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US4385432A Expired / Lapsed US ⏱️ 0.0 years remaining

Closely-spaced double level conductors for MOS read only

Assignee: Texas Instruments Inc
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Filing: 1978-05-18
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Granted: 1983-05-31
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Expires: 1998-05-18
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Abstract

Abstract Closely-spaced conductors can be used in a semiconductor integrated circuit such as an MOS read only memory or ROM formed by a process compatible with standard N-channel silicon gate manufacturing methods. Address lines and gates are polysilicon strips, and output and ground lines are defined by elongated N+ regions. To allow the spacing between adjacent polysilicon address lines to be closer, alternate rows employ first or second level polysilicon which can even overlap if necessary. Each potential MOS transistor in the array is programmed to be a logic "1" or "0", such as by ion implanting through the polysilicon gates and thin gate oxide.

Inventors

  • 👤 Chang-Kiang Kuo
  • 👤 Shyh-Chang Tsaur

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-28 12:04
CPC Classifications
G; G11; G11C; G11C17/00; G11C17/08; G11C17/10; G11C17/12; G11C17/126; H; H10; H10B; H10B20/00; H10B20/27; H10B20/30; H10B20/38; H10B20/383; H10B20/40; H10D; H10D64/00; H10D64/20; H10D64/27; H10D64/311; H10D64/411; H10D64/511; H10D64/512; H10D64/513

Claims Analysis

Total Claims: 11
Claim 1
Independent Claim 125 words
A method of making a read-only-memory comprising the steps of: forming a plurality of insulated gate field effect transistors in a face of a semiconductor body, each of the transistors having a source, a drain and a channel, the transistors being in a regular pattern of adjacent rows to provide an array of memory cells; applying a first pattern of conductive strips providing the gates of alternate rows of cells, and thereafter applying a second pattern of like conductive strips on said face parallel with and interleaved with the first pattern to provide the gates of the remaining rows of cells, the conductive strips of the first and second patterns being spaced closer to one another than the width of one of the conductive strips.
Claim 2
Independent Claim 125 words
A method of making a read-only-memory comprising the steps of: forming a plurality of insulated gate field effect transistors in a face of a semiconductor body, each of the transistors having a source, a drain and a channel, the transistors being in a regular pattern of adjacent rows to provide an array of memory cells; applying a first pattern of conductive strips providing the gates of alternate rows of cells, and thereafter applying a second pattern of like conductive strips on said face parallel with and interleaved with the first pattern to provide the gates of the remaining rows of cells, the conductive strips of the first and second patterns being spaced closer to one another than the width of one of the conductive strips.
Claim 3
Dependent Claim 35 words
A method according to claim 1, wherein the field effect transistors are N-channel silicon gate transistors, and the conductive strips are formed by two layers of polycrystalline silicon deposited separately in thin films and patterned.
Claim 4
Dependent Claim 163 words
In a method of making a read-only-memory which includes the steps of: forming a plurality of insulated gate field effect transistors in a face of a semiconductor body, each of the transistors having a source, a drain and a gate, the transistors being in a regular pattern of adjacent rows to provide an array of memory cells; applying parallel strips of polycrystalline silicon to said face to provide the gates and row address lines; the improvement comprising the steps of: applying the strips of polycrystalline silicon in two separate steps, the first step including applying a film of polycrystalline silicon and patterning it to provide a first set of alternate rows, then coating the film with insulating material, and the second step including applying another film of polycrystalline silicon and patterning it to provide the remaining rows interleaved with said first set of alternate rows, wherein the spacing between the strips of polycrystalline silicon is much less than the width of the strips.
Claim 5
Dependent Claim 163 words
In a method of making a read-only-memory which includes the steps of: forming a plurality of insulated gate field effect transistors in a face of a semiconductor body, each of the transistors having a source, a drain and a gate, the transistors being in a regular pattern of adjacent rows to provide an array of memory cells; applying parallel strips of polycrystalline silicon to said face to provide the gates and row address lines; the improvement comprising the steps of: applying the strips of polycrystalline silicon in two separate steps, the first step including applying a film of polycrystalline silicon and patterning it to provide a first set of alternate rows, then coating the film with insulating material, and the second step including applying another film of polycrystalline silicon and patterning it to provide the remaining rows interleaved with said first set of alternate rows, wherein the spacing between the strips of polycrystalline silicon is much less than the width of the strips.
Claim 6
Independent Claim 70 words
A method of making a semiconductor device comprising the steps of: forming a plurality of circuit elements in a pattern of adjacent rows at a face of a semiconductor body; and applying two separate patterns of interleaved conductive strips to said face to provide electrodes overlying the face, adjacent rows having overlying electrodes created of different ones of the two patterns, individual strips being wider than the spacing between strips.
Claim 7
Independent Claim 70 words
A method of making a semiconductor device comprising the steps of: forming a plurality of circuit elements in a pattern of adjacent rows at a face of a semiconductor body; and applying two separate patterns of interleaved conductive strips to said face to provide electrodes overlying the face, adjacent rows having overlying electrodes created of different ones of the two patterns, individual strips being wider than the spacing between strips.
Claim 8
Dependent Claim 50 words
A method according to claim 4 wherein a semiconductor device is a read-only-memory, the circuit elements are N-channel silicon gate transistors, the electrodes are formed by a first polysilicon layer deposited in a thin film and patterned prior to a second polysilicon layer deposited in a thin film and patterned.
Claim 9
Independent Claim 127 words
A method of making a semiconductor device comprising the steps of: forming a plurality of circuit elements in a pattern of adjacent rows at a face of a semiconductor body; and applying two separate patterns of interleaved parallel conductive strips to said face over the circuit elements to provide electrodes of the circuit elements, adjacent rows having electrodes formed by different ones of the two patterns, by depositing a first film of conductive material and selectively removing parts of it to define a first pattern, coating the first pattern with insulating material, depositing a second film of conductive material and selectively removing parts of it to define a second pattern; wherein the spacing between the conductive strips is much less than the width of the individual strips.
Claim 10
Independent Claim 127 words
A method of making a semiconductor device comprising the steps of: forming a plurality of circuit elements in a pattern of adjacent rows at a face of a semiconductor body; and applying two separate patterns of interleaved parallel conductive strips to said face over the circuit elements to provide electrodes of the circuit elements, adjacent rows having electrodes formed by different ones of the two patterns, by depositing a first film of conductive material and selectively removing parts of it to define a first pattern, coating the first pattern with insulating material, depositing a second film of conductive material and selectively removing parts of it to define a second pattern; wherein the spacing between the conductive strips is much less than the width of the individual strips.
Claim 11
Dependent Claim 36 words
A method according to claim 6 wherein a semiconductor device is a read-only-memory, the circuit elements are N-channel silicon gate transistors, and the electrodes are formed by polysilicon layer which comprises the first and second films.

References Cited (Backward Citations)

US3225261A Cited
US4347656A Cited
US4099317A Cited
US4143178A Cited
US4097885A Cited
US4151020A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-05-30 1986-11-29 1987-05-31 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-05-30 1990-11-29 1991-05-31 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-05-30 1994-11-29 1995-05-31 $7700.00 Window Closed / Lapsed

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