AlGaAs/GaAs Heterojunction Bipolar Transistor ICs for Optical Transmission Systems

Tetsuyuki SUZAKI
Masaaki SODA
Kazuhiko HONJO

IEICE TRANSACTIONS on Electronics   Vol.E76-C    No.6    pp.883-890
Publication Date: 1993/06/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: Special Section PAPER (Special Issue on Microwave and Millimeter-Wave Technology for Advanced Functions and Size-Reductions)
electronic circuits,  optical transmission,  HBT,  gallium arsenide,  uniformities,  

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AlGaAs/GaAs HBT ICs for high bit-rate optical transmission systems, such as preamplifier, D-F/F, differential amplifier, and laser driver, have been newly developed using the hetero guard-ring fully self-aligned HBT (HGFST) fabrication process. In this process, the emitter mesa is ECR-RIBE dry etched using a thick emitter-metal system of WSi and Ti-Pt-Au as etching mask, and a hetero guard-ring composed of a depleted AlGaAs layer is fabricated on p GaAs extrinsic base regions. This process results in highly uniform HBT characteristics. The preamplifier IC exhibits a DC to 18.5-GHz transimpedance bandwidth with a transimpedance gain of 49 dBΩ. The rise time and fall time for the D-F/F IC are 30 and 23 ps, respectively. The laser driver IC has a 40-mAp-p output current swing. The differential amplifier exhibits a DC to 12.1-GHz bandwidth with a 14.2-dB power gain.