Accession Number : ADA332544
Title : A Novel mm-Wave Heterojunction JFET Technology with Suppressed Hole Injection
Descriptive Note : Final progress rept. 15 Jan 93-14 Jan 96
Corporate Author : CALIFORNIA UNIV SANTA BARBARA
Personal Author(s) : Mishra, Umesh K. ; Shealy, Jeffrey B.
PDF Url : ADA332544
Report Date : SEP 1996
Pagination or Media Count : 185
Abstract : We have developed a device technology using n-AlInAs/GaInAs on InP substrates, where the gate technology incorporates a p-n junction barrier. The p-n junction exists between an undepleted p-type surface layer (p(+)-GaInAs) and the two-dimensional electron gas (2DEC) in the GaInAs channel. The p(+)-2DEG junction provides a sufficiently high gate barrier that exhibits low gate leakage current and a high breakdown voltage. At the same time, the fixed gate-to-channel separation (solely determined by the MBE growth) leads to a reproducible gate barrier height, resulting in high threshold voltage uniformity (sigma(Vth)=13.7mV). The junction barrier gate technology is the best choice of the three available gate technologies (namely insulator barrier gate, Schottky barrier gate, and the p-n junction barrier gate) for InP-based FETs. The low parasitic resistance and low gate leakage current produced state-of-the-art minimum noise figure (Fmin) and associated gain (Ga) of 0.45 dB and 14.5 dB at 12GHz. The combination of reduced gatelength (0.2 micrometers) and reduced parasitic transit delay translated into a unity gain cut-off frequency (ft) of 105 GHz. The low input resistance (due to high acceptor doping in the gate layer) and high Cgs/Cgd ratio (due to a high aspect ratio design) of the JHEMT improved the unity power gain cut-off frequency (fmax) to 220 GHz. This is the highest fmax ever reported for a junction-barrier FET (JFET).
Descriptors : *HETEROJUNCTIONS, *HOLES(ELECTRON DEFICIENCIES), *MILLIMETER WAVES, *FIELD EFFECT TRANSISTORS, TWO DIMENSIONAL, THRESHOLD EFFECTS, RESISTANCE, GATES(CIRCUITS), VOLTAGE, SUBSTRATES, ELECTRON GAS, SURFACES, ALUMINUM, GAIN, ARSENIDES, GALLIUM, DOPING, N TYPE SEMICONDUCTORS, NOISE, ELECTRIC CURRENT, LEAKAGE(ELECTRICAL), INDIUM PHOSPHIDES, ELECTRON ACCEPTORS, SCHOTTKY BARRIER DEVICES, INDIUM, REPRODUCIBILITY, BREAKDOWN(ELECTRONIC THRESHOLD), ASPECT RATIO, P TYPE SEMICONDUCTORS, HIGH VOLTAGE.
Subject Categories : Inorganic Chemistry
Electrical and Electronic Equipment
Distribution Statement : APPROVED FOR PUBLIC RELEASE