An image sensor includes a light-incidence regulating layer for compensating for a refractive index deflection between a micro lens array and the atmosphere between the micro lens array and an external lens is disposed at an upper portion of the micro lens array, so that light incident on the micro lens array has a vertical direction irrespective of which portion of the external lens the light is transmitted through. Therefore, the light is incident upon all photo diodes in a semiconductor substrate in a vertical direction, and an amount of light received by the photo diodes is uniform irrespective of the positions of the photo diodes. Photocharges generated and accumulated by the photo diodes are also uniform, and the presentation quality of the image is greatly improved.
1. An image sensor, comprising:
a micro lens array for refracting incident light;
a photo diode array disposed in an active region of a semiconductor substrate for generating and accumulating photocharges through receiving the incident light from the micro lens array;
a light-transmission layer deposited on an upper part of the semiconductor substrate to cover the photo diode array for transmitting the incident light from the micro lens array onto the photo diode array; and
a light-incidence regulating layer disposed on the micro lens array for selectively refracting the incident light in order for the light from the micro lens array to be transmitted to the photo diode array in a direction vertical to the photo diode array.
2. The image sensor of claim 1 , wherein the light-incidence regulating layer has a refractive index relatively smaller than a refractive index of the micro lens array.
3. The image sensor of claim 2 , wherein the light-incidence regulating layer has a refractive index of 1.1˜1.5.
4. The image sensor of claim 1 , wherein the light-incidence regulating layer comprises a multilayer having more than two layers whose refractive indexes are different from each other.
5. The image sensor of claim 4 , wherein an upper layer of the multilayer has a refractive index relatively smaller than a refractive index of a lower layer of the multilayer.
6. The image sensor of claim 1 , wherein the light-incidence regulating layer comprises a light-transmission oxide layer.
7. The image sensor of claim 6 , wherein the light-transmission oxide layer is any one of an Undoped Silicate Glass (USG) layer, a Boron-Phosphorus Silicate Glass (BPSG) layer, a Tetra Ethyl Ortho Silicate (TEOS) layer, a High Density Plasma (HDP) Oxide layer, and a TEOS/SiH 4 layer.
8. The image sensor of claim 1 , wherein the thickness of the light-incidence regulating layer is 0.6˜1.2 μm.