Title :
RF performance of diamond MISFETs
Author :
Umezawa, H. ; Taniuchi, H. ; Ishizaka, H. ; A-Firna, T. ; Fujihara, N. ; Tachiki, M. ; Kawarada, H.
Author_Institution :
CREST, Japan Sci. & Technol. Corp., Tokyo, Japan
fDate :
3/1/2002 12:00:00 AM
Abstract :
A cutoff frequency (fT) of 11 GHz is realized in the hydrogen-terminated surface channel diamond metal-insulator-semiconductor field-effect transistor (MISFET) with 0.7 μm gate length. This value is five times higher than that of 2 μm gate metal-semiconductor (MES) FETs and the maximum value in diamond FETs at present. Utilizing CaF2 as an insulator in the MIS structure, the gate-source capacitance is reduced to half that of the diamond MESFET because of the gate insulator capacitance being in series to the surface-channel capacitance. This FET also exhibits the highest fmax of 18 GHz and 15 dB of power gain at 2 GHz. The high-frequency equivalent circuits of diamond MISFET are deduced from the S-parameters obtained from RF measurement.
Keywords :
MISFET; calcium compounds; capacitance; diamond; equivalent circuits; microwave field effect transistors; microwave power transistors; power field effect transistors; semiconductor device models; 0.7 micron; 11 GHz; 15 dB; 18 GHz; 2 GHz; 2 micron; CaF/sub 2/ insulator; CaF/sub 2/-C; RF performance; S-parameters; cutoff frequency; diamond MISFETs; gate insulator capacitance; gate-source capacitance; high-frequency equivalent circuits; hydrogen-terminated surface channel MISFET; power field-effect transistor; power gain; surface-channel capacitance; Capacitance; Cutoff frequency; Equivalent circuits; FETs; Gain; Insulation; MESFETs; MISFETs; Metal-insulator structures; Radio frequency;
Journal_Title :
Electron Device Letters, IEEE
