Planar semipolar (101¯1) GaN on (112¯3) sapphire

Abstract

We report on the growth of planar semipolar ͑1011͒ GaN on ͑1123͒ prepatterned sapphire. This is a method that allows the growth of semipolar oriented ͑1011͒ GaN on large scale. Using x-ray diffraction only the peaks of the desired ͑1011͒ plane could be observed. Scanning electron, transmission electron, and atomic force microscopy measurements show an atomically flat surface. Further investigations using photoluminescence spectroscopy show spectra that are dominated by the near band edge emission. The high crystal quality is furthermore confirmed by the small full width at half maximum values of x-ray rocking curve measurements of less than 400 arcsec.

Growth and coalescence behavior of semipolar $(11{\bar {2}}2)$ GaN on pre‐structured r‐plane sapphire substrates

“…In particular, we have incorporated Si-doped marker layers (MLs) into our structures to trace the growth development on the structured substrates. As we observed similar defect behavior on these samples and on our ð1011Þ uncoalesced GaN structures [18], we suppose that the findings described below are also valid for other orientations grown using this approach. (Table 1).…”

“…In this manner, the groups of Okada et al and de Mierry et al achieved the growth of ð1122Þ GaN on dry and wet etched r-plane sapphire substrates, respectively [16,17]. Recently, we have shown that this approach also can be applied to grow ð1011Þ GaN [18]. This facet is regarded as being naturally stable since it typically develops on freely growing crystals and exhibits a very smooth surface [19].…”

Semipolar GaInN quantum well structures on large area substrates

“…3 Results 3.1 Semipolar GaN As reported earlier [3,11], semipolar GaN layers with f1122g and f1011g top surface could be obtained by growing out of grooves etched into respectively oriented sapphire wafers. The single phase character of these layers has been confirmed by HRXRD.…”

“…Hikosaka et al could grow closed f1011g GaN layers starting from {111} side facets of grooves etched into 78 offaxis oriented {001} Si substrates [10]. The development of an excellent f1011g GaN surface flatness could be confirmed by us when growing from c-plane like side-facets of grooves etched into f1123g (n-plane) sapphire wafers [11]. In the following, we describe some more studies about this approach including first results when depositing GaInN quantum well structures on such planar semipolar GaN layers.…”

Growth evolution and microstructural characterization of semipolar (112̄2) GaN selectively grown on etched r-plane sapphire

“…This method allows a new definition and design of epitaxial relations between the layer and the substrate. This method has also been applied to currently more commonly used sapphire substrates [13][14][15][16]. Using this method, Saito et al [17] have produced mW range heteroepitaxial m-plane LEDs using stripe etched a-plane sapphire substrates.…”