Patent ID: 6858459

Claim:
A method of forming a single crystal micro-mirror switching device comprising: forming n-type silicon on p-type silicon substrate; forming a p-n junction; forming deep trenches in n-type silicon; filling said trenches with sacrificial silicon dioxide and planarizing said sacrificial silicon dioxide; depositing sacrificial silicon dioxide layer-1 on said planarized surface and patterning said sacrificial silicon dioxide layer-1; depositing protective dielectric layers over said sacrificial silicon dioxide layer-1 and patterning said dielectric layers; depositing sacrificial silicon dioxide layer-2 over said patterned dielectric layers; depositing poly-silicon layer-1 over said sacrificial silicon dioxide layer-2 and patterning said poly-silicon layer-1; depositing sacrificial silicon dioxide layer-3 over said patterned poly-silicon layer-1 and patterning said sacrificial silicon dioxide layers-2 and -3; depositing poly-silicon layer-2 over said patterned silicon dioxide layers-2 and -3 and patterning said poly-silicon layer-2; forming metal mirror by depositing metal on the wafer and patterning metal; forming the device structures with a release process comprising of multiple etching steps.