Abstract

With appropriate device structures, bined lithographi and epitaxial scaling of HBTs,RTDs and S hottky diodes results in rapid in reases in device bandwidths.0.1 ¹m InGaAs RTDs have os illated at 650 GHz,Submi ron heterojunction bipolar sistors (HBTs)fabri ated with substrate transfer pro-esses have obtained 21 dB unilateral power gain at 100 GHz;if extrapolated at -20 dB/decade,this corresponds to a 1.1 THz power-gain uto ®frequency.HBT current-gain uto ®frequencies as high as 300 GHz have been obtained.