High-performance and high-uniformity InP/InGaAs/InP DHBT technology for high-speed optical communication systems

Recently, InP/InGaAs/InP double-heterostructure bipolar transistors (DHBT) have attracted a lot of attention in the realization of high-speed (>40 Gb/s) optical communication systems (G. Raghaven et al., IEEE Spectrum, Oct. 2000; Y. Baeyens et al, IEEE GaAs IC Symp. Tech. Dig., pp. 125-128, 2001; Y.K. Chen et al., IEDM Tech. Dig., 2001, and OFC Tech. Dig., 2002). Much progress has been made to improve the high-speed device performance and f/sub T/ values as high as 340 GHz have been reported (S. Lee et al, IEEE GaAs IC Symp. Tech. Dig., pp. 185-187, 2001; A. Fujihara et al., IEDM Tech. Dig., 2001; M. Ida et al., ibid., 2001.). However to our knowledge there have been few reports on the reproducibility, yield and robustness of these types of devices. For successful implementation of these devices in high speed ICs, in addition to high f/sub T/ and f/sub max/, a useful DHBT technology also needs to achieve low turn-on voltage V/sub ce,sat/, low knee voltage V/sub k/, high breakdown voltages BVCEO, BVCBO, and on-state breakdown voltage. Furthermore, excellent device yield, high circuit-performance and uniformity are required. Optimization of all these parameters is critical for any given technology to be practically useful. In this paper, we report on a high-yield, high performance InP/InGaAs DHBT process with excellent uniformity and reproducibility.