Elimination of the kink effects in InAlAs/InGaAs InP-based HEMT’s by means of InP etch-stop layer

In this paper we report on the elimination of the kink effect in InP-based HEMT's which results from the insertion of an InP etch stop layer. Devices without an InP recess-etch stopper have been found to be affected by a kink in the output I-V characteristics and by the presence of traps. Device with the InP recess-etch stopper are free from these parasitic effects. Since in both of these devices impact ionization is present, we therefore conclude that: a) at least in these structures impact-ionization alone is not sufficient to induce a kink; and b)the InP recess-etch stopper layer effectively removes the kink by passivating the InAlAs surface in the recess regions adjacent to the gate.