Solid state image pickup element and method of manufacturing a solid state pickup element

Abstract

Provided is a solid state image pickup element which can exponentially reduce the in-plane photoelectric conversion portion characteristic distribution that is created in forming color filters by a common photolithography technique and which, when color filters are formed by split exposure, can reduce image non-uniformity between exposure regions in a picked-up image, and a method of manufacturing the same. The method includes: applying negative type color resist for forming first color filters onto an entire surface of a given film; forming the first color filters by irradiation of given portions with exposure light and by subsequent development; applying negative type color resist for forming second color filters onto the entire surface of the first color filters while covering the first color filters; and forming the second color filters by irradiating an area smaller than a region that is surrounded by the first color filters with exposure light and by subsequent development. Further, in the solid state image pickup element with color filters of plural colors, one of adjacent color filters is tapered at the edges while the other color filter is reversely tapered at the edges, allowing the adjacent color filters to fit to each other. Furthermore, adjacent color filters are wedged at the edges, allowing the adjacent color filters to fit to each other.

What is claimed is:  
     
         1 . A method of manufacturing a solid state image pickup element with color filters of plural colors formed of color resist of negative type, comprising: 
 applying color resist of negative type for forming first color filters onto an entire surface of a given film;    forming the first color filters by irradiation of given portions with exposure light and by subsequent development;    applying color resist for forming second color filters onto the entire surface of the first color filters while covering the first color filters; and    forming the second color filters by exposure to light and subsequent development an area smaller than a region that is surrounded by the first color filters.    
     
     
         2 . A method of manufacturing a solid state image pickup element according to  claim 1 , wherein the region to be exposed to light during formation of the second color filters is overexposed at edges compared to standard exposure conditions.  
     
     
         3 . A method of manufacturing a solid state image pickup element according to  claim 1 , wherein, compared to standard exposure conditions, an exposure contrast is low at any of edges of the region to be exposed to light during formation of the first color filters and edges of the region to be exposed to light during formation of the second color filters.  
     
     
         4 . A method of manufacturing a solid state image pickup element according to  claim 1 , wherein, compared to standard exposure conditions, a focus point of the exposure light is shifted at any of edges of the region to be exposed to light during formation of the first color filters and edges of the region to be exposed to light during formation of the second color filters.  
     
     
         5 . A method of manufacturing a solid state image pickup element according to  claim 1 , wherein an optical density of the exposure light is gradated at any of edges of the region to be exposed to light during formation of the first color filters and edges of the region to be exposed to light during formation of the second color filters.  
     
     
         6 . A solid state image pickup element comprising color filters of plural colors, wherein one of adjacent color filters is tapered at edges while the other color filter is reversely tapered at the edges, allowing the adjacent color filters to fit to each other.  
     
     
         7 . A solid state image pickup element comprising color filters of plural colors, wherein adjacent color filters are wedged at edges, allowing the adjacent color filters to fit to each other.  
     
     
         8 . A solid state image pickup element according to  claim 7 , wherein at least one of the adjacent color filters is formed in corners of the adjacent color filters.  
     
     
         9 . A solid state image pickup element according to  claim 7 , wherein an overlapping amount of the adjacent color filters is 0.1 μm or more.