Enhanced lift-off techniques for use with dielectric optical coatings and light sensors produced therefrom

Abstract

Light sensors including dielectric optical coatings to shape their spectral responses, and methods for fabricating such light sensors in a manner that accelerates lift-off processes and increases process margins, are described herein. In certain embodiments, a short duration soft bake is performed. Alternatively, or additionally, temperature cycling is performed. Alternatively, or additionally, photolithography is performed using a photomask that includes one or more dummy corners, dummy islands and/or dummy rings. Each of the aforementioned embodiments form and/or increase a number of micro-cracks in the dielectric optical coating not covering the photodetector sensor region, thereby enabling an accelerated lift-off process and an increased process margin. Alternatively, or additionally, a portion of the photomask can include chamfered corners so that the dielectric optical coating includes chamfered corners, which improves the thermal reliability of the dielectric optical coating.