Influence of Substrate Temperature on the Morphology of Al x Ga1 − x As Grown by Molecular Beam Epitaxy
Influence of Substrate Temperature on the Morphology of Al x Ga1 − x As Grown by Molecular Beam Epitaxy
复制标题
衬底温度对分子束外延生长Al x Ga1−x As形貌的影响
DOI：
10.1149/1.2123980
复制
发表时间：
1982
影响因子：
3.9
通讯作者：
R. Fischer
中科院分区：
文献类型：
--
作者：
H. Morkoç;T. Drummond;W. Kopp;R. Fischer
用分子束外延方法生长了AlAs工具分数在0.25~0.5之间的(Al，Ga)As外延层。研究了600~176℃的衬底温度范围。在整个温度范围内，对于x-<；30%的AlAs刀具组分，获得了良好的表面形貌。然而，对于固定的V/III基团，当x->；40%时，观察到随着衬底温度的升高，表面形貌先降低后改善。增加V/III基团比改善了衬底温度范围内的表面形貌，x->；40%的衬底温度范围为630-690~。(Al，Ga)As三元化合物是一种重要的半导体材料，在光学(1)和电子器件(2)领域具有重要意义。这是因为它的晶格与砷化镓匹配，并且具有比砷化镓更大的带隙。尽管多年来，液相外延已成功地用于生长光学器件(3)和电子器件(4)质量的(Al，Ga)As，但它存在表面形貌问题，厚度不均匀，重复性差。另一方面，分子束外延(MBE)(5)能够产生具有良好表面形貌和重复性的(Al，Ga)As层。这项技术基本上是一种低温生长过程，然而，在低温下生长的(Al，Ga)As层的光学和电学性能并不是器件质量。当(Al，Ga)As在高温下生长时，(Al，Ga)As的输运(6)和光学(7，8)性质显著改善，例如在600~生长温度以上，降低了As在表面上的寿命，并需要更大的V/III族比。然而，在~650~以上，必须大大增加V/III族比，以保持良好的表面形态，特别是对于AlAs摩尔分数(~0.40)。在这份报告中，我们证明了在不增加V/III族比的情况下，可以在远高于转变温度的情况下获得具有良好表面形貌的(Al，Ga)As层。
ABSTRACT (A1, Ga) As epitaxial layers with AlAs tool fraction between 0.25 and 0.5 have been grown by molecular beam epitaxy. A substrate temperature range of 600~ 176 has been investigated. Excellent surface morphologies were obtained in this entire temperature range for AlAs tool fractions of x-< 30%. The surface morphology was, however, observed to first degrade and later improve with increasing substrate temperature for x-> 40% for a constant group V/III ratio. Increased group V/III ratio improved the surface morphology in the substrate temperature range of 630 690~ for x-> 40%.The ternary (A1, Ga) As compound is an important semiconducting material in the area of optical (1) and electronic (2) devices. This stems from the fact that its lattice matches GaAs and has a bandgap larger than that of GaAs. While liquid phase epitaxy has been successfully used to grow optical device (3) and electronic device (4) quality (A1, Ga) As for many years, it suffers from surface morphology problems, a lack of thickness uniformity, and a lack of reproducibility. Molecular beam epitaxy (MBE)(5), on the other hand, is capable of producing (A1, Ga) As layers with excellent surface morphology and reproducibility. This technique is basically a low temperature growth process, however, the optical aad electrical properties of (A1, Ga) As layers grown at low temperatures are not of device quality. Transport (6) and optical (7, 8) properties of (A1, Ga) As improve substantially when grown at high temperatures, eg, above 600~ Growth temperatures above 600~ reduce the As lifetime on the surface and require larger group V/III ratios. Above,~ 650~ however, this group V/III ratio must be increased very substantially to maintain good surface morphology, particularly for AlAs mol fractions (~ 0.40). In this report, we demonstrate that (A1, Ga) As layers with excellent surface morphology can be obtained well above the transition temperature without having to increase the group V/III ratio.