Rapid degradation of MESFET's under impact ionization and low-temperature conditions

Tests performed on power MESFET's under impact ionization and low-temperature conditions reveal a faster and higher device degradation than those at higher temperatures. Degradation produces a noticeable reduction in breakdown voltage together with an increase in gate leakage current. The same effect is exhibited in high-temperature tests, but is less severe, In this paper, the temperature effect of the degradation on the performance of high output power microwave devices under impact ionization conditions will be illustrated.