Method of fabricating an image sensor

A method of fabricating an image sensor on a semiconductor substrate having a sensor array, the fabricating method comprising steps of:

• forming a first planar layer on the semiconductor substrate;
• forming a color filter array on the first planar layer, wherein the color filter array is formed above the corresponding sensor array area;
• forming a second planar layer on the color filter array;
• forming a plurality of U-lenses on the second planar layer, wherein the U-lenses are formed above the corresponding color filter array;
• and
• performing a plasma-enhanced chemical vapor deposition process using tetraethosiloxane (TEOS) as a reactive gas to form a conformal passivation layer over the U-lenses and the second planar layer, wherein the passivation layer is formed under the conditions that include applying radio frequency at a power rating between about 250 W˜450 W, applying a pressure of between 2˜4 Torrs and passing TEOS gas at a mass flow rate between 150˜500 mg/m.