Low-temperature microwave characteristics of pseudomorphic In(x)Ga(1-x) As/In(0.52)Al(0.48)As modulation-doped field-effect transistors

• Published in: IEEE electron device letters Vol. 11; pp. 564 - 566
• Main Authors: Lai, R., Bhattacharya, Pallab K., Alterovitz, S. A., Downey, A. N., Chorey, C.
• Format: Journal Article
• Language: English
• Published: Legacy CDMS 01.12.1990
• Subjects: Electronics And Electrical Engineering
• ISSN: 0741-3106

Low-temperature microwave measurements of both lattice-matched and pseudomorphic In(x)Ga(1-x)As/In(0.48)As (x = 0.53, 0.60, and 0.70) channel MODFETs on InP substrates were carried out in a cryogenic measurement system. The measurements were done in the temperature range of 77 to 300 K and in the frequency range of 0.5 to 11.0 GHz at different bias conditions. The cutoff frequency (fT) for the In(x)Ga(1-x)As/In(0.52)Al(0.48)As MODFETs improved from 22 to 29 GHz, 29 to 38 GHz, and 39 to 51 GHz, for x = 0.53, 0.60, and 0.70, respectively, as the temperature was lowered from 300 to 77 K, which is approximately a 31 percent increase at each composition. No degradations were observed in device performance. These results indicate an excellent potential of the pseudomorphic devices at low temperatures.