CCD image sensor prodn. avoiding dry etching damage and thus image blurring - comprises forming 2nd conductivity type layer over 1st conductivity type semiconductor substrte, forming 1st impurity region acting as light collecting element and 2nd impurity region acting as charge transfer element etc.

摘要

A CCD image sensor prodn. process involves forming a second conductivity type layer over a first conductivity type semiconductor substrate, implanting first conductivity type impurity ions into the layer to form a first impurity region acting as a light collecting element and a second impurity region acting as a charge transfer element spaced from the first impurity region, forming a gate oxide film over the entire substrate surface, depositing a polysilicon film on the gate oxide film and patterning to form a gate between the first and second impurity regions. The novelty comprises (a) forming a first insulation film on the entire exposed surface after gate formation; (b) forming a second insulation film on the first insulation film and partially removing the second film to leave regions over the first and second impurity regions; (c) implanting second conductivity type impurity ions in the layer under the exposed first insulation film area to form a second conductivity type third impurity region; (d) forming a third insulation film on the entire exposed surface and removing the film portion selectively to expose the third impurity region; (e) forming a metal electrode over the third impurity region; (f) forming a fourth insulation film on the entire exposed surface; (g) removing the fourth insulation film portion above the first impurity region and then the third insulation film portion above the second impurity region for partial exposure of the second insulation film; (h) removing the exposed second insulation film portion; and (i) depositing a metal layer (64) on the entire exposed surface and removing the layer (64) selectively from above the first impurity region to form a photo-protective layer. ADVANTAGE - The process avoids damage to the substrate surface by dry etching of an insulation film portion above the light collection element and thus avoids the image blurring effect