共查询到18条相似文献,搜索用时 125 毫秒
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利用X射线双晶衍射(XRD)技术研究了原生及退火处理后的磷化铟单晶的晶格完整性.原生磷化铟单晶中由于存在着大量的位错和高的残留热应力,导致晶格产生很大的畸变,表现为XRD半峰宽的值较高并且分布不均匀,甚至有些原生的磷化铟单晶片出现XRD双峰等.通过降低晶体生长过程的温度梯度,降低位错密度并减小晶体中的残留热应力可以提高晶体的完整性.利用高温退火处理也可有效地降低磷化铟晶体中的残留热应力.对磷化铟晶体生长过程中熔体的配比、掺杂浓度等条件对结构完整性的影响进行了分析. 相似文献
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利用X射线双晶衍射(XRD)技术研究了原生及退火处理后的磷化铟单晶的晶格完整性.原生磷化铟单晶中由于存在着大量的位错和高的残留热应力,导致晶格产生很大的畸变,表现为XRD半峰宽的值较高并且分布不均匀,甚至有些原生的磷化铟单晶片出现XRD双峰等.通过降低晶体生长过程的温度梯度,降低位错密度并减小晶体中的残留热应力可以提高晶体的完整性.利用高温退火处理也可有效地降低磷化铟晶体中的残留热应力.对磷化铟晶体生长过程中熔体的配比、掺杂浓度等条件对结构完整性的影响进行了分析. 相似文献
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利用X射线双晶衍射(XRD)技术研究了原生及退火处理后的磷化铟单晶的晶格完整性. 原生磷化铟单晶中由于存在着大量的位错和高的残留热应力,导致晶格产生很大的畸变,表现为XRD半峰宽的值较高并且分布不均匀,甚至有些原生的磷化铟单晶片出现XRD双峰等. 通过降低晶体生长过程的温度梯度,降低位错密度并减小晶体中的残留热应力可以提高晶体的完整性. 利用高温退火处理也可有效地降低磷化铟晶体中的残留热应力. 对磷化铟晶体生长过程中熔体的配比、掺杂浓度等条件对结构完整性的影响进行了分析. 相似文献
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主要讨论热退火(850℃退火2小时)对GaAs半导体晶片的位错密度和电阻率的影响,阐述了位错密度的分布与电阻率分布之间的关系。通过特殊的实验方法得到的结果证明:适当的退火处理将改善GaAs晶片中缺陷密度、电阻率的大小及分布,从而得到均匀性较好的GaAs材料。 相似文献
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在水平法生长GaAs单晶过程中常常发生晶体与石英舟的沾润,而引起单晶位错大幅度增殖,严重时会导致长成李晶和多晶.近年来,国内外对沾润机理和解决措施进行了一些研究.山口正夫等喷砂的石英舟进行高温处理,舟表面形成α-方石英微晶层,可得到具有金属光泽的单晶.Yamayuchi等发现在生长GaAs单晶后石英舟喷砂表面形成α-方石英粉末层减少熔体与石英舟直接接触避免和舟沾润.本文采取HCI和Ga在H_2气氛下对石英舟进行高温处理工艺(简称HCl-H_2-Ga处理)配合合理的拉品工艺可避免沾润,降低位错,进一步提高GaAs纯度.并根据实验结果确定合理的处理舟工艺. 相似文献
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基于GaAs/Si材料中位错的运动反应理论,修正获得CdTe/Si和HgCdTe/Si外延材料中的位错运动反应模型.采用快速退火方法对Si基HgCdTe外延材料进行位错抑制实验研究,实验结果与理论曲线基本吻合,从理论角度解释了不同高温热处理条件对材料体内位错的抑制作用.对于厚度为4~10μnn的CdTe/Si进行500... 相似文献
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本文用4.2K光致发光研究了LEC GaAs的热感生缺陷.热退火时样品分别为无包封,包封或用一个未掺杂的SI-GaAs片覆盖.退火温度为650-850℃,退火在不同气氛下进行(真空,H_2,N_2,H_2+N_2或H_2+As_2). 与缺陷有关的发光带有1.443eV,1.409ev和0.67eV发光带.1.443eV发光带不仅在富Ga的GaAs中出现,而且在富As的热稳定性好的SI-GaAs晶体并经过850℃(在H_2中)热退火的样品中也观测到此发光带.这可能是在退火过程中促进反位缺陷GaAs的形成.1.443eV发光带与GaAs有关.GaAs晶体在H_2中退火后1.409eV峰很强,但在真空中退火末探测到此发光带.文中提出它可能是热退火时氢原子扩散到GaAs晶体中并与某些缺陷结合成络合物的新观点. 相似文献
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分析了GaAs/GaAsAl阴极粘结工艺中应力产生的根源和晶体中应力对X射线双晶衍射峰的宽度和强度的影响,用X射线双晶衍射仪测量阴极和玻璃热粘结工艺过程中的阴极材料外延层和衬底的双晶回摆曲线,实验结果表明,GaAs/GaAsAl阴极粘结工艺没有带来明显的附加应力,外延层衍射角的展宽是由于GaAs阴极组件窗玻璃的非晶态性所致。 相似文献
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通过使用激光散射扫描的方法,定性地研究非掺杂半绝缘LEC砷化镓(100)方向生产的晶体中砷沉淀在晶体径向截面分布,得到了在一种特定热场中生长的晶体中存在4个砷沉淀的聚集中心结论,而这4个聚集中心却正好是晶体上位错密度相对较低的区域.作者主要研究了这种分布和位错之间的关系,分析其形成过程,并得出在晶体生长及后期退火过程中,位错在晶体中起到了输送砷原子的管道作用,加速了砷原子在晶体中的扩散过程,导致网格位错密集区的大直径砷沉淀的密度相对位错稀疏区和位错线区的砷沉淀密度较低. 相似文献
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W. Z. Shen W. G. Tang S. C. Shen S. M. Wang T. Anderson 《Journal of Infrared, Millimeter and Terahertz Waves》1994,15(10):1643-1650
The influence of the GaAs cap layer thickness on the luminescence properties in strained In0.20Ga0.80As/GaAs single quantum well (SQW) structures has been investigated using temperature-dependent photoluminescence (PL) spectroscopy. The luminescence peak is shifted to lower energy as the GaAs cap layer thickness decreases, which demonstrates the effect of the GaAs cap layer thickness on the strain of InGaAs/GaAs single quantum wells (SQW). We find the PL quenching mechanism is the thermal activation of electron hole pairs from the wells into the GaAs cap layer for the samples with thicker GaAs cap layer, while in sample with thinner GaAs cap layer exciton trapping on misfit dislocations is dominated. 相似文献
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L. H. Kuo L. Salamanca-Riba J. M. Depuydt H. Chèng J. Qiu 《Journal of Electronic Materials》1994,23(3):275-281
Nitrogen doped ZnSe/GaAs heterostructures grown at 150 and 250°C were studied by transmission électron microscopy (TEM). The
density of threading dislocations and the interfacial dislocation structure in ZnSe/GaAs heterostructures are related to the
N-doping concentration. In addition, in-situ TEM heating studies show that Frank partial dislocations formed below critical
thickness in N-doped ZnSe/GaAs are the sources for nucleation of a regular array of misfit dislocations at the ZnSe/GaAs interface.
By the dissociation of the Frank partial dislocations and interaction reactions between the dislocations, the 60° misfit dislocations
form. The Frank partial dislocations bound stacking faults which usually form in pairs at the film/substrate interface. The
density of stacking faults increases with increasing N-doping concentration. Thus, at high N-doping levels, the dislocation
nucleation sources are close together and not all of the Frank partial dislocations dissociate, so that a high density of
threading dislocations results in samples with high N-doping concentrations. The high density of threading dislocations in
the ZnSe film are found to be associated with a reduction or saturation of the net carrier density. 相似文献
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<正> High qualities of GaAs layers directly grown on Si substrates have been obtained by MBE. The residual stress in those MBE grown GaAs layers on 相似文献
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用电子束蒸发LaB_6单晶的方法,制备了LaB_6/GsAs肖特基势垒,经800℃高温退火后,势垒高度为0.70eV,理想因子为1.15~1.2。用俄歇能谱观察到LaB_6/GaAs界面有良好的热稳定性,以LaB_6为栅得到了初步的全离子注入的MESFET特性。结果表明,LaB_6有希望用于GaAs集成电路。 相似文献
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Direct epitaxial growthⅢ–Ⅴquantum dot(QD)structures on CMOS-compatible silicon substrates is considered as one of the most promising approaches to achieve low-cost and high-yield Si-based lasers for silicon photonic integration.However,epitaxial growth ofⅢ–Ⅴmaterials on Si encounters the following three major challenges:high density of threading dislocations,antiphase boundaries and thermal cracks,which significantly degrade the crystal quality and potential device performance.In this review,we will focus on some recent results related to InAs/GaAs quantum dot lasers on Si(001)substrates byⅢ–Ⅴ/Ⅳhybrid epitaxial growth via(111)-faceted Si hollow structures.Moreover,by using the step-graded epitaxial growth process the emission wavelength of InAs QDs can be extended from O-band to C/L-band.High-performance InAs/GaAs QD microdisk lasers with sub-milliwatts threshold on Si(001)substrates are fabricated and characterized.The above results pave a promising path towards the on-chip lasers for optical interconnect applications. 相似文献
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Defects such as dislocations and interfaces play a crucial role in the performance of heterostructure devices. The full potential
of GaAs on Si heterostructures can only be realized by controlling the defect density. The reduction of threading dislocations
by the use of strained layer superlattices has been studied in these heterostructures. Several superlattice structures have
been used to reduce the density of threading dislocations in the GaAs epilayer. In this study, we have optimized the use of
strained layer superlattices with respect to the position, period and number to reduce and control the dislocation density.
The use of strained layer superlattices in conjunction with rapid thermal annealing was found to be a most effective method
for reducing the threading dislocation density. Transmission electron microscopy has been used to study the dislocation density
reduction and the interaction of threading dislocations with the strained layers. A model has been developed based on energy
considerations to determine the critical thickness required for the bending of threading dislocations. 相似文献