Bias process for heteroepitaxial diamond nucleation on Ir substrates

Wang Weihua,Yang Shilin,Liu Benjian,Hao Xiaobin,Han Jiecai,Dai Bing,Zhu Jiaqi 한국탄소학회 2023 Carbon Letters Vol.33 No.2

Heteroepitaxy is a better method of enlarging SCD wafer size than homoepitaxy. In this work, several aspects of the bias process for heteroepitaxial diamond nucleation are studied experimentally. First, with increasing bias time, the diamond-nucleation pathway is found to transform from “isolated-crystal nucleation” to “typical domain-nucleation” and back to “isolated-crystal nucleation.” An interdependent relationship between bias voltage and bias time is proposed: the higher the bias voltage, the shorter the bias time. Second, a correlation exists between the threshold bias voltage and reactor-chamber pressure: a higher reactor chamber pressure usually requires a higher threshold bias voltage to realize “typical domain nucleation.” Third, diamond bias-enhanced nucleation and growth is observed at a high CH4 content, where the dynamic equilibrium between amorphous-carbon-layer deposition and atomic-hydrogen etching is broken. Finally, epitaxial nucleation is obtained on a substrate with ∅30 mm in a home-made MPCVD setup.

Van der Waals Oxide Heteroepitaxy for Transparent and Flexible Electronics

Ying-Hao Chu 한국진공학회 2017 한국진공학회 학술발표회초록집 Vol.2017 No.8

Atomic Scale Study on Growth and Heteroepitaxy of ZnO Monolayer on Graphene

Hong, Hyo-Ki,Jo, Junhyeon,Hwang, Daeyeon,Lee, Jongyeong,Kim, Na Yeon,Son, Seungwoo,Kim, Jung Hwa,Jin, Mi-Jin,Jun, Young Chul,Erni, Rolf,Kwak, Sang Kyu,Yoo, Jung-Woo,Lee, Zonghoon American Chemical Society 2017 NANO LETTERS Vol.17 No.1

<P/><P>Atomically thin semiconducting oxide on graphene carries a unique combination of wide band gap, high charge carrier mobility, and optical transparency, which can be widely applied for optoelectronics. However, study on the epitaxial formation and properties of oxide monolayer on graphene remains unexplored due to hydrophobic graphene surface and limits of conventional bulk deposition technique. Here, we report atomic scale study of heteroepitaxial growth and relationship of a single-atom-thick ZnO layer on graphene using atomic layer deposition. We demonstrate atom-by-atom growth of zinc and oxygen at the preferential zigzag edge of a ZnO monolayer on graphene through <I>in situ</I> observation. We experimentally determine that the thinnest ZnO monolayer has a wide band gap (up to 4.0 eV), due to quantum confinement and graphene-like structure, and high optical transparency. This study can lead to a new class of atomically thin two-dimensional heterostructures of semiconducting oxides formed by highly controlled epitaxial growth.</P>

Enhancement of Surface Diffusivity for Waviness Evolution on Heteroepitaxial Thin Films

Yun Young Kim 한국표면공학회 2014 한국표면공학회지 Vol.47 No.6

The present study deals with a numerical analysis on the island growth of heteroepitaxial thin-films through local surface diffusivity enhancement. A non-linear governing equation for the surface waviness evolution in lattice-mismatched material systems is developed for the case of spatially-varying surface diffusivity. Results show that a flat film that is stable under constant diffusivity conditions evolves to form nanostructures upon externally-induced spatial diffusivity modulation. The periodicity of waviness can be controlled by changing the modulation parameters, which allows for generation of pattern arrays. The present study therefore points towards a post-deposition treatment technique that achieves controllability and order in the structure formation process for applications in nanoelectronics and thin-film devices.

대면적 2차원 나노소재 위에 이종에피택시로 제작된 반도체 구조물 및 이의 광전소자 응용

오홍석 한국세라믹학회 2022 세라미스트 Vol.25 No.4

Semiconductor nanostructures or thin films are vital components of modern optoelectronic devices, such as light-emitting diodes, sensors, or transistors. While single crystalline wafers are used as heteroepitaxial templates for them, increasing demands on flexibility or transferability require separation of the grown semiconductor structures on such substrates, which is technically challenging and expensive. Recent research suggests that large-scale 2D nanomaterials can serve as heteroepitaxial templates and provide additional functionalities such as transferability to foreign substrates or mechanical flexibility. In this paper, growth, structural properties, and optoelectronic device applications of semiconductor nanostructures or thin films which are heteroepitaxially grown on large-scale 2D nanomaterials are reviewed.

화학기상증착법에 의한 6H-SiC 기판상의 3C-SiC 이종박막 성장

장성주,박주훈 한국결정성장학회 2003 한국결정성장학회지 Vol.13 No.6

본 연구에서는 열화학기상증착법을 사용하여 6H-SiC 기판 위에 silane($SiH_4$)과 prophane($C_3H_8$)을 사용하여 3C-SiC 이종박막을 성장시키고 이의 성장 특성을 조사하였다. C/Si 유량 비율이 4.0, 운반기체의 유량은 5 slm이고 성장온도가 $1200^{\circ}C$인 경우의 박막성장율은 약 1.8 $\mu$m/h이었다. 성장박막의 Nomarski 표면형상, X-선 회절분광, Raman 산란 특성 및 광발광(PL) 특성 등을 측정하고 성장조건에 따른 결정성을 비교하였다. 이러한 평가를 통하여 성장온도 $1150^{\circ}C$ 이상에서 양질의 결정성 3C-SiC 이종박막이 성장점을 확인하였다. The heteroepitaxial growth of crystalline 3C-SiC on 6H-SiC substrates using high purity silane ($SiH_4$) and prophane ($C_3H^8$) was carried out by thermal chemical vapor deposition, and growth characteristics were investigated in this study. In case that the flow ratio of C/Si and flow rate of $H_2$ were 4.0 and 5.0 slm, respectively, the growth rate of epilayers was about 1.8 $\mu$m/h at growth temperature of $1200^{\circ}C$. The Nomarski surface morphology, X-ray diffraction, Raman spectroscopy, and photoluninescence of grown epilayers were measured to investigate the crystallinity. In this study, the high quality of crystalline 3C-SiC heteropitaxial layers was observed at growth temperature of above $1150^{\circ}C$.

표면개질에 의한 헤테로에피텍시 단결정 다이아몬드의 결정성 향상

배문기 ( Mun Ki Bae ),김민수 ( Min Su Kim ),김성우 ( Seong Woo Kim ),윤수종 ( Su Jong Yoon ),김태규 ( Tae Gyu Kim ) 한국열처리공학회 2020 熱處理工學會誌 Vol.33 No.3

Recently, many studies on growth of single crystal diamond using MPECVD have been conducted. The heteroepitaxial method is one of the methods for growing diamonds on a large-area substrate, and research on synthesis of single crystal diamonds using SrTiO₃, MgO, and sapphire substrates has been attempted. In addition, research is being conducted to reduce the internal stress generated during diamond growth and to improve the crystallinity of the diamond. The compressive stress generated therein causes peeling and bowing from the substrate. This study aimed to synthesize heteroepitaxial single crystal diamonds with high crystallinity by surface modification. A diamond thin film was first grown on a sapphire/Ir substrate by MPECVD, and then etched with H₂ gas to modified the morphology and roughness of the surface. A secondary diamond layer was grown on the surface, and the internal stress, crystallinity of the diamond were investigated. As a result, the fabrication of single crystal diamonds with improved crystallinity was confirmed. (Received May 10, 2020; Revised May 15, 2020; Accepted May 22, 2020)

미스트화학기상증착 시스템의 Hot Zone 내 사파이어 기판 위치에 따른 β-Ga2O3 이종 박막 성장 거동 연구

김경호,이희수,신윤지,정성민,배시영 한국전기전자재료학회 2023 전기전자재료학회논문지 Vol.36 No.5

In this study, the heteroepitaxial thin film growth of β-Ga2O3 was studied according to the position of the susceptor in mist-CVD. The position of the susceptor and substrate was moved step by step from the center of the hot zone to the inlet of mist in the range of 0~50 mm. It was confirmed that the average thickness increased to 292 nm (D1), 521 nm (D2), and 580 nm (D3) as the position of the susceptor moved away from the center of the hot zone region. The thickness of the lower region of the substrate is increased compared to the upper region. The surface roughness of the lower region of the substrate also increased because the nucleation density increased due to the increase in the lifetime of the mist droplets and the increased mist density. Therefore, thin film growth of β-Ga2O3 in mist-CVD is performed by appropriately adjusting the position of the susceptor (or substrate) in consideration of the mist velocity, evaporation amount, and temperature difference with the substrate, thereby determining the crystallinity of the thin film, the thickness distribution, and the thickness of the thin film. Therefore, these results can provide insights for optimizing the mist-CVD process and producing high-quality β-Ga2O3 thin films for various optical and electronic applications.

Heteroepitaxial Growth of Diamond Films Synthesized by Microwave Plasma Enhanced Chemical Vapor Deposition

Kim, Yoon-Kee,Lee, Jai-Young The Korean Ceramic Society 1996 The Korean journal of ceramics Vol.2 No.4

The highly oriented diamond particles were deposited on the mirror-polished (100) silicon substrates in the bell-jar type microwave plasma deposition system using a three-step process consisting if carburization, bias-enhanced nucleation and growth. By adjusting the geometry of the substrate and substrate holder, very dense disc-shaped plasma was formed over the substrate when the bias voltage was below -200V. Almsot perfectly oriented diamond films were obtained only in this dense disc-shaped plasma. From the results of the optical emission spectra of the dense disc-shaped plasma, it was found that the concentrations of atomic hydrogen and hydrocarbon radical were increased with negative bias voltage. It was also found that the highly oriented diamonds were deposited in the region, where the intensity ratios of carbonaceous species to atomic hydrogen are saturated.

Nucleation Layer의 표면 거칠기가 GaAs 기판 위에 성장된 InP 에피층의 품질에 미치는 영향

유충현,Yoo, Choong-Hyun 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.8

Heteroepitaxial InP films have been grown on GaAs substrates to study the effects of the nucleation layer's surface roughness on the epitaxial layer's quality. For this, InP nucleation layers were grown at $400^{\circ}C$ with various ethyldimethylindium (EDMIn) flow rates and durations of growth, annealed at $6200^{\circ}C$ for 10 minutes and then InP epitaxial layers were grown at $550^{\circ}C$. It has been found that the nucleation layer's surface roughness is a critical factor on the epitaxial layer's quality. When a nucleation layer is grown with an EDMIn flow rate of 2.3 ${\mu}mole/min$ for 12 minutes, the surface roughness of the nucleation layer is minimum and the successively grown epitaxial layer's qualities are comparable to those of the homoepitaxial InP layers reported. The minimum full width at half maximum of InP (200) x-ray diffraction peak and that of near-band-edge peak from a 4.4 K photoluminescence are 60 arcmin and 6.33 meV, respectively.