Color filter including clear pixel and hard mask

A process for forming a color filter arrangement, the process comprising:

• depositing a clear layer over a surface of a substrate, the substrate having a pixel array formed therein;
• patterning and etching the clear layer to form a first opening;
• depositing a first color filter material in the first opening;
• depositing a first clear hard mask layer over the clear layer and the first color filter material;
• patterning and etching the first clear hard mask layer and the clear layer to form a second opening;
• depositing a second color filter material in the second opening;
• depositing a second clear hard mask layer over the first clear hard mask layer and the second color filter material;
• patterning and etching the second clear hard mask layer, the first clear hard mask layer, and the clear layer to form a third opening;
• and
• depositing a third color filter material in the third opening.

An apparatus comprising:

• a substrate having a front side and a back side;
• an image sensor including a pixel array formed in or on the front side of the substrate;
• a color filter arrangement formed over a corresponding number of pixels of the pixel array, the color filter arrangement including a set of filters comprising:
• a clear filter having a first clear hard mask layer and a second clear hard mask layer formed thereon;
• a first color filter having the first clear hard mask layer and the second hard mask layer formed thereon;
• a second color filter having the first clear hard mask layer formed thereon, and
• a third color filter having no clear hard mask layer formed thereon.