Semiconductor structure and method for manufacturing the same

A semiconductor structure, comprising:

• a semiconductor substrate including a front surface and a back surface;
• a color filter arranged over the back surface of the semiconductor substrate;
• an optical lens arranged over the color filter;
• and
• a heterogeneous radiation-sensing region in the semiconductor substrate and adjacent to the front surface of the semiconductor substrate;
• wherein the semiconductor substrate has a crystal orientation allowing a cavity with a sidewall perpendicular to the front surface of the semiconductor substrate to be formed when the semiconductor substrate is wet etched at the front surface;
• wherein a facet of the semiconductor substrate adjacent to each of the sidewalls of the heterogeneous radiation-sensing region is in <111> direction.

A semiconductor structure, comprising:

• a semiconductor substrate including a front surface and a back surface;
• a color filter arranged over the back surface of the semiconductor substrate;
• an optical lens arranged over the color filter;
• and
• a heterogeneous radiation-sensing region in the semiconductor substrate at the front surface of the semiconductor substrate, and sidewalls of the heterogeneous radiation-sensing region being perpendicular to the front surface of the semiconductor substrate;
• wherein a facet of the semiconductor substrate adjacent to each of the sidewalls of the heterogeneous radiation-sensing region is in <111> direction.