Patent ID: 8883021

Claim:
A method of forming a plurality of MEMS nano structures, the method comprising: recessing a portion of a substrate to form a plurality of mesas in the substrate, wherein at least one mesa of the plurality of mesas has a top surface and a sidewall surface adjacent to the top surface; depositing a light reflecting layer that comprises aluminum, copper, gold, silver, chromium, titanium, or mixtures thereof, over the substrate thereby covering the top surface and the sidewall surface of the at least one mesa of the plurality of mesas; forming a protection layer that comprises an oxide or nitride over the light reflecting layer; forming an anti-reflective coating (ARC) layer that comprises titanium nitride over the protection layer; forming an opening in a photo resist layer over the ARC layer over the at least one mesa of the plurality of mesas; removing a portion of the ARC layer, the protection layer and the light reflecting layer through the opening to expose the top of the at least one mesa of the plurality of mesas; and removing the photo resist layer and the ARC layer over the top surface of the at least one mesa of the plurality of mesas, wherein the ARC layer is removed in a wet solution comprising H 2 O 2 , and the ARC layer is exposed to the H 2 O 2 at a flow rate in a range of about 10 standard cubic centimeters per minute (sccm) to about 500 sccm.