【摘要】 通过干法刻蚀,在Si衬底上制备出高深宽比的台阶结构是MEMS加工的基础工艺之一。多层台阶的刻蚀,是一种重要的折线断面制备方法,使实现结构更加复杂的器件成为可能。利用LPCVD生长1μm厚SiO2作为钝化层,围绕多层台阶掩膜的制备方法和移除方法展开实验,以3层台阶为例,开发出一套使用一块光刻版制造任意宽度的台阶掩膜的方法。该方法节约成本、操作简便、重复性好,为加工复杂的三维结构提供了一种新的手段。另外,针对在深刻蚀过程中残留的掩膜会破坏Si台阶完整性的问题,研究了刻蚀过程中SiO2掩膜的去除方法对台阶的表面形貌造成的影响。通过实验发现,采用干湿腐蚀结合的方法可以有效地去除台阶掩膜,获得良好的Si深台阶结构。更多还原

【Abstract】 Dry etching of high aspect ratio Si steps is a basic technique in MEMS.Many complicated MEMS-chips are fabricated by multi-step etching method.1 μm SiO2 as a passive layer was prepared by LPCVD.The experiments of depositing and removing passive layers were studied.And taking three steps as an example,a method of preparing passive layers by using one mask was developed.Instead of using different masks,this method is economy,easy to operate,and repeatable.What’s more,the remaining of passive layers may damage the step surface in the process of dry etching.Therefore,the effect of removing method of SiO2 masks on the step surface during the process was studied.The experiment shows that the method combined dry etching and wet etching can remove the step mask effectively and obtain a better Si step structure.更多还原