Abstract: An image sensor structure includes a semiconductor substrate, a plurality of image sensing elements, a reflective element, and a high-k dielectric structure. The image sensing elements are in the semiconductor substrate. The reflective element is in the semiconductor substrate and between the image sensing elements. The high-k dielectric structure is between the reflective element and the image sensing elements.

Abstract: A semiconductor structure is disclosed. The semiconductor structure includes a number of pixels and neighboring pixels are isolated by deep trench isolation structures. In an embodiment, a method of forming the semiconductor structure includes epitaxially growing a p-type semiconductor layer on a substrate, epitaxially growing an n-type semiconductor layer over the p-type semiconductor layer, after the epitaxially growing of the n-type semiconductor layer, forming a p-type well in the n-type semiconductor layer, forming an n-type doped region in the n-type semiconductor layer and surrounded by the p-type well, forming a first trench extending through the n-type semiconductor layer and the p-type semiconductor layer and surrounding the p-type well, and forming a first isolation structure in the first trench.