IMPURITY SEGREGATION IN BINARY COMPOUNDS
IMPURITY SEGREGATION IN BINARY COMPOUNDS
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DOI：
10.1149/1.2424026
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发表时间：
1966-01-01
影响因子：
3.9
通讯作者：
BLUM, SE
中科院分区：
文献类型：
--
作者：
LORENZ, MR;BLUM, SE
考虑二元化合物成分的压力对取代杂质的偏析系数(ko)的影响。简要回顾了有关杂质掺入的理论，并针对杂质的电特性和杂质占据的位点的各种组合给出了 ko 对 PM 的依赖性。研究了 CdTe 中的杂质 In 和 Sb。 ko (In) 与 PCd 成反比，ko (Sb) 与 POd 成正比。如果假设原生缺陷作为自由载流子源或电荷补偿的作用可以忽略不计，那么结果与理论预测在定量上一致。通过直拉法在不同的砷压力下拉晶，研究了 InAs 中的施主 Te、受主 Zn 和两性杂质 Sn。 ko 遵循预测的行为。简要讨论了 ko 与材料制备相关的化合物成分压力的依赖性的实际意义。半导体系统的研究使人们对二元系统中的偏析过程和控制分配系数的因素有了更好的理解 (1)。在此类双组分系统中获得的知识也已应用于更复杂的三元系统。已经有许多研究涉及二元化合物中杂质分离的各个方面。这项工作大部分是针对 III-V 族化合物完成的，其中大部分最近已得到审查 (2)。在许多此类研究中，偏析系数是通过假设伪二元系统（即杂质（一种组分）和二元化合物（第二种组分））来确定的。一般来说，研究涉及液-固相平衡中的分离。最近，Chang 和 Pearson (3) 从气固平衡研究了 Zn 在 GaAs 和 GaP 中的溶解度和分配系数，而 McCaldin (4) 研究了 Zn-GaAs 系统作为真正的三组分系统。研究了 Ge 在 GaAs 中的液固相平衡行为 (5)。还研究了不同成分的固体 InSb 和 In-Sb 熔体之间的 Zn 偏析 (6)。 Trumbore 等人研究了 II、IV 和 VI 族元素在 GaP 中的溶解度(7, 8)。这项研究的主要目的是检查分布系数对杂质占据位置的依赖性、杂质电特性的影响以及通常占据该位置的组分的化学势的作用。在我们的实验研究中，我们选择 In-As 体系作为 III-V 族化合物的代表，选择 Cd-Te 体系作为 II-VI 族化合物的代表。这两种化合物都是低熔点的，因此实验难度最小。研究了 InAs 中的三种杂质，研究了 CdTe 中的两种杂质。
The effect of the pressure of the constituents of a binary compound on the segregation coefficient (ko) of a substitutional impurity is considered. The theory concerning the incorporation of an impurity is briefly reviewed, and the dependence of ko on PM is given for various combinations of electrical character of an impurity and the site the impurity occupies. The impurities In and Sb were studied in CdTe. ko (In) is inversely proportional to PCd and ko (Sb) directly proportional to POd. The results are in quantitative agreement with the theoretical prediction if it is assumed that native defects play a negligible role as a source of free carriers or charge compensation. The donor Te, the acceptor Zn, and the amphoteric impurity Sn were studied in InAs by pulling crystals by the Czochralski method at various arsenic pressures. The ko's follow the predicted behavior. The practical significance of the dependence of ko on the pressure of compound constituents in relation to materials preparation is discussed briefly.Research on semiconductor systems has brought about a good understanding of segregation processes and of the factors governing distribution coefficients in binary systems (1). The knowledge acquired in such two-component systems has also been applied to the more complex ternary systems. There have been a number of investigations concerned with various aspects of the segregation of an impurity in a binary compound. Most of this work was done on III-V compounds and much of it has been recently reviewed (2). In many of these studies the segregation coefficients were determined by assuming a pseudobinary system, ie, an impurity (one component) and a binary compound (the second component). In general the investigations were concerned with segregation in liquid-solid phase equilibria. More recently Chang and Pearson (3) studied solubilities and distribution coefficients of Zn in GaAs and GaP from vapor-solid equilibria while McCaldin (4) studied the Zn-GaAs system as a true three-component system. The behavior of Ge in GaAs was investigated in liquid-solid phase equilibria (5). Segregation of Zn between solid InSb and In-Sb melts of various compositions has also been investigated (6). The solubility of group II, IV, and VI elements in GaP was studied by Trumbore et al.(7, 8). The major aim of this study was to examine the dependence of the distribution coefficient on the site the impurity occupies, the effects of the electrical characteristics of the impurity, and the role of the chemical potential of the component that normally occupies the site. For our experimental investigation we chose the In-As system as a representative of the III-V compounds and the Cd-Te system as a representative of the II-VI compound family. Both compounds are low melting and therefore presented the least difficulty experimentally. Three impurities were studied in InAs, and two impurities were investigated in CdTe.