Titanium isotropic and anisotropic etching for MEMS applications
Résumé
Titanium (Ti) exhibits several advantages for the fabrication of microelectromechanical systems (MEMS), due to its remarkable properties such as good corrosion resistance and biocompatibility. Recent advances in titanium micromachining provide an opportunity to create such microdevices. Motivated by this opportunity, we discuss our efforts to advance Ti MEMS technology by developing a novel fluorine-based reactive ion etching (RIE) process. Bulk Ti was etched in an inductively coupled plasma (ICP) using a mixture of sulfur hexafluoride, oxygen, and argon. Etch rates and anisotropy have been investigated as a function of gas flow rates and self-bias voltage. Ti structures with smooth etched surfaces were performed isotropically and anisotropically, with vertical etch rates of 3 and 2 µm/min respectively.