Formation of buried color filters in a back side illuminated image sensor using an etching-stop layer

摘要

A semiconductor image sensor includes a substrate having a first side and a second side that is opposite the first side. An interconnect structure is disposed over the first side of the substrate. A plurality of radiation-sensing regions is located in the substrate. The radiation-sensing regions are configured to sense radiation that enters the substrate from the second side. A buffer layer is disposed over the second side of the substrate. A plurality of elements is disposed over the buffer layer. The elements and the buffer layer have different material compositions. A plurality of light-blocking structures is disposed over the plurality of elements, respectively. The radiation-sensing regions are respectively aligned with a plurality of openings defined by the light-blocking structures, the elements, and the buffer layer.

主权项

1. A semiconductor image sensor device, comprising:
a substrate having a first side and a second side that is opposite the first side; an interconnect structure disposed over the first side of the substrate; a plurality of radiation-sensing regions located in the substrate, the radiation-sensing regions being configured to sense radiation that enters the substrate from the second side; a buffer layer disposed over the second side of the substrate; a plurality of elements disposed over the buffer layer, wherein the elements and the buffer layer have different material compositions; a plurality of light-blocking structures disposed over the plurality of elements, respectively; and a plurality of color filters; wherein the radiation-sensing regions are respectively aligned with a plurality of openings defined by the light-blocking structures, the elements, and the buffer layer, and wherein each of the color filters is disposed in a respective one of the openings.