Solar cell and fabrication method thereof

A method of fabricating a solar cell including a substrate of a first conductivity type, a region of a second conductivity type formed at a light receiving side of said substrate, an electrode formed at the region of the second conductivity type, and a region of higher concentration than said substrate, arranged in contact with both said substrate and said region of the second conductivity type and not in contact with said electrode, wherein said substrate includes a reflectionless surface construction and a planar portion at the light receiving side, said reflectionless surface construction having a plurality of grid configurations, and including a first grid portion and a second grid portion having a grid configuration differing in size from the grid configuration of the first grid portion, said region of higher concentration than said substrate being formed at said first grid portion,

• said fabrication method comprising the step of forming a masking pattern on said substrate using an oxide film, and etching said substrate with said masking pattern as a mask,
• wherein a line width of the masking pattern located at said second grid configuration is greater than the line width of the masking pattern located at said first grid portion.

A fabrication method of a solar cell including a substrate of a first conductivity type, a region of a second conductivity type formed at a light receiving side of said substrate, an electrode formed at said region of the second conductivity type, and a region of higher concentration than said substrate, arranged in contact with both said substrate and said region of the second conductivity type and not in contact with said electrode, said region of higher concentration than said substrate being formed in a recess,

• said fabrication method comprising the steps of:
• etching a portion of a window of a patterned surface oxide film using an alkaline solution to form a recess, and
• forming said region of higher concentration by diffusing impurities using said surface oxide film as a diffusion mask.