Abstract

We investigate the low-energy (0.7-0.9eV) electroluminescence (EL) at low temperature (30 - 100 K) of short gate lattice-matched InP based HEMTs. This study allows to observe directly impact ionization in the "on" and "off" state Ino.53Gao.47As channel. In the on-state, the evolution of the luminescence as a function of the bias applied to the device shows that the electroluminescence intensity depends on two parameters: the gate-drain electric field and the drain current intensity. The voltage breakdown in the off-state is discussed in term of impact ionization in the InGaAs channel due to hot carriers originating from the gate leakage current.