石英音叉微细加工若干问题探讨

Investigation of Some Problems on Micromachining Process for Quartz Tuning Fork

采用基于半导体工艺的光刻、化学腐蚀等微细加工方法在石英晶体基片上批量制作石英音叉。化学腐蚀石英音叉时,叉指的一个侧面中央有棱角,腐蚀速率先慢后快有利于棱角的消除,但去掉棱角的主要方法是增加腐蚀时间;实验探索了能够耐受长时间腐蚀液浸泡的Cr/Au掩模的制作方法和工艺,成功地腐蚀出石英音叉样品;选用黑白反相的十字套准标记进行石英音叉图形的双面光刻套准可以减小人为对准误差,腐蚀出的双面音叉图形的套准精度可小于3μm。石英晶体结构的三角对称性和Cr/Au掩模的耐腐蚀性是限制微细加工制作石英音叉达到理想形状的关键。

The quartz tuning fork is manufactured by means of the batch-fabrication of the micromachining process based on semiconductor industry,such as photolithography,chemical etching etc,and the samples of the quartz tuning fork are successfully made out.There is a pointed edge on the center of the one side face of the quartz tuning fork,which should be get rid of by prolonging the etching time.The etching rate is slow at first,and becomes faster in the last of etching duration to help the edge pointless.The process of Cr/Au mask coating which is dipped in the etching solvent for tens hours are investigated by experiments.The superposition accuracy of double-side tuning fork pattern is less 3?μm on condition that cross mark symbols with opposite phases are used.The trigonal symmetry of the quartz crystal and the corrosive-resistance of Cr/Au mask are the keys to limit the outline of the quartz tuning fork.