Plasma treatment method and apparatus
AssigneeTokyo Electron Limited
InventorsMasayuki Tomoyasu, Akira Koshiishi
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Abstract
A plasma treatment method comprising exhausting a process chamber so as to decompress the process chamber, mounting a wafer on a suscepter, supplying a process gas to the wafer through a shower electrode, applying high frequency power, which has a first frequency f.sub.1 lower than an inherent lower ion transit frequencies of the process gas, to the suscepter, and applying high frequency power, which has a second frequency f.sub.2 higher than an inherent upper ion transit frequencies of the process gas, whereby a plasma is generated in the process chamber and activated species influence the wafer.
Claims2
A plasma treatment apparatus for plasma-treating a substrate under a reduced pressure, comprising:
- a chamber electrically connected to ground;
- gas supply means for supplying a process gas into said chamber;
- exhaust means for exhausting the chamber;
- a lower electrode on which said substrate is disposed;
- an upper electrode mounted within the chamber to face said lower electrode;
- a first power supply connected to the lower electrode through a first matching circuit to apply a high frequency signal to the lower electrode, said high frequency signal having a first frequency f.sub.1 lower than an inherent lower ion transit frequency of the process gas;
- a second power supply to generate a high frequency signal having a second frequency f.sub.2 higher than an inherent upper ion transit frequency of the process gas;
- and
- an amplitude modulation circuit connected to each of said first and second power supplies for receiving high frequency signals having the first and second frequencies f.sub.1 and f.sub.2, the amplitude of the high frequency signal having the second frequency f.sub.2 being modulated by the high frequency signal having the first frequency f.sub.1, and said amplitude-modulated signal being applied to the upper electrode through the second matching circuit.
Dependencies are inferred from the claim text.