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采用有限元模拟软件对液封直拉(LEC)法生长锑化镓晶体过程进行计算机建模。模拟分析了晶体旋转、坩埚旋转及隔热屏等因素对GaSb固-液界面形貌的影响。结果表明,晶体旋转与坩埚旋转分别具有促使凸向熔体的固-液界面曲率减小及增大的作用,且同等转速条件下,坩埚旋转对固-液界面形貌影响更大。此外,减小放肩角度、去除炉体上部的隔热屏等措施,均具有使凸向熔体的固-液界面曲率降低的作用。而使用液封剂使凸向熔体的固-液界面曲率增大。坩埚在加热器中存在某一位置,使熔体内部轴向梯度最大。炉膛内氩气流速最剧烈部位为保温罩与拉晶杆间的区域,Ar气对流导致上炉膛温度提高,并降低熔体表面温度约8℃。 相似文献
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垂直Bridgman生长CdTe过程的数值模拟 总被引:7,自引:1,他引:6
采用 Galerkin有限元算法 ,计算了垂直 Bridgman生长 Cd Te过程中的温场分布、液体流动和固液界面的形状 ,分析了生长速率、温区分布等参数对固液界面的影响 .计算结果表明 ,较小的生长速率可以获得更为平坦的固液界面 ,适当增加结晶区域的温度梯度也是改善固液界面形状的一个有效方法 .同时 ,通过对生长系统中的热流分析 ,表明在生长过程的中间阶段 ,热量交换主要集中在梯度区附近 ,而坩埚两端与外部环境的热量交换较少 相似文献
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利用Fluent软件,模拟计算了垂直Bridgman法大尺寸氟化钙晶体生长的具体过程,研究了晶体生长过程中的热传递和熔体对流传热,分析了固相、液相和坩埚的热导率的差异对坩埚中心轴的轴向温度分布和轴向温度梯度以及界面处的径向温度分布和径向温度梯度的影响。分析结果表明:熔体对流传热的效果随晶体生长的不断进行逐渐减弱;固相、液相和坩埚的热导率的差异对坩埚中心轴的轴向温度分布和轴向温度梯度以及界面处的径向温度分布和径向温度梯度有重要影响;晶体的结晶速度和坩埚的下降速度存在不一致性。 相似文献
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采用数值模拟技术模拟了10cm(4 in)VOF法GaAs单晶生长过程中的温场分布、固液界面形貌以及热应力分布.推导得到了固液界面形状与轴向温度梯度和径向温度梯度之间的关系,定义了一个固液界面形状函数,用以表征固液界面偏离度.固液界面偏离度可定义为晶体边缘和晶体中心轴向位置的差值.计算得到固液界面凹(凸)度的临界值,小于该值时,固液界面附近的热应力低于临界分解剪切应力(CRSS).模拟计算了两个时刻的晶体中的热应力分布:当偏离度大于临界值时,晶体中的热应力大于CRSS,反之,晶体中的热应力小于CRSS,验证了理论推导的结果. 相似文献
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本文介绍一种经改进的采用加速坩埚旋转技术的Bridgman方法(ACRT-B)及ACRT-B用于生长MCT晶体得到的重要结果。与传统Bridgman方法生长的晶体相比,ACRT-B生长的晶体的径向组份均匀性得到很大改善;有用组份的晶片较多;晶体的结晶度好;主晶粒数目减少。ACRT-B工艺中,影响晶体质量最重要的旋转参数是最大旋转速率,而保持在最大旋转速率的时间和停止时间及反向旋转对结果的影响都很小。 相似文献
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布里奇曼法生长碲镉汞晶体的缺陷及其展望 总被引:2,自引:0,他引:2
简单介绍了布里奇曼法生长碲镉汞晶体的主要缺陷以及缺陷的控制原理,回顾了国内进行磅镉汞晶体生长的布里奇曼法及加速坩埚旋转技术的布里奇曼法(ACRT-B)研究的情况,并提出了进一步研究的问题。 相似文献
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InSb and GaSb single crystals were grown by the Czochralski method. The impurity concentration distribution in the melt and
crystal was investigated experimentally and computationally as a function of the interface segregation coefficient, the shape
of the solid-liquid interface and the growth rate. It was found that the impurity concentration distribution in the melt was
largely influenced by the interface segregation coefficient; the impurity concentration in the crystal increased as the shape
of the solid-liquid interface became more planar and also as the growth rate increased; the impurity concentration was more
markedly influenced by the growth rate than by the shape of the solid-liquid interface. When the growth rate was large, the
impurity concentration increased and the shape of the solid-liquid interface was concave toward the melt near the crystal
periphery. When the growth rate was small, the impurity concentration decreased and the shape of the solid-liquid interface
was convex toward the melt. 相似文献
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David F. Bliss Robert M. Hilton Stephen Bachowski Joseph A. Adamski 《Journal of Electronic Materials》1991,20(12):967-971
We have used a combined magnetic liquid encapsulated Kyropoulos/Czochralski (MLEK/ MLEC) technique to produce twin-free indium
phosphide (InP) crystals. This technique has advantages over the standard LEC method used for commercial production of InP.
By stabilizing convective flows with a magnetic field and controlling the angle between solid and liquid, one can grow large
diameter twin-free (100) InP crystals; they are shaped with a flat top as is typical for Kyropoulos growth, and then pulled
from the magnetically stabilized melt as in Czochralski growth. This shaping method has the benefit of maximizing the number
of single crystal wafers which can be sliced from the boule. MLEK InP growth is distinguished from other methods such as LEC
and MLEC with respect to solid-liquid interface shape, dislocation density, and impurity distribution. This process has demonstrated
that twin-free InP (100) crystals can be consistently grown. 相似文献
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Semiconductors - FeIn2S3.6Se0.4 single crystals are grown by planar crystallization of the melt (the vertical Bridgman method). The composition and crystal structure of the crystals are determined.... 相似文献
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M. A. Abdullaev Dz. Kh. Magomedova R. M. Gadzhieva E. I. Terukov Yu. A. Nikolaev Yu. V. Rud’ P. P. Khokhlachev 《Semiconductors》2001,35(8):870-872
The results of studying the photoelectric properties of bulk CuInSe2 crystals grown at various deviations from the stoichiometry are reported. The crystals were grown by the Bridgman method. The concentration and mobility of charge carriers were measured. The dependence of the properties of CuInSe2 crystals with n-and p-type conductivities on the deviation of composition from the stoichiometry is discussed. 相似文献
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Semiconductors - Cu2ZnGeSe4 and Cu2ZnSnSe4 and Cu2ZnGe1 –xSnxSe4-alloy crystals are grown by the Bridgman method (vertical variant). The composition and structure of the crystals are... 相似文献
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Semiconductors - In2S3, AgIn5S8, and (In2S3)x(AgIn5S8)1 – x-alloy single crystals are grown by the Bridgman method. The composition and structure of the crystals are determined. It is... 相似文献
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MINJia-hua SANGWen-bing LIWan-wan LIUHong-tao YUFang WANGKun-shu CAOZe-chun 《半导体光子学与技术》2005,11(1):20-27
During the crystal grown by VBM, the solid/liquid interface configurations greatly influence the quality of as-grown crystals. In this paper, finite element method (FEM) was used to simulate the growth process of CdZnTe crystal. The effects of different crucible moving rates and temperature gradient of adiabatic zone on crystal growth rate and solid-liquid interface configuration were studied as well. Simulation results show that when crucible moves at the rate of about 1 mm/h, which is nearly equal to crystal growth rate, nearly flat solid/liquid interface and little variation of axial temperature gradient near it can be attained, which are well consistent with the results of experiments. CdZnTe crystal with low dislocation density can be obtained by employing appropriate crucible moving rate during the crystal growth process. 相似文献