Dependence of sidegating effect in InAlAs/InGaAs HEMTs upon impact ionization

The InAlAs/lnGaAs HEMT is a key electron device used in optoelectronic integrated circuits (OEICs) operating in the 1.3 and 1.5 /spl mu/m optical wavelength ranges. But OEIC performances can be degraded by side gating effects associated with the HEMT. A side gate current is demonstrated to be due to a hole current induced by an impact ionization mechanism into the HEMT InGaAs channel and flowing through the InAlAs buffer layer.