Uniform hot-wall MOCVD epitaxial growth of 2 inch AlGaN/GaN HEMT structures

The hot-wall metalorganic chemical vapor deposition (MOCVD) concept has been applied to the growth of AlxGa1-xN/GaN high electron mobility transistor (HEMT) device heterostructures on 2 inch 4H-SiC wafers. Due to the small vertical and horizontal temperature gradients inherent to the hot-wall MOCVD concept the variations of all properties of a typical HEMT heterostructure are very small over the wafer: GaN buffer layer thickness of 1.83 mu m +/- 1%, Al content of the AlxGa1-xN barrier of 27.7 +/- 0.1%, AlxGa1-xN barrier thickness of 25 nm +/- 4%, sheet carrier density of 1.05 x 10(13) cm(-2) +/- 4%, pinch-off voltage of -5.3 V +/- 3%, and sheet resistance of 449 Omega +/- 1%. (c) 2006 Elsevier B.V. All rights reserved.