Plasma cvd apparatus and method

Abstract

The objective of this invention is to provide a plasma CVD apparatus and method of forming a high quality thin film having an excellent uniformity of thickness on a large-sized substrate. A plasma CVD apparatus of the invention comprises, in a reaction chamber, an inductively coupled electrode which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, wherein the electrode has a diameter of 10 mm or less partially or entirely between the feeding portion and the grounded portion, the diameter of the electrode is changed, or the electrode is partially or entirely covered with a dielectric, and whereby high frequency power is fed so as to establish a standing wave of natural number multiple of a half wavelength between the feeding portion and the grounded portion or between the feeding and grounded portions and the turning portion.

1 . A plasma CVD apparatus comprising, in a reaction chamber, an inductively coupled electrode which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, said electrode having a diameter of 10 mm or less partially or entirely between said feeding portion and said grounded portion, whereby high frequency power is fed to said feeding portion so as to establish a standing wave of a half wavelength or natural number multiple of a half wavelength between said feeding portion and said grounded portion or between said feeding and grounded portions and said turning portion.  
     
     
         2 . The plasma CVD apparatus according to  claim 1 , wherein said electrode has a diameter of 1 mm-10 mm partially or entirely between said feeding portion and said grounded portion.  
     
     
         3 . The plasma CVD apparatus according to  claim 1  or  2 , wherein the diameter of said electrode is varied.  
     
     
         4 . A plasma CVD apparatus comprising, in a reaction chamber, an inductively coupled electrode which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, the diameter of said electrode being varied, whereby high frequency power is fed to said feeding portion so as to establish a standing wave of a half wavelength or natural number multiple of a half wavelength between said feeding portion and said grounded portion or between said feeding and grounded portions and the turning portion.  
     
     
         5 . The plasma CVD apparatus according to one of claims  1  through  4 , wherein said inductively coupled electrode is partially or entirely covered with a dielectric.  
     
     
         6 . A plasma CVD apparatus comprising, in a reaction chamber, an inductively coupled electrode which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, said electrode being partially or entirely covered with a dielectric, whereby high frequency power is fed to said feeding portion so as to establish a standing wave of a half wavelength or natural number multiple of a half wavelength between said feeding portion and said grounded portion or between said feeding and grounded portions and said turning portion.  
     
     
         7 . The plasma CVD apparatus according to  claim 5  or  6 , wherein the thickness of said dielectric is varied in the longitudinal direction of the electrode.  
     
     
         8 . The plasma CVD apparatus according to  claim 5  or  6 , wherein the edge of said dielectric is tapered in the cross-section.  
     
     
         9 . The plasma CVD apparatus according to one of claims  5  through  8 , wherein said dielectric is formed spirally about the longitudinal direction of the electrode.  
     
     
         10 . The plasma CVD apparatus according to one of claims  1  through  9 , wherein said high frequency is 60 MHz or higher.  
     
     
         11 . The plasma CVD apparatus according to one of claims  1  through  10 , wherein a plurality of said inductively coupled electrodes are arranged in parallel in a common plane.  
     
     
         12 . The plasma CVD apparatus according to  claim 11 , wherein high frequency power is fed so that the phase should have a prescribed relation among said plurality of inductively coupled electrodes.  
     
     
         13 . The plasma CVD apparatus according to  claim 12 , wherein high frequency power is fed so that the phase is made in anti-phase between the adjacent feeding portions of said plurality of inductively coupled electrodes.  
     
     
         14 . A plasma CVD apparatus comprising, in a reaction chamber, a plurality of inductively coupled electrodes, each of which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, whereby the phase of high frequency power is made in anti-phase between the feeding portions of adjacent electrodes, and high frequency power is fed so as to establish a standing wave of a half wavelength or natural number multiple of a half wavelength between said feeding portion and said grounded portion or between said feeding and grounded portions and said turning portion.  
     
     
         15 . The plasma CVD apparatus according to one of claims  1  through  14 , wherein said inductively coupled electrodes are arranged in a plurality of layers, and substrates are arranged on both sides of each layer.  
     
     
         16 . A plasma CVD method comprising, arranging, in a reaction chamber, an inductively coupled electrode which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, said electrode having a diameter of 10 mm or less partially or entirely between said feeding portion and said grounded portion, and feeing high frequency power so as to establish a standing wave of a half wavelength or natural number multiple of a half wavelength between said feeding portion and said grounded portion or between said feeding and grounded portions and said turning portion to generate a plasma of reactive gas introduced in said reaction chamber to form a thin film including at least one element constituting the reactive gas.  
     
     
         17 . The plasma CVD method according to  claim 16 , wherein said electrode has a diameter of 1 mm-10 mm partially or entirely between said power feeding portion and said grounded portion.  
     
     
         18 . The plasma CVD method according to  claim 17 , wherein the diameter of said electrode is varied.  
     
     
         19 . A plasma CVD method of this invention comprises, arranging, in a reaction chamber, an inductively coupled electrode which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, the diameter of said electrode being varied, and feeding high frequency power so as to establish a standing wave of a half wavelength or natural number multiple of a half wavelength between said feeding portion and said grounded portion or between said feeding and grounded portions and said turning portion to generate a plasma of reactive gas introduced in the reaction chamber to form a thin film including at least one element constituting said reactive gas.  
     
     
         20 . The plasma CVD method according to one of claims  16  through  19 , wherein said inductively coupled electrode is partially or entirely covered with a dielectric.  
     
     
         21 . A plasma CVD method comprising, arranging, in a reaction chamber, an inductively coupled electrode which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, said electrode being partially or entirely covered with a dielectric, and feeding high frequency power so as to establish a standing wave of a half wavelength or natural number multiple of a half wavelength between said feeding portion and said grounded portion or between said feeding and grounded portions and said turning portion.  
     
     
         22 . The plasma CVD method according to one of claims  16  through  21 , wherein a plurality of said inductively coupled electrodes are arranged in parallel in a common plane and high frequency power is fed so that the phase should have a prescribed relation among said plurality of inductively coupled electrodes.  
     
     
         23 . The plasma CVD method according to  claim 22 , wherein high frequency power is fed so that the phase is made in anti-phase between adjacent feeding portions of said plurality of inductively coupled electrodes.  
     
     
         24 . A plasma CVD method comprising arranging a plurality of inductively coupled electrodes, each of which is straight line or folded back at the center and has a feeding portion at the first end and a grounded portion at the second end, in parallel in a deposition chamber, and feeding a high-frequency power to establish a standing wave of a half wavelength or natural number multiple of a half wavelength between said feeding portion and said grounded portion or between said feeding and grounded portions and said turning portion to generate a plasma of reactive gas introduced in the reaction chamber to form a thin film including at least one element constituting said reactive gas, wherein the phase of the high frequency power is made in anti-phase between the adjacent feeding portions.  
     
     
         25 . The plasma CVD method according to one of claims  16  through  24 , wherein said inductively coupled electrodes are arranged in a plurality of layers, and substrates are arranged on both sides of each layer.