GAAS HBTS FOR HIGH-SPEED DIGITAL INTEGRATED-CIRCUIT APPLICATIONS

GaAs HBT technology has emerged as one of the most important developments for digital circuits operating at clock frequencies of 100 MHz and higher. High-speed frequency dividers operating as high as 34.8 GHz and VLSI circuits as complex as 32-b CPU's operating at 200-MHz clock rate have been demonstrated. This paper reviews the role of GaAs HBT technologies for high-speed digital IC applications. The requirements for high-speed IC's and the characteristics of various HBT device structures and logic families are discussed. A summary of published results of the ultrahigh-speed circuits and the status of several high-speed VLSI circuits are presented to provide a guide for future developments.