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US 4,905,070 AGranted
Semiconductor device exhibiting no degradation of low current gain
AssigneeMotorola, Inc.
InventorsIsrael A. Lesk, Peter J. Zdebel, Han-Bin K. Liang
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Abstract
The degradation of the low current gain, which is exhibited during emitter-base reverse bias breakdown testing, is prevented by providing an emitter-base resistive shunt on the surface. This resistive shunt, preferably made of silicon nitride. utilizes surface recombination to reduce the low current gain permanently, thus a degradation is not exhibited upon testing.
Claims9
An integrated semiconductor device comprising:
- a semiconductor substrate of a first conductivity type having a surface, a first doped region of opposite conductivity type than the substrate, and a second doped region of the first conductivity type inside the first doped region;
- and
- a resistive film disposed on the surface of the substrate partially overlaying the first and second doped regions, wherein the resistive film acts as a shunt which prevents a degradation of low current gain.
A bipolar transistor comprising:
- a semiconductor substrate having a top surface, a collector region of a first conductivity type, a base region of a second conductivity type, and an emitter region of the first conductivity type disposed in the base region, and wherein the base, emitter, and collector regions extend to the top surface of the semiconductor substrate;
- and
- a silicon nitride layer disposed on the surface of the semiconductor substrate partially overlaying the emitter and base regions wherein the silicon nitride prevents a degradation of current gain.
An integrated semiconductor device having improved gain, comprising:
- a semiconductor substrate;
- a P-N junction formed in the substrate;
- and a resistive surface shunt positioned on the substrate to overlap the P-N junction to prevent a surface channel from forming and to prevent reverse bias P-N junction ageing induced reduction of low and high current gain.
Dependencies are inferred from the claim text.