An investigation of breakdown in power HEMTs and MESFETs utilising an advanced temperature-dependent physical model

This paper presents a physical model and experimental validation for the breakdown process in HEMTs and MESFETs. The model is integrated into a fast quasi-two-dimensional physical simulation. The model takes account of the tunnelling effects in the region of the gate metallization. A new thermal model monitors the channel temperature and controls the tunnelling mechanism. The effects of the substrate conduction on breakdown in HEMTs is highlighted. Experimental results are presented which confirm the physical interpretations of the numerical model