Growth of InAsSb alloy layrs by compositional conversition and its application to mid-infrared sensing devices

InAsSb合金是一种很有前途的中红外器件材料。然而，缺乏与合金系统匹配的衬底晶格使得制造高性能器件变得困难。为了克服这一问题，将“成分转换”应用于在目前可用的复合晶体衬底上形成具有所需成分的InAsSb合金层。在该技术中，材料的熔点（Tf）对合金层的生长起着重要的作用。首先，研究了低Tf晶体（InSb）在高Tf衬底（InAs）上的生长，并明确了在相对较高的生长温度下获得层模式生长。在InAs衬底上生长InSb的情况下，温度范围在390C和440C之间是优选的。将所制备的样品与饱和合金成分的三元溶液接触，称为“转化过程”。实验明确了以下几点：高Tf合金成分向低Tf生长层的扩散非常高；因此，低Tf生长层的组成立即发生变化；在随后的一段时间里，成分均质化和晶格修复进展；最终合金成分与所用溶液达到平衡成分；因此，可以通过调整溶液的组成来实现具有所需成分的合金层；在此转换过程中，具有最高Tf的衬底是稳定的。合金在转化层上的连续生长表明，生长合金的结晶质量显著提高。展望了铟assb合金在器件中的应用前景。根据所获得的知识，可以制造中红外装置，为不久的将来的信息通信系统和/或空气污染监测系统奠定基础。

InAsSb alloy is a promising material for mid-infrared devices. However the lack of a substrate lattice-matched to the alloy system makes it difficult to fabricate the higt performance devices. To overcome this problem, "compositional conversion" was applied to the formation of InAsSb alloy layrs with desired composition on a compound crystalline substrate available at present. In this technique, melting point (Tf) of the materials plays an important role to grow the alloy layr.At first, the growth of low Tf crystal (InSb) on a higt Tf substrate (InAs) was investigated and made it clear that layr-mode growth is obtained at relatively higt growth temperature. In the case of InSb growth on InAs substrates, the temperature range between 390C and 440C is preferable.The samples prepared were contacted to ternary solution saturated with alloy components, named "conversion process". The experiments made clear the following points : the diffusion of a high Tf alloy components into the low Tf grown layr is very high ; therefore the low Tf grown layr converts immediately in its composition ; homogenization in composition and lattice repairing advances in the following period ; the final alloy composition reaches to an equilibrium composition with the solution used ; therefore the alloy layrs with desired composition can be realized by adjusting the composition of the solution ; the substrate with the highest Tf is stable during this conversion process. Successive growth of alloy on the converted alloy layrs showed that the crystalline quality of grown alloy is drastically improved.Thus, the prospects for device application of InAsSb alloy was developed. Based on the knowledge obtained, the mid-infrared devices could be fabricated, making progress an information-communication system and/or an air pollution watching system demanded in near future.