Low Frequency and Microwave Characterization of Submicron-Gate In(0.52)Al(0.48)As/In(0.53)Ga(0.47)As/In(0.52)Al(0.48)As Heterojunction Metal-Semiconductor Field-Effect Transistors Grown by Molecular-Beam Epitaxy.

摘要

Doped-channel(i)-In(0.52)Al(0.48)As/(n(+)-In(0.53)Ga(0.47)As/(i)- In(0.52)Al(0.48) As heterojunction metal-semiconductor field-effect transistors lattice matched to the Indium Phosphide substrates with gate lengths in the submicron range have been fabricated and characterized. The dc and microwave performance of the devices are presented in this paper. Drain current anomalities, or the kink effects, were observed at room temperatures as well as at 77 k in the dc measurements. The kinks are associated with the deep-level electron trapping, and are not present at microwave frequencies. The dc and microwave bias points for achieving maximum transconductance are different. Normal microwave characteristics are exhibited. A compression of transconductance g(m) is observed in the dc measurement, while such g(m) degradation phenomenon does not appear at microwave frequencies. At 10 GHz, an extrinsic g(m) of 507 mS/mm, a current-gain-cutoff frequency f(t) of 49.5 GHz, and a power-gain cutoff frequency (fmax) of 70.5 GHz were observed for a 0.25 micrometer-gate device. For a 0.3 micrometer-gate device, a g(m) of 545 mS/mm, an f(t) of 42 GHz, and an f(max) of 114 GHz were measured. Output conductance as low as 7.7 mS/mm was measured. A voltage gain (g(m)/g(ds) as high as 64 was observed. The voltage gain for measured devices is well above 20 for a wide range of bias conditions. Fabricated devices show their potential for high-frequency operations. Reprints. (AW)