Patent ID: 8137901

Claim:
A method for fabricating an image sensor, comprising: providing a semiconductor substrate having a photosensitive region defined thereon; forming at least one photosensitive material on the semiconductor substrate; performing a first exposure process for forming a tapered pattern and a first exposure depth in the photosensitive material, wherein the first exposure depth is less than an entire thickness of the photosensitive material using a photomask and defocussed light; performing a second exposure process for forming a straight foot pattern and a second exposure depth in the photosensitive material using the photomask after performing the first exposure process for forming the tapered pattern, wherein the wavelength of the first exposure process is greater than or equal to the wavelength of the second exposure; and the first exposure depth is less than the second exposure depth; performing a developing process after two sequential exposure processes to form the photosensitive material into a plurality of photosensitive blocks; and performing a reflow process to form the photosensitive blocks into a plurality of microlenses.