Electrothermal Mapping of AlGaN/GaN HEMTs Using Microresistance Thermometer Detectors.

Self-heating effects in AlGaN/GaN high-electron mobility transistors (HEMTs) can notably reduce electron mobility and produce reliability concerns. Electrothermal characterization and appropriate thermal management are required to address this situation. This letter presents the measurement of channel temperature ( \mathbf Tch ) of GaN HEMTs in multiple bias conditions with a good accuracy. The measurements are executed using the integrated microresistance thermometer detector ( \mu RTD) technique in AlGaN/GaN HEMTs on SiC and sapphire substrates. The integrated Ti/Pt \mu RTD sensor with linear resistance-temperature characteristic is used to obtain an Ids – Vds – Tch map for each device. Thermal resistances are compared for similar operation conditions, obtaining RTH = 34.7\, \mathrm ^\circ \mathbfC \boldsymbol \cdot \mathbfW^-\mathbf1 for the HEMT on SiC and R \rm TH = 157.2~ {\mathrm { {^{\circ }}{\mathbf{C}} \boldsymbol {\cdot } {\mathbf{W}}^{-{\mathbf{1}}} }} for the HEMT on sapphire. [ABSTRACT FROM PUBLISHER]