Plasma processing system and plasma processing method
First Claim
1. A plasma process apparatus comprising a vacuum process chamber, a plasma generation means containing a pair of electrodes placed at the top and bottom inside of said vacuum process chamber, a sample table having a sample placement surface on which the sample to be process is placed, said table being one of said pair of electrodes, and a vacuum exhaust means that evacuates said vacuum process chamber, wherein said top electrode has a bottom surface which is flat and forms part of said process chamber,a high frequency power source that applies high frequency power at 40 MHZ to 150 MHZ between said pair of electrodes and provides an electric field, a magnetic field forming means for forming an electron sheath resonance (ESR), said magnetic field forming means generating one of a low frequency alternating magnetic field and a static magnetic field having an intensity controllable to a value in the range of 2 gauss to 60 gauss, wherein said magnetic field which is generated is formed in a region immediately below said top electrode, is concentrated on the region and is formed substantially parallel to the bottom surface of said top electrode, said magnetic field forming means containing a plural number of pairs of electromagnetic coils placed on a left and right exterior side of said process chamber and a current control means for controlling the current passed through said electromagnetic coils so that said electron sheath resonance (ESR) is formed at an electron resonance magnetic field intensity due to mutual effect of the magnetic field generated by said magnetic field forming means and the electric field in a sheath part of said plasma over substantially the entire surface in the neighborhood of the sheath of the plasma at the bottom surface of said top electrode, the condition of said plasma being controlled by controlling said electron resonance through the control of the current flowing through said electromagnetic coils of said magnetic field forming means.
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Accused Products
Abstract
A plasma processing apparatus and a method therefor which can achieve a preferred process rate, a fine pattern process capability, a selectivity and uniformity of processing at the same time compatibly for a large size wafer, which effects are achieved by controlling the plasma state and the dissociation state of etching gas through control of the electron resonance through application of a magnetic field thereto. A high frequency power at 20-300 MHz is applied across a pair of electrodes in a vacuum process chamber, and a magnetic field is formed parallel to the plane of the electrodes in the space between the electrodes. By controlling the intensity of the magnetic field in a range of 100 gauss or smaller, formation of electron cyclotron resonance and electron sheath resonance occurring from interaction between the electrical field and the magnetic field in the electrode sheath portion is controlled. Thereby, the plasma state, i.e., the electron density, electron energy distribution and dissociation state of the process gas in the plasma, can be controlled. The magnetic field is generated by a plurality of coils, an outer shield, and pendant yoke to form magnetic field parallel to the plane of the electrodes in the space between the upper and the bottom electrodes.
182 Citations
10 Claims
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1. A plasma process apparatus comprising a vacuum process chamber, a plasma generation means containing a pair of electrodes placed at the top and bottom inside of said vacuum process chamber, a sample table having a sample placement surface on which the sample to be process is placed, said table being one of said pair of electrodes, and a vacuum exhaust means that evacuates said vacuum process chamber, wherein said top electrode has a bottom surface which is flat and forms part of said process chamber,
a high frequency power source that applies high frequency power at 40 MHZ to 150 MHZ between said pair of electrodes and provides an electric field, a magnetic field forming means for forming an electron sheath resonance (ESR), said magnetic field forming means generating one of a low frequency alternating magnetic field and a static magnetic field having an intensity controllable to a value in the range of 2 gauss to 60 gauss, wherein said magnetic field which is generated is formed in a region immediately below said top electrode, is concentrated on the region and is formed substantially parallel to the bottom surface of said top electrode, said magnetic field forming means containing a plural number of pairs of electromagnetic coils placed on a left and right exterior side of said process chamber and a current control means for controlling the current passed through said electromagnetic coils so that said electron sheath resonance (ESR) is formed at an electron resonance magnetic field intensity due to mutual effect of the magnetic field generated by said magnetic field forming means and the electric field in a sheath part of said plasma over substantially the entire surface in the neighborhood of the sheath of the plasma at the bottom surface of said top electrode, the condition of said plasma being controlled by controlling said electron resonance through the control of the current flowing through said electromagnetic coils of said magnetic field forming means.
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5. A plasma processing method for a plasma process apparatus having a vacuum process chamber, a plasma generation means containing a pair of electrodes placed at the top and bottom inside of said vacuum process chamber, a sample table having a sample placement surface on which the sample to be processed is placed said table being one of said pair of electrodes, and a vacuum exhaust means that evacuates said vacuum process chamber, said method comprising the steps of:
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applying a high frequency power at 20 MHz to 300 MHz from a high frequency power generation means between said pair of electrodes to generate an electric field;
generating one of a low frequency alternating magnetic field and a static magnetic field having an intensity controllable to a value of no greater than 100 gauss with said magnetic field being at right angles to the electric field generated by said high frequency power source at the surface coming into contact with the plasma of at least one of said pair of electrodes;
forming electron sheath resonance (ESR) at the electron resonance magnetic field intensity due to mutual effect of said magnetic field and said electric field at a position that extends over substantially the entire surface in the neighborhood of the surface coming into contact with the plasma at at least one of said pair of electrodes; and
controlling at least one of plasma density, electron energy distribution in the plasma, and the condition of dissociation of the process gas by controlling said electron resonance using said magnetic field forming means. - View Dependent Claims (6, 7, 8, 9, 10)
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Specification