Control of surface states for III-V semiconductor quantum structures and its application to novel optical devices

本研究的目的是研究III-V型化合物半导体量子结构中表面态与约束能级之间的相互作用机制，并利用超薄硅界面控制层（SiICL）来控制表面性质，以制备新型光学器件。得到的主要结果如下：(1)研究发现，距离为5nm的近表面量子阱（OW）的光致发光强度比距离为5nm的参考量子阱（OW）的光致发光强度降低了1000倍。我们发现这种现象是由近表面量子阱的量子化态和表面态之间的强相互作用引起的。采用Si-ICL基钝化技术实现了光强的完全恢复。(2) x射线光电子能谱分析表明，钝化膜/半导体界面处半导体表面没有氧化相和氮化相。(3)采用Si-ICL钝化方法，InGaAs量子线的PL强度几乎完全恢复，最大恢复系数为400。SiICL钝化后的量子线即使在室温下也表现出较强的发光强度。(4)将Si-ICL钝化技术成功应用于湿法蚀刻制备InGaAs量子线的侧壁钝化。(5)详细的计算机模拟表明，Si-ICL基钝化技术显著降低了表面态，可以解释明显的钝化效果

The purpose of this study is to investigate the interaction mechanism between surface states and confined levels in III-V compound semiconductor quantum structures and to control the surface properties by use of ultrathin silicon interface control layr (SiICL) for fabrication of novel optical devices. The main results obtained are listed below :(1) It was found that the photoluminescence (PL) intensity from the near-surface quantum well (OW) with the surface-to-well distance of 5nm, was reduced by a factor of 1000 as compared with that from the reference QW located deeply inside. We revealed that this phenomenon is caused by strong interaction between the quantized states in near-surface QW and surface states. Acomplete recovery of PL intensity was achieved by use of Si-ICL based passivation technique.(2) X-ray photoelectron spectroscopy analysis revealed that there were no oxidized and nitrided phase of semiconductor surface at the passivation film/semiconductor interfaces.(3) By applying the Si-ICL passivation method, a nearly complete recovery of PL intensity was achieved with an observed maximum recovery factor of 400 for the InGaAs quantum wires. The quantum wires passivated with SiICL showed strong PL intensity even at room temperature.(4) The Si-ICL passivation technique was successfully applied to passivation of side walls of InGaAs quantum wires fabricated by wet etching process.(5) Detailed computer simulation pointed out that a clear passivation effects can be explained by substantial reduction of surface states by Si-ICL based passivation technique