Growth of m ‐GaN layers by epitaxial lateral overgrowth from sapphire sidewalls

Abstract

Nonpolar m ‐plane GaN layers were fabricated by epitaxial lateral overgrowth from etched sapphire sidewalls. The m ‐plane GaN layers with c ‐direction growth were grown from patterned c ‐plane and a ‐plane sapphire substrates with a ‐plane or c ‐plane sidewalls using a low‐temperature buffer layer. The growth of GaN from the surface was prevented by a SiO2 mask, and that from the bottom of grooves was also prevented by deep grooves. Thus, the growth orientation relative to the surface of the GaN layer was determined by the growth of the GaN layer from the sapphire sidewalls. Consequently, m ‐plane GaN layers were grown on c ‐plane sapphire with a ‐plane sidewalls or on a ‐plane sapphire with c ‐plane sidewalls with the terrace regions covered with a SiO2 mask and deep grooves. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Semipolar GaInN quantum well structures on large area substrates

“…1). Similar studies have been reported by Okada et al using a-, r-, m-, and c-oriented sapphire wafers [4,5]. Singularly oriented GaN growth from c-oriented side-facets was only obtained for r-and m-sapphire, whereas growth from the terraces or trench bottom areas or mixed growth was obtained in the other cases.…”

Enhanced Performance of LEDs Using Periodic Tent-Like Post Patterns on A-plane Sapphire Substrates

“…In this case, most of the growth of GaN was initiated not from sidewall surfaces but a-planes. As the growth time increased, GaN epilayers on the bottom a-plane covered these sidewall surfaces by lateral growth, which is similar to the epitaxial lateral overgrowth (ELOG) mode [16], [17].…”

“…This orientation relationship is usually seen in the case of a GaN epitaxially grown on an a-plane sapphire [16]- [18]. On the other hand, the relationship between GaN II and sapphire is established as and .…”

“…2(c) and (d)). GaN I film was polar GaN layer (0001) [15], [16]. The crystallographic relationship between GaN I and sapphire is established as , and…”

Growth mechanism of nonpolar m ‐plane GaN on maskless patterned a ‐plane sapphire substrate

“…Thus, we focused on the growth of high-quality and large-diameter m-plane GaN. Then, we successfully demonstrated the growth of nonpolar m-plane GaN layers on the patterned a-plane sapphire substrate (a-PSS) and c-PSS with an SiO2 mask by selective GaN growth on the c-plane-like sapphire sidewall and the a-plane-like sapphire sidewall, respectively [5,6]. On the other hand, nonpolar m-plane GaN growth on the a-PSS without the SiO2 mask has also been reported [7].…”