Plasma processing apparatus and plasma processing method

Abstract

A plasma processing apparatus capable of reducing the use amount of a dielectric member is provided. The plasma processing apparatus 1 includes a metal processing chamber 4 configured to accommodate therein a substrate G to be plasma-processed; an electromagnetic wave source 34 that supplies an electromagnetic wave necessary to excite plasma in the processing chamber 4 ; one or more dielectric members 25 provided on a bottom surface of a cover 3 of the processing chamber 4 and configured to transmit the electromagnetic wave supplied from the electromagnetic wave source 34 into the inside of the processing chamber 4 , a portion of each dielectric member 25 being exposed to the inside of the processing chamber 4 ; and a surface wave propagating section 51 installed adjacent to the dielectric member 25 and configured to propagate the electromagnetic wave along a metal surface exposed to the inside of the processing chamber 4.

1 . A plasma processing apparatus comprising:
 a metal processing chamber configured to accommodate therein a substrate to be plasma-processed;   an electromagnetic wave source that supplies an electromagnetic wave necessary to excite plasma in the processing chamber;   one or more dielectric members provided on a bottom surface of a cover of the processing chamber and configured to transmit the electromagnetic wave supplied from the electromagnetic wave source into the inside of the processing chamber, a portion of each dielectric member being exposed to the inside of the processing chamber; and   a surface wave propagating section installed adjacent to the dielectric member and configured to propagate the electromagnetic wave along a metal surface exposed to the inside of the processing chamber.   
   
   
       2 . The plasma processing apparatus of  claim 1 , wherein an area of the exposed portion of the dielectric member is equal to or less than about ½ of an area of the surface wave propagating section. 
   
   
       3 . The plasma processing apparatus of  claim 1 , wherein an area of the exposed portion of the dielectric member is equal to or less than about ⅕ of an area of the surface wave propagating section. 
   
   
       4 . The plasma processing apparatus of  claim 1 , wherein an area of the exposed portion of the dielectric member is equal to or less than about ⅕ of a surface area of the substrate. 
   
   
       5 . The plasma processing apparatus of  claim 1 , wherein a frequency of the electromagnetic wave supplied from the electromagnetic wave source is equal to or less than about 2 GHz. 
   
   
       6 . The plasma processing apparatus of  claim 1 , wherein a continuous groove is provided in an inner surface of the processing chamber, and the dielectric member is positioned within an area surrounded by the groove. 
   
   
       7 . The plasma processing apparatus of  claim 6 , wherein the surface wave propagating section is partitioned by the groove. 
   
   
       8 . The plasma processing apparatus of  claim 1 , wherein a continuous protrusion is provided in an inner surface of the processing chamber, and the dielectric member is positioned within an area surrounded by the protrusion. 
   
   
       9 . The plasma processing apparatus of  claim 8 , wherein the surface wave propagating section is partitioned by the protrusion. 
   
   
       10 . The plasma processing apparatus of  claim 1 , wherein one or more metal rods serving to propagate the electromagnetic wave to the dielectric member are provided in a top portion of the dielectric member such that a bottom end of each metal rod is adjacent or close to a top surface of the dielectric member. 
   
   
       11 . The plasma processing apparatus of  claim 10 , wherein the dielectric member has a substantially circular column shape, and a sealing member is installed at a peripheral surface of the dielectric member to make a space between the inside and the outside of the processing chamber. 
   
   
       12 . The plasma processing apparatus of  claim 10 , wherein a sealing member is installed between the metal rod and the cover to make a space between the inside and the outside of the processing chamber. 
   
   
       13 . The plasma processing apparatus of  claim 1 , further comprising:
 one or more gas discharge holes through which a gas necessary for a plasma process is discharged into the processing chamber.   
   
   
       14 . The plasma processing apparatus of  claim 13 , wherein the gas discharge hole is provided in the bottom surface of the cover. 
   
   
       15 . The plasma processing apparatus of  claim 1 , wherein a metal electrode is installed on a bottom surface of the dielectric member, and the dielectric member is exposed to the inside of the processing chamber in the vicinity of or inside the metal electrode. 
   
   
       16 . The plasma processing apparatus of  claim 15 , further comprising:
 a metal rod electrically connected with the metal electrode through the dielectric member and configured to transmit the electromagnetic wave to the dielectric member.   
   
   
       17 . The plasma processing apparatus of  claim 16 , wherein a sealing member is installed between the metal rod and the cover to make a space between the inside and the outside of the metal chamber. 
   
   
       18 . The plasma processing apparatus of  claim 15 , wherein sealing members are installed between a top surface of the dielectric member and the cover and between the bottom surface of the dielectric member and the metal electrode to make a space between the inside and the outside of the processing chamber. 
   
   
       19 . The plasma processing apparatus of  claim 16 , wherein the metal electrode is provided with one or more gas discharge holes through which the gas necessary for the plasma process is discharged into the processing chamber, and the metal rod is provided with a gas passage through which the gas flows to reach the gas discharge hole. 
   
   
       20 . The plasma processing apparatus of  claim 15 , further comprising:
 one or more connecting members provided to connect the metal electrode and the cover through a hole in the dielectric member.   
   
   
       21 . The plasma processing apparatus of  claim 20 , wherein the connecting member is made of metal. 
   
   
       22 . The plasma processing apparatus of  claim 20 , wherein the metal electrode is provided with one or more gas discharge holes through which the gas necessary for the plasma process is discharged into the processing chamber, and the connecting member is provided with a gas passage through which the gas flows to reach the gas discharge hole. 
   
   
       23 . The plasma processing apparatus of  claim 1 , further comprising:
 one or more waveguides configured to propagate the electromagnetic wave supplied from the electromagnetic wave source to the dielectric member.   
   
   
       24 . The plasma processing apparatus of  claim 23 , wherein the dielectric member is inserted into a slot formed in a bottom surface of the waveguide. 
   
   
       25 . The plasma processing apparatus of  claim 23 , further comprising:
 a wavelength control mechanism that controls a wavelength of the electromagnetic wave propagated in the waveguide.   
   
   
       26 . The plasma processing apparatus of  claim 23 , wherein a sealing member is provided between the dielectric member and the cover to make a space between the inside and the outside of the processing chamber. 
   
   
       27 . The plasma processing apparatus of  claim 1 , wherein the dielectric member is embedded within the cover, and a bottom surface of the dielectric member is partially exposed to the inside of the processing chamber through one or more openings in the bottom surface of the cover. 
   
   
       28 . The plasma processing apparatus of  claim 27 , wherein the openings are concentrically arranged in the bottom surface of the cover. 
   
   
       29 . The plasma processing apparatus of  claim 28 , wherein the bottom surface of the cover is a radial line slot antenna. 
   
   
       30 . The plasma processing apparatus of  claim 1 , wherein a protective film is formed on the bottom surface of the cover. 
   
   
       31 . The plasma processing apparatus of  claim 1 , wherein at least the surface of the surface wave propagating section is made of metal and the surface wave propagating section is defined by a groove or a protrusion extended on the surface of the metal. 
   
   
       32 . The plasma processing apparatus of  claim 1 , wherein a surface of the dielectric member exposed to the inside of the processing chamber is surrounded by the surface wave propagating section. 
   
   
       33 . The plasma processing apparatus of  claim 1 , wherein a surface of the dielectric member exposed to the inside of the processing chamber is extended along the inside of the processing chamber, and both ends of the extended surface are surrounded by the surface wave propagating section. 
   
   
       34 . The plasma processing apparatus of  claim 1 , wherein a plurality of surfaces of the dielectric members exposed to the inside of the processing chamber are spaced apart from each other. 
   
   
       35 . The plasma processing apparatus of  claim 1 , wherein a surface of the dielectric member exposed to the inside of the processing chamber is extended discontinuously or continuously while forming a circle or a polygon. 
   
   
       36 . The plasma processing apparatus of  claim 35 , wherein a surface wave non-propagating section is formed in a central portion of the surface wave propagating section within the circle or the polygon. 
   
   
       37 . The plasma processing apparatus of  claim 35 , wherein the surface wave non-propagating portion within the circle or the polygon is defined by a groove or a protrusion. 
   
   
       38 . The plasma processing apparatus of  claim 1 , wherein plasma is excited between the surface wave propagating section and a processing surface of the substrate by the electromagnetic wave propagated along the surface wave propagating section. 
   
   
       39 . The plasma processing apparatus of  claim 1 , further comprising:
 a gas discharge opening, installed in a non-exposed area of the dielectric member and in an inner surface of the processing chamber, configured to discharge a plasma exciting gas into the processing chamber.   
   
   
       40 . The plasma processing apparatus of  claim 1 , wherein a surface of the surface wave propagating section is covered with a protective film having a thin thickness so as not to substantially affect the propagation of the electromagnetic wave. 
   
   
       41 . The plasma processing apparatus of  claim 1 , wherein a center line average roughness of the surface wave propagating section is equal to or less than about 2.4 μm. 
   
   
       42 . A plasma processing method for processing a substrate by supplying an electromagnetic wave into a metal processing chamber accommodating the substrate therein by transmitting the electromagnetic wave from an electromagnetic wave source through one or more dielectric members exposed on a bottom surface of a cover of the processing chamber and exciting plasma in the processing chamber, the method comprising:
 supplying a processing gas into the processing chamber;   supplying the electromagnetic wave of a frequency equal to or less than about 2 GHz from the electromagnetic wave source; and   processing the substrate by exciting the plasma in the processing chamber by way of propagating the electromagnetic wave along an inner surface of the processing chamber from a dielectric member's surface exposed to the inside of the processing chamber.