Pixel sensor cell including light shield

摘要

CMOS image sensor pixel sensor cells, methods for fabricating the pixel sensor cells and design structures for fabricating the pixel sensor cells are designed to allow for back side illumination in global shutter mode by providing light shielding from back side illumination of at least one transistor within the pixel sensor cells. In a first particular generalized embodiment, a light shielding layer is located and formed interposed between a first semiconductor layer that includes a photoactive region and a second semiconductor layer that includes the at least a second transistor, or a floating diffusion, that is shielded by the light blocking layer. In a second generalized embodiment, a thin film transistor and a metal-insulator-metal capacitor are used in place of a floating diffusion, and located shielded in a dielectric isolated metallization stack over a carrier substrate.

主权项

1. A pixel sensor cell comprising:
a photoactive region located within a first semiconductor layer, wherein the first semiconductor layer is located a second semiconductor layer; a transistor located partially within the second semiconductor layer, wherein the second semiconductor layer is located a carrier substrate; a light blocking layer located interposed between the first semiconductor layer and the second semiconductor layer and shielding the transistor from back side illumination; and a contact region comprised of a semiconductor material extending through the light blocking layer, wherein the contact region contacts the first semiconductor layer and the second semiconductor layer.