Image sensor and method for manufacturing the sensor
An image sensor and a method for manufacturing the sensor are provided for reducing loss of light reflected from photodiodes, and thus, improving light efficiency. The method of manufacturing an image sensor can include providing a semiconductor substrate having a photodiode; and then forming a reflective film frame on the photodiode, the reflective film frame having sidewalls that are inclined with respect to the uppermost surface of the photodiode; and then forming an opening over the surface of the reflective film frame and corresponding to the photodiode by forming a reflective film on the sidewalls of the reflective film frame.
1. An image sensor comprising:
a plurality of photodiodes formed on a semiconductor substrate;
a reflective film frame formed directly on each of the photodiodes, the reflective film frame having sidewalls that are inclined with respect to the uppermost surface of the photodiodes; and
a reflective film formed directly on the sidewalls of the reflective film frame, the reflective film forming an opening over a respective one of the photodiodes for receiving light, wherein a bottom surface of the reflective film returns light reflected by the respective one of the photodiodes to the respective one of the photodiodes.
2. The image sensor of claim 1 , further comprising:
an interlayer insulating film formed on the semiconductor substrate including the reflective film;
a protective film formed on the interlayer insulating film;
a plurality of color filter layers formed on the protective film at specific intervals;
a planarization layer formed on the semiconductor substrate including the color filter layers; and
a micro lens formed on the planarization layer corresponding to a respective one of the photodiodes.
3. The image sensor of claim 1 , wherein the reflective films are composed of a metal material.
4. The image sensor of claim 1 , wherein the opening occupies between 70 to 90% of an uppermost surface area of a respective one of the photodiodes.
5. The image sensor of claim 1 , wherein the reflective film frame is composed of an oxide material.
6. The image sensor of claim 2 , wherein the interlayer insulating film comprises a plurality of insulating layers.
7. The image sensor of claim 2 , wherein the color filter layers comprise red, green and blue color filter layers.