Very-high-performance highly strained Ga0.23In0.77 As channel MODFETs

Summary form only given. The authors report a transconductance of 843 mS/mm and a cutoff frequency 45.3 GHz for 1.2-μm FETs and 33 GHz for 1.9-μm FETs obtained by using a MODFET structure containing a highly strained Ga_0.23In_0.77As channel on InP substrate. It is important to either keep the gate recess quite shallow (~7 nm total) or control the process with a stop-etch layer for the achievement of these exceptionally high f_T×L_g products. In device processing, three different gate-recess processes were used. Each is described. Results show that the combination of Ga_0.23In_0.77As and selective etch gate recess is an excellent technology for realizing fast FETs