline silicon.
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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) | 1989-03-10 | 1989-09-09 | 1990-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-03-10 | 1993-09-09 | 1994-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-03-10 | 1997-09-09 | 1998-03-11 | $7700.00 | Window Closed / Lapsed |