Cleaning agent for semiconductor substrates and method for processing semiconductor substrate surface

A method for processing a semiconductor substrate surface, comprising:

• a process for treating a surface of a semiconductor substrate having a tungsten wiring or a tungsten alloy wiring, and a silicon oxide film, by chemical mechanical polishing;
• and
• a process for cleaning the semiconductor substrate after the process by the chemical mechanical polishing, with a cleaning agent for a semiconductor substrate comprising (A) a phosphonic acid-based chelating agent, (B) a primary or secondary monoamine having at least one alkyl group or hydroxyalkyl group in a molecule represented by the general formula [6] or [7],
• wherein R10 and R11 each independently represent a monohydroxyalkyl group having 1 to 3 carbon atoms;
• and R12 represents a hydrogen atom, an alkyl group having 1 to 3 carbon atoms or a monohydroxyalkyl group having 1 to 3 carbon atoms,
• wherein R13 represents a hydrogen atom or an alkyl group having 1 to 3 carbon atoms;
• and R14 represents a dihydroxyalkyl group having 1 to 3 carbon atoms, and (C) water, wherein a pH of the cleaning agent is over 6 and below 7.