DC and Microwave Characteristics of InAlAs/InGaAs Single-Quantum-Well MODFET's with GaAs Gate Barriers

摘要

The design and performance of In(0.53)Ga(0.47)As/In(0.52)Al (0.48)As modulation-doped field-effect transistors (MODFET's) have been optimized by incorporating a single In(0.53)Ga(0.47)As quantum-well channel and a thin strained GaAs gate barrier layer. These help to lower the output conductance and gate leakage current of the device, respectively. The dc performance of 1 - micrometers gate devices is characterized by extrinsic transconductances of 320 mS/mm at 300 K and 450 mS/mm at 77K and a best value of fT = 35 GHZ is derived from S-parameter measurements. This value of the cutoff frequency is the best reported for a 1 - micrometer gate device with this material system. Keywords include: Single-quantum-well MODFET's, GaAs gate barriers, and MODFET's. Reprints. (rh)