On-state breakdown measurements in GaAs MESFETs and InP-based HEMTs

摘要

In this paper we will show that the breakdown voltage BV_(DS), measured at constant gate current, has a non-monotonic behaviour as a function of I_D, which is a direct consequence of the non-monotonic "bell-shape" behaviour shown by the I_G vs V_(GS) characteristics. All kinds of DC measurements of onstate breakdown are remarkably affected by thermal effects which, especially in power devices, may lead to an underestimation of the actual breakdown voltage. Furthermore, due to the positive thermal coefficient of the electron multiplication factor in In_(0.53)Ga_(0.47)As lattice-matched on InP, on-state breakdown voltages of InP-based HEMTs and of GaAs-based MESFETs and HEMTs have opposite behaviour as a function of temperature: BV_(DS) decreases at increasing T in InP-based HEMTs, increases in GaAs-based devices.