TEM study of GaN-based nanopillar-shaped-crystals grown on a multicrystalline Si substrate

Abstract

A gallium nitride-based thin film is grown on a multicrystalline Si substrate by a molecular beam epitaxy apparatus. The microstructure of the crystalline film is closely examined by transmission electron microscopy (TEM). It is revealed that the film is composed of nanopillar-shaped-crystal grains with their diameters of 100 nm and heights of 400 nm approximately. Each nanopillar-crystal grain is based on highly-ordered wurtzite crystal structure and strongly textured with its c-axis oriented perpendicular to the substrate surface. The TEM observations also evidence that there are two kinds of basal stacking faults widely distributed in the nanopillar-crystal.

Growth and characterization of Mg-doped GaN and InGaN nanopillar-crystals based on steering-crystal-formed multi-crystalline Si substrates

“…We also have tried to grow GaN-based nanopillar crystals directly on several non-single-crystalline substrates. [26][27][28] However, these substrates also have some shortcomings, such as quartz glass does not have electrical conductivity, and the thermal expansion coefficient of Ti and GaN is relatively large. These are not conducive to the growth of GaN and the fabrication of optoelectronic devices.…”