A Comparison Between GaAs Mesfet and Si NMOS ESD Behaviour

Abstract

Work is in hand at Loughborough University to investigate and compare the ESD sensitivity of GaAs D-MESFETs and unprotected enhancement mode NMOS structures.The work to date has shown that GaAs MESFET structures can be severely degraded with ESD pulses above 600V as compared with 200V for Si NMOS. It has also been shown that both GaAs and NMOS structures are polarity sensitive.The behaviour of the Schottky barrier is used to explain the polarity behaviour in GaAs MESFETs. The breakdown of the oxide in the NMOS devices can be explained by impact ionisation.