Title :
Effects of neutral buried p-layer on high-frequency performance of GaAs MESFETs
Author :
Onodera, Kiyomitsu ; Tokumitsu, Masami ; Tomizawa, Masaaki ; Asai, Kazuyoshi
Author_Institution :
NTT LSI Lab., Kanagawa, Japan
fDate :
3/1/1991 12:00:00 AM
Abstract :
Fully ion-implanted n+ self-aligned GaAs MESFETs with Au/WSiN refractory metal gates have been fabricated by adopting neutral buried p-layers formed by 50-keV Be-implantation. S-parameter measurements and equivalent circuit fittings are discussed. When the Be dose is increased from 2×1012 cm-2 to 4×1012 cm-2, the maximum value of the cutoff frequency with a 0.2-μm gate falls off from 108 to 78 GHz. This is because a neutral buried player makes the intrinsic gate-source capacitance increase markedly, while its influence on gate-drain capacitance and gate-source fringing capacitance is negligible. The maximum oscillation frequency recovers, however, due primarily to the drain conductance suppression by the higher-concentration buried p-layer. An equivalent value of over 130 GHz has been obtained for both 0.2-μm-gate GaAs MESFETs
Keywords :
III-V semiconductors; Schottky gate field effect transistors; beryllium; equivalent circuits; gallium arsenide; gold; ion implantation; metallisation; tungsten compounds; 0.2 micron; 50 keV; 78 to 108 GHz; MESFETs; S-parameter measurements; cutoff frequency; drain conductance suppression; equivalent circuit; gate-drain capacitance; gate-source fringing capacitance; high-frequency performance; intrinsic gate-source capacitance; ion-implanted n+ self-aligned devices; maximum oscillation frequency; neutral buried p-layer; refractory metal gates; Capacitance; Cutoff frequency; Equivalent circuits; Gallium arsenide; Gold; Leakage current; MESFETs; Performance evaluation; Scattering parameters; Transconductance;
Journal_Title :
Electron Devices, IEEE Transactions on
