Normally-off gallium nitride-based semiconductor devices

摘要

A method includes forming a relaxed layer in a semiconductor device. The method also includes forming a tensile layer over the relaxed layer, where the tensile layer has tensile stress. The method further includes forming a compressive layer over the relaxed layer, where the compressive layer has compressive stress. The compressive layer has a piezoelectric polarization that is approximately equal to or greater than a spontaneous polarization in the relaxed, tensile, and compressive layers. The piezoelectric polarization in the compressive layer could be in an opposite direction than the spontaneous polarization in the compressive layer. The relaxed layer could include gallium nitride, the tensile layer could include aluminum gallium nitride, and the compressive layer could include aluminum indium gallium nitride.

主权项

1. A method comprising:
forming a relaxed layer in a semiconductor device; forming a tensile layer over the relaxed layer, the tensile layer having tensile stress; and forming a compressive layer over the relaxed layer, the compressive layer having compressive stress, wherein forming the tensile layer comprises forming the tensile layer next to the compressive layer; wherein the compressive layer has a piezoelectric polarization that is approximately equal to or greater than a spontaneous polarization in the relaxed, tensile, and compressive layers.