InAlAs/pseudomorphic InGaAs/InP high electron mobility transistor with doped InAs/AlAs superlattice

We have demonstrated a novel indium phosphide high electron mobility transi stor (HEMT) which has prevented sheet carrier density degradation. The fabr icated structure replaces n-In0.52Al0.48As with an n-InAs/n-AlAs superlatti ce (doped InAs/AlAs superlattice; DIAS), preventing carrier density degrada tion of the n-type doped carrier supply layer on HEMT. DIAS requires a two- dimensionally grown seven-period superlattice each period of which has two monolayers of InAs and two monolayers of AlAs. The fabricated HEMT exhibits improved prevention of sheet carrier density degradation compared with the conventional HEMT with an n-In0.52Al0.48As carrier supply layer in the cas e of 300-450 degrees C annealing and a 125 degrees C bias temperature (BT) rest.