High-speed p/sup +/ GaInAs-n InP heterojunction JFET's (HJFET's) grown by MOCVD

The authors report the high-frequency characteristics of a new type of InP-JFET having p/sup +/ GaInAs as the gate material grown by MOCVD (metalorganic chemical vapor deposition) using tertiarybutylphosphine (TBP) and tertiarybutylarsine (TBA) as the alternative source for phosphine and arsine, respectively. Using selective wet chemical etching, heterojunction JFETs (HJFETs) with gate length of 0.6 mu m led to a unity current gain cutoff frequency and power gain cutoff frequency of 14.3 and 37.5 GHz, respectively. The large valence band discontinuity ( triangle E/sub v/ approximately=0.37 eV) considerably suppresses hole injection into the channel in the HJFET as compared to homojunction InP-JFETs, making the HJFET a preferred device for high-speed logic circuits based on JFET technology.<
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