| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for fabricating a solid state image sensor in which a diffusion layer can be formed at a light receiving part without requiring any additional fabrication step while preventing a semiconductor substrate from being cut through etching and poly-Si from being left. SOLUTION: A solid state image sensor comprises a light receiving part provided on a semiconductor substrate, and a vertical transfer part comprising a plurality of layers of poly-Si film formed through an oxide film and reading out charges stored at the light receiving part. A first (second layer) poly-Si film 32 is formed on the semiconductor substrate 10, an Si oxide film 25 is formed on the light receiving part and an oxide film is formed on the first poly-Si film. Subsequently, a second (third layer) poly-Si film 33 is formed on the oxide film on the first poly-Si film and the second poly-Si film is subjected to anisotropic etching using a resist opened at the light receiving part before an electrode DV3 is formed. Thereafter, ions are implanted into a P type well layer 11 at the light receiving part while leaving the resist to form a diffusion layer 14. The light receiving part for removing the residual poly-Si produced through anisotropic etching is etched simultaneously with the second Si film for forming an electrode at a vertical transfer part.
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