磷化铟的CH_4／H_2反应离子腐蚀研究

Methane/Hydrogen-based Reactive Ion Etching of InP

研究了用来制作ＩｎＰ微细结构的反应离子腐蚀（ＲＩＥ）技术，采用ＰＬＡＳＭＡＬａｂμＰＭｏｄｕｌａｒ反应离子腐蚀系统，在ＣＨ４／Ｈ２／Ａｒ环境中，研究了ＩｎＰ的腐蚀速率、表面形貌、剩余损伤层等随反应气体组分、压力等的变化。发现速率随ＣＨ４／Ｈ２比值增大而增大，随工作压强的增大而减小。测得的腐蚀速率很慢：从４ｎｍ／ｍｉｎ到１６ｎｍ／ｍｉｎ，腐蚀图形的方向性好，因而特别适合制作尺寸为微米级的ＩｎＰ微细结构，在ＣＨ４／Ｈ２＝０．１８５时，腐蚀后的表面光亮，腐蚀速率为１４．５ｎｍ／ｍｉｎ，剩余损伤层的厚度约为１５～３０ｎｍ。与参考文献报导不同处是：在腐蚀后较为粗糙的表面上，并不总是富Ｉｎ，有时是富Ｐ。由此提出了平衡腐蚀的概念。

CH4/H2 reactive ion etching(RIE) for processing InP fine structures has been studied. We have investigated etch rates, surface morphologies, residual damage layer of InP reactive ion etched in CH4/H2/Ar ambient of PLASMA Lab μp Modular plasma system. Etch rates increase with increasing of ratio of CH4/H2 and with decreasing of operating pressure under our conditions. Etch rates are very slow,from 4 nm/min to 16 nm/min. InP surface etched is very smooth,and the etch rate is 14. 5 nm/min when CH4/H2 =0. 185 and operating pressure equals 20 m Torr,the thickness of residual damage layer is normally 30 nm. It is quite different from references that the etched rough surface sometimes shows a little depletion of In, not always In-rich,under our condition. A concept of balancing etch has been suggested.