Silicon-backed microdisplay with a glass-side passivation layer

Abstract

A silicon-backed microdisplay with reduced flicker and a protected glass-side conductive layer. The silicon-backed microdisplay includes a silicon die, a silicon-side conductive layer disposed on the silicon die, and a silicon-side passivation layer arranged on the silicon-side conductive layer. The silicon-backed microdisplay also includes a cover glass, a glass-side conductive layer disposed on the cover glass and a glass-side passivation layer of a predetermined material and thickness arranged on the glass-side conductive layer. Liquid crystal material is sandwiched between the glass-side passivation layer and the silicon-side passivation layer in the silicon-backed microdisplay. Visible flicker is suppressed in the microdisplay by selecting a glass-side passivation layer material (for example, CeO, InO, MgO, SnO, TaO, TiO, YO, ZnO, SiO, AlO, BeO or MgF) and thickness (for example, in the range of 300 angstroms to 900 angstroms) that improve the work function balance between (i) a combination of the glass-side conductive layer and the glass-side passivation layer and (ii) a combination of the silicon-side passivation layer and the silicon-side conductive layer. The presence of a glass-side passivation layer will also help maintain the work function balance by protecting the glass-side conductive layer surface from exposure to impurities.