In this paper the effect of a body contact to increase the breakdown voltage in GaAs based pseudomorphic HEMT has been theoretically investigated. The body contact is formed by a p-doped substrate connected to an ohmic back contact. By using a Monte Carlo simulation we show that the body contact reduces the density of holes generated by impact ionization and prevents holes from accumulating in the channel. ‘The breakdown effect is quenched as the density of acceptors in the substrate increases. This extends the range of the usable drain voltages
