EP0166344A2
Expired / Lapsed
EP
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Means for alleviating emitter contact stress in bipolar transistors
Assignee: International Business Machines Corp
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Filing: 1985-06-19
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Granted: —
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Expires: 2005-06-19
Abstract
Abstract An emitter contact structure is disclosed for alleviating forward bias beta degradation in a bipolar transistor. The structure comprises an emitter contact metallurgy stripe (3) which travels over a dielectric insulating layer (9) having an area of increased thickness (10) adjacent to a contact opening (11) between the metallurgy stripe (3) and the emitter (1).
Inventors
- 👤 Gary Robert Hueckel
- 👤 George Stephen Prokop
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-09 16:45
CPC Classifications
H; H10; H10W; H10W20/00; H10W20/40; H10D; H10D64/00; H10D64/20; H10D64/23; H10D64/231
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
51 words
Means for alleviating electromigration-induced emitter contact stress in bipolar transistors susceptible to forward bias beta degradation, characterized by metallurgy means (3) insulated from the emitter area (1), except for a contact opening (11), for concentrating electromigration-induced stress in said metallurgy means (3) in an area adjacent to the contact opening (11).
Claim 2
Dependent Claim
51 words
Means for alleviating electromigration-induced emitter contact stress in bipolar transistors susceptible to forward bias beta degradation, characterized by metallurgy means (3) insulated from the emitter area (1), except for a contact opening (11), for concentrating electromigration-induced stress in said metallurgy means (3) in an area adjacent to the contact opening (11).
Claim 3
Dependent Claim
62 words
Means in accordance with claim 1, characterized by a layer (9) of insulating material disposed on the emitter (1), base (4) and collector (5) areas of the transistor (2) with an opening (11) over the said emitter area (1) and metallurgy stripe (3) on top of said insulating layer (9) and extending into said opening (11) for contacting said emitter area (1).
Claim 4
Dependent Claim
44 words
Means in accordance with claim 2, characterized in that said insulating layer (9) has an area (10) of increased thickness adjacent to said opening (11), and that said metallurgy stripe (3) contacts said emitter area (1) after traversing said area (10) of increased thickness.
Claim 5
Dependent Claim
23 words
Means in accordance with claim 3, characterized in that said area (10) has a thickness in the range between 400 and 500 nm.
Claim 6
Dependent Claim
26 words
Means in accordance with claim 2, characterized in that said metallurgy stripe consists of a chromium- aluminium-copper alloy and has a thickness of about 1 µm.
Claim 7
Dependent Claim
36 words
Means in accordance with claim 3, characterized in that said area (10) of increased thickness is spaced from the center of said opening (11) at a distance (11) in the range between 5 and 10 µm.
References Cited (Backward Citations)
No citation records indexed.
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