METHOD OF PLASMA TREATMENT

摘要

A method of plasma treatment by which the contamination of a semiconductor wafer with particles can be reduced at the time of treating the wafer with plasma. When plasma is generated by using electron cyclotron resonance for forming, for example, a thin film of SiOF, etc., a sheath area having a thickness of, for example, several mm is formed between the wafer and plasma so as to trap the particles in the boundary area between the sheath area and plasma. In order to trap the particles, microwave power is not suddenly reduced to zero, but to a small value of, for example, about 1 kw, and the power is maintained at about 1 kw for, for example, about 10 seconds after film forming treatment is performed. When the microwave power is maintained at the small value for about 10 seconds, the particles come off from the surface of the wafer, because the density of the plasma becomes smaller and the thickness of the sheath area increases, and, when the microwave power is turned off, the probability of the particles adhering to the wafer becomes smaller even when the particles freely get about.