RF power silicon-on-glass VDMOSFETs

Applicability of vertical double-diffused MOSFETs for future base station power amplifiers has been demonstrated by characterizing the first devices fabricated in a substrate transfer silicon-on-glass technology. For a gate length of 0.8 μm and gate width of 350 μm, the measured f_T/f_max is 6/10 GHz, and the breakdown voltage approaches 100 V. The devices feature an output power of 12 dBm at the 1-dB compression point, excellent linearity (IM3/IM5 of -50/ -70 dBc at 10-dB backoff) and high power gain (14 dB) at 2 GHz, and are the first vertical DMOSFETs suitable for 2-GHz power applications. Excellent heat sinking and no significant degradation of the quiescent current due to hot-carrier injection ensure thermal stability and good long-term reliability of the fabricated devices.