Method of manufacturing LCOS spacers

A method for forming a liquid crystal on silicon (LCOS) display spacer and groove in a multi-step etching process comprising the steps of:

• providing a silicon substrate comprising a first overlying silicon oxide layer and metal pixel electrodes;
• forming a second silicon oxide layer over the metal pixel electrodes;
• forming a hardmask layer comprising silicon nitride over the second silicon oxide layer;
• photolithographically patterning a resist layer and performing a first plasma etch process to form a spacer spanning a first pair of metal pixel electrodes including forming a polymer passivation layer over the spacer sidewalls;
• removing remaining resist layer portions and polymer passivation layer according to a wet etching process;
• and,
• carrying out a second plasma etching process to etch a groove into the first silicon oxide layer between a metal pixel electrode formed adjacent the first pair of metal pixel electrodes and the first pair of metal pixel electrodes.