Semiconductor device having stress-neutralized film stack and method of fabricating same
AssigneeTaiwan Semiconductor Manufacturing Company, Ltd.
InventorsChi-Ming Lu, Chih-Hui Huang, Sheng-Chan Li, Jung-Chih Tsao, Yao-Hsiang Liang
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Abstract
A method of fabricating a semiconductor device includes forming a first film having a first film stress type and a first film stress intensity over a substrate and forming a second film having a second film stress type and a second film stress intensity over the first film. The second film stress type is different than the first film stress type. The second film stress intensity is about same as the first film stress intensity. The second film compensates stress induced effect of non-flatness of the substrate by the first film.
Claims20
A method comprising:
- forming a metal grid over an image sensor device, wherein the metal grid includes an opening aligned with a light sensing region of the image sensor device, and further wherein the forming the metal grid includes:
- forming a first metal film consisting of a first metal having a first stress type over a substrate;
- and
- forming a second metal film consisting of a second metal having a second stress type over the first metal film, wherein the second stress type is different than the first stress type.
A method comprising:
- forming a pair of metal films over a substrate that includes a plurality of image sensor elements, the pair of metal films having a first metal film consisting of a first metal with a compressive stress and a second metal film consisting of a second metal having tensile stress;
- forming a patterned resist layer over the pair of metal films, wherein the patterned resist layer has a plurality of openings, each of the plurality of openings aligned with a respective one of the plurality of image sensor elements;
- and
- etching the pair of metal films through the plurality of openings.
A method comprising:
- forming a metal layer stack that includes a first metal layer consisting of a first metal having a first stress type and a second metal layer consisting of a second metal having a second stress type, wherein the first stress type is opposite the second stress type;
- and
- patterning the metal layer stack to form an opening in the metal layer stack that is aligned with an image sensor element.
Dependencies are inferred from the claim text.