Image sensor and method for forming isolation structure for photodiode

摘要

An image sensor provided with: a plurality of photodiodes arranged on a surface of a semiconductor substrate, the photodiodes each including a first region of a first conductivity type provided on the semiconductor substrate, a second region of a second conductivity type provided on the first region, the second conductivity type being different from the first conductivity type, and a signal extraction region of the second conductivity type provided on the second region; and an isolation region which electrically isolates the second regions of each adjacent pair of photodiodes from each other, the isolation region including a first trench provided between the second regions of the adjacent photodiodes and an oxide film provided on the first trench in the vicinity of surfaces of the second regions and having a greater width than the first trench.