Grids in Backside Illumination Image Sensor Chips and Methods for Forming the Same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsShiu-Ko JangJian, Szu-An Wu, Sheng-Wen Chen
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Abstract
A device includes a semiconductor substrate, which has a front side and a backside. A photo-sensitive device is disposed on the front side of the semiconductor substrate. A first and a second grid line are parallel to each other, and are disposed on the backside of, and overlying, the semiconductor substrate. A stacked layer includes an adhesion layer, a metal layer over the adhesion layer, and a high-refractive index layer over the metal layer. The adhesion layer, the metal layer, and the high-refractive index layer are substantially conformal, and extend on top surfaces and sidewalls of the first and the second grid lines.
Claims20
A method comprising:
- forming a plurality of photo-sensitive devices in a semiconductor substrate;
- forming a grid layer on a backside of the semiconductor substrate;
- patterning the grid layer to form a plurality of grid lines, wherein grid openings between the plurality of grid lines are aligned to the plurality of photo-sensitive devices;
- forming a stacked layer on top surfaces and sidewalls of the plurality of grid lines, wherein the forming the stacked layer comprises:
- forming an adhesion layer;
- forming a metal layer over the adhesion layer;
- and
- forming a dielectric layer over the metal layer;
- and
- patterning the stacked layer to remove portions of the stacked layer in the grid openings.
A method comprising:
- forming a grid comprising a plurality of grid lines, and grid openings defined by, and between, the grid lines;
- forming a stacked layer on top surfaces and sidewalls of the plurality of grid lines, wherein the forming the stacked layer comprises:
- blanket forming a first metal layer;
- blanket forming a second metal layer over the first metal layer, wherein the first metal layer and the second metal layer comprise different metals;
- and
- forming a dielectric layer over the second metal layer;
- and
- removing portions of the stacked layer in the grid openings.
A method comprising:
- forming a grid comprising a plurality of grid lines, with grid openings between the grid lines;
- forming a stacked layer on top surfaces and sidewalls of the plurality of grid lines, wherein the forming the stacked layer comprises:
- forming a first metal layer;
- forming a second metal layer over the first metal layer;
- and
- forming a first transparent layer over the second metal layer, wherein each of the first metal layer, the second metal layer, and the first transparent layer comprises first portions on sidewalls of the grid lines, and second portions at bottoms of the grid opening;
- removing the second portions of the stacked layer;
- and
- filling remaining portions of the grid openings with a second transparent layer.
Dependencies are inferred from the claim text.