Methods and features of measuring the thermal resistance of integrated microwave amplifiers on heterojunction bipolar transistors

The method of measuring the thermal resistance (TR) of semiconductor devices (SD) according to OST 11 0944-96 and the original modulation method implemented in the hardware and software package developed by the authors are described. In both methods, the SD is heated by pulsed power, and the temperature of its active region (transition) is determined by a change in the temperature–sensitive parameter (TSP) - the voltage at the SD at a low current passed through the SD in the pauses between the pulses of the heating current. The measurement error of the vehicle by the standard method strongly depends on the choice of the duration of the heating current pulses and the delay time when measuring the voltage at the SD after switching off the heating current. In the modulation method, the duration of the heating current pulses is changed according to the harmonic law, and according to the results of measuring the voltage at the SD during the passage of the heating and measuring current, the modulus of the thermal impedance of the SD is determined as the ratio of the first harmonic of the transition temperature to the first harmonic of the heating power. According to the frequency dependence of the thermal impedance module, the components of the vehicle of the object are determined, while the requirements for maintaining the temperature of the device body are significantly reduced and, as a result, the measurement error of the vehicle is reduced. The results of comparative measurements of the TR of integrated microwave amplifiers (amplifying cascades) on InGaP/GaP HBT by the standard and modulation method at different values of the amplitude of the heating current are presented. It is shown that the results of measuring the TR of integrated microwave amplifiers by both methods are in good agreement with each other. It is established that with an increase in the amplitude of the heating current, the TR junction-case of integrated microwave amplifiers decreases, which is due to the alignment of current distribution in the structure of the GBT during heating.