Epitaxy and Growth Mechanism of Gallium Antimonide by MOCVD

GaSb epilayers were grown on GaAs and/or GaSb substrates by MOCVD respectively.The influenceof growth conditions on the properties of the epilayers was studied in order to improve the growth pro-cesses.The growth mechanism of MOCVD GaSb was investigated.An equation derived for chemical reac-tion controlled growth rate of MOCVD GaSb was verified by the experiments.The typical FWHM of doub-le crystal X-ray diffraction(DCXD)spectra of GaSb epilayers on GaSb and/or GaAs substrates are 20arcsec and 150 arcsec,respectively.The 300 K hole concentration of p=1.2×10~(16)cm~(-3) with Hall mobilityof 898 cm~2/V·s is obtained.     

金属有机物化学气相沉积法制备铱涂层的形貌与结构分析

采用金属有机物化学气相沉积法，在不通入活性气体的条件下，研究了三乙酰丙酮铱先驱体挥发温度对铱涂层显微结构的影响。在500℃的金属铌和陶瓷石英基片上制备出亮银白色的多晶相铱涂层。分析表明：铌和石英基片上沉积的铱涂层均由两层不同结构的薄膜构成，220℃挥发先驱体沉积出由纳米级颗粒疏松堆积构成的涂层，185℃挥发先驱体沉积出致密的涂层。铱涂层表面光滑均匀，无明显缺陷。     

Growth of MgO Thin Film on Silicon Substrate by MOCVD

Highly oriented MgO(111)and MgO(100)thin films have been deposited on Si(111)and Si(100)substratesby using Low Pressure MOCVD(LPMOCVD).Magnesium 2,4-pentanedionate was used as the source ma-terial.The films have a very smooth surface morphology and optical transparency with an index of refractionof 1.71(632.8 nm).Typical growth rate of the films is 1.0 μm/h.The data of X-ray diffraction analysis indi-cate that the films are fully textured with(111)and(100)orientation perpendicular to the substrate surfacerespectively.The main parameters having influence on the deposition are the substrate temperature,the totalpressure in the reaction chamber,the reaction gases and its flowrate.     

MOCVD制备的Pt/C薄膜的结构与性能研究

以乙酰丙酮铂为前驱体,采用金属有机化合物化学气相沉积(MOCVD)法在石英及YSZ基体上制备Pt/C薄膜,研究了Pt/C薄膜的结构和电化学性能.沉积过程中通入一定量的氧气可以大幅降低Pt/C薄膜中的含C量,含C较高的Pt/C薄膜的XRD谱线低而宽,具有非晶态衍射特征.在500℃测量温度下,以Pt/C薄膜为电极的YSZ氧气浓差电池的电动势及电流输出高于传统的Pt电极.     

MOCVD Growth of Doped GaAs/AlGaAs Quantum Heterostructures

The influences of growth techniques of AP-MOCVD GaAs/AlGaAs silicon-doped multi-quantum wells(MQWs), heterostructure bipolar transistors (HBTs), double barrier resonant tunneling diodes(DBRTDs) ontheir structures and performances were studied. Continuously grown MQWs, that is, no growth interruption atthe heterointerfaces, shown blue-shifted, narrower and stronger photoluminescence(PL) compared withinterruptedly grown ones.TEM examination of the interrupted interfaces revealed a bright line correspondingto the compositional fluctuation and impurity adsorption, and indicated noncommutative structures ofAlGaAs/GaAs and GaAs/AlGaAs interfaces. High performance HBTs and DBRTDs were obtained bycontinuously grown method while growth interruption caused performance degradation. It was concluded thatgrowth interruption may cause accumulation of residua1 impurities in the ambient as well as compositionalfluctuation while continuous growth at very low growth rates can overcome such problems.     

Growth Kinetic Studies for MOCVD CdTe and HgCdTe Epilayers on GaAs Substrates

The growth rates of CdTe and CMT on GaAs and on CdTe / GaAs substrates were studied as a functionof temperature and gas composition. A Langmuir-Hinshelwood Model for surface reaction control region issuggested. The CdTe/GaAs interface was examined by X-ray double crystal diffraction, laser Ramanspectroscopy and transmission electron microscopy (TEM). A defect layer was observed at CdTe / GaAs inter-face. The relationship between interface qualities and electrical properties of CMT overlayers was discussed.     

用MOCVD法生长GaN基自组装量子点的相关实验及其分析

GaN基相关材料的量子点生长是半导体材料研究的一个热点，尤其是用MOCVD方法生长GaN基自组装量子点占了相当的比例，因此相关的文献较多，但综述性文章却不多见。鉴于此，本文综述了用MOCVD法制备GaN基量子点的不同实验方法，并对影响量子点牛长的实验条件和参数做了简要的分析。希望能够对相关的实验研究工作提供一些参考。     

铱薄膜的MOCVD沉积效果研究

以乙酰丙酮铱为前驱体,采用金属有机化合物化学气相沉积(MOCVD)技术在Mo基体上制备Ir薄膜。研究Ir的沉积效果与沉积温度及反应气体(O2)间的关系。Ir薄膜的沉积速率与沉积温度之间的关系不符合Arrhenius方程,沉积速率与沉积温度绝对温度的倒数呈抛物线关系,当温度为750℃时,Ir的沉积速率达到最大值,沉积温度对Ir薄膜的显微形貌有显著影响;O2的流量对薄膜的成分、形貌及结构等均有显著影响。     

MOCVD生长GaN力学性能研究

采用MOCVD技术在蓝宝石衬底（0001）面上生长了GaN外延膜，利用原子力显微镜AFM、扫描电镜SEM分析了薄膜表面形貌，利用纳米压痕仪和UMT试验机考察了GaN膜的硬度、临界载荷以及摩擦学性能等。结果表明，薄膜以二维模式均匀生长，表面平整，硬度达22．1MPa，弹性模量为299．5GPa，与衬底结合紧密，临界载荷达1．6N，与GCr15钢球对磨时摩擦系数仅为0．13，与Si3N4陶瓷球摩擦时膜很快就磨穿。     

Preparation of TiO_2 Film Deposited by MOCVD and Quality of Film Measured by Impedance Method

ＰｒｅｐａｒａｔｉｏｎｏｆＴｉＯ＿２ＦｉｌｍＤｅｐｏｓｉｔｅｄｂｙＭＯＣＶＤａｎｄＱｕａｌｉｔｙｏｆＦｉｌｍＭｅａｓｕｒｅｄｂｙＩｍｐｅｄａｎｃｅＭｅｔｈｏｄＣｈｅｎＹａｎｓｈｅｎｇａｎｄＤｕａｎＳｈｕｚｈｅｎ（陈燕生）（段淑贞）Ｕｎｉｖｅｒｓｉｔｙ...     

MOCVD Growth of GaAs / Al_xGa_(1-x) As Superlattices

ＭＯＣＶＤＧｒｏｗｔｈｏｆＧａＡｓ／Ａｌ＿ｘＧａ＿（１－ｘ）ＡｓＳｕｐｅｒｌａｔｔｉｃｅｓＸｕＸｉａｎ＇ｇａｎｇ；ＨｕａｎｇＢａｉｂｉａｏ；ＲｅｎＨｏｎｇｗｅｎ；ＬｉｕＳｈｉｗｅｎａｎｄＪｉａｎｇＭｉｎｈｕａ（徐现刚）（黄柏标）（任红文）（刘士文）（...     

Preparation of Ga_(1-x)In_xAs_(1-y)Sb_y by MOCVD

The GalnAsSb quaternary alloys for 2～4 μm long wavelength optoelectronics have been prepared byMOCVD.The growth of buffer layers and the employment of GaSb/GaAs and GaSb/GaSb hybridsubstrates are mentioned,which effectively improve the properties of GalnAsSb epilayers.In order to controlthe epitaxial growth of GaSb and GalnAsSb,emphasis is given on the deposition rates,growth temperaturesand the relationship between growth conditions and the distribution coefficients of In and Sb.The experimen-tal solid compositions in this work are predicted by the thermodynamic calculations.Whether the growth ofGalnAsSb epilayers is controlled by chemical reactions or by mass diffusions depends on growth temperatures.This argument is verified by kinetic considerations.The FWHMs of the DCXD (double crystal X-raydiffraction)spectra of GalnAsSb epilayers grown on GaSb/GaSb and GaSb/GaAs hybrid substrates areabout 200～300 arcsec and 800 arcsec respectively.The unintentionally doped GalnAsSb epilayers have themobilities of μp=100～240 cm~2/V·s at 300 K.The corresponding wavelength ofMOCVD GaInAsSb alloysis calculated from EPMA(electronic probe microanalysis)data and determined by FTIR(Fourier transformedinfrared spectroscopy)measurement.     

Investigation of niobium nitride and oxy-nitride films grown by MOCVD

Niobium nitride (NbN) and niobium oxy-nitride (NbO_xN_y) thin films were grown by metalorganic chemical vapor deposition (MOCVD) on Si(100) and Si(111) substrates using [Nb(N^tBu)(NMe₂){C(NⁱPr)₂(NMe₂)}₂] [NB; ^tBu = (CH₃)₃C; Me = CH₃; ⁱPr = (CH₃)₂CH] as a simultaneous Nb and N precursor. While NbN films were synthesized under a pure N₂ atmosphere, NbO_xN_y films were synthesized under N₂-O₂ flow (N₂:O₂ = 1-5) in the temperature range 400-600 °C, as well as by NbN deposition followed by ex-situ thermal treatments under flowing O₂ at 400-600 °C. The samples were subjected to a multi-technique characterization in order to elucidate the interplay between their structure, morphology and composition and the adopted processing parameters. Particular attention was devoted to the presence of Nb-N and Nb-O-N phases and their distribution in the films, as well as to surface oxidation phenomena. For the first time, niobium oxy-nitride coatings were obtained by CVD starting from the above precursor compound, with growth rates up to 270 Å/min on Si(111) at 600 °C. The films were characterized by a columnar-like/globular morphology when supported on Si(100)/Si(111) and revealed a higher crystallinity on the latter substrate. Surface and in-depth compositional analyses evidenced a limited carbon contamination and the Co-existence of niobium nitride, NbON and Nb₂O₅. In particular, the presence of the latter in the outermost sample layers was explained by oxidation phenomena occurring upon contact with the outer atmosphere.     

Growth of Ga_xIn_（1－x）Sb Alloys by MOCVD—Solid Composition Surface Morphology and Electrical Propert

ＧｒｏｗｔｈＯｆＧａ＿ｘＩｎ＿（１－ｘ）ＳｂＡｌｌｏｙｓｂｙＭＯＣＶＤ—ＳｏｌｉｄＣｏｍｐｏｓｉｔｉｏｎＳｕｒｆａｃｅＭｏｒｐｈｏｌｏｇｙａｎｄＥｌｅｃｔｒｉｃａｌＰｒｏｐｅｒｔｉｅｓＺｈａｎｇＢａｏｆｉｎ，ＺｈｏｕＴｉａｎｍｉｎｇ，ＪｉａｎｇＨｏｎ...     

Homo-and Hetero-epitaxial GaSb Layers by MOCVD

Metalorganic chemical vapor deposition(MOCVD) growth of homo-and hetero-epitaxial GaSb has beeninvestigated,by using trimethylgallium(TMGa)and trimetbylantimony(TMSb)as source materials on n-typeGaSb and semi-insulating GaAs substrates.The influence of Ⅲ/Ⅴ ratio on the growth of GaSb was studiedin detail and it was found that the Ⅲ/Ⅴ ratio range proper for good quality epi-layers is narrow.The carriermobility and concentration of undoped GaSb epi-layers are about 600 cm~2/Ⅴ·s and 2～4×10~(16)cm~(-3)atroom temperature,respectively.The low temperature(77K)mobility is about 5 times of the roomtemperature's one.The low temperature(11K)photoluminescence(PL)spectrum and the temperature depen-dence of PL spectrum were investigated.The red shift of bound exciton with temperature was observed.     

Preliminary Study on Electrical and Optical Properties of ZnO Film Grown by MOCVD

1 ＩｎｔｒｏｄｕｃｔｉｏｎＺｎＯｉｓａｗｉｄｅ ｇａｐ ( 3.2ｅＶａｔｒｏｏｍｔｅｍｐｅｒａｔｕｒｅ)ｓｅｍｉｃｏｎｄｕｃｔｏｒｍａｔｅｒｉａｌｈａｖｉｎｇｔｈｅｗｕｒｔｚｉｔｅｓｔｒｕｃｔｕｒｅｗｉｔｈｄｉｒｅｃｔｅｎｅｒｇｙｂａｎｄ .Ｉｔｈａｓｂｅｅｎｃｏｎｓｉｄｅｒｅｄａｓａｐｒｏｍｉｓ ｉｎｇｍａｔｅｒｉａｌｆｏｒｏｐｔｏｅｌｅｃｔｒｏｎｉｃｄｅｖｉｃｅｓｉｎｔｈｅｎｅａｒｕｌｔｒａｖｉｏｌｅｔ(ＵＶ)ａｎｄｂｌｕｅｓｐｅｃ ｔｒａ .ＡｎｉｎｔｅｒｅｓｔｉｎｇｆｅａｔｕｒｅｏｆＺｎＯｉｓｉｔｓｌ…     

Growth and Characterization of AlInAs on InP Substrate by Molecular Beam Epitaxy

ＧｒｏｗｔｈａｎｄＣｈａｒａｃｔｅｒｉｚａｔｉｏｎｏｆＡｌＩｎＡｓｏｎＩｎＰＳｕｂｓｔｒａｔｅｂｙＭｏｌｅｃｕｌａｒＢｅａｍＥｐｉｔａｘｙＣｈｅｎＪｉａｎｘｉｎ；ＬｉＡｉｚｈｅｎａｎｄＱｉｕＪｉａｎｈｕａ（陈建新）（李爱珍）（邱建华）（Ｓｈａｎｇｈａ...     

MOCVD Growth of Quaternary Ga_xIn_(1-x)As_(1-y)Sb_yAlloys:Solid Composition

ＭＯＣＶＤＧｒｏｗｔｈｏｆＱｕａｔｅｒｎａｒｙＧａｘＩｎ１－ｘＡｓ１－ｙＳｂｙＡｌｏｙｓ：ＳｏｌｉｄＣｏｍｐｏｓｉｔｉｏｎＺｈａｎｇＢａｏｌｉｎ，ＪｉｎＹｉｘｉｎ，ＺｈｏｕＴｉａｎｍｉｎｇ，ＮｉｎｇＹｏｎｇｑｉａｎｇ（张宝林）（金亿鑫）（周天明）（宁永强）ＪｉａｎｇＨｏｎｇａｎｄＬｉＳｈｕｗｅｉ（蒋红）（李树纬）ＣｈａｎｇｃｈｕｎＩｎｓｔｉｔｕｔｅｏｆＰｈｙｓｉｃｓ，ＣｈｉｎｅｓｅＡｃａｄｅｍｙｏｆＳｃｉｅｎｃｅｓ，Ｃｈａｎｇｃｈｕｎ，１３００２１，ＣｈｉｎａＲｅｃｅｉｖｅｄ２５Ｊｕｌｙ１９９…     

MOCVD法制备钯膜用的前驱体研究现状

金属钯薄膜作为一种新型的稀贵金属低维材料,因为其优异的物理和化学性能,在耐高温涂层、微电子、膜反应器、催化等领域有着非常重要的应用。钯薄膜优异的性能及广阔的应用前景引起人们广泛的关注。介绍了金属有机化学气相沉积(MOCVD)法制备钯膜用前驱体的研究进展以及MOCVD工艺中各类前驱体的优缺点,概述了其目前研究的热点和进一步研究的方向。     

Morphological, structural, and mechanical characterizations of InGaN thin films deposited by MOCVD

Presented in this study are surface roughness, crystalline structure, and nanomechanical properties of InGaN thin films deposited under various growth temperatures, obtained by means of X-ray diffraction (XRD), atomic force microscopy (AFM), and nanoindentation techniques. The InGaN thin films with different In contents were deposited on sapphire substrates through a metal-organic chemical-vapor deposition (MOCVD) system. Changes in mechanical properties for InGaN thin films are discussed in conjunction with deposition temperature, surface morphology and crystalline structure. The XRD measurements showed that there was no phase separation of In as the In composition went from 25 at.% to 34 at.%. Moreover, both XRD and AFM showed larger grain and surface roughness in In_0.25Ga_0.75N thin films. Nanoindentation results indicate that hardness and Young's modulus both decreased as the indentation depth increased. The contact stress–strain relationships were also analyzed.