Crystals

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11 pages, 1308 KiB

Open AccessArticle

Numerical Simulations of Space Charge Waves Amplification Using Negative Differential Conductance in Strained Si/SiGe at 4.2 K

by Abel Garcia-Barrientos, Natalia Nikolova, Lado Filipovic, Edmundo A. Gutierrez-D., Victoria Serrano, Sharon Macias-Velasquez and Sarai Zarate-Galvez

Crystals 2023, 13(9), 1398; https://doi.org/10.3390/cryst13091398 - 20 Sep 2023

Viewed by 1217

Abstract

This paper introduces a two-dimensional (2D) numerical simulation of the amplification of space charge waves using negative differential conductance in a typical MOS silicon–germanium (SiGe)-based field-effect transistors (FET) and complementary metal oxide semiconductor (CMOS) technology at 4.2 K. The hydrodynamic model of electron [...] Read more.

This paper introduces a two-dimensional (2D) numerical simulation of the amplification of space charge waves using negative differential conductance in a typical MOS silicon–germanium (SiGe)-based field-effect transistors (FET) and complementary metal oxide semiconductor (CMOS) technology at 4.2 K. The hydrodynamic model of electron transport was applied to describe the amplification of space charge waves in this nonlinear medium (i.e., the negative differential conductance). This phenomenon shows up in GaAs thin films at room temperature. However, this can be also observed in a strained Si/SiGe heterostructure at very low temperatures (T < 77 K) and at high electric fields (E > 10 KV/cm). The results show the amplification and non-linear interaction of space charge waves in a strained Si/SiGe heterostructure occurs for frequencies up to approximately 60 GHz at T = 1.3 K, 47 GHz at T = 4.2 K, and 40 GHz at T = 77 K. The variation of concentration and electric field in the Z and Y directions are calculated at 4.2 K. The electric field in the Z direction is greater than in the Y direction. This is due to the fact that this is the direction of electron motion. In addition to deep space applications, these types of devices have potential uses in terrestrial applications which include magnetic levitation transportation systems, medical diagnostics, cryogenic instrumentation, and superconducting magnetic energy storage systems. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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11 pages, 804 KiB

Open AccessArticle

High Uniformity 6-Inch InGaP Epitaxial Growth

by Shangyu Yang, Ning Guo, Yicheng Pei, Weilong Yuan, Yunkai Li, Siqi Zhao, Yang Zhang and Xingfang Liu

Crystals 2023, 13(8), 1165; https://doi.org/10.3390/cryst13081165 - 27 Jul 2023

Viewed by 1314

Abstract

The growth of 6-inch In_0.485Ga_0.515P has been examined in this study. The effects of growth temperature, the V/III ratio, and the H₂ total flow on solid composition, growth rate, and crystal quality have been systematically investigated and discussed. [...] Read more.

The growth of 6-inch In_0.485Ga_0.515P has been examined in this study. The effects of growth temperature, the V/III ratio, and the H₂ total flow on solid composition, growth rate, and crystal quality have been systematically investigated and discussed. Additionally, the effect of growth conditions on doping efficiency has been investigated. Finally, the relationship between electrical uniformity, optical uniformity, and the growth conditions of the 6-in epitaxial layer is discussed. At a growth temperature of 600 °C and a V/III of 250, a high uniformity 6-in InGaP epitaxial layer with an electrical uniformity of 0.33% and optical uniformity of 0.03% was produced. InGaP was grown by the metal-organic chemical vapor deposition method in an Aixtron 2800G4 reactor. High resolution X-ray diffraction (HRXRD), photoluminescence (PL), sheet resistance, electrochemical capacitance-voltage (ECV), and the Hall effect were used to characterize the characteristics of InGaP epitaxial layers. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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13 pages, 6971 KiB

Open AccessArticle

Layered Epitaxial Growth of 3C/4H Silicon Carbide Confined by Surface Micro-Nano Steps

by Ning Guo, Yicheng Pei, Weilong Yuan, Yunkai Li, Siqi Zhao, Shangyu Yang, Yang Zhang and Xingfang Liu

Crystals 2023, 13(7), 1123; https://doi.org/10.3390/cryst13071123 - 19 Jul 2023

Cited by 2 | Viewed by 1943

Abstract

In this study, we used a horizontal hot-wall CVD epitaxy apparatus to grow epitaxial layers on 4° off-axis 4H-SiC substrates. Epitaxial films were grown by adjusting the flow rate of the source gas at different levels. With an increase in the source gas [...] Read more.

In this study, we used a horizontal hot-wall CVD epitaxy apparatus to grow epitaxial layers on 4° off-axis 4H-SiC substrates. Epitaxial films were grown by adjusting the flow rate of the source gas at different levels. With an increase in the source gas flow rate, a notable transition in the crystalline structure of the epitaxial layer was observed, gradually shifting from 4H-SiC to 3C-SiC. Furthermore, the quality of the epitaxial layer correspondingly exhibited degradation. Specifically, for epitaxial films grown under moderate gas flow rates, the central region demonstrated a crystalline structure of 4H-SiC, while the outer ring region exhibited a crystalline structure of 3C-SiC. Using a scanning electron microscope (SEM) to observe the transition zone of the two regions, a region of 3C/4H overlapping growth below it was found. Bright areas corresponded to 3C, while dark areas corresponded to 4H, as confirmed by Raman spectroscopy and other SEM images. The growth interfaces of the two crystal types were clearly discernible and relatively compact. Furthermore, the growth angles of the two crystal types and their correlation with the cutting direction strongly suggest that this overlap is related to the formation of micro-nano steps on the substrate surface. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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10 pages, 3800 KiB

Open AccessArticle

Temperature-Dependent Optical Behaviors and Demonstration of Carrier Localization in Polar and Semipolar AlGaN Multiple Quantum Wells

by Ping Ouyang, Kunzi Liu, Jiaxin Zhang, Qiushuang Chen, Liqiong Deng, Long Yan, Jason Hoo, Shiping Guo, Li Chen, Wei Guo and Jichun Ye

Crystals 2023, 13(7), 1076; https://doi.org/10.3390/cryst13071076 - 8 Jul 2023

Cited by 1 | Viewed by 1288

Abstract

Semipolar AlGaN multiple quantum wells (MQWs) have unique advantages in deep ultraviolet light emitters due to the weak Quantum-Confined Stark Effect. However, their applications are hampered by the poor crystalline quality of semipolar AlGaN thin films. Different treatments were developed to improve the [...] Read more.

Semipolar AlGaN multiple quantum wells (MQWs) have unique advantages in deep ultraviolet light emitters due to the weak Quantum-Confined Stark Effect. However, their applications are hampered by the poor crystalline quality of semipolar AlGaN thin films. Different treatments were developed to improve the crystal quality of semipolar AlGaN, including a multistep in situ thermal annealing technique proposed by our group. In this work, temperature-dependent and time-resolved photoluminescence characterizations were performed to reveal the carrier localization in the MQW region. The degree of carrier localization in semipolar AlGaN MQWs grown on top of the in situ-annealed AlN is similar to that of conventional ex situ face-to-face annealing, both of which are significantly stronger than that of the c-plane counterpart. Moreover, MQWs on in situ-annealed AlN show drastically reduced dislocation densities, demonstrating its great potential for the future development of high-efficiency optoelectronic devices. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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11 pages, 3208 KiB

Open AccessArticle

Multiple-Layer Triangular Defects in 4H-SiC Homoepitaxial Films Grown by Chemical Vapor Deposition

by Yicheng Pei, Weilong Yuan, Ning Guo, Yunkai Li, Xiuhai Zhang and Xingfang Liu

Crystals 2023, 13(7), 1056; https://doi.org/10.3390/cryst13071056 - 4 Jul 2023

Viewed by 2010

Abstract

In this study, a special triangular defect (TD) was identified on 4H-SiC epitaxial wafers. The morphology and composition characteristics of these special TDs were revealed by Raman, atomic force microscope (AFM), and scanning electron microscope (SEM). Compared to ordinary triangular defects, this defect [...] Read more.

In this study, a special triangular defect (TD) was identified on 4H-SiC epitaxial wafers. The morphology and composition characteristics of these special TDs were revealed by Raman, atomic force microscope (AFM), and scanning electron microscope (SEM). Compared to ordinary triangular defects, this defect protruded from the epitaxial layer and exhibited a laminated shape. The study also discussed the effects of several factors, such as C/Si ratio and growth time, on the triangular defects. Through analysis of these results, we developed methods to suppress the triangular defects. This research provides new insights into the morphology, structure, and composition of this serious destructive defect and is helpful for improving the performance of SiC epitaxial wafers. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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10 pages, 2969 KiB

Open AccessArticle

Novel Functional Materials of Hydrogen Storage B₂₀N₂₄: A First-Principles Calculation

by Jing Zhao, Zhongtang Huo, Shuailei Xu, Mei Xiong, Dezheng Liu, Yikun Wang and Xin Jia

Crystals 2023, 13(7), 1029; https://doi.org/10.3390/cryst13071029 - 28 Jun 2023

Cited by 1 | Viewed by 1069

Abstract

In this paper, a N-rich B–N polymorph named as B₂₀N₂₄ is proposed through first-principles calculations. The stability of the B₂₀N₂₄ polymorph at ambient conditions is confirmed using the phonon dispersion spectra and the Born stability criteria. Electronic [...] Read more.

In this paper, a N-rich B–N polymorph named as B₂₀N₂₄ is proposed through first-principles calculations. The stability of the B₂₀N₂₄ polymorph at ambient conditions is confirmed using the phonon dispersion spectra and the Born stability criteria. Electronic properties calculations show that B₂₀N₂₄ exhibits a semiconducting feature, with a 0.87 eV direct band gap derived from HSE06 functions, which is much lower than many other B–N polymorphs. Specifically, owing to its cage-like framework, B₂₀N₂₄ may be used in hydrogen storage at a capacity of ~6.8 wt.%. The B₂₀N₂₄ polymorph enriches the B–N system theoretically, and this polymorph is promising for use in electronic devices and hydrogen storage. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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12 pages, 2504 KiB

Open AccessArticle

The Optimizing Effect of Nitrogen Flow Ratio on the Homoepitaxial Growth of 4H-SiC Layers

by Weilong Yuan, Yicheng Pei, Ning Guo, Yunkai Li, Xiuhai Zhang and Xingfang Liu

Crystals 2023, 13(6), 935; https://doi.org/10.3390/cryst13060935 - 10 Jun 2023

Cited by 2 | Viewed by 1553

Abstract

In this study, a 4H-SiC homoepitaxial layer was grown on a 150 mm 4° off-axis substrate using a horizontal hot-wall CVD reactor. The research aimed to investigate the impact of varying the C/Si ratio and temperature while also changing the N₂ flow [...] Read more.

In this study, a 4H-SiC homoepitaxial layer was grown on a 150 mm 4° off-axis substrate using a horizontal hot-wall CVD reactor. The research aimed to investigate the impact of varying the C/Si ratio and temperature while also changing the N₂ flow rate and N₂ flow ratio on the growth rate (thickness), doping, surface roughness, and uniformity of the large-size 4H-SiC epitaxial layer. The results indicate that the growth rate and thickness uniformity of the film increases with an increase in the C/Si ratio. Additionally, adjusting the N₂ flow rate in a timely manner based on the change in the C/Si ratio is crucial to achieving the best epitaxial layer doping concentration and uniformity. The study found that, as the temperature increases, the film thickness and thickness uniformity also increase. The maximum thickness recorded was 6.2 μm, while the minimum thickness uniformity was 1.44% at 1570 °C. Additionally, the surface roughness reached its lowest point at 0.81 nm at 1570 °C. To compensate for the difference in thickness and doping concentration caused by temperature distribution and uneven airflow, the N₂ flow ratio was altered. In particular, at a growth temperature of 1570 °C, a N₂ flow ratio of 1.78 can improve the uniformity of doping by 4.12%. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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13 pages, 31336 KiB

Open AccessArticle

Calculated Outstanding Energy-Storage Media by Aluminum-Decorated Carbon Nitride (g-C₃N₄): Elucidating the Synergistic Effects of Electronic Structure Tuning and Localized Electron Redistribution

by Peng Gao, Zonghang Liu, Jiefeng Diao, Jiaao Wang, Jiwen Li, Yuebin Tan, Guangtong Hai and Graeme Henkelman

Crystals 2023, 13(4), 655; https://doi.org/10.3390/cryst13040655 - 11 Apr 2023

Cited by 1 | Viewed by 1968

Abstract

Hydrogen, as an important clean energy source, is difficult to store and transport, which hinders its applications in real practice. Developing robust yet affordable storage media remains to be a challenge for scientists. In this study, Ab Initio Molecular Dynamics (AIMD) simulations were [...] Read more.

Hydrogen, as an important clean energy source, is difficult to store and transport, which hinders its applications in real practice. Developing robust yet affordable storage media remains to be a challenge for scientists. In this study, Ab Initio Molecular Dynamics (AIMD) simulations were employed to evaluate the performance of aluminum (Al) decorated carbon nitride (g-C₃N₄, heptazine structure) in hydrogen storage; and a benchmarking study with Mg-doped g-C₃N₄ was also performed to provide theoretical insights for future study. We found that each 2 × 2 supercell can accommodate four Al atoms, and that partial charge from single Al sites can be transferred to adjacent nitrogen atoms of g-C₃N₄. These isolated Al sites tend to be electronically positive charged, serving as active sites for H₂ adsorption, predominately by triggering enhanced electrostatic interactions. The H₂ molecules are adsorbed by both Al and N atoms, and are easily polarized, giving rise to electrostatic interactions between the gas molecules and the surface. Effective adsorption sites were determined by electronic potential distribution maps of the optimized configurations. Each 2 × 2 supercell can adsorb up to 36 H₂ molecules, and the corresponding adsorption energies are within the range of −0.10 to −0.26 eV. The H₂ storage capacity of the Al-decorated g-C₃N₄ is 7.86 wt%, which surpasses the goal of 5.5 wt%, set by the US department of energy. This proposed Al-decorated g-C₃N₄ material is therefore predicted to be efficient for hydrogen storage. This work may offer some fundamental understandings from the aspect of electronic sharing paradigm of the origin of the excellent hydrogen storage performance by metal decorated 2D materials, acting as an demonstration for guiding single metal atom site-based materials’ designing and synthesis. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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13 pages, 1791 KiB

Open AccessArticle

Investigation of the Temperature Dependence of Volt-Ampere Characteristics of a Thin-Film Si₃N₄ Memristor

by Dmitry Mizginov, Oleg Telminov, Sergey Yanovich, Dmitry Zhevnenko, Fedor Meshchaninov and Evgeny Gornev

Crystals 2023, 13(2), 323; https://doi.org/10.3390/cryst13020323 - 15 Feb 2023

Cited by 1 | Viewed by 1859

Abstract

The compatibility of memristor materials with advanced complementary metal-oxide-semiconductor (CMOS) technology is a key factor for microelectronics element base manufacturing. Therefore, we continued studying previously fabricated CMOS-compatible Ni/Si₃N₄/SiO₂/p+-Si samples. We approximated volt-ampere characteristics (VAC) at different temperatures [...] Read more.

The compatibility of memristor materials with advanced complementary metal-oxide-semiconductor (CMOS) technology is a key factor for microelectronics element base manufacturing. Therefore, we continued studying previously fabricated CMOS-compatible Ni/Si₃N₄/SiO₂/p+-Si samples. We approximated volt-ampere characteristics (VAC) at different temperatures using the general form of the spatial charge-limiting current (SCLC) equation assuming exponential and Gaussian trap distribution within the band gap of Si₃N₄. Our approximation demonstrated better experimental data matching compared to previous work, where the approximation was based on the uniform trap distribution law. Further, we performed another additional sample measurement set of the samples to evaluate the parameters of the low-resistance state (LRS) variations at different temperatures. Analysis of these measurements allowed us to estimate the temperatures at which the samples will retain LRS for 10 years. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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9 pages, 2748 KiB

Open AccessArticle

Study of the Bonding Characteristics at β-Ga₂O₃(201)/4H-SiC(0001) Interfaces from First Principles and Experiment

by Bei Xu, Jichao Hu, Jiaqi Meng, Xiaomin He, Xi Wang and Hongbin Pu

Crystals 2023, 13(2), 160; https://doi.org/10.3390/cryst13020160 - 17 Jan 2023

Cited by 4 | Viewed by 1994

Abstract

For the first time, β-Ga₂O₃ were prepared on 4H-SiC (0001) substrates using a low-pressure chemical vapor deposition (LPCVD) technique. The obtained β-Ga₂O₃/4H-SiC heterostructures display strongly preferential growth orientation along the <201> of β-Ga₂ [...] Read more.

For the first time, β-Ga₂O₃ were prepared on 4H-SiC (0001) substrates using a low-pressure chemical vapor deposition (LPCVD) technique. The obtained β-Ga₂O₃/4H-SiC heterostructures display strongly preferential growth orientation along the <201> of β-Ga₂O₃. Combining the experimental results, interfacial properties, such as the work of adhesion (Wad), electronic properties and bonding characteristics of β-Ga₂O₃(201)/4H-SiC(0001) heterointerface were systemically studied using first principles. Four different β-Ga₂O₃(201)/4H-SiC(0001) interface models composed of different atom stacking sequences were established. It was found that the interface consisting of silicon terminated of 4H-SiC (0001), and oxygen terminated of β-Ga₂O₃(201) (Si-O) has the lowest relaxation energy and the highest stability. Results indicated that the binding of interface Si and C to the O atoms is stronger than that to the Ga atoms. The results of the difference charge density and electron localization function reveals that the Si and C atoms at interface are bonded with O atoms of β-Ga₂O₃ by covalent bonds, in which Si-O and C-O covalent bonds play a favorable role in the final stable configurations formation. This work will provide a further understanding of the various electronic behaviors of the β-Ga₂O₃(201)/4H-SiC(0001) heterointerface. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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14 pages, 4112 KiB

Open AccessArticle

Diameter Prediction of Silicon Ingots in the Czochralski Process Based on a Hybrid Deep Learning Model

by Xiaoguo Zhao, Ding Liu and Xiaomei Yan

Crystals 2023, 13(1), 36; https://doi.org/10.3390/cryst13010036 - 25 Dec 2022

Cited by 2 | Viewed by 2757

Abstract

The diameter prediction of silicon ingots in the Czochralski process is a complex problem because the process is highly nonlinear, time-varying, and time-delay. To address this problem, this paper presents a novel hybrid deep learning model, which combines the deep belief network (DBN), [...] Read more.

The diameter prediction of silicon ingots in the Czochralski process is a complex problem because the process is highly nonlinear, time-varying, and time-delay. To address this problem, this paper presents a novel hybrid deep learning model, which combines the deep belief network (DBN), support vector regression (SVR), and the ant lion optimizer (ALO). Continuous restricted Boltzmann machines (CRBMs) are used in DBN for working with continuous industrial data. The feature aggregates the outputs from various DBNs through an SVR model. Additionally, the ALO algorithm is used for the parameter’s optimization of SVR. The newly developed model is verified with the actual production data and compared with the back propagation neural network (BPNN) and the SVR model. The simulation results demonstrate the availability and accuracy of the CRBM-DBN-ALO-SVR hybrid deep learning model. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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17 pages, 7473 KiB

Open AccessArticle

Cl-Doped CdTe Crystal Growth for Medical Imaging Applications

by Rubi Gul, John Stuart McCloy, Magesh Murugesan, Benjamin Montag and Jasdeep Singh

Crystals 2022, 12(10), 1365; https://doi.org/10.3390/cryst12101365 - 27 Sep 2022

Cited by 2 | Viewed by 1945

Abstract

CdTe:Cl doped single crystals were grown under conditions of tellurium excess by using an accelerated crucible rotation technique, modified vertical Bridgman (ACRT-MVB) method. Chlorine dopant levels were kept at 4.4 × 10¹⁹ at·cm⁻³, for all growths, while the Te excess [...] Read more.

CdTe:Cl doped single crystals were grown under conditions of tellurium excess by using an accelerated crucible rotation technique, modified vertical Bridgman (ACRT-MVB) method. Chlorine dopant levels were kept at 4.4 × 10¹⁹ at·cm⁻³, for all growths, while the Te excess level varied from 3.5 to 15% by weight. The relationship between the detector performance, Te inclusions, and resistivity was investigated in detail. Tellurium excess caused additional nucleation which decreased the average single crystal grain size. At the same time, the increasing Te excess level improved the electrical transport properties. In the three Cl-doped, and one In-doped CdTe crystals, detectors from Cl-doped CdTe grown under 15% Te excess showed better response to gammas and alphas, and high µτ for electrons (1.8 × 10⁻³ cm²/V), as well as for holes (5.1 × 10⁻⁴ cm²/V). The full-width half maximum for the Cl-doped CdTe were very large, as the peaks were broadened, especially at high bias. This could be due to hole trapping in a Cl-related A-center (V_Cd-Cl_Te)⁻, and in Cd- vacancies (V_Cd)⁻, and electron trapping in Te-antisites (Te_Cd)⁺. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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13 pages, 3791 KiB

Open AccessArticle

A Cost-Effective Long-Wave Infrared Detector Material Based on Graphene@PtSe₂/HfSe₂ Bidirectional Heterostructure: A First-Principles Study

by Jianzhi Zhang, Hongfu Huang, Junhao Peng, Chuyu Li, Huafeng Dong, Sifan Kong, Yiyuan Xie, Runqian Wu, Minru Wen and Fugen Wu

Crystals 2022, 12(9), 1244; https://doi.org/10.3390/cryst12091244 - 2 Sep 2022

Viewed by 1980

Abstract

The Graphene@PtSe₂ heterostructure is an excellent long-wave infrared detection material. However, the expensive cost of PtSe₂ prevents its widespread use in infrared detection. In this paper, Hf was used to partially replace Pt to form Graphene@(PtSe₂)_n(HfSe₂ [...] Read more.

The Graphene@PtSe₂ heterostructure is an excellent long-wave infrared detection material. However, the expensive cost of PtSe₂ prevents its widespread use in infrared detection. In this paper, Hf was used to partially replace Pt to form Graphene@(PtSe₂)_n(HfSe₂)_4−n (n = 1, 2, and 3) bidirectional heterostructures consisting of graphene and lateral PtSe₂/HfSe₂ composites based on first-principles calculations. Then, the new bidirectional heterostructures were compared with heterostructures formed by graphene with pure MSe₂ (M = Pt, Hf). It was found that the band gaps of the bidirectional heterostructures were between those of Graphene@PtSe₂ and Graphene@HfSe₂. Among these heterostructures, the Graphene@(PtSe₂)₃(HfSe₂)₁ bidirectional heterostructure has almost the same optical absorption properties in the infrared wavelength region of 1.33~40 µm as the Graphene@PtSe₂ heterostructure, and it improves the absorption in the near-infrared wavelength region of 0.75~1.33 µm. Such a designment may bring the material costs down (since PtSe₂ costs approximately five times more than HfSe₂). This study on the designment of the bidirectional Graphene@(PtSe₂)₃(HfSe₂)₁ heterostructure also illustrates a cost-effective design method for Pt-based IR detectors. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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9 pages, 2667 KiB

Open AccessArticle

Investigation on Step-Bunched Homoepitaxial Layers Grown on On-Axis 4H-SiC Substrates via Molten KOH Etching

by Jiulong Wang, Siqi Zhao, Guoguo Yan, Zhanwei Shen, Wanshun Zhao, Lei Wang and Xingfang Liu

Crystals 2022, 12(6), 788; https://doi.org/10.3390/cryst12060788 - 30 May 2022

Cited by 4 | Viewed by 2660

Abstract

Wafer-scale on-axis 4H-SiC epitaxial layers with very low roughness were obtained in this study. By performing carbon-rich hydrogen etching and epitaxial growth of the epitaxial layer at different temperatures, local mirror regions (LMRs) with root mean square (RMS) roughness less than 0.2 nm [...] Read more.

Wafer-scale on-axis 4H-SiC epitaxial layers with very low roughness were obtained in this study. By performing carbon-rich hydrogen etching and epitaxial growth of the epitaxial layer at different temperatures, local mirror regions (LMRs) with root mean square (RMS) roughness less than 0.2 nm were obtained on the epitaxial layer surface. The LMRs’ length is tens of millimeters, and the width is sub-millimeters. The step-flow growth induced by threading screw dislocations (TSDs) was observed on the epitaxial layer surface by atomic force microscopy (AFM), together with the double bi-atomic step-flow growth induced by the step bunch, which was the cause of LMRs. Furthermore, the growth mechanism was investigated by wet etching. The etching pits were found to be associated with 3C-SiC and their effect on the growth rate of epitaxial layers was further explored. Full article

(This article belongs to the Special Issue Semiconductor Materials and Devices)

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