Striped channel field effect transistors with a modulation doped structure

The authors report the fabrication and performance of the striped channel field effect transistor, which consists of a multiple number of narrow channels fabricated on a modulation-doped heterostructure. The two-dimensional squeezing of the conducting channel by applying gate voltage has been confirmed from the channel width dependence of the drain current. By reducing the channel width of the fabricated 0.25- mu m-gate-length striped channel devices, the authors have observed an enhancement in transconductance as well as improved high-frequency performances. Furthermore, more-than-three-times improvement in the maximum transconductance has been obtained when the device is cooled to 77 K. These results are interpreted based on the improved charge controllability due to the channel squeezing effect as well as on the excellent electron transport properties of ultrafine channels.<>