Optical apparatus including multilayered optical film structure and method and apparatus for planarizing the multilayered optical film structure

A method of manufacturing an optical apparatus, the method comprising:

• forming a lower optical layer;
• forming a reflective pad in an edge region of an upper surface of the lower optical layer;
• forming an etch stop layer to a constant thickness to cover both the lower optical layer and the reflective pad;
• forming a first dielectric on the etch stop layer to a constant thickness;
• patterning a portion of the first dielectric disposed within an active region of the optical apparatus;
• forming a second dielectric to be filled in a space between patterns of the patterned first dielectric and to cover the first dielectric;
• and
• planarizing an upper surface of the second dielectric;
• wherein the planarizing comprises:
• irradiating illumination light to the reflective pad and detecting reflected light from the reflective pad;
• and
• determining a polishing speed, a thickness of the second dielectric, and an end time of the planarizing by comparing a simulated reflectance spectrum of reflected light according to the thickness of the second dielectric obtained previously through simulation with an actually measured reflectance spectrum obtained by the detecting of the reflected light,
• wherein an edge of the reflective pad proximate to the active region is disposed away from a boundary between the active region and the non-active region to form an offset away from the boundary, and
• wherein a size of the reflective pad is smaller than a size of the non-active region.

An image sensor comprising:

• a sensor substrate comprising a plurality of light sensing cells and a driving circuit;
• a meta lens layer disposed on the sensor substrate, the meta lens layer comprising an active region facing the plurality of light sensing cells and a non-active region facing the driving circuit;
• and
• a reflective pad disposed between the sensor substrate and the meta lens layer to face the non-active region of the meta lens layer,
• wherein the meta lens layer comprises a first dielectric patterned in the active region and unpatterned in the non-active region and a second dielectric filled between patterns of the first dielectric,
• wherein the first dielectric comprises a first material and the second dielectric comprises a second material different from the first material and having a different refractive index from a refractive index of the first material,
• wherein an edge of the reflective pad proximate to the active region is disposed away from a boundary between the active region and the non-active region to form an offset away from the boundary,
• wherein a size of the reflective pad is smaller than a size of the non-active region.