Image sensor device and manufacturing method thereof

Abstract

The invention relates to an image sensor device and a manufacturing method thereof. The method includes forming a first photoresist layer on a front side of a device substrate and having first trenches spaced apart from each other. A first implantation process is performed using the first photoresist layer as a mask to form first isolation regions in the device substrate. A second photoresist layer is formed on the front side and has second trenches. A second implantation process is performed using the second photoresist layer as a mask to form second isolation regions in the device substrate and crossing over the first isolation regions. A third photoresist layer is formed on the front side and has third trenches spaced apart from each other. A third implantation process is performed using the third photoresist layer as a mask to form third isolation regions in the device substrate and crossing over the first isolation regions but spaced apart from the second isolation regions.

Description

technical field [0001] The present disclosure relates to image sensor devices and methods of manufacturing the same. Background technique [0002] Image sensor devices are widely used in various imaging applications and products, for example, digital still camera or mobile phone camera applications. These devices utilize arrays of sensor elements (pixels) in a substrate. A pixel may be a photodiode, or other photosensitive element adapted to absorb light projected towards the substrate and convert the sensed light into an electrical signal. In order to obtain higher resolution, it is advantageous to increase the number of pixels in an image sensor device. [0003] The ever-shrinking geometries pose challenges to the fabrication of image sensor devices. For example, a fabrication process may require a high aspect ratio photoresist mask to produce micron or sub-micron sized pixels. However, photoresist masks with high aspect ratios are more susceptible to capillary forces....

AI Technical Summary

Problems solved by technology

However, photoresist masks with high aspect ratios are more susceptible to capillary forces

These effects are exacerbated as the aspect ratio of the mask is increased and / or the pitch is reduced

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