MOVPE法生长AlGaAs过程中Al分配系数的动力学研究  

Kinetic Study of Al Distribution Coefficient in MOVPE Growth of AlGaAs

作　　者：公延宁[1] 莫金玑[1] 余海生[1] 夏冠群[1] 

机构地区：[1]中国科学院上海冶金研究所,上海200050

出　　处：《Journal of Semiconductors》2000年第2期137-141,共5页半导体学报（英文版）

摘　　要：从固态组分控制方面，对ＡｌＧａＡｓ 的常压金属有机物气相外延（ＡＰ－ＭＯＶＰＥ）生长技术进行了研究．首先，在假定体系中所涉及气体为理想气体的前提下，经理论推导，给出了ＡｌＧａＡｓＡＰ－ＭＯＶＰＥ生长过程中控制参数和Ａｌ在固、气相间的分配系数ｋＡｌ之间的关系式．之后，依据该关系式分析实验数据，并对ｋＡｌ的动力学行为规律进行了研究．结果表明，ｋＡｌ值大小与ＡｌＡｓ 和ＧａＡｓ 的生长效率（单位ⅢＡ 族原子输入量下材料的生长速率）之比Ｋ 的大小有关：ｋＡｌ随Ｋ 的增加而增大；当Ｋ＞ １ 时，ｋＡｌ＞ １，当Ｋ＜ １ 时，ｋＡｌ＜ １，实际情况以前者居多；只有当Ｋ＝ １ 时才ｋＡｌ＝ １．此外，生成ＧａＡｓ和ＡｌＡｓ 的表观反应活化能Ｅａ１和Ｅａ２的不同会导致Ｋ，进而ｋＡｌ随生长温度发生变化：当Ｅａ１＞ Ｅａ２时，ｋＡｌ随生长温度的升高而减小，当Ｅａ１＜ Ｅａ２时，ｋＡｌ随生长温度的升高而增大，论文得到的结果属后种；只有当Ｅａ１＝ Ｅａ２时，ｋＡｌ才不随生长温度发生变化．再者，ｋＡｌ还会随Ａｌ在气相ⅢＡ 族原子中的原子百分含量ｘⅤＡｌ的增加而减小．The relation between control parameters and the Al solid\|vapor distribution coefficient kAl is deduced for the atmospheric pressure MOVPE (AP\|MOVPE) growth of AlGaAs and based on this relation the data from AP\|MOVPE growth of AlGaAs are analyzed. Then the kinetic characteristics of k Al in the AP\|MOVPE growth of AlGaAs are studied. The ratio of growth efficiency of AlAs relative to GaAs, denoted by K , determines the value of k Al . k Al increases with increasing K. k Al >1 when K>1 , and k Al <1 when K<1 , and the former one as the usual case. k Al =1 only when K=1 . In addition, the change of K with growth temperature T, due to the difference between the apparent activation energies E a1 and E a2 respectively for the formation of GaAs and AlAs, can result in the change of k Al with T. k Al decreases with increasing T when E a1 > E a2 , and k Al increases with increasing T when E a1 < E a2 . The latter one is the case in this work. Only when E a1 = E a2 does k Al not change with T . Furthermore, k Al can also decrease with increasing x \+Ⅴ Al , the Al mole fraction in the group\|ⅢA atoms in vapor.

关 键 词：镓铝砷化合物 气相外延 分配系数 动力学 MOVPE 

分 类 号：TN304.054[电子电信—物理电子学]