Investigation of GaN Films Grown on Liquid-Phase Deposited SiO₂Nanopatterned Sapphire Substrates

Abstract

A simple, easy and relatively inexpensive liquid phase deposition (LPD) method was used to introduce nano SiO 2 on sapphire substrates to fabricate nanoscale patterned sapphire substrates (PSS). Two kinds of nanoscale PSS were used to grow GaN, namely "NPOS" which is nano-pattern oxide on sapphire substrate and "NPSS" which is nano-patterned sapphire substrate. It was found that upper region of NPSS-GaN had the best quality. This is because as the growth time increased, laterally-grown GaN caused the threading dislocations to bend toward the patterns. Besides, voids formed on the NPSS pattern sidewalls caused more threading dislocation bending toward these voids.

Reduced Residual Stress and Enhanced Performance of GaN-Based LEDs Prepared by Liquid Phase Deposition Silicon Oxide-Nano Patterned Sapphire Substrate

“…8 Both EPD and FWHM of MNPSS-GaN were less than those of NPSS-GaN. This is because GaN was not initiated from the top oxide-covered c-plane of MNPSS as shown in Figs.…”

“…Samples designated as "FLAT" are flat sapphire substrates, while "MNPSS" are nano-patterned sapphire substrates with top oxide layers prepared by LPD method. 8 For MNPSS, substrate was immersed in mixed solution of H 2 SiF 6 saturated with silica gel and H 3 BO 3 (0.01 mol/l). The related LPD reactions on sapphire were listed as follows:…”

“…7 In this study, liquid phase deposition (LPD) was used to introduce nano-sized PSS. 8 After growth of the GaN layer, the crystallinity, indium fraction and the residual stress were investigated.…”

Surface modification of metal mesh with SiO2 films for enhanced corrosion protection

“…In this respect, corrosion protection is necessary and urgent. Many efforts have been made to protect the metal materials from corrosion, among which ceramics are the most widely used materials to coat and protect the metal substrates . Ceramics and ceramic coatings are of excellent insulating and resistivity properties and high resistance to oxidation, wear and corrosion even under high temperature condition .…”

Evolution of Bottomc-Plane on Wet-Etched Patterned Sapphire Substrate

“…[6][7][8][9] In recent years, PSS has attracted much attention because it can improve both IQE and LEE. [10][11][12][13] There are two methods for fabricating PSSs: (1) dry etching and (2) wet etching. In dry etching, ion bombardment damaged PSS surface and increased the threading dislocation density in GaN epitaxial layers.…”