Substrate thinning and external stress effect on the output characteristics of AlGaN/GaN HEMTs

The residual stress of AlGaN/GaN HEMT was changed by substrate thinning process. The residual compressive stress of GaN increased, while the residual tensile stress of AlGaN layer decreased. We applied an external tensile stress parallel to the 2DEG channel, causing a decrease of $\mathrm {I}_{DS}$. In addition, the kink effect and the traps behavior were also affected by the external tensile stress.