US4701695A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Short detector for PROMS
Assignee: Advanced Micro Devices Inc
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Filing: 1986-02-14
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Granted: 1987-10-20
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Expires: 2006-02-14
Abstract
Abstract Test circuitry is included in a PROM memory for detecting shorts between bit lines and word lines and shorts or leaks in a memory cell. The circuitry enables a selected positive voltage to be applied across all memory cells in the memory so that the existence of leaky memory cells or shorts in the memory can be detected during testing. The test circuitry has no appreciable effect on the memory during normal operation of the memory.
Inventors
- 👤 Albert Chan
- 👤 Mark Fitzpatrick
- 👤 Don Goddard
- 👤 Robert J. Bosnyak
- 👤 Cyrus Tsui
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:10
CPC Classifications
G; G11; G11C; G11C29/00; G11C29/02; G11C29/025; G11C29/04; G11C29/50; G11C17/00; G11C17/14; G11C2029/5006
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
109 words
A semiconductor device comprising: a programmable cell including a programmable element and a bipolar transistor coupled to said programmable element, said bipolar transistor having first and second current-carrying leads and a control lead, said first current-carrying lead being coupled to said programmable element; and means for applying a test voltage to said first current-carrying lead of said bipolar transistor relative to said control lead of said bipolar transistor to thereby reverse-bias the junction between said first current carrying lead and said control lead and, and for determining whether current through said first current-carrying lead indicates the presence of shorts or leakages so as to render said semiconductor device unacceptable.
Claim 2
Dependent Claim
109 words
A semiconductor device comprising: a programmable cell including a programmable element and a bipolar transistor coupled to said programmable element, said bipolar transistor having first and second current-carrying leads and a control lead, said first current-carrying lead being coupled to said programmable element; and means for applying a test voltage to said first current-carrying lead of said bipolar transistor relative to said control lead of said bipolar transistor to thereby reverse-bias the junction between said first current carrying lead and said control lead and, and for determining whether current through said first current-carrying lead indicates the presence of shorts or leakages so as to render said semiconductor device unacceptable.
Claim 3
Dependent Claim
29 words
The semiconductor device of claim 1 wherein said programmable element is a fuse coupled to said transistor, whereby current from said transistor can be used to open said fuse.
Claim 4
Dependent Claim
20 words
The semiconductor device of claim 1 wherein said first and second current carrying leads comprise emitter and collector leads, respectively.
Claim 5
Independent Claim
125 words
A method for testing a semiconductor device, said semiconductor device including a fuse and programming means having a programming lead coupled to said fuse, said programming means being capable of providing a programming current on said programming lead to thereby open said fuse, said method comprising the steps of: applying a voltage to said programming lead; and sensing the current flowing through said programming lead to thereby detect the presence of shorts or leakages in said semiconductor device, wherein said programming means is a bipolar transistor having an emitter coupled to said fuse, said voltage applied to said programming lead reverse-biasing the base-emitter junction of said bipolar transistor, whereby said sensed current is indicative of the presence of shorts or leakages across said base-emitter junction.
Claim 6
Independent Claim
125 words
A method for testing a semiconductor device, said semiconductor device including a fuse and programming means having a programming lead coupled to said fuse, said programming means being capable of providing a programming current on said programming lead to thereby open said fuse, said method comprising the steps of: applying a voltage to said programming lead; and sensing the current flowing through said programming lead to thereby detect the presence of shorts or leakages in said semiconductor device, wherein said programming means is a bipolar transistor having an emitter coupled to said fuse, said voltage applied to said programming lead reverse-biasing the base-emitter junction of said bipolar transistor, whereby said sensed current is indicative of the presence of shorts or leakages across said base-emitter junction.
Claim 7
Independent Claim
90 words
A method for testing a semiconductor device, said semiconductor device comprising a programmable element and means for programming said programmable element, said means for programming comprising a bipolar transistor having a current-carrying lead coupled to said programmable element and a control lead, said method comprising the steps of: applying a voltage to said current-carrying lead of said bipolar transistor to reverse-bias the junction between said current-carrying lead and said control lead; and sensing the current flowing through said current-carrying lead to thereby detect shorts or leakages in said semiconductor device.
Claim 8
Independent Claim
90 words
A method for testing a semiconductor device, said semiconductor device comprising a programmable element and means for programming said programmable element, said means for programming comprising a bipolar transistor having a current-carrying lead coupled to said programmable element and a control lead, said method comprising the steps of: applying a voltage to said current-carrying lead of said bipolar transistor to reverse-bias the junction between said current-carrying lead and said control lead; and sensing the current flowing through said current-carrying lead to thereby detect shorts or leakages in said semiconductor device.
Claim 9
Dependent Claim
27 words
The method of claim 5 wherein said step of sensing the current is performed to detect shorts or leakages across the base-emitter junction of said bipolar transistor.
Claim 10
Dependent Claim
78 words
In a programmable semiconductor device comprising at least one programmable cell comprising a bipolar transistor and a fuse, a method of detecting shorts and leakages in said programmable cell comprising the steps of: applying a voltage to said programmable cell so that the base-emitter junction of said bipolar transistor becomes reverse biased; measuring the current carried through said at least one cell; and using said measured current to determine the presence of shorts or leakages in said cell.
Claim 11
Dependent Claim
78 words
In a programmable semiconductor device comprising at least one programmable cell comprising a bipolar transistor and a fuse, a method of detecting shorts and leakages in said programmable cell comprising the steps of: applying a voltage to said programmable cell so that the base-emitter junction of said bipolar transistor becomes reverse biased; measuring the current carried through said at least one cell; and using said measured current to determine the presence of shorts or leakages in said cell.
Claim 12
Dependent Claim
124 words
In a programmable semiconductor device having at least one data lead and comprising at least one programmable cell in turn comprising a transistor having a base, an emitter, and a collector and also having a fuse connected in series between said emitter and said data lead, a method for determining acceptability of said at least one programmable cell comprising the steps of: applying a range of voltages to said programmable cell sufficient to allow detection of shorts and leakages in said cell but not sufficient to open said fuse; and determining from the current carried by said at least one cell in response to said range of voltages whether said shorts and leakages are present to a degree which makes said semiconductor device unacceptable.
Claim 13
Dependent Claim
124 words
In a programmable semiconductor device having at least one data lead and comprising at least one programmable cell in turn comprising a transistor having a base, an emitter, and a collector and also having a fuse connected in series between said emitter and said data lead, a method for determining acceptability of said at least one programmable cell comprising the steps of: applying a range of voltages to said programmable cell sufficient to allow detection of shorts and leakages in said cell but not sufficient to open said fuse; and determining from the current carried by said at least one cell in response to said range of voltages whether said shorts and leakages are present to a degree which makes said semiconductor device unacceptable.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-10-19 | 1991-04-20 | 1991-10-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-10-19 | 1995-04-20 | 1995-10-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-10-19 | 1999-04-20 | 1999-10-20 | $7700.00 | Window Closed / Lapsed |