Provided is a process for producing a modified polymer, characterized by carrying out primary modification in which a hydrocarbyloxysilane compound is reacted with the active site of a polymer having an active site of an organic metal type in a molecule and then carrying out secondary modification in which the hydrocarbyloxysilane compound is further reacted therewith. In addition to rule setting, the method automatically adjusts fields with abnormal properties. The cylindrical sidewall of the socket defines an engaging slot, which comprises a guiding portion and a retaining portion connected with each other. The upper portion of the insulating layer is removed and then a spacer is formed on the side-wall of the trench.