High quality GaN high-voltage HFETs on silicon

摘要

Substrates of GaN over silicon suitable for forming electronics devices such as heterostructure field effect transistors (HFETs), and methods of making the substrates, are disclosed. Voids in a crystalline Al2O3 film on a top surface of a silicon wafer are formed. The top surface of the silicon wafer is along the <111> silicon crystal orientation. A plurality of laminate layers is deposited over the voids and the Al2O3 film. Each laminate layer includes an AlN film and a GaN film. A transistor or other device may be formed in the top GaN film.

主权项

1. A HFET comprising:
an active GaN layer having an active area of the HFET therein; a first AlN layer beneath the active GaN layer; a second GaN layer beneath the first AlN layer; a second AlN layer beneath the second GaN layer; and a third GaN layer beneath the second AlN layer,
wherein a threading dislocation density of the third GaN layer is higher than a threading dislocation density of the second GaN layer, andthe threading dislocation density of the second GaN layer is higher than a threading dislocation density of the active GaN layer.