Crystal Growth of InGaAsSb Compound Semiconductors for Infrared Devices

为了生长红外材料InGaAsSb晶体，了解三元化合物半导体的晶体生长过程是非常重要的。首先，研究了Cz法生长的InGaSb和GaAlSb以及温差法和旋转布里奇曼法生长的InGaSb的组份比、偏析和晶体质量的控制。此外，对晶体生长模型进行了模拟，并与实验结果进行了比较。在异质外延生长方面，采用横向过生长技术在SiNx薄层上获得了低缺陷密度(104/cm2)的单晶层。In在InGaAs中的组成比从0.06增加到0.1，晶体质量没有改变。其次，在不同组份比例的多层膜的生长中，研究了InAs衬底上InAsSb的光学性质；随着外延层数的增加，截止波长向长波方向移动。4个表面层的截止波长为8微米，但吸收边不是很锐利。最后，在InGaAsSb/(100)InAs的研究中，在In-Ga-As-Sb源溶液中添加Gd组分，使生长的外延层的电学性能有所提高。从SIMS测量可以看出，溶液中的Gd与S组分反应，从而减少了S向表层的偏析。在300K和77K下生长的InGaAsSb的迁移率分别为3.0×10~(-4)cm~(-2)和8.2×10~(-4)cm~(2/vs)。载流子密度在300K和77K时分别为5.7×10~(-1)和4.0×10~(-3)cm~(-3)，明显优于InAs衬底。实验事实有望为红外材料的制备做出贡献。

It is very important to understand the crystal growth of ternary compound semiconductors in order to grow InGaAsSb crystals used as infrared materials. First, the control of compositional ratio, segregation, and crystal quality were investigated in Cz-grown InGaSb and GaAlSb, and also in InGaAs grown by both the temperature difference method and the rotary Bridgman method. Further, the model of crystal growth was simulated compared with the experimental results. Concerning the hetero growth of InGaAs on GaAs, crystal layrs of low defect density (10^4/cm^2) was obtained on the SiN_x thin layr by the lateral over growth technique. The crystal quality was not changed even if the compositional ratio of In in InGaAs was increased from 0.06 to 0.1. Next, in the growth of multi-layrs with different compositional ratios, the optical properties of InAsSb on InAs were studied ; The cutoff wavelength shifted to the longer wavelength with the number of epi-layrs. The cutoff one of 4 epi-layrs was 8mum though the absorption edge was not so sharp. Finally, in study of InGaAsSb/(100) InAs, the addition of Gd component into the In-Ga-As-Sb source solution made the electrical properties of grown epi-layrs raise. From the SIMS measurement, it was understood that Gd in the solution reacted with S component and as a result the segregation of S into the epi-layr was reduced. The mobility of grown InGaAsSb was 3.0*10^4 and 8.2*10^4cm^2/Vs at 300K and 77K,respectively. The carrier density was 5.7*10^<15> at 300K and 4.0*10^<15>cm^<-3> at 77K.These values were relatively superior to those of the InAs substrate. Experimental facts were expected to contribute to the fabrication of infrared materials.