電感耦合電漿蝕刻系統對磷化銦鎵鋁蝕刻之研究

Abstract

本論文研究電感耦合電漿蝕刻系統對磷化銦鎵鋁樣品進行電漿乾蝕刻。本實驗以 Cl2 和 BCl3 為蝕刻氣體，其混合比例對蝕刻的結果有相當大的影響，由數據顯示，當兩者之混合比例接近於 1:1 時，可以得到較高的蝕刻速率。此外因此樣品含有銦的成分，對於氯氣會產生反應，形成氯化銦化合物，此化合物具有極低的揮發性，在進行蝕刻後會附著在樣品表面，不易移除，嚴重影響蝕刻結果。在此研究中，我們添加了 CH4 氣體，用以與 In 化合而成 In(CH3)3 化合物，而減少 InClx 的產生。但同時也因 CH4 所形成的多分子聚合物，導致蝕刻速率的下降。另外直流偏壓的增加，使得蝕刻速率增加，並使蝕刻表面的平滑度增加，直到偏壓大於 200V 之後，樣品表面的平整度才再度下降。

In this thesis, we study the dry etch of the AlGaInP by using inductively coupled plasma (ICP) etching system. In this study, we use Cl2 and BCl3 as the etching gases. According to the etching results, when the mix ratio is 1:1, we can get the maximum etching rate. Because of indium component in the sample, the resulting product InClx which is involatile and adsorptive on the sample surface leads to a cease of etching. In order to minimize the InClx, we add the CH4 gas in the process to produce the In(CH3)3 compound which is much more volatile. Meanwhile, CH4 will creat the polymer in the surface and lead to the decreasing of etching rate. Considering the etching effect of DC bias, we found that the etching rate will increase with DC bias. The sample surface morphology is optimized as the DC bias is around 200V.