Hot carrier reliability in high-power PHEMT's

PECVD nitride passivated high-power PHEMT's were used to study their hot carrier reliability. The typical hot carrier induced device degradation characteristics are often observed in devices with a less-than-ideal double gate recess and material layers design. With additional drain engineering work to optimize device power performance, the hot carrier effects can be alleviated drastically. However, depending on nitride deposition processes and nitride quality, Schottky diode degradation (a barrier height increase) was also observed during hot carrier stress. This study facilitates a comprehensive characterization of the hot carrier induced effects in power PHEMT's and recommends an alternative to improve the hot carrier reliability.