Multi-substrate image sensor device and method with metalens

A method of forming an image sensor device comprising:

• providing a first substrate including at least one visible light photosensor configured to detect visible light;
• forming a first dielectric region on a first side of the first substrate that includes one or more patterned metallization layers, the first dielectric region having a first side distal from the first substate;
• providing a second substrate including at least one infrared light photosensor configured to detect infrared light;
• forming a second dielectric region disposed on a first side of the second substrate that includes one or more patterned metallization layers, the second dielectric region having a first side distal from the second semiconductor;
• forming a metalens in the second side of the second substrate, the first side of the first dielectric region, or the first side of the second dielectric region, the forming of the metalens including etching a grid structure and coating a surface of the grid structure with a TiO2, Ta2O5, or ZrO2 coating;
• and
• bonding together the first sides of the respective first and second dielectric regions, the bonding including electrically connecting the one or more patterned metallization layers of the first dielectric region and the one or more patterned metallization layers of the second dielectric region.

An RGB (Red Green Blue) CIS (CMOS Image Sensor) device comprising:

• a first substrate including a back surface and a front surface opposite the back surface, the first substrate including:
• a red photosensitive region, a green photosensitive region, and a blue photosensitive region, the red, green, and blue photosensitive regions disposed between the front surface and the back surface, and the photosensitive regions separated by deep isolation trenches;
• and
• a dielectric region extending from the photosensitive regions to the front surface;
• and
• a second substrate including a back surface and a front surface opposite the back surface, the second substrate including a radiation sensing detector region disposed between the back surface and the front surface, and a dielectric region extending from the radiation sensing detector region to the back surface,
• wherein one of the first substrate dielectric region and the second substrate dielectric region includes a metalens grid structure optically aligned with each of the red, green, and blue image detection regions to focus incident radiation of a target wavelength to the second substrate radiation sensing detector and to direct light of an unwanted wavelength away from the second substrate radiation sensing detector, the incident radiation passing thru the first substrate to the second substrate radiation sensing detector, and the first substrate and second substrate are stacked and bonded to:
• a) connect the first substrate dielectric region and the second substrate dielectric region and b) optically align the photosensitive and the radiation sensing detector region.