Optical device and method for fabricating the same, camera module using optical device, and electronic equipment mounting camera module

A method for fabricating an optical device, the method comprising the steps of:

• preparing a light-receiving-element wafer in which a plurality of light receiving element chips each including an active region, a circuit region, a penetrating conductor, and an external connection terminal are arranged at regular arrangement pitches, the active region being formed on a principal plane of a substrate and made by arranging a plurality of light receiving pixels, the circuit region being disposed around an outer circumference of the active region, the penetrating conductor being provided to penetrate the substrate in the thickness direction of the substrate, the external connection terminal being provided on a back surface of the substrate facing the principal plane thereof and connected to the penetrating conductor;
• forming, in the state of the light-receiving-element wafer, a microlens over the active region to be associated with each of the light receiving pixels;
• forming, in the state of the light-receiving-element wafer, a planarization film over the principal plane of the light receiving element chip to cover the microlens and planarize unevenness of the microlens, the planarization film being made of a transparent member having a lower refractive index than the microlens;
• removing, in the state of the light-receiving-element wafer, portions of the planarization film located in and around a dicing region for cutting the wafer into the light receiving element chips, thereby exposing portions of the principal plane of the substrate;
• forming, in the state of the light-receiving-element wafer, a transparent protective film to continuously extend from a top surface of the planarization film to and along a side surface of the planarization film, the transparent protective film being made of a transparent inorganic material transparent to visible light;
• and
• subjecting the light-receiving-element wafer to dicing along the dicing region to cut the wafer into chips.