Cleaning Agent for Silicon Wafer

A method for cleaning a surface of a silicon wafer using a cleaning agent, comprising:

• a water-based cleaning liquid;
• and
• a water-repellent cleaning liquid for providing at least a recessed portion of the uneven pattern with water repellency during a cleaning process, the water-repellent cleaning liquid comprising a mixture of a water-repellent compound and an organic solvent, the water-repellent compound having a hydrophobic group and a reactive moiety chemically bondable to Si element in the silicon wafer, the organic solvent containing at least an alcoholic solvent;
• the method comprising a step of removing the cleaning agent from the surface of the silicon wafer, after removing the cleaning liquid from the surface of the silicon wafer;
• wherein the water-repellant cleaning liquid is used in a manner as to substitute a liquid having been retained in the recessed portion of the uneven pattern of the surface, after cleaning with the water-based cleaning liquid.