Bulk Micromachined Titanium Micromirror Device with Sloping Electrode Geometry

This paper reports the fabrication of a bulk micromachined hybrid torsional micromirror device composed of titanium mirror structures bonded to an underlying silicon sloping electrode structure. The fabrication of the device is enabled by two recent innovations: 1) the Metal Anisotropic Reactive Ion etching with Oxidation (MARIO) Process [1], which provides, for the first time, high aspect ratio micromachining capability in bulk titanium; and 2) the High Aspect Ratio Laminated Metal Micromachining (HARLMM) Process, which allows for creation of complex, multilayer titanium devices and heterointegration of these devices with dissimilar material substrates. This work represents the first demonstration of the MARIO and HARLMM Processes in a device application. Details on the fabrication of the device are presented illustrating the simplifications made possible by these two processes and additional simplifications made possible by the single-mask process used to create the sloping electrode structure.