7740玻璃湿法腐蚀凹槽及槽内光刻图形的研究

Studies of Wet Etching of 7740 Glass and Lithography in Grooves

用玻璃腐蚀工艺制作MEMS器件,腐蚀非常困难.通过对PYREX7740玻璃在Buffer溶液中腐蚀速率的研究发现,PYREX7740玻璃腐蚀1μm的槽需要25min,而作为掩膜的光刻胶在腐蚀液中只能保持10min不浮胶.为此,文中详细介绍了运用一次光刻,多次坚膜,多次腐蚀的工艺,来达到对PYREX7740玻璃进行深腐蚀的方法.实验结果表明,光刻胶厚度、坚膜时间、坚膜次数和坚膜温度都与光刻胶的浮胶有关,最后给出了不同条件下凹槽深度与所需的曝光和显影时间的关系,槽越深需要的曝光和显影时间越长.这对于用PYREX7740玻璃制作MEMS器件具有重要意义.

In general,the MEMS devices are not fabricated by glass etching because the glass etching technology is quite difficulty.The study of etching rate of PYREX7740 glass in Buffer solution indicated that more than 25 minutes should be spent to get 1 μm grooves in PYREX7740 glass,whereas photoresist can stand ten minutes in Buffer solution at most.In order to obtain deep grooves in PYREX7740 glass,a method of lithography only once,multiple hardening and etching was introduced.The experiment results show that the photoresist thickness,the hardening time and times as well as the hardening temperature all affect the floating of photoresist.Final,the relation of etching depth with exposure and development time in different conditions is given.The deeper the groove is,the more exposure and development time will be needed.It is very important for fabricating MEMS devices.