A method for manufacturing an image sensor device

A method for fabricating an image sensor device is disclosed. The method for fabricating an image sensor device comprises forming a photosensitive layer on a substrate. The photosensitive layer is exposed through a first photomask to form an exposed portion and an unexposed portion. The unexposed portion is partially exposed through a second photomask to form a trimmed part, wherein the second photomask comprise a first segment and a second segment that has a transmittance greater than that of the first segment. The trimmed part is removed to form photosensitive structures. The photosensitivestructures are reflowed to form a first microlens and a second microlens having different heights. The method can simply contorl the each microlens, so as to have an optimul height to improve the photosensitivity of the image sensor device.