采用CHF_3和O_2等离子体刻蚀PI的各向异性研究

研究了一种有效刻蚀聚酰亚胺(PI)的干法刻蚀方法,以金属铬为掩膜,刻蚀经涂胶并亚胺化而得到具有一定厚度的PI薄膜。利用反应离子刻蚀设备(RIE)将O2和CHF3按一定比例混合,适当调节刻蚀压力、气体比例、功率、时间等因素,可以得到侧壁和底面光洁、具有不同表面形貌的刻蚀结构。借助台阶仪和显微测量工具测定刻蚀样片,进一步得到不同工艺参数下刻蚀深宽比,并通过分析得出其他因素对PI刻蚀深宽比的影响趋势。该项研究避免了"微掩膜"效应所产生的表面粗糙问题,同时优化了刻蚀工艺,得到各向异性刻蚀的具体工艺参数,为PI不同应用目的选择刻蚀工艺提供了理论依据。

Anisotropic Study on the Plasma Etching of the Polyimide with the Mixture of CHF3 and O2

An effective dry etching process to etch the polyimide(PI) was studied.Using chromium as the mask,the PI film with a certain thickness was obtained by coating and imidization.With the equipment of the reactive ion etching(RIE),the structures of various surface morphologies which have smooth side-wall and bottom surface can be obtained by mixing O2 and CHF3 according to a certain ratio of the gases and adjusting the etching pressure,gases ratio,power,time and other factors.The etching pattern was measured with the step tester and microscopic measu-ring tools,thus the aspect ratio was obtained further.By analysis,the influence trends of other factors on the aspect ratio were achieved.The problem of the rough surface due to the effect of the micro mask exposure was avoided in the study,and the etching process was also optimized.Besides that,technological parameters of the anisotropic etching were obtained,providing the theory basis to choose etching process for different applications of the PI.