Development of RFCMOS Technologies in the 1990s in Toshiba

In recent years, RF Si CMOS technologies have become dominant in RF frontend circuits for high-frequency operations, up to 60/300 GHz for 5G/6G telecommunication circuits. During the 1990s, when Si/SiGe bipolar and GaAs devices were the primary RF technologies operating for the 2G system with the 800 MHz to 2.5 GHz range for mobile telecommunications, CMOS technology was not initially considered suitable. However, Toshiba was one the first companies to embark on the development of state of the art high-performance RF CMOS device technologies in the mid1990s and eventually took a leading role in advancing these technologies worldwide by the end of that decade. The first successful application was Bluetooth by Ericsson, featuring the first 2.4 GHz RF CMOS devices for commercial use. This paper describes the development of cutting-edge high-performance RF CMOS technologies at Toshiba in the 1990s.