HVPE법에 의한 Si 기판 위의 질화물 반도체 성장에 관한 연구

Abstract

III-V nitrides compound semiconductors have attracted much attention because of their applications in blue/UV optoelectronic devices high power and high temperature electronic devices. Indium gallium nitride(InGaN), in particular, is a promising material for the fabrication of optical devices emitting photons from 0.7 eV to 3.4 eV.

Especially, for a nano or micro-scale sized structures, the indium gallium nitride ternary alloys are expected to show novel optical characteristics by reduced density of states and improved carrier confinement.

GaN-based devices such as light emitting diodes (LED) are usually grown on sapphire or SiC substrates. Compared to sapphire and SiC, Si substrates offer the advantages of low cost, large-scale availability, good thermal and electrical conductivities, top-down electrode formation and the feasibility of removing the Si substrate with wet etching.

In this paper, the growth of GaN-based compound semiconductors has been attempted on Si substrate in experiment of three types

First of all, the thickness GaN layers are grown on GaN(1-101) template by hydride vapor phase epitaxy(HVPE). The GaN(1-101) template was selectively grown on a 8-degree off-oriented (001) patterned Si substrate by metalorganic chemical vapor deposition(MOCVD). The grown morphology of GaN layers are investigated by scanning electron microscopy(SEM) and cathodoluminescence(CL).

Secondly, the structural change of InGaN quantum sized structures on Si substrate grown by mixed-source HVPE. The grown InGaN structures are analyzed by X-ray photoelectron spectroscopy(XPS) to characterize the InGaN ternary crystal alloy.

Finally, the SAG(selective area growth)-LEDs are grown on GaN/Si(111) substrate by mixed-source HVPE. AlGaN and InAlGaN are used as active layers. The GaN template layer on Si(111) substrate is grown by MOCVD and the SAG-double-hetero(DH) structures are grown by HVPE with multi sliding boat system. The grown SAG-LEDs are characterized by SEM, current-voltage(I-V) measurement and electroluminescence(EL).