Rapid degradation of MESFETs under impact ionization and low-temperature conditions

Tests performed on power MESFETs 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 is illustrated.