Reliability study of parasitic source and drain resistances of InP-based HEMTs

The reliability of InP-based HEMTs is studied, focusing on how it is affected by the doped layer material and gate recess structure. Bias and temperature (BT) stress tests reveal that fluorine-induced donor passivation in the recess region, formed adjacent to the gate electrode, causes the source resistance (R/sub s/) to increase at large drain bias voltages. The increase in R/sub s/ can be prevented by using InP or InAlP as the carrier supply layer material instead of InAlAs. On the other hand, drain resistance (R/sub d/) increased due to carrier depletion in the drain ohmic region, which occurs not only in the recess region but also in the n/sup +/-capped region between the gate recess and the drain electrode, which is also affected by hot-carrier-induced damage.