Influence of Substrate Surface Polarity on Epitaxial Layer Growth of CuInSe2 on GaAs

CuInSe₂ thin films with thicknesses of about 0.1 μm were deposited onto (III) B-oriented GaAs substrates by flash evaporation. At substrate temperatures T_sub = 695–820 K the films have the chalcopprite structure with some admixture of the cubic sphalerite phase. At T_sub > 820 K only the sphalerite phase was found All the films are partly polycrystalline. From the electrical properties it follows that the films are characterized by nearly complete compensation at T_sub = 695–820 K. At T_sub = 870 K the films are p-type conducting and show two acceptor states with ionization energies of about 8 meV and 105 meV.     

SiC衬底上生长的GaN外延层的高分辨X射线衍射分析

通过高分辨X射线衍射(HRXRD)技术,对金属有机化合物气相外延(MOCVD)生长的GaN外延膜及SiC衬底的相对取向,晶格常数和应力情况,位错密度等进行了分析.分析表明,GaN和SiC具有一致的a轴取向,GaN外延层弛豫度超过90;,GaN外延层的晶格常数与体块材料相近,在GaN中存在压应力,SiC衬底和GaN外延层中的位错密度分别为107和108量级.     

Growth and Characterization of Direct-connecting AlGaAs/GaAs TJS Light Emitting Device on SI GaAs Substrate by LPE

High output power (above 3 mW/facet) AlGaAs/GaAs Transverse-Junction Stripe light emitting diodes have been grown on Semi-Insulating (100) GaAs substrates by Liquid Phase Epitaxy. these light emitting diodes utilize a “Direct-connecting” transverse-junction stripe structure, which can confine the transverse-current and reduce the series resistance. By thinning the thickness of the “effective active-layer” of this structure, a room-temperature pulsed lasing operation is also achieved with a threshold current as low as 35 mA and a peak wavelength around 904 nm. This “Direct-connecting” transverse-Junction Stripe light emitting device with a Metal-Semiconductor Field Effect Transistor on an electrical isolated semi-insulating substrate in the future.     

Liquid Phase Epitaxy of AlGaInP on GaAs Substrate Using AlGaAs Buffer Layer

Liquid phase epitaxial layers of AlGaInP were successfully grown on Al_0.9Ga_0.1 As buffer layer with varying aluminum melt composition. Epitaxial layers were characterised by using a scanning elelctron microscope, X-ray diffraction, photoluminescence (PL) and Auger depth profile measurements. The shortest peak wavelength of PL spectra obtained in the samples was 630 nm at room temperature. It was found that the thickness of the AlGaInP layer is very small due to rapid change of aluminum in the melt composition.     

The Energy State of Epitaxial Layers in a Multilayer Heterostructure,Grown on a (001)GaAs Substrate

Crystallography Reports - It is shown based on the structural analysis by reciprocal space mapping and the experimental secondary ion mass spectrometry and transmission electron microscopy data...     

Epitaxial layers of CuGaTe2 on GaAs

CuGaTe₂ thin films with thicknesses in the range from 0.1 to 0.2 μm were deposited onto semi-insulating (111) A-oriented GaAs substrates by flash evaporation under controlled growth conditions. Epitaxial growth begins at a substrate temperature of T_sub = 695 K. In the range T_sub = 695 … 820 K the films have the chalcopyrite structure, at T_sub = 820 to 840 K a second phase was observed besides the chalcopyrite phase. At T_sub > 840 K the films become polycrystalline. All epitaxial films were p-type conducting and showed an increase of the hole concentration with rising substrate temperature. The measured mobilities indicate to the presence of a high concentration of neutral impurities or defects.     

A Method of Determining the Liquid Phase Epitaxial GaAs Growth Mechanism Based on Growth Rate Measurements

It has been proved that the dependence of the growth rate V of a LPE GaAs layer on the relative supersaturation σ of the solution at the interphase boundary can be determined on the basis of growth rate measurements of this layer in the case when crystallization is controlled by the kinetics of surface processes. The relation V = f(σ) obtained for homoepitaxial GaAs layers grown at different solution cooling rates are compared with the theoretical relations derived by BRICE making use of a single growth mechanism assumption. Based on the above and by use of the experimental data of MUSZYńSKI the growth mechanism of homoepitaxial GaAs layers on a substrate oriented in the [100] direction is determined. The results are in accordance with the crystallization model of A^IIIB^V semiconductor compounds from the liquid phase proposed by FAUST and JOHN .     

Epitaxial layers of CuInTe2 on GaAs

CuInTe₂ thin films were deposited onto semi-insulating (111)A-oriented GaAs substrates by flash evaporation. Epitaxial growth was found in the substrate temperature range T_sub = 620 … 790 K. Above 750 K a second phase was found besides the chalcopyrite phase. All epitaxial films were p-type conducting and showed an increase of the hole concentration with rising substrate temperature above T_sub = 720 K. Three acceptor states with ionization energies of 350 … 500 meV, 135 … 150 meV, and of some 10⁻³ eV were found.     

ZnO纳米棒在Si衬底上外延生长研究

运用热蒸发ZnO粉末法,以金做催化剂,分别在Si(100)和Si(111)两种基片上外延生长了ZnO纳米棒(样品分别标为1#和2#).通过X射线衍射(XRD)和扫描电子显微镜(SEM)分析,结合ZnO与Si的晶格结构特征,从理论上得出了两个样品的晶格匹配关系.1#样品:[0001]ZnO∥[114]Si,[0001]ZnO∥[1-1-4]Si,[0001]ZnO∥[11-4]Si,[0001]ZnO∥[1-14]Si,失配度为1.54;;2#样品:[0001]ZnO∥[111]Si,[21-1-0]ZnO∥[11-0]Si,[1-21-0]ZnO∥[1-01]Si ,[1-1-20]ZnO∥[011-]Si,失配度为18.12;.研究表明Si衬底对ZnO纳米棒生长方向具有调控作用.     

Epitaxial Mechanism of Diamond Crystal Nucleation on a Mo {110} Substrate during Chemical Vapor Deposition

Crystallography Reports - The epitaxial mechanism of diamond crystal nucleation by the (110) face on the Mo(110) face during chemical vapor deposition on a molybdenum plate has been established. It...     

Electron Microscopy Study of Surface Islands in Epitaxial Ge3Sb2Te6 Layer Grown on a Silicon Substrate

Crystallography Reports - Islands in the form of truncated triangular pyramids on the surface of an epitaxial Ge3Sb2Te6 layer grown on a Si(111) substrate are identified by scanning electron...     

Erratum to: Electron Microscopy Study of Surface Islands in Epitaxial Ge3Sb2Te6 Layer Grown on a Silicon Substrate

Crystallography Reports - An Erratum to this paper has been published: https://doi.org/10.1134/S1063774521330014     

The Back-Side Morphology of LPE-Grown AlGaAs/GaAs/AlGaAs Heterostructures after the Complete Removal of the GaAs Substrate by Selective Etching

As-grown surfaces of AlGaAs/GaAs/AlGaAs heterostructures were stuck down the glass disks and after that the GaAs substrates were removed completely by selective chemical etching. As a result the back-surface of the heterostructures became open to light. The influence of different factors on the back-surface planarity and on the density of such specific defects as holes in the GaAs layer have been investigated. It is shown that the density of holes can be decreased to a value less than 1 hole/cm² if a glove-box maintained under a pure N₂ atmosphere and connected with LPE installation is used.     

100 mm GaAs PHEMT外延材料生长稳定性控制研究

研究了100 mm GaAs赝配高电子迁移率晶体管(PHEMT)外延材料量产的稳定性控制.通过选择控制参数和控制周期,提高了外延材料性能的重复性和稳定性.12个样品方阻的标准差为0.53;,全部偏差1.66;.通过优化生长工艺有效的降低了样品表面颗粒,样品表面颗粒数量减小到612/片,这些参数均达到或超过国外主流外延厂商水平.     

A combined carbon and oxygen segregation model for the LEC growth of SI GaAs

The segregation behavior of carbon during the GaAs LEC process is described by a combined carbon and oxygen transport model. For this attempt the well-known Scheil formalism was extended by consideration of the incorporation and extraction of carbon via CO transport through the encapsulating boron oxide. The influence of the changing oxygen potential was included in order to describe the experimental data, especially for low carbon levels. The model is helpful for the adjustment of growth parameters relevant for carbon doping in order to achieve a homogeneous carbon distribution at any specified level.     

不同衬底温度下ZnO外延薄膜的结构及光学特性分析

采用螺旋波等离子体辅助射频溅射沉积技术在Al2O3(0001)衬底上沉积ZnO外延薄膜,通过对其结构及光学性质的分析,探讨了衬底温度对薄膜生长特性的影响.实验结果表明,由于等离子体对反应气体的活化及载能粒子对表面反应的辅助作用,采用该等离子体辅助溅射技术能够在较低的衬底温度下实现较高质量的ZnO薄膜外延生长,然而,较高的衬底温度所引起的表面反应不利于薄膜中的氧空位及锌填隙等缺陷的减少,这将限制薄膜的外延质量及光学特性的进一步提高.     

三维生长温度对非故意掺杂GaN外延层性能的影响

利用金属有机化学气相沉积(MOCVD)技术在蓝宝石(0001)面上生长GaN外延层,并系统研究了三维生长温度对外延层晶体质量和残余应力的影响机理.利用高分辨X射线衍射仪(HRXRD)、原子力显微镜(AFM)、光致发光光谱仪(PL)和拉曼光谱仪(Raman)分别对外延层的位错密度、表面形貌、发光性能和应力情况进行了分析.当三维生长温度分别为1060℃、1070℃和1080℃时,外延层刃位错密度分别为5.09×108/cm3、3.58×108/cm3和5.56×108/cm3,呈现先减小后增大的现象,而螺位错密度变化不显著,分别为1.06×108/cm3、0.98×108/cm3和1.01×108/cm3,同时外延层残余应力分别为0.86 GPa、0.81 GPa和0.65 GPa,呈现逐渐减小的趋势.这可能是由于三维生长温度不同时,外延层生长模式和弛豫程度发生改变所致.     

在蓝宝石衬底上外延生长ZnGa2O4纳米线及其表征

使用一种简单的化学气相沉积法成功地在c面蓝宝石衬底上外延生长了整齐排列的ZnGa2O4单晶纳米线.研究了在不同生长温度和生长压力下外延生长ZnGa2O4纳米线,并使用XRD,SEM和TEM对产物进行了表征.结果 表明,在生长条件为980℃和100 Torr时,可以外延生长出整齐排列的ZnGa2O4纳米线.所制备的ZnGa2O4纳米线直径为60 ～ 150 nm,并遵循Au催化的VLS生长机制沿其四个结晶学方向在蓝宝石上外延生长.分析了纳米线沿四个方向生长的原因,并对纳米线的光致发光性能进行了探讨.     

成核层温度对非掺杂GaN外延薄膜结晶质量的影响

利用金属有机化学气相沉积系统(MOCVD),在蓝宝石的(0001)面采用不同的成核层生长温度,通过两步法获得不同质量的GaN外延薄膜.利用HALL测试仪,高分辨X射线衍射仪(HRXRD),原子力显微镜(AFM)和光致发光光谱仪(PL)对GaN薄膜的表面形貌,位错密度,光学性能等进行表征,研究不同的成核温度对GaN外延薄膜晶体质量的影响.结果表明,在成核层生长温度为650℃时,所得到的GaN外延薄膜表面粗糙度和位错密度均达到最低,并且同时具有最高的带边发光峰强度,最高的载流子迁移率以及最低的载流子浓度.过低或过高的成核温度都会导致GaN外延层的晶体质量和光电性能变差.