Epitaxial lateral overgrowth of GaAs: Principle and growth mechanism
TL;DR: The results on growth mechanism of GaAs layers by epitaxial lateral overgrowth (ELO) technique from the liquid phase are reviewed in this article, in particular, effects of melt supersaturation, seed orientation, density of surface steps and growth temperature on properties of ELO layers are discussed.
Abstract: The results on growth mechanism of GaAs layers by epitaxial lateral overgrowth (ELO) technique from the liquid phase are reviewed. In particular, effects of melt supersaturation, seed orientation, density of surface steps and growth temperature on properties of ELO layers are discussed. It is shown that the results obtained are not a specific attribute of LPE ELO growth of GaAs layers on GaAs substrates but represent a more general phenomena encountered during the ELO growth of other epitaxial systems.
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TL;DR: A general review of the epitaxial lateral overgrowth (ELO) technology and application of ELO layers as substrates with adjustable value of lattice constant is provided in this paper.
77 citations
21 Dec 2020
TL;DR: In this paper, the recent advances in the heteroepitaxial growth of III-V on Si substrates, particularly GaAs and InP, are discussed, and recent approaches for resolving growth issues and future direction towards monolithic integration of IIIV-on-Si platform are discussed.
Abstract: Monolithic integration of III-V semiconductor devices on Silicon (Si) has long been of great interest in photonic integrated circuits (PICs), as well as traditional integrated circuits (ICs), since it provides enormous potential benefits, including versatile functionality, low-cost, large-area production, and dense integration. However, the material dissimilarity between III-V and Si, such as lattice constant, coefficient of thermal expansion, and polarity, introduces a high density of various defects during the growth of III-V on Si. In order to tackle these issues, a variety of growth techniques have been developed so far, leading to the demonstration of high-quality III-V materials and optoelectronic devices monolithically grown on various Si-based platform. In this paper, the recent advances in the heteroepitaxial growth of III-V on Si substrates, particularly GaAs and InP, are discussed. After introducing the fundamental and technical challenges for III-V-on-Si heteroepitaxy, we discuss recent approaches for resolving growth issues and future direction towards monolithic integration of III-V on Si platform.
45 citations
TL;DR: In this paper, the progress in selective epitaxial growth of cubic silicon carbide (3C-SiC) to make it a cheap and practical material for high temperature and high power, high frequency and MEMS (Micro Electromechanical Systems) applications is presented.
28 citations
TL;DR: In this article, a three-stage epitaxial lateral overgrowth (ELO) method was proposed to achieve uniform coalescence and flat surface smoothing by smoothing the rough surface caused by the coalescence of different growth fronts.
Abstract: The coalescence of selective area grown GaAs regions has been performed on patterned 1.8 μm GaAs buffer layer on Si via metal-organic chemical vapor deposition. We propose a promising method of three-stage epitaxial lateral overgrowth (ELO) to achieve uniform coalescence and flat surface. Rough surface caused by the coalescence of different growth fronts is smoothened by this method. Low root-mean-square surface roughness of 6.29 nm has been obtained on a 410-nm-thick coalesced ELO GaAs layer. Cross-sectional transmission electron microscope study shows that the coalescence of different growth fronts will induce some new dislocations. However, the coalescence-induced dislocations tend to mutually annihilate and only a small part of them reach the GaAs surface. High optical quality of the ELO GaAs layer has been confirmed by low temperature (77 K) photoluminescence measurements. This research promises a very large scale integration platform for the monolithic integration of GaAs-based device on Si.
22 citations
TL;DR: In this paper, the lattice and thermal expansion coefficient mismatch between the subsequent layers and the substrate, as well as the built-in strain in the SiO2 masking film, lead to long-range deformations (macroscopic bending) extending over the whole area of the sample.
Abstract: High resolution x-ray diffraction has been used to study strain in GaAs layers grown on GaAs substrates by the liquid phase epitaxial lateral overgrowth (ELO) technique. We show that the lattice and thermal expansion coefficient mismatch between the subsequent layers and the substrate, as well as the built-in strain in the SiO2 masking film, lead to long-range deformations (macroscopic bending) extending over the whole area of the sample. Moreover, we show evidences that microscopic bending of individual ELO stripes takes place due to adhesion of their laterally overgrown parts to the masking film.
22 citations
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TL;DR: The extent and microstructural characteristics of the lateral overgrowth were a strong function of stripe orientation and threading dislocations, originating from the interface of the underlying GaN with the AlN buffer layer were contained in the GaN grown in the window regions.
Abstract: Organometallic vapor phase lateral epitaxy and coalescence of GaN layers originating from GaN stripes deposited within 3-μm-wide windows spaced 3 μm apart and contained in SiO2 masks on GaN/AlN/6H–SiC(0001) substrates are reported. The extent and microstructural characteristics of the lateral overgrowth were a strong function of stripe orientation. A high density of threading dislocations, originating from the interface of the underlying GaN with the AlN buffer layer, were contained in the GaN grown in the window regions. The overgrowth regions, by contrast, contained a very low density of dislocations. The coalesced layers had a rms surface roughness of 0.25 nm.
744 citations
TL;DR: In this paper, a GaN layer above the SiO2 mask area surrounding the window, corresponding to the lateral overgrowth, was nearly free of the threading dislocations and a high density was observed in the vicinity of GaN grown in the window regions.
Abstract: Epitaxially laterally overgrown GaN on sapphire was used to reduce the number of threading dislocations originating from the interface of the GaN epilayer with the sapphire substrate. The GaN layer above the SiO2 mask area surrounding the window, corresponding to the lateral overgrowth, was nearly free of the threading dislocations. A high density of threading dislocations was observed in the vicinity of GaN grown in the window regions. InGaN multi-quantum-well-structure laser diodes (LDs) grown on pure GaN substrates, which were fabricated by removing the sapphire substrate, were demonstrated. The LDs with an output power of 5 mW exhibited a lifetime of more than 290 h and an estimated lifetime of 10,000 h despite a relatively large threshold current density. The far-field pattern of the LDs with a cleaved mirror facet revealed single-mode emission without any interference effects.
253 citations
TL;DR: In this paper, a GaAs layer (2.4 µm) was grown by MBE prior to the deposition of SiO2 by P-CVD, and the results showed that cracks are observed in ELO layers due to the difference in thermal expansion coefficients between GaAs and Si.
Abstract: Epitaxial lateral overgrowth (ELO) of GaAs on a Si substrate was successfully achieved by a combination of LPE and MBE. To prevent meltback of the Si substrate by Ga solution, a thin GaAs layer (2.4 µm) was grown by MBE prior to the deposition of SiO2 by P-CVD. Uniform GaAs ELO layers with mirror surface were grown through a line-shaped window cut in SiO2 film on a Si substrate with a GaAs layer. Chemical etching with an RC-1 etchant showed that there were no etch pits observed in ELO layers except in the region just over the line seed. Although cracks are observed in ELO layers due to the difference in thermal expansion coefficients between GaAs and Si, it is concluded that this technique is promising for obtaining dislocation- free GaAs on a Si substrate.
187 citations
TL;DR: In this article, the effect of Mg incorporation on the growth anisotropy of the localized GaN islands was investigated by varying the ratio [Mg]/[Ga] of bis-methylcyclopentadienyl-magnesium and trimethylgallium partial pressures.
Abstract: Atmospheric pressure metalorganic vapor phase epitaxy is used to perform selective regrowth of GaN on a silicon nitride patterned mask, capping a GaN epitaxial layer deposited on (0001) sapphire substrate. The basic pattern is constituted by a 15 μm period hexagonal array of hexagonal openings in the mask, these openings being circumscribed into 10 μm diam circles. We investigate the effect of Mg incorporation on the growth anisotropy of the localized GaN islands by varying the ratio [Mg]/[Ga] of bis-methylcyclopentadienyl-magnesium and trimethylgallium partial pressures. Both undoped and Mg-doped GaN hexagonal pyramids, delimited by C (0001) and R (1 101) facets, are achieved with a good selectivity. It is found that the GaN growth rates VR and VC, measured in the R〈1101〉 and C 〈0001〉 directions respectively, are drastically affected by the Mg incorporation. By adjusting the Mg partial pressure in the growth chamber, the VR/VC ratio can be increased so that the delimiting top C facet does not vanish as...
131 citations