Direct-current and radio-frequency characterizations of GaAs metal-insulator-semiconductor field-effect transistors enabled by self-assembled nanodielectrics

H C. Lin, Purdue University
S K. Kim, Purdue University
D Chang, Purdue University
Y Xuan, Purdue University
Saeed Mohammadi, School of Electrical and Computer Engineering, Purdue University
P. D. Ye, Birck Nanotechnology Center and School of Electrical and Computer Engineering, Purdue University
G Lu, Department of Chemistry, Northwestern University
A Facchetti, Department of Chemistry, Northwestern University
T J. Marks, Department of Chemistry, Northwestern University

Abstract

Direct-current and radio-frequency characterizations of GaAs metal-insulator-semiconductor field-effect transistors (MISFETs) with very thin self-assembled organic nanodielectrics (SANDs) are presented. The application of SAND on compound semiconductors offers unique opportunities for high-performance devices. Thus, 1 mu m gate-length depletion-mode n-channel SAND/GaAs MISFETs exhibit low gate leakage current densities of 10(-2)-10(-5) A/cm(2), a maximum drain current of 260 mA/mm at 2 V forward gate bias, and a maximum intrinsic transconductance of 127 mS/mm. These devices achieve a current cutoff frequency (f(T)) of 10.6 GHz and a maximum oscillation frequency (f(max)) of 6.9 GHz. Nearly hysteresis-free I-ds-V-gs characteristics and low flicker noise indicate that a high-quality SAND-GaAs interface is achieved.