TEMPERATURE-DEPENDENCE OF DC AND RF CHARACTERISTICS OF ALINAS GAINAS HBTS/

Device characteristics of compositionally graded AlInAs/GaInAs heteroj unction bipolar transistors have been measured and analyzed from cryog enic temperatures up to 250-degrees-C. Excellent stability in dc and R F performance is observed at elevated temperatures, desirable for high -speed and high-density integrated circuit applications. DC current ga in exhibits about 10% variation over the entire measured temperature r ange. F(T) and f(max) at 125-degrees-C decreased by approximately 10% from their room-temperature values while improving steadily when devic e was cooled down to near-liquid-helium temperature. The common-emitte r breakdown voltage, BV(CEO), is 8.0 V at room temperature and reduces to 7.5 V at 125-degrees-C. Likewise, the collector-base breakdown vol tage, BV(CBO), and the base-emitter breakdown voltage, BV(EBO), reduce by about 0.5 V over the same temperature range. The breakdown voltage s increase significantly at cryogenic temperatures. The low turn-on vo ltage and excellent low-temperature characteristics make the AlInAs/Ga InAs HBT attractive for cryogenic applications.