Image sensor pixels with vertical charge transfer

摘要

Image sensors having image sensor pixels with stacked photodiodes are provided. An image sensor pixel may include a shallow potential well located in a shallow implant region and a deep potential well located in a deep implant region. The shallow implant region and the deep implant region may be separated by a potential barrier. The image sensor pixel may have a given transfer gate to transfer charge from the shallow well to a floating diffusion node. The image sensor pixel may have an additional transfer gate to transfer charge from the deep well to the shallow well via a vertical transfer region located under the additional transfer gate. Image sensor pixels formed using this structure may exhibit higher pixel densities, higher image resolution, and higher sensitivity.