CMOS image sensor and method for manufacturing the same

A CMOS image sensor comprising:

• a plurality of first micro-lenses, each of the first micro-lenses arranged over a corresponding photodiode;
• and
• a plurality of second micro-lenses formed on the planarization layer, each of the plurality of second micro-lenses wrapping a corresponding first micro-lens respectively;
• wherein the index of refraction of the first micro-lenses is smaller than the index of refraction of the second micro-lenses.

A method for manufacturing a CMOS image sensor comprising the steps of:

• forming an inter-insulation layer over a semiconductor substrate;
• forming a plurality of color filter layers on the inter-insulation to be arranged with a predetermined distance therebetween;
• forming a planarization layer on the overall surface of the semiconductor substrate including the color filter layers;
• forming a plurality of trenches having a predetermined depth in upper part of the planarization layer to correspond to the photodiodes in a one-to-one ratio;
• forming first micro-lenses in the trenches, respectively;
• and
• forming second micro-lenses on the planarization layer to wrap the first micro-lenses, respectively.