Patent ID: 9093576
Filing Date: 2015-07-28
Classification: B29D,H01L

Abstract:
1. A method of manufacturing an image sensor including a microlens array, the method comprising: (a) forming a microlens-forming layer on one side of a substrate, wherein the microlens-forming layer comprises a multinary compound semiconductor material whose composition ratio of oxidation element is gradually increased in a direction away from the substrate; (b) forming photo-detector forming layer on opposite side of the substrate, the photo-detector forming layer including a lower ohmic contact layer, an active layer, and an upper ohmic contact layer; (c) after step (b), forming a plurality of mesa structures by etching a predetermined region of the microlens-forming layer until the substrate is exposed, the plurality of mesa structures spaced a predetermined distance apart from one another and having exposed lateral surfaces, respectively; (d) oxidizing a lateral surface of each of the mesa structures and thereafter selectively removing oxidized regions to form microlenses having a radius of curvature in the centers of the respective mesa structures; and, (e) forming a plurality of photo-detectors on the opposite side of the substrate to respectively correspond to the microlenses, by performing a process including; a step of selectively etching both of the active layer and the upper ohmic contact layer; a step of selectively etching the lower contact layer to selectively, expose the opposite side of the substrate; and a step of forming a passivation layer on the lower contact layer and the upper ohmic contact layer.