Yankov D Y, Schreiter S
Inst. of Solid State Phys., Bulgarian Acad. of Sci., Sofia.
IEEE Trans Ultrason Ferroelectr Freq Control. 1993;40(4):431-4. doi: 10.1109/58.251296.
A hollow cathode maskless plasma etching method for fabrication of thin quartz membranes is presented. A special geometric arrangement of electrodes and substrates allows the complete plasma structure (plasma sheath, bulk plasma) to be transferred to the substrate area during the etching process. The process has successfully been used in preparing thin quartz membranes with plane-convex and plane-parallel shape, and thicknesses of less than 5 mum. Vibration modes in these thin quartz membranes are calculated using the method of equivalent resonant radius. The membranes are used for realization of bulk acoustic wave resonators at fundamental frequencies above 60 MHz. Good agreement between theoretical and experimental characteristics is achieved.
本文介绍了一种用于制造薄石英膜的空心阴极无掩膜等离子体蚀刻方法。电极和基板的特殊几何排列使得在蚀刻过程中完整的等离子体结构（等离子体鞘层、体等离子体）能够转移到基板区域。该工艺已成功用于制备平面凸面和平面平行形状、厚度小于5微米的薄石英膜。使用等效共振半径法计算这些薄石英膜中的振动模式。这些膜用于实现60 MHz以上基频的体声波谐振器。理论特性与实验特性之间取得了良好的一致性。
