Single-crystalline semipolar GaN on Si(001) using a directional sputtered AlN intermediate layer

We obtained single crystalline semipolar (10 (1) over bar3)GaN on a nominal Si(001) substrate with sputtered AlN using the directional feature of sputtering. One dominated orientation of AIN was chosen to set Si[110] in the direction of the deposition. Microscopic characterizations using electron backscattering diffraction and macroscopic characterizations using X-ray diffraction revealed that GaN has an epitaxial relationship, which corresponds to [10 (1) over bar3](GaN parallel to)[001](Si) and [11 (2) over bar0](GaN)parallel to[1 (1) over bar0](si). The density of the stacking fault in GaN with low temperature AIN insertion was estimated to be 3 x 10(4) cm(-1) using transmission electron microscopy. Directional sputtering is a promising method that can be applied to the next generation of GaN-on-Si technologies for obtaining single-crystalline semipolar GaN on a Si(001) substrate. (C) 2015 Elsevier B.V. All rights reserved.