Effect of Critical Miscut Angle on Growth of Thin InGaN in Metal-Organic Chemical Vapor Deposition Method

doi:10.16553/j.cnki.issn1000-985x.2025.0209

Abstract

Abstract: This study systematically investigates the effects of the miscut angle of c-plane GaN substrates on the morphology， indium incorporation behavior， and optical properties of InGaN epitaxial layers grown by metal-organic chemical vapor deposition （MOCVD） method. The results demonstrate that as the substrate miscut angle increases， the morphology of InGaN transitions from two-dimensional island-like structures to step-like structures， primarily driven by a reduction in surface supersaturation. The critical miscut angle for the transition from two-dimensional islands to step structures increases with higher vapor-phase supersaturation， which can be achieved by lowering the growth temperature or increasing the growth rate. Furthermore， both the InN mole fraction and photoluminescence intensity reach their maximum values near the critical miscut angle. This study elucidates the mechanism by which the miscut angle and growth conditions jointly regulate the morphology and properties of InGaN， providing both theoretical underpinnings and experimental guidance for the fabrication of high-quality InGaN-based optoelectronic devices.

Key words: InGaN; MOCVD; substrate miscut angle; surface morphology; surface supersaturation; photoluminescence

CLC Number:

O781

ZHANG Dongyan, LIN Wang, GAO Shoushuai, JIN Chao, HAN Baoyi, LI Xin, ZHONG Jiyu, LI Weihuan, LIU Hongwei. Effect of Critical Miscut Angle on Growth of Thin InGaN in Metal-Organic Chemical Vapor Deposition Method[J]. Journal of Synthetic Crystals, 2026, 55(3): 431-438.

Figures/Tables 6

Table 1 Growth conditions for InGaN epitaxial layers

Series	Sample	Mis-cut angle/（°）	T_g/℃	Flow rate/（μmol·min^-1）			Growth time/s
Series	Sample	Mis-cut angle/（°）	T_g/℃	TEG	TMI	NH₃	Growth time/s
Ⅰ	A	0.24	730	14.1	19.0	0.34	100
	B	0.33
	C	0.42
	D	0.51
	E	0.97
Ⅱ	F	0.28	730	4.7	6.3	0.34	300
	G	0.36
	H	0.46
Ⅲ	I	0.26	745	4.7	6.3	0.34	300
	J	0.32
	K	0.44

Table 2 InN mole fraction， PL peak wavelength and surface roughness of InGaN layers

Series	Sample	Miscut angle/（°）	Mole fraction of InN	PL peak wavelength/nm	Surface roughness/nm
Ⅰ	A	0.24	0.217±0.005	483.6±2.0	0.198±0.005
	B	0.33	0.224±0.005	485.1±2.0	0.192±0.005
	C	0.42	0.228±0.005	485.4±2.0	0.178±0.005
	D	0.51	0.220±0.005	480.2±2.0	0.105±0.005
	E	0.97	0.200±0.005	473.9±2.0	0.806±0.005
Ⅱ	F	0.28	0.193±0.005	461.3±2.0	0.129±0.005
	G	0.36	0.197±0.005	460.4±2.0	0.103±0.005
	H	0.46	0.190±0.005	453.8±2.0	0.092±0.005
Ⅲ	I	0.26	0.150±0.005	433.3±2.0	0.100±0.005
	J	0.32	0.142±0.005	432.6±2.0	0.093±0.005
	K	0.44	0.130±0.005	429.0±2.0	0.093±0.005

Fig.1 AFM images of samples under different growth condition and miscut angles

Fig.2 Evolution of Ga atom surface saturation. （a） Calculated values of Ga surface supersaturation；（b） Ga gas-phase supersaturation versus miscut angle. Where ○， □， and ▽ stand for the step structure， two-dimensional island， and step aggregation， respectively

Fig.3 Dependence of InN mole fraction on sample miscut angle. （a） InN molar fractions of InGaN layers at different miscut angles （○ = step structure， □ = 2D island， ▽ = step aggregation）；（b） relationships between growth rate， step migration rate and miscut angle

Fig.4 Effect of miscut angle on PL peak intensity and FWHM of sample. （a） PL measurement position schematic； PL peak intensity （b） and FWHM （c） versus miscut angle （○=step structure， □=two-dimensional island， and ▽=stepped aggregation）

References 27

[1]	MATSUOKA T. Progress in nitride semiconductors from GaN to InN： movpe growth and characteristics［J］. Superlattices and Microstructures， 2005， 37（1）： 19-32.
[2]	CHO H K， LEE J Y， KIM K S， et al. Phase separation and stacking fault of In _x Ga_1- _x N layers grown on thick GaN and sapphire substrate by metalorganic chemical vapor deposition［J］. Journal of Crystal Growth， 2000， 220（3）： 197-203.
[3]	MASSABUAU F C P， SAHONTA S L， TRINH-XUAN L， et al. Morphological， structural， and emission characterization of trench defects in InGaN/GaN quantum well structures［J］. Applied Physics Letters， 2012， 101（21）： 212107.
[4]	DAMILANO B， GIL B. Yellow-red emission from （Ga， In）N heterostructures［J］. Journal of Physics D： Applied Physics， 2015， 48（40）： 403001.
[5]	OLIVER R A， KAPPERS M J， HUMPHREYS C J， et al. Growth modes in heteroepitaxy of InGaN on GaN［J］. Journal of Applied Physics， 2005， 97（1）： 013707.
[6]	HASHIMOTO R， HWANG J， SAITO S， et al. High-efficiency green-yellow light-emitting diodes grown on sapphire （0001） substrates［J］. Physica Status Solidi （c）， 2013， 10（11）： 1529-1532.
[7]	TIAN A Q， LIU J P， ZHANG L Q， et al. Significant increase of quantum efficiency of green InGaN quantum well by realizing step-flow growth［J］. Applied Physics Letters， 2017， 111（11）： 112102.
[8]	LIU Z B， NITTA S， ROBIN Y， et al. Morphological study of InGaN on GaN substrate by supersaturation［J］. Journal of Crystal Growth， 2019， 508： 58-65.
[9]	LESZCZYNSKI M， CZERNECKI R， KRUKOWSKI S， et al. Indium incorporation into InGaN and InAlN layers grown by metalorganic vapor phase epitaxy［J］. Journal of Crystal Growth， 2011， 318（1）： 496-499.
[10]	KRYŚKO M， FRANSSEN G， SUSKI T， et al. Correlation between luminescence and compositional striations in InGaN layers grown on miscut GaN substrates［J］. Applied Physics Letters， 2007， 91（21）： 211904.
[11]	NAKAMURA A， YANAGITA N， MURATA T， et al. Effects of sapphire substrate misorientation on the GaN-based light emitting diode grown by metalorganic vapour phase epitaxy［J］. Physica Status Solidi C， 2008， 5（6）： 2007-2009.
[12]	PERLIN P， FRANSSEN G， SZESZKO J， et al. Nitride-based quantum structures and devices on modified GaN substrates［J］. Physica Status Solidi （a）， 2009， 206（6）： 1130-1134.
[13]	FORONDA H M， ROMANOV A E， YOUNG E C， et al. Curvature and bow of bulk GaN substrates［J］. Journal of Applied Physics， 2016， 120（3）： 035104.
[14]	RAO Z W， SHAN X Y， WANG G B， et al. 10.5 gbps visible light communication systems based on C-plane freestanding GaN micro-LED［J］. Journal of Lightwave Technology， 2024， 42（13）： 4360-4364.
[15]	ZHOU K， REN H J， LIU J P， et al. Surface morphology and optical properties of InGaN/GaN multiple quantum wells grown on freestanding GaN （0001） substrates［J］. Superlattices and Microstructures， 2016， 100： 968-972.
[16]	KUMAGAI Y， KIKUCHI J， MATSUO Y， et al. Thermodynamic analysis of InN and In _x Ga_1- _x N MOVPE using various nitrogen sources［J］. Journal of Crystal Growth， 2004， 272（1/2/3/4）： 341-347.
[17]	KOUKITU A， SEKI H. Thermodynamic calculation of the VPE growth of In_1- _x Ga _x As by the trichloride method［J］. Japanese Journal of Applied Physics， 1984， 23（1R）： 74.
[18]	BRYAN I， BRYAN Z， MITA S， et al. Surface kinetics in AlN growth： a universal model for the control of surface morphology in Ⅲ-nitrides［J］. Journal of Crystal Growth， 2016， 438： 81-89.
[19]	BORTON W K， CABRERA N， FRANK F C. The growth of crystals and the equilibrium structure of their surfaces［J］. Philosophical Transactions of the Royal Society of London Series A， Mathematical and Physical Sciences， 1951， 243（866）： 299-358.
[20]	SHITARA T， NISHINAGA T. Surface diffusion length of gallium during MBE growth on the various misoriented GaAs（001） substrates［J］. Japanese Journal of Applied Physics， 1989， 28（7R）： 1212.
[21]	NORTHRUP J E， NEUGEBAUER J， FEENSTRA R M， et al. Structure of GaN（0001）： the laterally contracted Ga bilayer model［J］. Physical Review B， 2000， 61（15）： 9932-9935.
[22]	KIM S， LEE K， LEE H， et al. The influence of ammonia pre-heating to InGaN films grown by TPIS-MOCVD［J］. Journal of Crystal Growth， 247： 55-61.
[23]	ZYWIETZ T， NEUGEBAUER J， SCHEFFLER M. Adatom diffusion at GaN （0001） and （0001） surfaces［J］. Applied Physics Letters， 1998， 73（4）： 487-489.
[24]	FRANSSEN G， SUSKI T， KRYŚKO M， et al. Influence of substrate misorientation on properties of InGaN layers grown on freestanding GaN［J］. Physica Status Solidi C， 2008， 5（6）： 1485-1487.
[25]	YAMADA H， ISO K， SAITO M， et al. Impact of substrate miscut on the characteristic of m-plane InGaN/GaN light emitting diodes［J］. Japanese Journal of Applied Physics， 2007， 46（46）： L1117-L1119.
[26]	YAMADA H， ISO K， MASUI H， et al. Effects of off-axis GaN substrates on optical properties of m-plane InGaN/GaN light-emitting diodes［J］. Journal of Crystal Growth， 2008， 310（23）： 4968-4971.
[27]	YAMAMOTO A， KODAMA K， MATSUOKA T， et al. Low-temperature （≤600 ℃） growth of high-quality In _x Ga_1- _x N（x∼0.3） by metalorganic vapor phase epitaxy using NH₃ decomposition catalyst［J］. Japanese Journal of Applied Physics， 2017， 56（4）： 041001.