Layers for increasing performance in image sensors

摘要

An imaging device (100) includes a semiconductor substrate (140) having a photosensitive element (145) for accumulating charge in response to incident image light. The semiconductor substrate includes a light-receiving surface positioned to receive the image light. The imaging device also includes a negative charge layer (127) and a charge sinking layer (123). The negative charge layer is disposed proximate to the light-receiving surface of the semiconductor substrate to induce holes in an accumulation zone in the semiconductor substrate along the light-receiving surface. The charge sinking layer is disposed proximate to the negative charge layer and is configured to conserve or increase an amount of negative charge in the negative charge layer. The negative charge layer is disposed between the semiconductor substrate and the charge sinking layer.