Numéro
J. Phys. IV France
Volume 06, Numéro C3, Avril 1996
WOLTE 2
Proceedings of the Second European Workshop on Low Temperature Electronics
Page(s) C3-73 - C3-78
DOI https://doi.org/10.1051/jp4:1996311
WOLTE 2
Proceedings of the Second European Workshop on Low Temperature Electronics

J. Phys. IV France 06 (1996) C3-73-C3-78

DOI: 10.1051/jp4:1996311

Threshold Voltage Characteristics of Superconductor Gate nMOSFET at 4.2 K

I. Kurosawa1, M. Maezawa1, M. Aoyagi1, H. Nakagawa1, K. Yamamoto2 and S. Matsumoto2

1  Electrotechnical Laboratory, 1-1-4 Umezono, Tsukuba, Ibaraki 305, Japan
2  Keio University, Hiyoshi, Yokohama 223, Japan


Abstract
We propose a high mobility superconductor gate nMOSFET using undoped Si as the substrate. We have studied superconducting NbN gate nMOSFETs fabricated on p-type Si, undoped Si and n-type Si substrate, respectively. The nMOSFETs on undoped Si and n-type Si have operated properly at 4.2 K. The transconductance of nMOSFETs on undoped Si substrate is higher than that of nMOSFET on p-type Si. The difference in transconductance is attributed to the difference of impurity density in channels. The observed threshold voltages of NbN gate nMOSFETs on p-type Si, undoped Si and n-type Si have little difference at 4.2K.



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