Engineering Commons^™

Simulation Study Of Hemt Structures With Hfo2 Cap Layer For Mitigating Inverse Piezoelectric Effect Related Device Failures, Deepthi Nagulapally, Ravi P. Joshi, Aswini Pradhan

Electrical & Computer Engineering Faculty Publications

The Inverse Piezoelectric Effect (IPE) is thought to contribute to possible device failure of GaN High Electron Mobility Transistors (HEMTs). Here we focus on a simulation study to probe the possible mitigation of the IPE by reducing the internal electric fields and related elastic energy through the use of high-k materials. Inclusion of a HfO₂ "cap layer" above the AlGaN barrier particularly with a partial mesa structure is shown to have potential advantages. Simulations reveal even greater reductions in the internal electric fields by using "field plates" in concert with high-k oxides