Abstract: Surface polysilicon micromachined micromirrors require ultra-flat surfaces for advance optical applications such as adaptive optics. This paper details the planarization of micromirrors using chemical-mechanical polishing. We show that the increase in topography is due to a high temperature anneal step downstream for the CMP process itself. Two process alternatives were investigated: (1) perform a CMP step after the high temperature anneal step, and (2) perform a CMP step on a final polysilicon mirror surface. Both process alternatives produced acceptable flatness requirements for micromirror applications.!14
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