NOVELTY - A composition for semiconductor substrate passivation-film formation contains organoaluminum compound and glass powder consisting of acceptor element.    USE - A composition for semiconductor substrate passivation-film formation and p-type diffusion layer formation used for solar cell element (all claimed).    ADVANTAGE - Semiconductor substrate passivation film and p-type diffusion layer can be formed in a desired shape by a simple, and excellent passivation effect is achieved.    DETAILED DESCRIPTION - A composition for semiconductor substrate passivation-film formation contains organoaluminum compound of formula (I) and glass powder consisting of acceptor element.    R1=1-8C alkyl;    n=0-3;    X2, X3=O or methylene; and    R2-R4=H or 1-8C alkyl.    INDEPENDENT CLAIMS are included for:    (1) semiconductor substrate comprising sintered product layer of the composition for semiconductor substrate passivation-film formation provided on a part or the whole surface of semiconductor substrate and forming p-type diffusion layer on surface side which contacts sintered product layer;    (2) manufacture of semiconductor substrate with passivation film which involves providing a part or the whole surface of semiconductor substrate with the composition for semiconductor substrate passivation-film formation to form composition layer and heat-processing the composition layer to form semiconductor substrate passivation film and p-type diffusion layer;    (3) solar cell element comprising semiconductor substrate to which pn junction of p-type layer and n-type layer is carried out, sintered product layer of the composition for semiconductor substrate passivation-film formation provided on a part or the whole surface of semiconductor substrate, p-type diffusion layer formed on surface side which contacts calcined product layer, and electrode arranged on p-type layer and/or n-type layer; and    (4) manufacture of solar cell element which involves arranging electrode on p-type layer and/or n-type layer on surface of semiconductor substrate where pn junction is carried out, providing the composition for semiconductor substrate passivation-film formation to form composition layer, and heat-processing the composition layer to form semiconductor substrate passivation film and p-type diffusion layer.