Plasma processing apparatus

Abstract

A plasma processing apparatus includes a vacuum processing container, and a placing table for placing an object which is arranged in the container and is to be processed. The processing container includes a tubular container body having an upper opening, and a dielectric top plate attached hermetically to the upper opening of the body and transmitting an electromagnetic wave. The plasma processing apparatus further includes an electromagnetic wave supplying system for supplying an electromagnetic wave for generating plasma into the container through the top plate, and a gas supplying system for supplying a gas containing a processing gas into the container. A gas ejecting hole for ejecting the gas supplied from the gas supplying system into the container is formed on the top plate. A discharge prevention member having a permeability is arranged in each ejection hole.

1 . A plasma processing apparatus comprising;
 a vacuum processing container having a container body in a tubular shape with an upper opening and a top plate comprised of a dielectric body transmitting an electromagnetic wave, and attached hermetically to the upper opening;   a placing table located in the vacuum processing container for placing an object to be processed;   an electromagnetic wave supplying system for supplying the electromagnetic wave for generating a plasma into the vacuum processing container through the top plate; and   a gas supplying system for supplying a gas containing a processing gas into the processing container;   wherein a gas ejection hole is formed on the top plate for ejecting the gas supplied from the gas supplying system into the vacuum processing container; and   a discharge prevention member comprised of a dielectric body having a permeability located inside the gas ejection hole.   
     
     
         2 . The plasma processing apparatus according to  claim 1 , wherein a plurality of gas ejection holes are provided to the top plate, with each gas ejection hole spaced apart from each other; and
 the discharge prevention member is located in each of the gas ejection holes.   
     
     
         3 . The plasma processing apparatus according to  claim 1 , wherein a gas channel is formed in the top plate for guiding the gas supplied from the gas supplying system to the gas ejection hole and the discharge prevention member is also located in the gas channel. 
     
     
         4 . The plasma processing apparatus according  claim 1 , wherein a main material comprising the discharge prevention member is the same as a material comprising the top plate. 
     
     
         5 . The plasma processing apparatus according to  claim 1 , wherein the discharge prevention member is comprised of a porous material. 
     
     
         6 . The plasma processing apparatus according to  claim 5 , wherein a diameter of a pore in the porous material is 0.1 mm or less. 
     
     
         7 . The plasma processing apparatus according to  claim 1 , wherein a diameter of the gas ejection hole is not more than ½ of a wave length of the electromagnetic wave. 
     
     
         8 . The plasma processing apparatus according to  claim 1 , the electromagnetic wave supplying system further comprising;
 a planar antenna member provided on the top plate;   a microwave generator for generating a microwave; and   a waveguide for propagating the microwave generated from the microwave generator to the planar antenna member.   
     
     
         9 . The plasma processing apparatus according to  claim 1 , wherein the electromagnetic wave supplying system further comprises;
 a high-frequency wave generator for generating a high-frequency wave; and   an induction coil arranged on the top plate and connected to the high-frequency wave generator.   
     
     
         10 . The plasma processing apparatus according to  claim 1 , wherein the discharge prevention member further comprises;
 a discharge prevention member body comprised of a dielectric body having a permeability; and   a dense member comprised of a dielectric body without a permeability covering at least a side face of the discharge prevention member body.   
     
     
         11 . The plasma processing apparatus according to  claim 10 , wherein the dense member is formed in a tubular shape. 
     
     
         12 . The plasma the processing apparatus according to  claim 10 , wherein the dense member further comprises an adhesive layer formed by curing an adhesive coated on the surface of the discharge prevention member body. 
     
     
         13 . The plasma processing apparatus according to  claim 10 , wherein a gas channel is formed in the top plate for guiding the gas supplied from the gas supplying system to the gas ejection hole; and
 a gas head space having a cross-sectional area larger than the cross-sectional area of the gas channel located between the gas channel and the gas ejection hole.   
     
     
         14 . The plasma processing apparatus according to  claim 10 , wherein the discharge prevention member body further comprises;
 a gas ejection face corresponding to an opening of the gas ejection hole;   a gas introducing face on an opposite side of the gas ejection face; and   a gas introducing depression formed on the gas introducing face.   
     
     
         15 . A plasma processing apparatus comprising;
 a vacuum processing container;   a placing table located in the vacuum processing container for placing an object to be processed;   a shower head provided on an upper section of the vacuum processing container, the shower head including a plurality of gas ejection openings for ejecting a gas containing a process gas into the vacuum processing container;   a high-frequency wave supplying system for supplying a high frequency wave applied between two electrodes, with the placing table comprising a lower electrode and the shower head comprising an upper electrode;   wherein a discharge prevention member comprised of a dielectric body having a permeability is attached to the gas ejection openings of the shower head.   
     
     
         16 . The plasma processing apparatus according to  claim 15 , wherein the discharge prevention member is comprised of a porous material. 
     
     
         17 . The plasma processing apparatus according to  claim 16 , wherein a diameter of a pore of the porous material is 0.1 mm or less. 
     
     
         18 . A top plate hermetically attached to an upper opening of a tubular shaped container body for forming a processing container of a plasma processing apparatus comprising;
 a top plate body comprised of a dielectric body for transmitting an electromagnetic wave, and having a gas ejection hole for ejecting a gas into the processing container; and   a discharge prevention member comprised of a dielectric body having a permeability located in the gas ejection hole of the top plate body.   
     
     
         19 . The top plate according to  claim 18 , wherein a gas channel is formed in the top plate body for guiding the gas to the gas ejection hole. 
     
     
         20 . A method for manufacturing a top plate hermetically attached to an upper opening of a tubular shaped container body for forming a processing container of a plasma processing apparatus, the method comprising the steps of;
 preparing a top plate body comprised of a dielectric body for transmitting an electromagnetic wave, and having a gas ejection hole for ejecting a gas into the processing container;   forming a discharge prevention member having a discharge prevention member body comprised of a dielectric body having a permeability, and a dense member comprised of a dielectric body without a permeability covering at least a side face of the discharge prevention member body; and   attaching the discharge prevention member in the gas ejection hole of the top plate body.   
     
     
         21 . The manufacturing method of the top plate according to  claim 20 , wherein the process for forming the discharge prevention member further comprises the steps of;
 preparing the dense member formed in a tubular shape; and   baking the tubular shaped dense member filled with a material comprising the discharge prevention member body.   
     
     
         22 . The manufacturing method of the top plate according to  claim 20 , wherein the process for forming the discharge prevention member further comprises the steps of;
 forming an adhesive layer by curing the adhesive, the adhesive layer comprising a material of the dense member in a dissolved state, coated on an entire surface of the discharge prevention member body;   removing the adhesive layer from a gas ejection face of the discharge prevention member corresponding to an opening of the gas ejection hole; and   forming a gas introducing depression on a gas introducing face on an opposite side of the gas ejection face of the discharge prevention member body.   
     
     
         23 . The method for manufacturing the top plate according to  claim 20 , wherein an adhesive is applied between the discharge prevention member and the gas ejection hole. 
     
     
         24 . The method for manufacturing the top plate according to  claim 20 , wherein the discharge prevention member and the top plate are baked as a unit.