Controlling the orientations of directional sputtered non- and semi-polar GaN/AlN layers. (22nd May 2019)

• Record Type: Journal Article
• Authors: Nan, HU; Dinh, Duc V.; Pristovsek, Markus; Honda, Yoshio; Amano, Hiroshi
• Is Part Of: Japanese journal of applied physics. Volume 58:Number SC(2019)
• Publication Date: 2019-05-22
• Subjects: Physics -- Periodicals; 621.05
• DOI: 10.7567/1347-4065/ab1252
• Languages: English
• ISSNs: 0021-4922

Abstract

Abstract: We have studied the impact on the surface orientation of different sputtered Al layers followed by AlN layers sputtered on m-plane sapphire. These initial layers were then overgrown by AlN and followed by GaN using metal-organic vapor phase epitaxy (MOVPE). By increasing sputtering time of the initial Al layer from 0 s to 15 s, we obtained single phase (10-10), (10-13) and (10-14) GaN/AlN layers. The thickness of the initial Al layer was estimated by optical transmission measurements to be about 0.5–1 nm for the (10-13) orientation, and >1 nm for the (10-14) orientation. After MOVPE growth, no trace of metallic Al was found by transmission electron microscopy, indicating that this layer was fully converted to AlN.