Effect of the non-annealed ohmic-recess approach on temperature-dependent properties of a metamorphic high electron mobility transistor

The reliability-related properties of an InAlAs/InGaAs metamorphic high electron mobility transistor (MHEMT), using the non-annealed ohmic-recess (NAOR) approach, are studied and demonstrated. The NAOR device shows significantly improved dc and radio frequency (RF) performance over a wide temperature range (300–500 K). With a 1 × 100 µm2 gate-dimension MHEMT by the NAOR approach, the considerably improved thermal stability and dc performances, including lower temperature variation coefficients on turn-on voltage (−1.38 mV K−1) and gate-drain breakdown voltage (−30.4 mV K−1), and on-resistance (2.41 × 10−3 Ω mm K−1), are obtained as the temperature is increased from 300 to 500 K. For RF characteristics, the NAOR device also shows a low degradation rate on drain saturation current operating regimes (−5.52 × 10−4 K−1) as the temperature is increased from 300 to 400 K. In addition, based on the lifetime tests, an activation energy of 1.33 eV and a projected median lifetime of 1.2 × 107 h at Tch = 125 °C are obtained for the NAOR MHEMT.