Patent ID: 7557031

Claim:
A method for fabricating a liquid crystal on silicon (“LCOS”) device, the method comprising: providing a silicon substrate having a surface region; forming an interlayer dielectric layer overlying the surface region of the substrate; patterning the interlayer dielectric layer to form a plurality of recessed regions, each of the recessed regions corresponding to a pixel element for a LCOS device, each of the recessed regions being isolated by a portion of dielectric material defining a border for each of the recessed regions, each of the border regions forming a peripheral region surrounding each recessed region; depositing an aluminum material or aluminum alloy material within each of the recessed regions to fill each of the recessed regions and to cover exposed portions of the border regions; forming a photomask overlying the aluminum material; patterning the photomask to expose regions corresponding to the recessed regions and protecting regions corresponding to the border regions; removing exposed regions of the aluminum material using an etching process while protecting the regions corresponding to the border regions with the photomask; continuing the removing using the etching process until the aluminum material has been removed to a vicinity of an upper region of the border regions; stripping the patterned photomask to expose protruding aluminum material, the protruding aluminum material surrounding the patterned aluminum material; and touch-up polishing the protruding aluminum material and portions of the patterned aluminum material while using the border regions as a polish stop to planarize an upper surface region formed by the border regions and the patterned aluminum material; whereupon each of the border regions being characterized by a thickness of about 1 micron and less.