CW measurement of HBT thermal resistance

Measurements of the temperature dependence of beta and V/sub BE/ were made on AlGaAs-GaAs HBTs and used to determine device thermal resistance. The measurements were CW and not switched or pulsed in order to have a simpler procedure. With base doping greater than 10/sup 19/ cm/sup -3/, HBTs have negligible base-width modulation (i.e., flat I/sub C/ versus V/sub CE/ characteristics) which makes CW thermal resistance measurement especially direct and simple. >