Dynamics of Semiconductor Vapor Growth with Photocatalytic Surface Reactions

本研究旨在通过对生长动力学、生长控制、杂质掺杂和材料控制等方面的研究，将本课组已经探索的光催化表面反应作为未来器件应用的新技术进行开发。结果总结如下：1。通过对ZnSe生长过程的现场监测，发现ZnSe的基本生长过程是由光生载体相关的烷基锌分解，进而引发烷基硒的分解。重要的知识是；(1)生长的最初始阶段以热分解为主，其次是光催化；(2)层层生长得到证实；(3)生长过程与表面化学计量学密切相关。将该技术应用于ZnSe的p型掺杂，成功地获得了10^<17>cm^<-3>量级的净受体浓度。光学和电学表征显示了非辐射缺陷，通过选择最佳生长条件可以减少这些缺陷。利用该技术制备的ZnCdSe/ZnSe/ZnSSe量子阱激光器在77K下实现了连续激光，这在气相生长器件中尚为首次。

This research was carried out aimed at developing the photocatalytic surface reactions, which had been explored by our group, as a new technology for future device applications with the investigations on growth dynamics, growth control, impurity doping, and material control. The results are summarized as follows ;1.With in-situ monitoring during the grwoth of ZnSe, the fundamental growth processes were found to ve decomposition of alkylzinc associated with photogenerated carries, and then this brought in decomposition of alkylselenium.2.Important knowledges were ; (i) the most initial stage the growth was dominated by thermal decomposition and the photocatalysis followed, (ii) the layr-by-layr growth was confirmed, and (iii) the growth processes were closely related to the surface stoichiometry.3.This technique was applied for p-type doping of ZnSe, which had been a difficult subject in vapor growth, and successfully resulted in the net acceptor concentration of the order of 10^<17>cm^<-3>. The optical and electrical characterizations revealed non-radiative defects, and they could be reduced by choosing the optimum growth conditions.ZnCdSe/ZnSe/ZnSSe quantum well lasers grown by this technique achieved CW lasing at 77K,which was for the first time in vapor-grown devices.