Buried-channel GaAs MESFET's with immunity to ionizing optical radiation effects

The effects of high-intensity visible light upon various GaAs MESFET structures are examined and compared. The buried-channel MESFET's were found to be insensitive to ionizing radiation both in terms of increases of the drain current due to photocurrents and in terms of long-term transients due to charging of deep levels as is found in standard FET's. These results indicate that the buried-channel MESFET's should be significantly more immune to transient radiation effects in severe radiation environments.