Growth of thick InGaN layers by tri-halide vapor phase epitaxy

Abstract

This is the first study to report InGaN growth by tri-halide vapor phase epitaxy (THVPE) using InCl3 and GaCl3 generated by the reactions between metal sources (i.e., metallic indium and gallium) and gaseous chlorine. The influence of the surface orientation of the initial substrate on InGaN-THVPE growth was investigated using freestanding (0001) and GaN substrates. Only a N-polar InGaN epitaxial layer was obtained by THVPE because of the instability of GaCl3 adsorption toward nitrogen atoms on the Ga-polar surface. In addition, we investigated the influence of the group-III input partial pressure on the growth rate and solid composition of InGaN layers grown on a GaN substrate. The growth rate increased linearly with group-III concentration, and a maximum growth rate of 15.6 µm/h was achieved at P III = 2.0 × 10−3 atm.

Quasiequilibrium crystal shape and kinetic Wulff plot for GaN grown by trihalide vapor phase epitaxy using GaCl3

“…GaN could be grown on − 5° off, , and but not on , , which was in agreement with the facets that appeared for the SAG by THVPE, as shown in Fig. c and d. Furthermore, our previous study revealed that GaN could not be grown on and as well as by THVPE . Thus, planes were not stable for THVPE condition, which caused an irregular –like shape to appear for the SAG.…”

“…ð and 30 31Þ ð as well as 10 11Þ ð by THVPE [17]. Thus, h0 h1 È É planes were not stable for THVPE condition, which caused an irregular h0 h1 È É -like shape to appear for the SAG.…”

Growth of Highly Crystalline GaN at High Growth Rate by Trihalide Vapor‐Phase Epitaxy

“…During the bulk growth of GaN, as the crystal growth direction of conventional HVPE is along <0001> gallium polar face, the crystal diameter is reduced by inclination of the sidewall facet (10–11) or (11–22) toward the center of the substrate as growth proceeds. Herein, we propose a novel trihalide vapor‐phase epitaxy (THVPE) growth method using GaCl 3 as the Ga precursor . This method results in an enlarged crystal diameter because the GaN growth by THVPE is conducted along <000‐1>, which is the direction opposite to that in conventional HVPE, and the sidewall facet inclination occurs toward the periphery of the substrate as growth proceeds.…”

“…[7] Therefore, the outer rim of the crystal must be ground off, that results in a reduced crystal diameter. During the bulk growth of GaN, as the crystal growth direction of conventional HVPE is along <0001> gallium polar face, the crystal diameter is reduced by inclination of the sidewall facet (10)(11) or (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) toward the center of the substrate as growth proceeds. Herein, we propose a novel trihalide vapor-phase epitaxy (THVPE) growth method using GaCl 3 as the Ga precursor.…”

“…Herein, we propose a novel trihalide vapor-phase epitaxy (THVPE) growth method using GaCl 3 as the Ga precursor. [8][9][10] This method results in an enlarged crystal diameter because the GaN growth by THVPE is conducted along <000-1>, which is the direction opposite to that in conventional HVPE, [11] and the sidewall facet inclination occurs toward the periphery of the substrate as growth proceeds. Thermodynamic analysis revealed that THVPE has a large driving force at growth temperatures even above 1100 C, whereas the driving force of conventional HVPE falls around 1100 C. [11] To compare THVPE with HVPE, GaN crystals were grown experimentally in the same reactor using both HVPE and THVPE, employing equivalent flowrates and partial pressures of the gallium precursor at various growth temperatures.…”