Metal-organic vapor-phase epitaxy of pseudomorphic InAlP/InGaAs high electron mobility transistor wafers

InP-based high electron mobility transistor (HEMT) structures with a pseudomorphic InAlP barrier/spacer and an InGaAs channel were grown by metal-organic vapor-phase epitaxy (MOVPE). The thickness and composition of the InAlP/InGaAs heterostructure were optimized to reduce the gate-channel distance and obtain high electron mobility. The mobility of over 10000 CM2/V-S(.) with the sheet carrier concentration (N-s) of around 2 x 10(12) CM-2 was successfully obtained at room temperature in an In0.75Al0.25P/In0.75Ga0.25As pseudomorphic HEMT. The reliability of the InAlP layer as a gate-recess wet-etching stopper was also confirmed. The pseudomorphic In0.75Al0.25P-barrier/In0.75Ga0.25As-channel layer structure is suitable for practical ultrahigh-speed InP-based HEMTs.