Graded pseudomorphic channel AlInP/AlInAs/GaInAsHEMTs with high channel breakdown voltage

Abstract
The Letter reports effects of the composition grading of the channel on the device characteristics of Al0.48In0.52As/Ga1-xInxAs pseudomorphic HEMTs. Systematic studies reveal that the modification of the quantum-well channel by grading the composition considerably changes the channel breakdown (BVds) and output conductance (G o) characteristics. HEMTs with graded Ga1-xInxAs channel (from x = 0.7 to x = 0.6) exhibited significantly improved BVds (11 V) and go (40 mS/mm) compared with HEMTs with uniform composition (x = 0.7) in the channel (BVds = 4 V and g o = 80 mS/mm).