Patent ID: 7898049
Filing Date: 2011-03-01
Classification: H01L

Abstract:
1. A method for fabricating a microlens structure in a pixel sensor array comprising the steps of: a. providing a substrate including a plurality of light sensitive elements adapted to receive light incident to a respective pixel microlens; b. forming a single photoresist material layer over said substrate; c. applying an anti-reflective coating layer on top of said single photoresist material layer; d. patterning said single photoresist layer using a first sub-resolution condition to form microlens structure images, said first sub-resolution condition applied in a manner sufficient to form partially connected lens portions at gaps between adjacent microlens structures; e. developing said single photoresist layer to partially form the patterned microlens structures having partially connected lens portions at said gaps; f. blanket applying a second sub-resolution condition to the partially formed microlens structures; and g. thermally reflowing said partially formed microlens structures, wherein each microlens structure is webbed such that said microlens structure touches a microlens structure of an adjacent pixel in said array, wherein said thermally reflowing increases a curvature of said microlens structure to be uniform in all directions to thereby maximize collection of light incident to the microlens structure from all directions, said microlens structure of each microlens having a curvature uniformity exhibited at all pixel locations including those at a pixel array edge or corner.