Cmos image sensor including infrared pixels having improved spectral properties, and method of manufacturing same

A CMOS image sensor CMOS image sensor including an infrared pixel with enhanced spectral characteristics, comprising:

• a photodetection layer formed over a semiconductor substrate and including a first photodiode for receiving light of a first color, a second photodiode for receiving light of a second color with a wavelength longer than that of the first color, a third photodiode for receiving light of a third color with a wavelength longer than that of the second color, and a fourth photodiode for receiving light of an infrared area;
• an interconnection layer formed over the photodetection layer;
• an insulating layer formed over the interconnection layer;
• a color filter layer formed over the insulating layer and including a first color filter, a second color filter, a third color filter, and an infrared filter formed at positions respectively corresponding to the first photodiode, the second photodiode, the third photodiode, and the fourth photodiode;
• a transparent planar layer formed over the color filter layer;
• and
• a microlens layer formed over the transparent planar layer and including a first microlens, a second microlens, a third microlens, and a fourth microlens formed at positions respectively corresponding to the first color filter, the second color filter, the third color filter, and the infrared filter,
• wherein thicknesses of the first color filter, the second color filter, the third color filter, and the infrared filter are different from one another.

A CMOS image sensor CMOS image sensor including an infrared pixel with enhanced spectral characteristics, comprising:

• a photodetection layer formed over a semiconductor substrate and including a first photodiode for receiving light of a first color, a second photodiode for receiving light of a second color with a wavelength longer than that of the first color, a third photodiode for receiving light of a third color with a wavelength longer than that of the second color, and a fourth photodiode for receiving light of an infrared area;
• an interconnection layer formed over the photodetection layer;
• an insulating layer formed over the interconnection layer;
• a first transparent planar layer formed over the insulating layer;
• a color filter layer formed over the first transparent planar layer and including a first color filter, a second color filter, a third color filter, and an infrared filter formed at positions respectively corresponding to the first photodiode, the second photodiode, the third photodiode, and the fourth photodiode;
• a second transparent planar layer formed over the color filter layer;
• and
• a microlens layer formed over the second transparent planar layer and including a first microlens, a second microlens, a third microlens, and a fourth microlens formed at positions respectively corresponding to the first color filter, the second color filter, the third color filter, and the infrared filter,
• wherein thicknesses of the first color filter, the second color filter, the third color filter, and the infrared filter are different from one another.

A manufacturing method of a CMOS image sensor CMOS image sensor including an infrared pixel with enhanced spectral characteristics, comprising:

• a photodetection layer formation step of forming a photodetection layer including a first photodiode for receiving light of a first color, a second photodiode for receiving light of a second color with a wavelength longer than that of the first color, a third photodiode for receiving light of a third color with a wavelength longer than that of the second color, and a fourth photodiode for receiving light of an infrared area over a semiconductor substrate;
• a metal interconnection layer formation step of forming a metal interconnection layer over the photodetection layer;
• an insulating layer formation step of forming an insulating layer over the metal interconnection layer;
• an etching step of etching a part of the insulating layer;
• a color filter layer formation step of forming a color filter layer including a first color filter, a second color filter, a third color filter, and an infrared filter formed at positions respectively corresponding to the first photodiode, the second photodiode, the third photodiode, and the fourth photodiode over the insulating layer with the etched part;
• a transparent planar layer formation step of forming a transparent planar layer over the color filter layer;
• and
• a microlens layer formation step of forming a microlens layer including a first microlens, a second microlens, a third microlens, and a fourth microlens formed at positions respectively corresponding to the first color filter, the second color filter, the third color filter, and the infrared filter over the transparent planar layer,
• wherein thicknesses of the first color filter, the second color filter, the third color filter, and the infrared filter formed in the color filter layer formation step are different from one another.

A manufacturing method of a CMOS image sensor CMOS image sensor including an infrared pixel with enhanced spectral characteristics, comprising:

• a photodetection layer formation step of forming a photodetection layer including a first photodiode for receiving light of a first color, a second photodiode for receiving light of a second color with a wavelength longer than that of the first color, a third photodiode for receiving light of a third color with a wavelength longer than that of the second color, and a fourth photodiode for receiving light of an infrared area over a semiconductor substrate;
• a metal interconnection layer formation step of forming a metal interconnection layer over the photodetection layer;
• an insulating layer formation step of forming an insulating layer over the metal interconnection layer;
• a first transparent planar layer formation step of forming a first transparent planar layer over the insulating layer;
• an etching step of etching a part of the first transparent planar layer;
• a color filter layer formation step of forming a color filter layer including a first color filter, a second color filter, a third color filter, and an infrared filter formed at positions respectively corresponding to the first photodiode, the second photodiode, the third photodiode, and the fourth photodiode over the first transparent planar layer;
• a second transparent planar layer formation step of forming a second transparent planar layer over the color filter layer;
• and
• a microlens layer formation step of forming a microlens layer including a first microlens, a second microlens, a third microlens, and a fourth microlens formed at positions respectively corresponding to the first color filter, the second color filter, the third color filter, and the infrared filter over the second transparent planar layer,
• wherein thicknesses of the first color filter, the second color filter, the third color filter, and the infrared filter formed in the color filter layer formation step are different from one another.