大高宽比纳米硅立柱的感应耦合等离子体刻蚀工艺优化

Process optimization of inductively coupled plasma etching for large aspect ratio silicon nanopillars

针对氢基硅倍半氧烷(hydrogen silsesquioxane,HSQ)作为深反应离子刻蚀(DRIE)掩膜形成大高宽比纳米硅立柱的工艺进行了系统研究。优化了刻蚀工艺中线圈功率、极板功率和气体流量参数,减小了横向刻蚀,使形貌垂直性得到了更好的控制,并实现了13.3μm高度和低侧壁粗糙度的垂直硅纳米柱阵列,其高宽比(高度/半高宽)达到了36。利用不同的刻蚀工艺条件得到了不同侧壁形貌以及不同尺寸、高度的硅纳米柱结构。

Deep Reactive Ion Etching （DRIE） process on Si to achieve nanopillar arrays with large aspect ratio by using hydrogen silsesquioxane （HSQ） as etching masks has been systematically studied. Parameters in etching process such as coil power, platen power and gas flow have been optimized. The lateral etching has been reduced and the verticality has been controlled better. Under the optimized condition, 13.3 μm high Si nanopillars with good verticality, low roughness and the aspect ratio up to 36 （height/FWHM） were fabricated. And Si nanopillars with different sidewall profile, size and height were obtained using different etching conditions.