Plasma processing method and apparatus
With the evacuation of an interior of a vacuum chamber halted and with gas supply into the vacuum chamber halted, in a state that a mixed gas of helium gas and diborane gas is sealed in the vacuum chamber, a plasma is generated in a vacuum vessel and simultaneously a high-frequency power is supplied to a sample electrode. By the high-frequency power supplied to the sample electrode, boron is introduced to a proximity to a substrate surface.
1. A plasma processing method for introducing impurities into a sample or a film of a surface of the sample, the plasma processing method comprising:
placing the sample on a sample electrode within a vacuum chamber;
evacuating an interior of the vacuum chamber through a gas outlet of the vacuum chamber;
after setting a gas exhaust flow rate from within the vacuum chamber through the gas outlet to zero, supplying gas into the vacuum chamber from a gas inlet which is so provided that a shortest flow passage connecting the gas outlet and the gas inlet of the vacuum chamber to each other avoids an upward space of the sample surface, by which a flow of the gas supplied into the vacuum chamber from the gas inlet of the vacuum chamber is directed toward the gas outlet while avoiding the upward space of the sample surface;
setting a supply flow rate of the gas from the gas inlet to zero; and
supplying a high-frequency power to a plasma source to generate a plasma in the vacuum chamber, thereby introducing the impurities into the sample or the film of the sample surface.
2. The plasma processing method as claimed in claim 1 , wherein in, after setting the gas exhaust flow rate from within the vacuum chamber through the gas outlet to zero, the supplying of the gas into the vacuum chamber from the gas inlet comprises supplying the gas into the vacuum chamber from the gas inlet provided at a site closer to the gas outlet than to the sample electrode.
3. The plasma processing method as claimed in claim 1 , wherein in, after setting the gas exhaust flow rate from within the vacuum chamber through the gas outlet to zero, the supplying of the gas into the vacuum chamber from the gas inlet comprises supplying the gas into the vacuum chamber from the gas inlet provided at a site lower than the sample electrode.
4. The plasma processing method as claimed in claim 1 , wherein in, after setting the gas exhaust flow rate from within the vacuum chamber through the gas outlet to zero, the supplying of the gas into the vacuum chamber from the gas inlet comprises supplying the gas from the gas inlet toward the gas outlet.
5. The plasma processing method as claimed in claim 1 , wherein in, after setting the gas exhaust flow rate from within the vacuum chamber through the gas outlet to zero, the supplying of the gas into the vacuum chamber from the gas inlet comprises supplying the gas from the gas inlet toward an evacuator for performing the evacuation.
6. The plasma processing method as claimed in claim 1 , wherein in, while the evacuation is performed, the supplying of the gas into the vacuum chamber from the gas inlet comprises supplying the gas into the vacuum chamber from the gas inlet provided at a site which is not exposed to the plasma even when the plasma is generated.
7. The plasma processing method as claimed in claim 1 , wherein in, after setting the gas exhaust flow rate from within the vacuum chamber through the gas outlet to zero, the supplying of the gas into the vacuum chamber from the gas inlet comprises supplying the gas into the vacuum chamber from the gas inlet provided at a site where the gas inlet is shielded from the plasma by a shield plate when the plasma is generated.