International Conference Physics.SPb/2025
Spectroscopy of condensed matter

Features of measuring the thermal resistance of a microassembly of high-power gallium nitride HEMTs with a silicon MOSFET connected in a cascode circuit

V. I. Smirnov^ab, V. A. Sergeev^b, A. A. Gavrikov<sup>b

a</sup> Ul'yanovsk Branch of Institute of Radioengineering and Electronics, Russian Academy of Sciences
^b Ulyanovsk State Technical University

Abstract: Thermal electric processes in GaN transistors with a cascode structure consisting of a HEMT and a MOSFET connected in series are investigated. The possibility of determining the HEMT and MOSFET channel resistance based on the results of measuring the current-voltage characteristics of the cascode structure in various switching modes is demonstrated, and estimates of the thermal power dissipated in both crystals are presented. The transistor thermal resistance components were determined using a hardware and software complex implementing a modulation measurement method with heating the object with pulses of a heating current with pulse-width modulation according to the harmonic law. The obtained values of the thermal resistance components are in good agreement with the transistor specifications.

Keywords: gallium nitride transistor, cascode structure, HEMT, MOSFET, thermal resistance, modulation method, thermal radiation.

Received: 07.05.2025
Revised: 07.05.2025
Accepted: 24.10.2025

DOI: 10.61011/OS.2025.10.61939.8037-25