The present invention relates to a gas supply member and a plasma processing apparatus, and more particularly, to a gas supply member that supplies a reaction gas for plasma processing and a plasma processing apparatus that performs plasma processing by supplying the reaction gas into a processing container.
A semiconductor device, such as LSI (Large Scale Integrated circuit) or the like, is manufactured by performing a plurality of processes, such as etching, CVD (Chemical Vapor Deposition), sputtering, and the like, on a semiconductor substrate (wafer) that is a substrate to be processed. As for the processes, such as etching, CVD, sputtering, and the like, there are processing methods using plasma as an energy supply source, that is, plasma etching, plasma CVD, plasma sputtering, and the like.
When the aforesaid plasma etching and the like is performed on a substrate to be processed, a reaction gas for processing the substrate to be processed needs to be supplied into a processing container in which plasma is generated. According to Japanese Laid-Open Patent Publication No. hei 6-112163 (Patent Document 1), a plasma processing apparatus using an ECR plasma introduces a gas into a processing container by using a gas introduction nozzle (gas supply member) having a hollow doughnut shape.
A conventional gas introduction nozzle (gas supply member) having a hollow doughnut shape as disclosed in Patent Document 1 is generally manufactured by making a quartz pipe (quartz tube) having a cylindrical shape circular and connecting two ends of the quartz pipe to form a circular annular shape, and forming a gas supply hole through which a gas is supplied.
Here, a method of manufacturing the conventional gas supply member having a circular annular shape will be explained.
Next, annealing (thermal treatment) is performed (
Next, hydrofluoric acid (HF) cleaning is performed (
Here, when the supply member 101 as shown in
Also, since a stress is applied to the quartz pipe when the quartz pipe is bent into a circular annular shape and the directions in which the plurality of gas supply holes 104 are formed are different from one another as described above, once the gas supply member 101 with such low precision is used in, for example, a plasma processing apparatus, and the gas supply member 101 is cut off while being exposed to plasma and being used, degrees to which the plurality of gas supply holes 104 are corroded are different from one another, thereby making conductance more uneven.
As such, it is difficult to manufacture a gas supply member with high precision in conventional art. Also, if a gas supply member with low precision is used in a plasma processing apparatus, a reaction gas is irregularly supplied into a processing container. Then, it is difficult to perform plasma processing uniformly on a surface of a substrate to be processed. Also, in a plurality of plasma processing apparatuses including the gas supply member 101 with such low precision, a mechanical difference between the plasma processing apparatuses is increased. That is, degrees to which a substrate to be processed is processed are much different between the plasma processing apparatuses.
According to the present invention, there is provided a gas supply member that can uniformly supply a gas.
According to the present invention, there is also provided a plasma processing apparatus that can perform plasma processing uniformly on a surface of a substrate to be processed.
According to an embodiment of the present invention, there is provided a gas supply member which supplies a gas, the gas supply member including an annular portion in which a passage for a gas extending to have an annular shape is provided. The annular portion includes a first member having an annular shape and including a flat plate portion in which a plurality of gas supply holes through which a gas is supplied are formed, and a second member having an annular shape and forming the passage between the first member and the second member.
In such a gas supply member, since gas supply holes through which a reaction gas is supplied are formed in a flat plate portion, the gas supply holes can be formed at precise positions or with precise sizes. Also, since an annular portion includes a first member having an annular shape and a second member having an annular shape, it is easy to form a perfect circular shape with respect to the center of the annular portion. Also, since a passage for a reaction gas is formed by the first member having an annular shape and the second member having an annular shape, it is easy to make conductance of the passage for the reaction gas uniform. Accordingly, a gas can be uniformly supplied.
Preferably, the first member and the second member may be bonded to each other.
More preferably, the annular portion may have a circular annular shape.
Also, a cross-section of the second member may have a substantially ␣ shape.
More preferably, the plurality of the gas supply holes may be formed at regular intervals in a circumferential direction.
More preferably, materials of the first and second members may be quartz.
According to another embodiment of the present invention, there is provided a plasma processing apparatus including: a processing container in which plasma processing is performed to be performed on a substrate to be processed; a holding stage which is disposed in the processing container and holds the substrate to be processed thereon; a plasma generating unit which generates a plasma in the processing container; and a gas supply member which supplies a reaction gas for plasma processing into the processing container. The gas supply member includes an annular portion in which a passage for a gas extending to have an annular shape is provided. Here, the annular portion includes a first member having an annular shape and including a flat plate portion in which a plurality of gas supply holes through which a gas is supplied are formed, and a second member having an annular shape and forming the passage between the first member and the second member.
Since such a plasma processing apparatus includes a gas supply member that can uniformly supply a gas, the plasma processing apparatus can perform plasma processing uniformly on a surface of a substrate to be processed by uniformly supplying a reaction gas into a processing container.
More preferably, the plasma generating unit may include a microwave generator which generates a microwave for plasma excitation, and a dielectric plate which is disposed to face the holding stage and through which the microwave is introduced into the processing container.
According to such a gas supply member, since gas supply holes through which a reaction gas is supplied are formed in a flat plate portion, positions or sizes of the gas supply holes can be determined with high precision. Also, since an annular portion includes a first member having an annular shape and a second member having an annular shape, it is easy to form a perfect circular shape with respect to the center of the annular portion. Also, a passage for a reaction gas is formed by the first member having an annular shape and the second member having an annular shape, it is easy to make conductance of the passage for the reaction gas uniform. Accordingly, a gas can be uniformly supplied.
Also, according to such a plasma processing apparatus, since the plasma processing apparatus includes a gas supply member capable of uniformly supplying a gas, the plasma processing apparatus can perform plasma processing uniformly on a surface of a substrate to be processed by uniformly supplying a reaction gas into a processing container.
Hereinafter, embodiments of the present invention will be explained with reference to the drawings.
As shown in
The gas supply member 11 includes one pair of nozzles 15a and 15b that supply a gas into the annular portion 12. The nozzles 15a and 15b are hollow. The nozzles 15a and 15b are provided to straightly extend from an outer diameter surface 16 of the annular portion 12 to an outer diameter side. A gas is supplied through the nozzles 15a and 15b into the annular portion 12 from the outside of the annular portion 12, specifically, into the space 14 that becomes a passage for a gas in the annular portion 12. The one pair of nozzles 15a and 15b are disposed to face each other at positions separated by 180 degrees.
Also, the gas supply member 11 includes one pair of support portions 17a and 17b that support the annular portion 12. The one pair of support portions 17a and 17b are also provided to straightly extend from the outer diameter surface 16 of the annular portion 12 to the outer diameter side. The one pair of support portions 17a and 17b are disposed to face each other at positions separated by 180 degrees. Ends (not shown) of the support portions 17a and 17b at the outer diameter side are attached and fixed to another member. For example, the ends of the support portions 17a and 17b at the outer diameter side are fixed to a side wall of a processing container of a plasma processing apparatus that will be explained later. The one pair of support portions 17a and 17b support the annular portion 12 at predetermined places of another member. Also, the one pair of support portions 17a and 17b and the one pair of nozzles 15a and 15b are disposed on the outer diameter surface 16 of the annular portion 12 at about 90-degree intervals.
Here, a detailed configuration of the annular portion 12 will be explained. The annular portion 12 includes the first member 13a having an annular shape and the second member 13b having an annular shape. Materials of the first and second members 13a and 13b are quartz. The annular portion 12 is formed by bonding the first member 13a and the second member 13b.
The first member 13a includes a flat plate portion 18 having an annular flat plate shape. A plurality of, specifically, eight, gas supply holes 19 through which a gas is supplied are formed in the flat plate portion 18. The eight gas supply holes 19 are formed by making holes at predetermined places of the flat plate portion 18 by using a laser. The gas supply holes 19 each have a round hole shape. The eight gas supply holes 19 are formed in the flat plate portion 18 having the annular shape at regular intervals in a circumferential direction. That is, the eight gas supply holes 19 are formed at regular intervals in the circumferential direction of the flat plate portion 18 having the annular shape.
A cross-section of the second ember 13b has a substantially shape. That is, the second member 13b has a shape obtained by combining two cylindrical members having different diameters with one member having the same shape as that of the above flat plate portion 18.
The space 14 having an annular shape is formed between the first member 13a having an annular shape and the second member 13b having an annular shape. In the cross-section shown in
Next, a method of manufacturing the above gas supply member 11 will be explained.
First, a flat plate-shaped member is prepared. Next, a part of the flat plate-shaped member 21 shown in
Next, machine work is performed on the flat plate-shaped member 22 having a greater plate thickness such that a cross-section of the flat plate-shaped member 22 has a substantially shape. In this case, specifically, one surface side of the flat plate-shaped member 22 in a plate thickness direction is cut off to have a substantially shape.
As such, the annular second member 13b with a cross-section having a shape as shown in
Meanwhile, eight gas supply holes 19 through which a gas is supplied are formed in the flat plate-shaped member 22 having a smaller plate thickness by using a laser (
As such, the first member 13a in which the eight gas supply holes 19 shown in
Next, mirror surface finishing is performed on to-be-bonded portions of the first member 13a and the second member 13b (
Next, hydrofluoric acid (HF) cleaning is performed on the first and second members 13a and 13b (
Next, the first member 13a and the second member 13b are moved in directions indicated by arrows of
The bonding between the first member 13a and the second member 13b is finished by lowering a temperature and a pressure (
Next, the nozzles 15a and 15b and the support portions 17a and 17b are attached by welding to the annular portion 12 that is formed by bonding the first member 13a and the second member 13b (
Finally, after the annular portion 12 to which the nozzle 15a and the like are attached is boiled, hydrofluoric acid cleaning is performed again (
According to the gas supply member 11, since the gas supply holes 19 through which a reaction gas is supplied are formed in the flat plate portion 18, positions or sizes of the gas supply holes 19 can be determined with high precision. Also, since the annular portion 12 includes the first member 13a having an annular shape and the second member 13b having an annular shape, it is easy to form a perfect circular shape with respect to the center of the annular portion 12. Also, since a passage for a reaction gas is formed by the first member 13a and the second member 13b, it is easy to make conductance of the passage for the reaction gas uniform. Accordingly, a gas can be uniformly supplied.
Also, in the above embodiment, although the gas supply holes 19 are formed by drilling using a laser, the present invention is not limited thereto, and the gas supply holes 19 may be formed by drilling using a diamond tool.
Next, a configuration of a plasma processing apparatus including the gas supply member 11 according to the aforesaid embodiment of the present invention will be explained.
The processing container 32 includes a bottom portion 37 which is located under the holding stage 34, and a side wall 38 which extends upward from an outer circumference of the bottom portion 37. The side wall 38 has a cylindrical shape. An exhaust hole 39 for exhaust is formed in the bottom portion 37 of the processing container 32. An upper side of the processing container 32 is opened, and the processing container 32 can be sealed by the dielectric plate 36 that is disposed at an upper side of the processing container 32 and an O-ring 40 that is a sealing member disposed between the dielectric plate 36 and the processing container 32.
The microwave generator 35 including a matching 41 is connected to an upper portion of a coaxial waveguide 44 through which a microwave is introduced, with a mode converter 42 and a waveguide 43 interposed therebetween. A frequency of a microwave generated by the microwave generator 35 may be, for example, 2.45 GHz.
The dielectric plate 36 has a circular plate shape and is formed of a dielectric substance. A lower side of the dielectric plate 36 is flat. Also, a detailed material of the dielectric plate 36 may be quartz, aluminum, or the like.
Also, the plasma processing apparatus 31 includes a wavelength-shortening plate 48 through which a microwave introduced by the coaxial waveguide 44 is propagated, and a slot antenna 50 which has a thin circular plate shape and by which a microwave is introduced to the dielectric plate 36 through a plurality of slot holes 49. A microwave generated by the microwave generator 35 passes through the coaxial waveguide 44, is propagated to the wavelength-shortening plate 48, and is introduced to the dielectric plate 36 through the plurality of slot holes 49 formed in the slot antenna 50. The microwave having passed through the dielectric plate 36 generates an electric field right under the dielectric plate 36 to generate plasma in the processing container 32.
A high frequency power source 57 for RF bias is electrically connected to the holding stage 34 with a matching unit 58 and a power feed bar 59 interposed therebetween. An electrostatic chuck 61 for holding the substrate W to be processed by using an electrostatic adsorption force is provided on a top surface of the holding stage 34. A gas supply pipe 74 or a coolant chamber 71 having an annular shape and extending in a circumferential direction is provided in the holding stage 34. Due to the coolant chamber 71 and the gas supply tube 74, a processing temperature of the substrate W to be processed on the electrostatic chuck 61 can be controlled.
Here, the reaction gas supply unit 33 will be explained. The reaction gas supply unit 33 includes the above-described gas supply member 11. The annular portion 12 included in the gas supply member 11 is disposed over the substrate W to be processed between the holding stage 34 and the dielectric plate 36 in the processing container 32. The annular portion 12 is fixed to the inside of the processing container 32 by the one pair of support portions 17a and 17b. In detail, the annular portion 12 is fixed to the inside of the processing container 32 by attaching ends of the outer diameter sides of the support portions 17a and 17b to the side wall 38. Also, the one pair of nozzles 15a and 15b are also attached to the side wall 38. Also,
A reaction gas for plasma processing supplied from the outside of the processing container 32 is supplied into the gas supply member 11 through the nozzles 15a and 15b. The supplied reaction gas is uniformly supplied into the processing container 32 by the gas supply member 11. In detail, the supplied reaction gas is uniformly supplied with respect to each position on the substrate W to be processed.
Next, a method of performing plasma processing on the substrate W to be processed by using the plasma processing apparatus 31 according to an embodiment of the present invention will be explained.
First, the substrate W to be processed is held on the holding stage 34, which is provided in the processing container 32, by using the electrostatic chuck 61. Next, a microwave for plasma excitation is generated by the microwave generator 35. Next, the microwave is introduced into the processing container 32 by using the dielectric plate 36 or the like. After that, the gas supply member 11 included in the reaction gas supply unit 33 supplies a reaction gas to the substrate W to be processed in the processing container 32. As such, plasma processing is performed on the substrate W to be processed.
Since the plasma processing apparatus 31 includes the gas supply member 11 that can uniformly supply a gas, the plasma processing apparatus 31 can perform plasma processing uniformly on a surface of the substrate W to be processed by uniformly supplying a reaction gas into the processing container 32. Also, since the gas supply member 11 has high precision, a mechanical difference between a plurality of the plasma processing apparatuses 31 can be reduced.
Also, in the above embodiment, although a cross-section of the second member has a substantially shape, the present invention is not limited thereto, and the cross-section of the second member may have a substantially U shape. That is, as shown in
Also, as shown in
Also, as shown in
Also, in the above embodiment, two annular portions may be included in a gas supply member and the gas supply member may be formed twofold.
In this configuration, a gas can be uniformly supplied. Also, three or more annular portions may be included in a gas supply member and the gas supply member may be formed threefold or more. Also, in
Also, in the above embodiment, although a first member and a second member are bonded to each other, the present invention is not limited thereto, and the first member and the second member may be adhered to each other, and another member may be interposed between the first member and the second member.
Also, in the above embodiment, although an annular portion has a circular annular shape, the present invention is not limited thereto, and the annular portion may include a part having a straight line shape. Also, the annular portion may have an oval shape.
Also, in the above embodiment, although each of the first member and the second member is formed by using one member, the present invention is not limited thereto, and the first member or the second member may be configured by combining a plurality of members. That is, for example, the second member with a cross-section having a substantially shape may be formed by combining two cylindrical members with different diameters and one flat plate-shaped member. Also, the first member and the second member may be configured by combining a plurality of members having circular arc shapes divided in a circumferential direction.
Also, in the above embodiment, although nozzles and support portions included in a gas supply member straightly extend toward the outer diameter side, the present invention is not limited thereto, and the nozzles and the support portions may include portions extending in a plate thickness direction of a plane including an annular portion, that is, in a direction perpendicular to the drawing sheet of
Also, in the above embodiment, although a gas supply member includes two nozzles and two support portions, that is, four portions in total, the present invention is not limited thereto, and four nozzles, three nozzles, or five nozzles may be provided. Also, other number of nozzles and support portions may be provided.
Also, in the above embodiment, although 8 gas supply holes are formed, the present invention is not limited thereto, and, for example, 16, 32, or other number of gas supply holes may be formed.
Also, in the above embodiment, although a lower side of a dielectric plate included in a plasma processing apparatus is flat, the present invention is not limited thereto, and a recess portion having a tapered shape may be provided. That is, a lower portion of the dielectric plate may have a uneven shape. As such, plasma can be efficiently generated by using a microwave under the dielectric plate.
Also, in the above embodiment, although the plasma processing apparatus uses a microwave as a plasma source, the present invention is not limited thereto, and a plasma processing apparatus may use ICP (Inductively-coupled Plasma), ECR (Electron Cyclotron Resonance) plasma, a parallel flat plate-type plasma, or the like as a plasma source.
Also, in the above embodiment, although a gas supply member is applied to the plasma processing apparatus, the present invention is not limited thereto, and a gas supply member according to the present application can be applied to any apparatus that requires uniform supply of a gas.
While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, but the present invention is not limited thereto. It will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present invention as defined by the following claims.
A gas supply member according to the present invention is effectively used in a plasma processing apparatus that is required to supply a gas uniformly.
A plasma processing apparatus according to the present invention is effectively used to uniformly supply a reaction gas into a processing container.
Number | Date | Country | Kind |
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2008-226238 | Sep 2008 | JP | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/JP2009/064521 | 8/19/2009 | WO | 00 | 4/12/2011 |