Doping in Molecular Layer Epitaxy
Doping in Molecular Layer Epitaxy
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分子层外延中的掺杂
DOI：
10.1149/1.2096658
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发表时间：
1989
影响因子：
3.9
通讯作者：
T. Kurabayashi
中科院分区：
文献类型：
--
作者：
J. Nishizawa;H. Abe;T. Kurabayashi
本文报道了对GaAs分子层外延的掺杂特性的初步研究结果。P型薄膜的载流子浓度可控制在1.8·1016~1.9·1019cm3，n型薄膜的载流子浓度可控制在1.3·1017~2.2·109 cm-3。在本实验中，As化合物，AsH3和Ga化合物，以及Ga(C2H~)3(TEG)交替供应。分别在AsH3注入、TEG注入和疏散持续时间脉冲式供给掺杂气体分子，并对其差异进行了检验。薄膜中的载流子浓度强烈依赖于上述循环中杂质气体组分的注入顺序。控制掺杂的主要因素似乎是与衬底表面的化学相互作用的强度。近年来，对新的晶体生长技术的需求越来越大，以控制像单个原子尺寸一样精确的外延薄膜厚度。应用原子层外延(ALE)的思想，以AsH3为As源，TMG[Ga(CH3)3]为Ga源，作者(3，4)于1984年成功地实现了GaAs分子层外延(MLE)。最近，用TEG代替TMG作为Ga源，实现了较低的外延层载流子浓度和较低的晶体生长温度(5)，如MO-MBE(6)的情况。在另一篇文章中，我们报道了用MLE方法制备的GaAs薄膜的生长现象，并提出了将杂质能级降低到10以下的方法是cm~(-5)。MLE技术有可能实现所需的杂质浓度在生长方向上的分布，并具有原子有序分辨率。
This paper is to report preliminary results on the doping characteristics of GaAs molecular layer epitaxy. We could control the carrier concentration of GaAs films in the range from 1.8• 1016 to 1.9• 1019 cm 3 for p-type and from 1.3• 1017 to 2.2• 10 9 cm-3 for n-type, respectively. In this GaAs molecular layer epitaxy experiment, As compound, AsH3 and a Ga compound, and Ga (C2H~) 3 (TEG) are supplied, alternately. Dopant gas molecules are also pulsively supplied at the time duration of AsH3 injection, TEG injection, and evacuation, respectively, and the difference was tested. The carrier concentration in the films strongly depends on the order of the injection of impurity gas component in the cycles mentioned above. The principal factor in controlling doping seems to be the strength of the chemical interaction with the substrate surface.In recent years there has been an increasing demand for new crystal growth techniques to control epitaxial film thickness as accurate as a single atomic dimension. Applying the idea of the atomic layer epitaxy (ALE), which had been used to prepare II-VI polycrystalline fihns (1, 2), and using AsH3 as an As source and TMG [Ga (CH3) 3] as a Ga source, GaAs molecular layer epitaxy (MLE) has been successfully implemented by the authors (3, 4) in 1984. Recently, instead of TMG, TEG was used as a Ga source and lower carrier concentration in the epitaxial layers and lower temperature crystal growth were realized (5), as in the case of MO-MBE (6). In another paper we reported the growth phenomena of GaAs thin film layers prepared by MLE and the method of improvement of the impurity level to reduce less than 10 is cm-~(5). The MLE technique has the potential to realize a desired distribution of the impurity concentration in the growth direction with an atomic order resolution.