Impact of 20-MeV alpha-ray irradiation on the V-band performance of AlGaAspseudomorphic HEMTs

The irradiation damage in Si-planar-doped AlGaAs pseudomorphic HEMT's integ rated in 50 GHz monolithic microwave integrated circuits (MMIC's) and subje cted to 20-MeV alpha and gamma -ray irradiation is studied.. Both the stati c and the high frequency device parameters have been analyzed. It is shown that the drain current and the effective mobility decrease after irradiatio n, while the threshold voltage shifts in positive direction, The degradatio n of the device performance increases for higher fluence. The decrease of t he mobility is thought to result from the scattering of channel electrons b y the induced lattice defects and also from the decrease of the electron de nsity in the two dimensional electron gas (2DEG) region. Moreover, the nois e figure increases with increasing fluence, while the gain decreases. After 150 degreesC post-irradiation thermal annealing for 15 min, the noise figu re and gain for 1 x 10(12)alpha /cm(2) recovers by 67 and 19%, respectively .