Method and structure for fabricating smooth mirrors for liquid crystal on silicon devices

摘要

A liquid crystal on silicon (LCOS) device includes a semiconductor substrate, a metal-oxide semiconductor (MOS) device layer overlying the semiconductor substrate, a planarized interlayer dielectric layer overlying the MOS device layer, a plurality of recessed regions formed within a portion of the interlayer dielectric layer, a metal layer filling each of the recessed regions to form a plurality of respective electrode plates corresponding to each of the recessed regions. The LCOS device further includes a protective layer overlying a surface of each of the plurality of electrode plates, a liquid crystal film overlying the protective layer, and a mirror finish formed on each of the surface of the electrode plates for reflecting light. The mirror finish is substantially free from dishes and scratches from a chemical mechanical polishing process.

主权项

1. A liquid crystal on silicon (LCOS) device, the device comprising:
a semiconductor substrate; a metal-oxide semiconductor (MOS) device layer overlying the semiconductor substrate, the MOS device layer having a plurality of MOS devices; a planarized interlayer dielectric layer overlying the MOS device layer; a plurality of recessed regions formed within a portion of the planarized interlayer dielectric layer; an aluminum layer filling each of the recessed regions to form a plurality of respective electrode plates corresponding to each of the recessed regions, the aluminum layer having a smooth surface free from any dimple, each of the electrode plates being coupled to each one of the MOS devices; a protective layer of only an aluminum oxide layer directly overlying a surface of each of the plurality of electrode plates, the protective layer formed by exposing the electrode plates to an oxidizing fluid; a liquid crystal film directly overlying the protective layer; and a mirror finish formed on the surface of each of the electrode plates for reflecting light by a chemical mechanical polishing process, the mirror finish being substantially free from dishes and scratches.