Pixel structure to improve BSI global shutter efficiency

There is provided a structure to improve BSI global shutter efficiency. In a sensor pixel circuit, at least one strong electric field is formed at the position of a floating diffusion region to accordingly have the effect of shielding the floating diffusion region. Or, the semiconductor material from the floating diffusion node toward a light incident direction is removed in the manufacturing process such that a depletion region cannot be formed in this direction. Or, a reflection layer or a photoresist layer is formed in the light incident direction to block the light. In these ways, chargesgenerated by the undesired noises are reduced, and noise charges are difficult to reach the floating diffusion region thereby improving the shutter efficiency. 一种改善背照式全局快门效率的结构，藉由将感光像素电路中，在浮动扩散节点区域的位置，形成至少一个强电场，藉此产生屏蔽浮动扩散节点区域的效应，或者通过制程，将浮动扩散节点面向照光方向的半导体材料挖空，让此方向上无法形成空乏区，或者在照光方向形成阻挡光线的反射层或光阻层，减少非预期的感光噪声所产生的电荷，并使已经受到感光噪声影响而产生的电荷难以到达浮动扩散节点区域，藉此改善快门效率。