Modeling Hot Spot in Ultrashort Gate Length Pseudomorphic HEMTs

Self-heating effect in ultrashort gate length pseudomorphic HIEMTs is investigated. An original model is developed which accounts for both bidimensional heat transfer and quasi-bidimensional hydrodynamic carrier transport. In a room temperature simulated 0.15¿m gate length HEMT, the temperature rises at almost 400K at Vgs= 0.4V and Vds= 5V. The temperature gradients in the device can be neglected when the boundary temperature is maintained at 100K. These results are in good agreement with those of electroluminescence spectroscopy of a 0.1¿m HEMT realised at high drain current level.