The effect of external stress on the electrical characteristics of AlGaN/GaN HEMTs

•The DC output characteristics of the AlGaN/GaN HEMTs are investigated under an external uniform in-plane stress.•The change of the output current under external stress is discussed.•The kink effect can be adjusted by the tensile and compressive stress.•The results can be used to improve the performance of the AlGaN/GaN HEMTs.

The electrical characteristics of AlGaN/GaN high electron mobility transistors under the application of uniform in-plane tensile and compressive stress were measured. The results demonstrate the change of the drain–source Ids–Vds characteristics as a function of the external stress. The output current at Vds = 10 V increases linearly with the stress with the slope about 3 × 10−6 A MPa−1. It is associated with the piezoelectric effect and kink effect. Moreover, the magnitude of the kink effect is found to be affected by the stress. It displays a linear changing trend with the slope of 3.3 × 10−4 mS MPa−1 within the stress level. The energy band structure is suggested to be responsible for the dependence of the kink effect on the stress.