Nanoair-bridged lateral overgrowth of GaN on ordered nanoporous GaN template

Abstract

We report the growth of high-quality GaN epilayers on an ordered nanoporous GaN template by metalorganic chemical vapor deposition. The nanopores in GaN template were created by inductively coupled plasma etching using anodic aluminum oxide film as an etch mask. The average pore diameter and interpore distance is about 65 and 110nm, respectively. Subsequent overgrowth of GaN first begins at the GaN crystallite surface between the pores, and then air-bridge-mediated lateral overgrowth leads to the formation of the continuous layer. Microphotoluminescence and micro-Raman measurements show improved optical properties and significant strain relaxation in the overgrown layer when compared to GaN layer of same thickness simultaneously grown on sapphire without any template. Similar to conventional epitaxial lateral overgrown GaN, such overgrown GaN on a nanopatterned surface would also serve as a template for the growth of ultraviolet-visible light-emitting III-nitride devices.

Modeling of Threading Dislocation Density Reduction in Porous III-Nitride Layers

“…It has been experimentally demonstrated that the use of an intermediate porous layer results in the drastic reduction of TD density in growing III-nitride layers. [3][4][5] Nevertheless, nowadays, there is a lack of adequate explanation of porosity influence on TD density reduction. The aim of this work was to develop a model and to perform mathematical analysis of TD density evolution in growing porous polar (as this is one of the most commercially demanded III-nitride material growth configurations) GaN layers on the base of a reaction-kinetics approach.…”

Ordered Arrays of Nanostructures and Applications in High‐Efficient Nano‐Generators

“…[6,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] The structural parameters of the anodic alumina membranes, such as the pore diameter and spacing, can be tuned in the range of about 10-200 and 25-420 nm, respectively. Accordingly, the size and spacing of the above-mentioned three classes of nanostructures that are prepared using the alumina membranes can be adjusted in the similar size range.…”

“…[28][29][30][31][32] The UTAM is a through-hole alumina membrane with small thickness of about several hundred nanometers. It can be mounted or fabricated on substrates.…”

“…[7][8][9][10][11][12][13][14] Using a two-step replication process, metallic and semiconductor nano-porous membranes can be prepared using the alumina membranes as the original. [5,[15][16][17] Moreover, recent research concerning a surface nano-patterning technique [6,[18][19][20][21][22][23][24][25][26][27][28][29][30][31][32] using ultra-thin alumina membranes (UTAMs) has successfully fabricated ordered arrays of surface zero-dimensional nanostructures including nanodots and nanoholes.…”

Динамика проникающих дислокаций в пористых гетероэпитаксиальных пленках GaN

“…Из экспериментов известно, что применение пористых подложек приводит к значительному сниже-нию плотности ПД в растущих пленках GaN [11][12][13][14]. Тем не менее в настоящее время отсутствует пол-ное понимание влияния пористости на эволюцию ПД в заращенном слое GaN.…”