外加电压对激光电化学刻蚀硅的影响研究

The study of the voltage effect on laser-induced electrochemical etching of silicon

激光电化学刻蚀是将激光加工技术和电化学加工技术有机结合起来而形成的一种复合型刻蚀工艺。为了研究外加电压对激光电化学刻蚀硅的影响,本文采用248nmKrF准分子激光作为光源聚焦照射浸在KOH溶液中的阳极半导体n-Si上,实现激光诱导电化学刻蚀。在实验的基础上,详细分析外加电压对刻蚀工艺的影响,并对其产生的原因进行了分析。试验结果表明其影响主要有两个方面:(1)正的外加电压保证了Si02钝化膜生成,从而实现了选择性刻蚀;(2)外加电压的增大,刻蚀速率会相应减小。因而外加电压也是调节刻蚀速率的一个重要的手段。

laser electrochemical etching process, which combines laser direct etching process and electrochemical etching process, is a compound etching technique. In order to further understand the voltage effect on laser - induced electrochemical etching silicon, this paper adopts 248nm excimer laser as light source and uses KOH solution as electrolyte. The experiments of micromachining sihcon by laser - induced electrochemical etching are carried out. Based on the results of experiments, the voltage effect on laser electrochemical etching silicon is researched.The reasons of etching quality are analyzed in detail. The reasons of etching phenomena are analyzed in detail. The experiment results indicate that the effects are mainly two aspects： （1） positive voltage ensures passivation film creating which carries out selective etching; （2）etching rate reduces with the decrease of voltage. So voltage is an important means of regulating etching rate.