A CMOS image sensor and a method for fabricating the same for preventing contamination and peeling of an array of micro lenses. The CMOS image sensor includes a plurality of photodiodes formed on and/or over a substrate, an insulating film formed on and/or over an entire surface of the substrate including the photodiodes, color filter layers formed on and/or over the insulating film, a first oxide film formed on and/or over the color filter layers, an ion-rich oxide film formed by injecting silicon ions into the first oxide film, a second oxide film formed on and/or over the ion-rich oxide film, and a micro lens pattern formed corresponding to the photodiodes by patterning the second oxide film.