Oblique Trench Pixel Isolation for Higher-Sensitivity Image Sensors

The patent applies curvature by forming trenches with oblique side surfaces instead of vertical walls, creating curved light paths that increase absorption. The oblique orientation of trench walls causes incident light to reflect and travel through the semiconductor layer at angled trajectories, enhancing interaction length and absorption efficiency while maintaining high sensitivity.

The patent introduces a new dimensional aspect by extending trenches in oblique directions rather than perpendicular to the surface. This three-dimensional configuration with slanted walls adds optical path complexity, allowing light to traverse multiple reflections within the trench structure, thereby improving both absorption and sensitivity simultaneously.

The patent segments the semiconductor layer by forming isolated trenches between adjacent pixels. These trenches act as physical barriers that divide and separate the optical paths of neighboring pixels, preventing light from one pixel from interfering with adjacent pixels. This segmentation enables higher pixel density while maintaining signal isolation.

The patent extracts and removes semiconductor material to form trenches between pixels. By taking out material in these inter-pixel regions, the patent creates voids or filled structures that serve as optical isolation barriers, eliminating the harmful crosstalk effect while allowing pixels to be positioned closer together for increased density.