Method for washing surface of bonding pad

The invention discloses a method for washing the surface of a wafer bonding pad. The method comprises the steps as follows: soaking a wafer into a solution ACT940, washing the wafer for a first set time, and continuously filling CO2 gas into the solution ACT940 at the same time to remove fluorine ions on the surface of the wafer bonding pad; soaking the wafer into an N-methylpyrrolidone solution, and washing the wafer for a second set time to wash the solution ACT940 on the wafer; quickly dumping and rinsing the wafer to wash the N-methylpyrrolidone solution on the wafer; and drying the wafer. The filled CO2 gas is dissolved in the solution ACT940, and introduced hydrogen ions can be combined with the fluorine ions to generate hydrogen fluoride gas, so that the residual fluorine ions on the surface of the bonding pad are effectively reduced and CuF2 is inhibited from being generated, thereby improving the defect of the surface of the bonding pad.