US Patent 11177303 Image sensor and semiconductor structure

Present disclosure provides a pixel for receiving an incident light, the pixel including a semiconductor substrate, a photo diode in the semiconductor substrate, and a metasurface structure over the semiconductor substrate. The metasurface structure has a first side and a second side opposite to the first side, the first side of the metasurface structure facing the semiconductor substrate, the second side of the metasurface structure facing the incident light. The metasurface structure includes a plurality of trenches at the second side, wherein the plurality of trenches have a same profile from a cross-sectional view.