Plasma treatment apparatus, method for forming film, and method for manufacturing thin film transistor

Abstract

A structure of the plasma treatment apparatus is employed in which an upper electrode has projected portions provided with first introduction holes and recessed portions provided with second introduction holes, the first introduction hole of the upper electrode is connected to a first cylinder filled with a gas which is not likely to be dissociated, the second introduction hole is connected to a second cylinder filled with a gas which is likely to be dissociated, the gas which is not likely to be dissociated is introduced into a reaction chamber from an introduction port of the first introduction hole provided on a surface of the projected portion of the upper electrode, and the gas which is likely to be dissociated is introduced into the reaction chamber from an introduction port of the second introduction hole provided on a surface of the recessed portion.

1 . A plasma treatment apparatus where glow discharge plasma is generated in a reaction chamber and a product is deposited over a substrate in the reaction chamber, the plasma treatment apparatus comprising:
 in the reaction chamber,   a first electrode over which the substrate is placed;   a second electrode facing the first electrode, the second electrode comprising a plurality of protruding portions on a surface of the second electrode opposite to the first electrode; and   a high-frequency power source electrically connected to the second electrode,   wherein the second electrode has first gas introduction ports provided in a top surface of the plurality of protruding portions, and second gas introduction ports provided between the plurality of protruding portions, and   wherein an electron density of the glow discharge plasma generated over the plurality of protruding portions is higher than an electron density of the glow discharge plasma generated between the plurality of protruding portions when a high-frequency power is supplied to the second electrode.   
     
     
         2 . The plasma treatment apparatus according to  claim 1 , wherein the high-frequency power source which supplies the high-frequency power with a frequency of 13.56 MHz or lower is electrically connected to the second electrode. 
     
     
         3 . The plasma treatment apparatus according to  claim 1 , wherein a cross section of each of the plurality of protruding portions of the second electrode is monotonously reduced toward each of the first gas introduction ports. 
     
     
         4 . The plasma treatment apparatus according to  claim 1 , wherein an edge or a vertex of the plurality of protruding portions of the second electrode is rounded. 
     
     
         5 . The plasma treatment apparatus according to  claim 1 ,
 wherein a reactive gas is introduced into the reaction chamber through the first gas introduction ports, and   wherein a deposition gas is introduced into the reaction chamber through the second gas introduction ports.   
     
     
         6 . The plasma treatment apparatus according to  claim 5 ,
 wherein the reactive gas is a nitriding gas, an oxidizing gas, or a hydrogen gas, and   
     
     
         7 . A plasma treatment apparatus where glow discharge plasma is generated in a reaction chamber and a product is deposited over a substrate in the reaction chamber, the plasma treatment apparatus comprising:
 in the reaction chamber,   a first electrode over which the substrate is placed;   a second electrode facing the first electrode, the second electrode comprising a plurality of protruding portions on a surface of the second electrode opposite to the first electrode; and   a high-frequency power source electrically connected to the second electrode,   wherein the second electrode has first gas introduction ports provided in a top surface of the plurality of protruding portions, and second gas introduction ports provided between the plurality of protruding portions, and   wherein a distance between the plurality of protruding portions of the second electrode adjacent to each other, is smaller than twice a thickness of a sheath generated between the plurality of protruding portions of the second electrode due to the glow discharge plasma when a high-frequency power is supplied to the second electrode.   
     
     
         8 . The plasma treatment apparatus according to  claim 7 , wherein a gas introduced into the first gas introduction ports is different from a gas introduced into the second gas introduction ports. 
     
     
         9 . The plasma treatment apparatus according to  claim 7 , wherein the high-frequency power source which supplies the high-frequency power with a frequency of 13.56 MHz or lower is electrically connected to the second electrode. 
     
     
         10 . The plasma treatment apparatus according to  claim 7 , wherein a cross section of each of the plurality of protruding portions of the second electrode is monotonously reduced toward each of the first gas introduction ports. 
     
     
         11 . The plasma treatment apparatus according to  claim 7 , wherein an edge or a vertex of the plurality of protruding portions of the second electrode is rounded. 
     
     
         12 . The plasma treatment apparatus according to  claim 7 ,
 wherein a reactive gas is introduced into the reaction chamber through the first gas introduction ports, and   wherein a deposition gas is introduced into the reaction chamber through the second gas introduction ports.   
     
     
         13 . The plasma treatment apparatus according to  claim 12 ,
 wherein the reactive gas is a nitriding gas, an oxidizing gas, or a hydrogen gas, and   wherein the deposition gas contains silicon or germanium.   
     
     
         14 . A plasma treatment apparatus where glow discharge plasma is generated in a reaction chamber and a product is deposited over a substrate in the reaction chamber, comprising:
 in the reaction chamber,   a first electrode over which the substrate is placed;   a second electrode facing the first electrode, the second electrode comprising a plurality of protruding portions on a surface of the second electrode opposite to the first electrode; and   a high-frequency power source electrically connected to the second electrode,   wherein the second electrode has first gas introduction ports provided in a top surface of the plurality of protruding portions, and second gas introduction ports provided between the plurality of protruding portions, and   wherein a height of the plurality of protruding portions of the second electrode is smaller than a thickness of a sheath generated between the plurality of protruding portions of the second electrode due to the glow discharge plasma when a high-frequency power is supplied to the second electrode.   
     
     
         15 . The plasma treatment apparatus according to  claim 14 , wherein a gas introduced into the first gas introduction ports is different from a gas introduced into the second gas introduction ports. 
     
     
         16 . The plasma treatment apparatus according to  claim 14 , wherein the high-frequency power source which supplies the high-frequency power with a frequency of 13.56 MHz or lower is electrically connected to the second electrode. 
     
     
         17 . T The plasma treatment apparatus according to  claim 14 , wherein a cross section of each of the plurality of protruding portions of the second electrode is monotonously reduced toward each of the first gas introduction ports. 
     
     
         18 . The plasma treatment apparatus according to  claim 14 , wherein an edge or a vertex of the plurality of protruding portions of the second electrode is rounded. 
     
     
         19 . The plasma treatment apparatus according to  claim 14 ,
 wherein a reactive gas is introduced into the reaction chamber through the first gas introduction ports, and   wherein a deposition gas is introduced into the reaction chamber through the second gas introduction ports.   
     
     
         20 . The plasma treatment apparatus according to  claim 19 ,
 wherein the reactive gas is a nitriding gas, an oxidizing gas, or a hydrogen gas, and   wherein the deposition gas contains silicon or germanium.   
     
     
         21 . A plasma treatment apparatus where glow discharge plasma is generated in a reaction chamber and a product is deposited over a substrate in the reaction chamber, comprising:
 in the reaction chamber,   a first electrode over which the substrate is placed;   a second electrode facing the first electrode, the second electrode comprising a plurality of protruding portions on a surface of the second electrode opposite to the first electrode; and   a high-frequency power source electrically connected to the second electrode,   wherein the second electrode has first gas introduction ports provided in a top surface of the plurality of protruding portions, and second gas introduction ports provided between the plurality of protruding portions, and   wherein a gas introduced into the first gas introduction ports is different from a gas introduced into the second gas introduction ports, and   wherein an electron density of the glow discharge plasma generated over the plurality of protruding portions is higher than an electron density of the glow discharge plasma generated between the plurality of protruding portions when a high-frequency power is supplied to the second electrode.   
     
     
         22 . The plasma treatment apparatus according to  claim 21 , wherein the high-frequency power source which supplies the high-frequency power with a frequency of 13.56 MHz or lower is electrically connected to the second electrode. 
     
     
         23 . The plasma treatment apparatus according to  claim 21 , wherein a cross section of each of the plurality of protruding portions of the second electrode is monotonously reduced toward each of the first gas introduction ports. 
     
     
         24 . The plasma treatment apparatus according to  claim 21 , wherein an edge or a vertex of the plurality of protruding portions of the second electrode is rounded. 
     
     
         25 . The plasma treatment apparatus according to  claim 21 ,
 wherein a reactive gas is introduced into the reaction chamber through the first gas introduction ports, and   wherein a deposition gas is introduced into the reaction chamber through the second gas introduction ports.   wherein the deposition gas contains silicon or germanium.   
     
     
         26 . The plasma treatment apparatus according to  claim 25 ,
 wherein the reactive gas is a nitriding gas, an oxidizing gas, or a hydrogen gas, and   wherein the deposition gas contains silicon or germanium.   
     
     
         27 . A method for forming a film in a plasma treatment apparatus comprising a first electrode over which a substrate is placed; a second electrode facing the first electrode, the second electrode comprising a plurality of protruding portions on a surface of the second electrode opposite to the first electrode wherein the second electrode has first gas introduction ports provided in a top surface of the plurality of protruding portions and second gas introduction ports provided between the plurality of protruding portions; and a high-frequency power source electrically connected to the second electrode; the steps comprising:
 supplying power to the high-frequency power source while a reactive gas is introduced from the first gas introduction ports and a deposition gas is introduced from the second gas introduction ports;   generating bulk plasma with an electron density which is higher directly under the plurality of protruding portions of the second electrode than on a periphery of side surfaces of the plurality of protruding portions; and   forming the film over the substrate.   
     
     
         28 . The method for forming a film, according to  claim 27 ,
 wherein the reactive gas is a nitriding gas, an oxidizing gas, or a hydrogen gas, and   wherein the deposition gas contains silicon or germanium.   
     
     
         29 . A method for manufacturing a thin film transistor, comprising:
 forming the film over a gate electrode formed over the substrate, the film formed by the method for forming the film according to  claim 27 ;   forming a semiconductor layer over the film; and   forming a wiring connected to the semiconductor layer.   
     
     
         30 . A method for manufacturing a thin film transistor, comprising:
 forming the film over a semiconductor layer formed over the substrate, the film formed by the method for forming the film according to any one of  claims 27 ;   forming a gate electrode over the film; and   forming a wiring connected to the semiconductor layer.   
     
     
         31 . A method for forming a film in a plasma treatment apparatus comprising a first electrode over which a substrate is placed; a second electrode facing the first electrode, the second electrode comprising a plurality of protruding portions on a surface of the second electrode opposite to the first electrode wherein the second electrode has first gas introduction ports provided in a top surface of the plurality of protruding portions and second gas introduction ports provided between the plurality of protruding portions; and a high-frequency power source electrically connected to the second electrode; the steps comprising:
 supplying power to the high-frequency power source while a reactive gas is introduced from the first gas introduction ports and a deposition gas is introduced from the second gas introduction ports;   generating a sheath with a thickness which is larger or equal to a height of the plurality of protruding portions, directly under the second gas introduction ports; and   forming the film over the substrate.   
     
     
         32 . The method for forming a film, according to  claim 31 ,
 wherein the reactive gas is a nitriding gas, an oxidizing gas, or a hydrogen gas, and   wherein the deposition gas contains silicon or germanium.   
     
     
         33 . A method for manufacturing a thin film transistor, comprising:
 forming the film over a gate electrode formed over the substrate, the film formed by the method for forming the film according to  claim 31 ;   forming a semiconductor layer over the film; and   forming a wiring connected to the semiconductor layer.   
     
     
         34 . A method for manufacturing a thin film transistor, comprising:
 forming the film over a semiconductor layer formed over the substrate, the film formed by the method for forming the film according to any one of  claims 31 ;   forming a gate electrode over the film; and   forming a wiring connected to the semiconductor layer.