Patent ID: 7923798

Claim:
An optical device comprising: a light receiving element chip having an active region, a circuit region, a penetrating conductor, and an external connection terminal, 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; a microlens provided over the active region to be associated with each of the light receiving pixels; a planarization film which is formed over the principal plane of the light receiving element chip to cover the microlens and planarize unevenness of the microlens and which is made of a transparent member having a lower refractive index than the microlens; and a transparent protective film formed on the planarization film and made of a transparent inorganic material transparent to visible light, wherein the transparent protective film is formed to continuously extend from a top surface of the planarization film to and along a side surface of the planarization film.