Light receiving PN junction semiconductor device with silicon nitride film

A light receiving semiconductor device, comprising:

• a semiconductor substrate of a first conductivity type;
• a semiconductor layer of a second conductivity type formed on said first conductivity type substrate;
• isolation regions of the first conductivity type for separating said second conductivity type semiconductor layer into a plurality of islands, at least one of said second conductivity type islands and said first conductivity type substrate forming a p-n junction and constituting a light responsive element;
• an anti-reflection Si.sub.3 N.sub.4 film formed to cover at least the entire surface of said island of said light responsive element;
• and
• a first conductivity type layer formed between and in direct contact with said anti-reflection film and said second conductivity type island and extending to the first conductivity type isolation region surrounding said island of said light responsive element.