Characteristics of InAs/AlSb high electron mobility transistors grown on Si using a GaAsSb step-graded buffer layer

A GaAsSb step-graded metamorphic buffer layer is used for growing InAs/AlSb high electron mobility transistor structures on Si substrate by molecular beam epitaxy. The step-graded metamorphic buffer layer effectively reduces the number of microtwins and stacking faults penetrating to the InAs channel as evidenced by transmission electron microscopy. By reducing the planar defects with the metamorphic buffer layer, a significant improvement on electron mobility up to 18 100 cm(2)/V s and 39 700 cm(2)/V s at room temperature and 77 K, respectively, is achieved. (C) 2013 American Vacuum Society.