Mfg method of contact hole and mfg method of semiconductor element

The method includes following structure: first, forming several conduction structures on substrate provided; next, carrying out step of ion implantation; then, carrying out heat process in order to form lining on sidewall of conduction structure and on surface of substructure uncovered by conduction structure, and thickness of lining formed on sidewall is less than thickness of lining formed on surface of substructure; forming gap wall on two sides of the said conduction structure; finally, forming insulating layer above the substrate, and patternizing the insulating layer in order to form contact hole between two conduction structures. Since thickness of lining formed on sidewall of conduction structure is thinner, thus subsequent etching for lining on sidewall is not needed so as to ensure evenness of thickness of lining of surface of substrate.