Journal of the Korean Institute of Telematics and Electronics D (전자공학회논문지D)
- Volume 35D Issue 7
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- Pages.88-93
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- 1998
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- 1226-5845(pISSN)
Degradation analysis of AlGaAs/GaAs HBTs and improvement of reliability by using InGaP ledge emitter
AlGaAs/GaAs HBT의 열화분석과 InGaP ledge 에미터에 의한 신뢰도 개선
Abstract
For the self-aligned AlGaAs/GaAs HBTs, the surface states at the interface between the extrinsic base surface and the passivation nitride is a major cause of degradation of dc characteristics. In this paper the degradation mechanisms of self-aligned AlGaAs/GaAs HBT were analyzed, and GaAs HBTs, which employed an InGaP ledge emitter structure formed by the nonself-aligned process to cover the surface of the extrinsic base and reduce the surface states, produced high reliability. Accoridng to the acceleration lifetime test, the nonself-aligned InGaP/GaAs HBTs produced very reliable dc characteristics comparing with the self-aligned AlGaAs/GaAs HBTs. The activation energy was 1.97eV and MTTF
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