Metalorganic vapor phase epitaxial growth of a high quality GaN film using an AlN buffer layer

Abstract

Atmospheric pressure metalorganic vapor phase epitaxial growth and characterization of high quality GaN on sapphire (0001) substrates are reported. Using AlN buffer layers, GaN thin films with optically flat surfaces free from cracks are successfully grown. The narrowest x-ray rocking curve from the (0006) plane is 2.70' and from the (2024) plane is 1.86'. Photoluminescence spectra show strong near band edge emission. The growth condition dependence of crystalline quality is also studied.

Internal quantum efficiency enhancement of GaInN/GaN quantum-well structures using Ag nanoparticles

“…C-plane sapphire substrates were thermally cleaned in a H 2 ambient at approximately 1050 o C. After that, approximately 20-nm-thick low temperature (LT)-GaN buffer layer was deposited at 535 o C. 23 After annealing process a 2-µm-thick GaN layer was grown at 1050 o C on the annealed LT-GaN nucleation layer. The final LED structure consisted of a 2-µm-thick n-GaN:Si layer, a 10 periods of GaInN:Si (3 nm) / GaN:Si (2 nm) superlattice layer, a 5 periods of GaN:Si (11.5 nm) / GaInN (2 nm) QWs active region covered with 5-nm-thick GaN capping layer, a 20-nm-thick p-GaN:Mg, and a 5-nm-thick p + -GaN:Mg p-contact layer.…”

Annealing of an AlN buffer layer in N2–CO for growth of a high-quality AlN film on sapphire

“…13,14) Additionally, in the case of GaN grown on sapphire substrates, the solid-phase epitaxy of nucleation layers, such as GaN and AlN, by annealing is commonly used to improve the crystal quality of GaN films. [15][16][17] However, there are only a few reports on the effects of annealing AlN buffer layers on AlN growth.…”

Improved performance of GaN based light emitting diodes with ex-situ sputtered AlN nucleation layers

“…6 For the purpose of decreasing the energy difference from lattice constant and thermal expansion coefficient mismatch between sapphire substrates and GaN, early pioneers applied in-situ low temperature AlN or GaN film to form the nucleation layer which provide a stable surface condition to grow the following bulk GaN. 7,8 This two-step growth has made great success and become foundation in realization of commercial grade blue GaN-based LEDs. To further improve the GaN crystal quality, several growth methods, such as epitaxially lateral over-growth, 9,10 insertion of superlattice layers or SiN x nano-masks, 11,12 etc.…”