COMPLEMENTARY METAL OXIDE SEMICONDUCTOR IMAGE SENSOR AND METHOD FOR FABRICATING THE SAME

Abstract

Provided are a CMOS image sensor and a method for fabricating the same. A nanopillar is plurally formed at an upper end of a light receiving element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described in detail with reference to the following drawings in which like numerals refer to like elements.

FIG. 1 is a plan view illustrating a conventional CMOS image sensor;

FIG. 2 is a cross-sectional view taken along line 2-2′ of FIG. 1;

FIG. 3 is a plan view illustrating a CMOS image sensor according to the present invention;

FIG. 4 is a cross-sectional view taken along line 4-4′ of FIG. 3;

FIG. 5 is a sequential diagram illustrating a method for fabricating a CMOS image sensor according to an exemplary embodiment of the present invention;

FIG. 6 is a photograph taken by a scanning electron microscopy (SEM), for illustrating a CMOS image sensor fabricated by the method of FIG. 5;

FIG. 7 is a sequential diagram illustrating a method for fabricating a CMOS image sensor according to another exemplary embodiment of the present invention; and

FIG. 8 is a photograph taken by a SEM, for illustrating a CMOS image sensor fabricated by the method of FIG. 7.

Claims

1. A CMOS (complementary metal oxide semiconductor) image sensor comprising: a light receiving element; anda nanopillar formed at an upper end of the light receiving element.

2. The CMOS image sensor of claim 1, wherein the nanopillar is of crystalline silicon.

3. The CMOS image sensor of claim 1, wherein the nanopillar has a diameter of nanometer or less.

4. A method for fabricating a CMOS image sensor, the method comprising steps of: inducing a plasma discharge and forming nanodusts in a light receiving region;etching the light receiving region using the nanodusts as a mask; andremoving the nanodusts.

5. The method of claim 4, wherein the inducing of the plasma discharge comprises a step of injecting the plasma gas into the light receiving region.

6. The method of claim 5, wherein, in the inducing of the plasma discharge, the nanodusts are formed by a combination of the plasma gas and the light receiving element at the time of inducing the plasma discharge.

7. The method of claim 6, wherein the material of the light receiving element is silicon.

8. The method of claim 5, wherein the plasma gas is a halogen-based compound and oxygen (O2).

9. The method of claim 4, wherein the nanodusts have sizes of nanometer or less.

10. A method for fabricating a CMOS image sensor, the method comprising steps of: arranging nanometer sized particles in a light receiving region;etching the light receiving region using the particles as a mask; andremoving the particles.

11. The method of claim 10, wherein the particles are formed of polymer component.

12. The method of claim 10, wherein a diameter of a nanopillar formed by the etching is dependent on a diameter of the particle.

13. The method of claim 10, wherein a nanopillar formed by the etching has a diameter of nanometer or less.

14. The method of claim 10, wherein the particle is a sphere ball.