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.