Taiwan Semiconductor Manufacturing Comp. Ltd.

Yu-Hao Shih

Dun-Nian Yaung

Jen-Cheng Liu

Szu-Ying Chen

Volume Chien

Hsing-Lung Chen

Cheng-Ta Wu

Shih Pei Chou

U-Ting Chen

Chih-Chien Wang

Wei-Tung Huang

A method of forming an image sensor device where the method includes forming a first dielectric layer on a substrate. The method further includes patterning the first dielectric layer to define an area for a reflective shield, where the area defined for the reflective shield is above a photodiode. Additionally, the method includes forming the reflective shield on the substrate by filling the defined area with a high reflectivity material, and the high reflective material comprises a polymer.

Method of making image sensor devices having a concave reflective shield

A method of forming of an image sensor device includes a substrate having a pixel region and a periphery region. A plurality of first trenches is etched in the periphery region. Each of the first trenches has a depth D. A mask layer is formed over the substrate. The mask layer has a plurality of openings in the pixel region. A spacer is formed in an interior surface of each opening. A plurality of second trenches is etched through each opening having the spacer in the pixel region. Each of the second trenches has a depth D. The depth Dis larger than the depth D.

Image device and methods of forming the same

A method of creating a reflective shield for an image sensor device includes depositing a first dielectric layer on a substrate, wherein a photodiode is on the substrate. The method further includes removing surface topography by performing chemical mechanical polishing (CMP) on the first dielectric layer. The method further includes patterning the substrate to define an area on a surface of the first dielectric layer, wherein the area is directly above the photodiode. The method further includes depositing a layer of a material with high reflectivity on the substrate, wherein the material fills the area on the surface of the first dielectric layer. The method further includes removing excess material with high reflectivity, wherein the reflective shield is formed and is embedded in the first dielectric layer. The method further includes depositing a second dielectric material on the substrate, wherein the second dielectric material covers the reflective shield.

Method of making a reflective shield

The structures of reflective shields and methods of making such structures described enable reflection of light that has not be absorbed by photodiodes in image sensor devices and increase quantum efficiency of the photodiodes. Such structures can be applied (or used) for any image sensors to improve image quality. Such structures are particular useful for image sensors with smaller pixel sizes and for long-wavelength light (or rays), whose absorption length (or depth) could be insufficient, especially for backside illumination (BSI) devices. The reflective shields could double, or more than double, the absorption depth for light passing through the image sensors and getting reflected back to the photodiodes. Concave-shaped reflective shields have the additional advantage of directing reflected light toward the image sensors.

Inserted reflective shield to improve quantum efficiency of image sensors

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Yongkang, Taiwan

Yu-Hao Shih