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US5008729A Expired / Lapsed US ⏱️ 0.0 years remaining

Laser programming of semiconductor devices using diode make-link structure

Assignee: Texas Instruments Inc
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Filing: 1989-09-28
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Granted: 1991-04-16
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Expires: 2009-09-28
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Abstract

Abstract A semiconductor device is programmed by a laser beam which causes a PN junction in a silicon substrate to be permanently altered. This produces a leakage path between a program node and a tank region in the substrate; the program node can be an input to a transistor in a CMOS circuit, for example, so this node will always hold the transistor on or off depending whether or not it has been laser-programmed. Preferably, the tank region is of opposite type compared to the substrate, so the program node is electrically isolated from the substrate in either case.

Inventors

  • 👤 Kendall S. Wills
  • 👤 Paul A. Rodriguez

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 18:09
CPC Classifications
H; H10; H10D; H10D89/00; H10D84/00; H10D84/80; H10D84/82; H10D84/83; H10D84/85

Claims Analysis

Total Claims: 20
Claim 1
Independent Claim 194 words
An integrated circuit with laser programmable links in a semiconductor body comprising: (a) a first PN junction formed in a region of said body having a first conductivity type with a programming area within the PN junction for receiving a laser beam, said first PN junction being separate and distinct from other electrical components and normally presenting a high resistance to current flow in a certain direction; (b) a second PN junction formed in a region of said body having a second conductivity type with a programming area within the PN junction for receiving a laser beam, said second PN junction being separate and distinct from other electrical components and normally presenting a high resistance to current flow in a particular direction; (c) a circuit including said first and second PN junctions and having an input and an output, said output clamped at a first level if said first PN junction is make-link programmed to form a low resistance to current flow in said certain direction, and said output clamped at a second level if said second PN junction is make-link programmed to form a low resistance to current flow in said particular direction.
Claim 2
Dependent Claim 194 words
An integrated circuit with laser programmable links in a semiconductor body comprising: (a) a first PN junction formed in a region of said body having a first conductivity type with a programming area within the PN junction for receiving a laser beam, said first PN junction being separate and distinct from other electrical components and normally presenting a high resistance to current flow in a certain direction; (b) a second PN junction formed in a region of said body having a second conductivity type with a programming area within the PN junction for receiving a laser beam, said second PN junction being separate and distinct from other electrical components and normally presenting a high resistance to current flow in a particular direction; (c) a circuit including said first and second PN junctions and having an input and an output, said output clamped at a first level if said first PN junction is make-link programmed to form a low resistance to current flow in said certain direction, and said output clamped at a second level if said second PN junction is make-link programmed to form a low resistance to current flow in said particular direction.
Claim 3
Dependent Claim 22 words
The integrated circuit as in claim 1 wherein said first PN junction is located in a well of said first conductivity type.
Claim 4
Dependent Claim 22 words
The integrated circuit as in claim 1 wherein said second PN junction is located in a well of said second conductivity type.
Claim 5
Dependent Claim 37 words
The integrated circuit as in claim 1 wherein said first PN junction is located in a well of said first conductivity type and said second PN junction is located in a well of said second conductivity type.
Claim 6
Dependent Claim 23 words
The integrated circuit as in claim 1 wherein a region above said first and second PN junctions is not disrupted by make-link programming.
Claim 7
Dependent Claim 19 words
The integrated circuit as in claim 1 wherein said certain direction and said particular direction are the same direction.
Claim 8
Dependent Claim 18 words
The integrated circuit as in claim 1 wherein said certain direction and said particular direction are different directions.
Claim 9
Dependent Claim 224 words
A programmable integrated CMOS inverter circuit comprising: a semiconductor material having a surface of a first conductivity type; a well of a second conductivity type formed in said surface; a first transistor having first and second source/drain regions of the second conductivity type formed in said surface of the first conductivity type and a gate electrode, said first region connectable to a first voltage level; a second transistor having first and second source/drain regions of the first conductivity type formed in said well and a gate electrode, said second region connectable to a second voltage level, said first transistor gate electrode electrically connected to said second transistor gate electrode to form a first inverter input node, said second source/drain region of said first transistor connected to said first source/drain region of said second transistor to form a first inverter output node; a resistance programmable area formed of a PN junction, separate and distinct from each transistor, formed in said surface of the first conductivity type for selectably connecting, without melting, said first and second source/drain regions of said first transistor with a low resistance; and a circuit including said PN junction and having an input and an output, said output clamped at a first level if said PN junction is make-link programmed to form a low resistance to current flow in a certain direction.
Claim 10
Dependent Claim 224 words
A programmable integrated CMOS inverter circuit comprising: a semiconductor material having a surface of a first conductivity type; a well of a second conductivity type formed in said surface; a first transistor having first and second source/drain regions of the second conductivity type formed in said surface of the first conductivity type and a gate electrode, said first region connectable to a first voltage level; a second transistor having first and second source/drain regions of the first conductivity type formed in said well and a gate electrode, said second region connectable to a second voltage level, said first transistor gate electrode electrically connected to said second transistor gate electrode to form a first inverter input node, said second source/drain region of said first transistor connected to said first source/drain region of said second transistor to form a first inverter output node; a resistance programmable area formed of a PN junction, separate and distinct from each transistor, formed in said surface of the first conductivity type for selectably connecting, without melting, said first and second source/drain regions of said first transistor with a low resistance; and a circuit including said PN junction and having an input and an output, said output clamped at a first level if said PN junction is make-link programmed to form a low resistance to current flow in a certain direction.
Claim 11
Dependent Claim 26 words
The circuit of claim 8 wherein said resistance programmable area formed of a PN junction connects said first and second source/drain regions of said second transistor.
Claim 12
Dependent Claim 96 words
The circuit of claim 8 further including a second resistance programmable area formed of a second PN junction, separate and distinct from each transistor, formed in said well for selectably connecting said first and second source/drain regions of said second transistor, said output clamped at said first level if said first PN junction is make-link programmed to form a low resistance to current flow in said certain direction, and said output clamped at a second level if said second PN junction is make-link programmed to form a low resistance to current flow in a particular direction.
Claim 13
Dependent Claim 17 words
The circuit of claim 10 wherein said certain direction and said particular direction are the same direction.
Claim 14
Dependent Claim 16 words
The circuit of claim 10 wherein said certain direction and said particular direction are different directions.
Claim 15
Dependent Claim 12 words
The circuit of claim 8 wherein said well is of p-conductivity type.
Claim 16
Dependent Claim 13 words
The circuit of claim 8 wherein said semiconductor material is a silicon substrate.
Claim 17
Dependent Claim 17 words
The circuit of claim 8 wherein the PN junction is convertible into a shorting resistor by irradiation.
Claim 18
Dependent Claim 12 words
The circuit of claim 8 wherein said PN junction is a diode.
Claim 19
Dependent Claim 114 words
The circuit of claim 8 further including: a third transistor having first and second source/drain regions of the second conductivity type formed in said surface of the first conductivity type and a gate electrode connected to the first inverter output node, said first region connectable to the first voltage level; and a fourth transistor having first and second source/drain regions of the first conductivity type formed in said well and a gate electrode connected to the first inverter output node, said second region connectable to the second voltage level, said second source/drain region of said third transistor connected to said first source/drain region of said fourth transistor to form a second inverter output node.
Claim 20
Dependent Claim 41 words
The circuit of claim 4 further including a second resistance programmable area formed of a second PN junction, separate and distinct from each transistor, formed in said well for selectably connecting said first and second source/drain regions of said second transistor.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1994-04-15 1994-10-15 1995-04-16 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1998-04-15 1998-10-15 1999-04-16 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2002-04-15 2002-10-15 2003-04-16 $7700.00 Window Closed / Lapsed

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