SOLID-STATE IMAGING ELEMENT, AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To improve pixel characteristics of a solid-state imaging element with a lateral overflow drain (LOD) structure by reducing an interface level etc., nearby a junction part between a barrier region adjacent to a photodetection part and a drain region being an n+region contacting the barrier region. SOLUTION: The LOD structure 26 having the drain region 40 discharging electric signal charges of an N well 36 accumulating signal electric charges and the barrier region 42 disposed between the N well 36 and drain region 40 to form a potential barrier is formed adjacently to the N well 36. The LOD structure 26 has a buffer region 44 having a lower concentration than that of the drain region 40 at a boundary part between the barrier region 42 and drain region 40 to make gentle impurity concentration variation between the barrier region 42 and drain region 40. Consequently, electric field intensity between the barrier region 42 and drain region 40 in electronic shutter operation is reduced to suppress the generation of an interface level due to a hot hole. COPYRIGHT: (C)2009,JPO&INPIT