硅微电容传声器的防粘连结构

粘连是硅微电容传声器释放牺牲层过程中不容忽视的一个严重问题,大大降低了器件的成品率.在背板上制备微突出(bump)结构,可以较彻底阻止粘连现象发生,提高传声器的成品率.以往的防粘连微突出结构大都制备在上背板结构硅微电容传声器的背板上,它制备工艺简单,但是无法得到厚背板,形成“软“背板,影响传声器的性能.本文提出在下背板上制备防粘连微突出结构,因为其可以做的较厚,避免了软背板的缺点,这时利用氮化硅形成微突出,运用该法制备的硅微电容传声器有效的防止粘连现象发生.对该方案还可进行改进,利用重硼掺杂单晶硅形成微突出,该工艺流程重复性好.最终我们研制成具有防粘结构的硅微电容传声器.

Anti-Stiction Structure for Silicon Condenser Microphone

Stiction during the releasing sacrifice layers of silicon condenser microphone is a serious problem in micro-electromechanical systems (MEMS). The bumps fabricated on the backplate can effectively prevent stiction and increase the product yield. The bumps were fabricated on the upper backplate in the past. This method is simple, but it will cause a thin, flexible backplate, which decrease the sensitivity of microphone. We present an anti-stiction structure for silicon condenser microphone, which makes use of Si_3N_4 as bumps material on the lower thick backplate. The microphone fabricated using this method effectively prevents stiction. The bumps can be fabricated using heavy boron doping silicon also. This process is reproducible. Finally, the silicon condenser microphone with this anti-stiction structure was fabricated successfully.