Patent Publication Number: US-2012040132-A1

Title: Protective film, method for forming the same, semiconductor manufacturing apparatus, and plasma treatment apparatus

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2010-181188, filed on Aug. 13, 2010 and the prior Japanese Patent Application No. 2011-172820, filed on Aug. 8, 2011; the entire contents of all of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a protective film, a method for forming the same, a semiconductor manufacturing apparatus, and a plasma treatment apparatus. 
     BACKGROUND 
     In a conventional art, in a microfabrication process for manufacturing a semiconductor device, a liquid crystal display apparatus and so forth, a RIE (reactive ion etching) apparatus is used. In the RIE apparatus, a chamber is made in a low pressure state, fluorine-based gas or chlorine-based gas is introduced into the chamber to generate a plasma phase, and etching is performed. Since a member constituting the inner wall and inner portion of the RIE apparatus is easily corroded when it is exposed to plasma, a material having a high plasma resistance such as yttria or alumina as a protective film is coated. 
     However, when the protective film including yttria, alumina and so forth is coated onto the member constituting the inner wall and inner portion of the RIE apparatus, the protective film may be easily stripped off if it is exposed to plasma for a long time in some places. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a sectional view schematically illustrating an example of the configuration of a plasma treatment apparatus; 
         FIGS. 2A and 2B  are partial sectional views schematically illustrating the structure of a shower head according to a first embodiment; 
         FIG. 3  is a partial plan view schematically illustrating an example of a base film formed at a lower surface side of a shower head according to a first embodiment; 
         FIGS. 4A ,  4 B,  5 A,  5 B,  6 A,  6 B,  7 A,  7 B,  8 A,  8 B,  9 A,  9 B,  10 A, and  10 B are sectional views schematically illustrating an example of the procedure of a method for forming a protective film according to a first embodiment; 
         FIGS. 11A and 11B  are diagrams illustrating an example of a pattern forming tool; 
         FIG. 12  is a sectional view schematically illustrating an example of a method for forming a pattern in resist; 
         FIGS. 13A to 13C  are sectional views schematically illustrating the overview of the procedure of a general method for forming a protective film to a shower head; 
         FIGS. 14A and 14B  are partial sectional views schematically illustrating the structure of a shower head according to a second embodiment; 
         FIGS. 15A ,  15 B,  16 A,  16 B,  17 A,  17 B,  18 A,  18 B,  19 A,  19 B,  20 A, and  20 B are sectional views schematically illustrating an example of the procedure of a method for forming a protective film according to a second embodiment; 
         FIGS. 21A and 21B  are partial sectional views schematically illustrating the structure of a shower head according to a third embodiment; 
         FIGS. 22A ,  22 B,  23 A,  23 B,  24 A,  24 B,  25 A,  25 B,  26 A,  26 B,  27 A, and  27 B are sectional views schematically illustrating an example of the procedure of a method for forming a protective film according to a third embodiment; 
         FIG. 28  is a sectional view schematically illustrating another example of the procedure of a method for forming a protective film according to a third embodiment; 
         FIGS. 29A and 29B  are partial sectional views schematically illustrating the structure of a shower head according to a fourth embodiment; 
         FIGS. 30A ,  30 B,  31 A,  32 B,  33 A,  33 B,  34 A,  34 B,  35 A, and  35 B are sectional views schematically illustrating an example of the procedure of a method for forming a protective film according to a fourth embodiment; 
         FIG. 36  is a sectional view schematically illustrating the structure of a protective film according to a fifth embodiment; 
         FIGS. 37A to 37E  are sectional views schematically illustrating an example of the procedure of a method for forming a protective film according to a fifth embodiment; 
         FIG. 38  is a sectional view schematically illustrating another example of the structure of a protective film according a fifth embodiment; and 
         FIGS. 39A to 39E  are sectional views schematically illustrating another example of the procedure of a method for forming a protective film according to a fifth embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     In general, according to one embodiment, a protective film is formed on a component in a plasma treatment apparatus and having a plasma resistance. The protective film includes a base film formed on the component and having a concave-convex structure, and an upper film formed on the base film to cover the concave-convex structure. 
     Exemplary embodiments of a protective film, a method for forming the same, a semiconductor manufacturing apparatus, and a plasma treatment apparatus will be explained below in detail with reference to the accompanying drawings. The present invention is not limited to the following embodiments. The present invention is not limited to these embodiments. Furthermore, sectional views of protective films used in the following embodiments are schematic, and relation between the thickness and width of layers and the ratio of thicknesses of the layers are not real. 
     First Embodiment 
     In the first embodiment, an example in which a protective film having a resistance against the exposure to plasma is applied to the inner wall of a plasma treatment apparatus will be described.  FIG. 1  is a sectional view schematically illustrating an example of the configuration of a plasma treatment apparatus. Here, an RIE apparatus is used as a plasma treatment apparatus  10 . The plasma treatment apparatus  10  includes a chamber  11  airtightly sealed, for example, made of aluminum. The chamber  11  is grounded. 
     The chamber  11  is provided therein with a support table  21  that horizontally supports a wafer  100  as a target and serves as a lower electrode. The support table  21  is provided on the surface thereof with a holding mechanism such as an electrostatic chuck mechanism (not illustrated) that electrostatically attracts the wafer  100 . An insulating ring  22  is provided to cover the edges of lateral side and bottom side of the support table  21 , and a focus ring  23  is provided on the outer periphery of the upper portion of the support table  21  covered by the insulating ring  22 . The focus ring  23  is a member provided in order to adjust an electric field such that the electric field is not biased with respect to the vertical direction (direction vertical to a wafer surface) at the edges of the wafer  100  when the wafer  100  is etched. 
     Furthermore, the support table  21  is supported on a support section  12  cylindrically protruding upright from the bottom wall near the center of the chamber  11  via the insulating ring  22  such that the support table  21  is positioned near the center of the chamber  11 . A baffle plate  24  is provided between the insulating ring  22  and the sidewall of the chamber  11 . The baffle plate  24  is formed with a plurality of gas discharge holes  25  passing through the plate in the thickness direction of the plate. Furthermore, a power feed line  31  for supplying radio frequency power is connected to the support table  21 , and a blocking condenser  32 , a matching device  33 , and a radio frequency power source  34  are connected to the power feed line  31 . Radio frequency power with a predetermined frequency is supplied from the radio frequency power source  34  to the support table  21 . 
     A shower head  41  serving as an upper electrode is provided above the support table  21  to face the support table  21  serving as the lower electrode. The shower head  41  is grounded. The shower head  41  is fixed to the sidewall near the upper portion of the chamber  11  while being spaced apart from the support table  21  by a predetermined distance, thereby facing the support table  21  in parallel to the support table  21 . With such a structure, the shower head  41  and the support table  21  form a pair of parallel flat plate electrodes. Furthermore, the shower head  41  is formed with a plurality of gas supply passages  42  passing through the plate in the thickness direction of the plate. 
     A gas supply port  13  is provided near the upper portion of the chamber  11  to supply treatment gas used in plasma treatment, and a gas supply apparatus (not illustrated) is connected to the gas supply port  13  through a pipe. 
     A gas exhaust port  14  is provided at a lower portion of the chamber  11  below the support table  21  and the baffle plate  24 , and a vacuum pump (not illustrated) is connected to the gas exhaust port  14  through a pipe. 
     As described above, an area of the chamber  11  partitioned by the support table  21 , the baffle plate  24 , and the shower head  41  becomes a plasma treatment chamber  61 , an upper area of the chamber  11  partitioned by the shower head  41  is a gas supply chamber  62 , and a lower area of the chamber  11  partitioned by the support table  21  and the baffle plate  24  is a gas exhaust chamber  63 . 
     A protective film  50  is formed on the surface of a member constituting the plasma treatment apparatus  10  with such a configuration, which is in contact with a plasma generation area, that is, on the surface of a member constituting the plasma treatment chamber  61 . In detail, the protective film  50  including an yttria-containing film (hereinafter, referred to as a yttria film) is formed on the inner wall surface of the chamber  11 , which constitutes the plasma treatment chamber  61 , the surface of the shower head  41  facing the plasma treatment chamber  61 , the surface of the baffle plate  24  facing the plasma treatment chamber  61 , the surface of the focus ring  23 , and the surface of the support table  21  onto which the wafer  100  is loaded. 
     The overview of processes performed by the plasma treatment apparatus  10  configured as above will be described below. First, the wafer  100  as a target is loaded onto the support table  21 , for example, the wafer  100  is fixed by the electrostatic chuck mechanism. Next, a vacuum is formed in the chamber  11  by the vacuum pump (not illustrated) connected to the gas exhaust port  14 . At this time, since the gas exhaust chamber  63  and the plasma treatment chamber  61  are connected to each other through gas discharge holes  25  formed through the baffle plate  24 , a vacuum is formed in the whole of the chamber  11 . 
     Then, when the chamber  11  reaches predetermined pressure, the treatment gas is supplied from the gas supply apparatus (not illustrated) to the gas supply chamber  62 , and is supplied to the plasma treatment chamber  61  through the gas supply passages  42  of the shower head  41 . When pressure in the plasma treatment chamber  61  reaches predetermined pressure, a radio frequency voltage is applied to the support table  21  (the lower electrode) in the state in which the shower head  41  (the upper electrode) is grounded, so that plasma is generated in the plasma treatment chamber  61 . Here, since self-bias is applied to the lower electrode due to the radio frequency voltage, potential gradient occurs between the plasma and the wafer, so that ions in plasma gas are accelerated toward the wafer  100  and thus an anisotropic etching process is performed. 
       FIGS. 2A and 2B  are partial sectional views schematically illustrating the structure of the shower head according to the first embodiment, wherein  FIG. 2A  is a sectional view schematically illustrating the structure in the vicinity of the exhaust port, and  FIG. 2B  is a partially enlarged sectional view of a protective film forming position. The shower head  41  (the gas supply member) is provided with the gas supply passages  42 . The gas supply passages  42 , for example, pass through a plate-shaped member constituting the shower head  41  toward the bottom surface from the top surface of the shower head  41  as illustrated in  FIG. 1 . The gas supply passage  42  includes a gas flow channel  421  with a first diameter, and an exhaust port  422  with an opening diameter increasing in a tilted manner from one end portion of the gas flow channel  421  so as to be a second diameter which is larger than the first diameter. In an example, the shower head  41  is processed to have a tapered shape in which the opening diameter of the shower head  41  increases in the vicinity of the exhaust port  422  of the gas supply passage  42 . 
     The above-mentioned shower head  41  includes a base material  411 , a base film  51  formed on an inner surface of the gas supply passage  42  of the base material  411  and a plane of a plasma-exposed side thereof, and a plasma protective film  53  which is an upper film formed on the base film  51 . The protective film  50  is formed of the base film  51  and the plasma protective film  53 . 
     The base material  411 , for example, is formed of a material including aluminum (Al). The base film  51  has a function of protecting the surface of the gas flow channel  421 , on which the plasma protective film  53  is hardly formed, from the exposure to plasma, wherein the surface of the base film  51  is formed of an anodic oxidation film. Furthermore, the base film  51  also has a function of preventing the base material  411  from being damaged by plasma even when the plasma protective film  53  is formed with a hole or is broken. 
     The plasma protective film  53  is formed of a material formed on the base film  51  and having a plasma resistance. As the plasma protective film  53 , for example, an yttria film, an alumina film and so forth can be used. 
     Here, the base film  51  is formed with grooves (e.g., patterns) in order to improve adhesion property to the plasma protective film  53  formed thereon.  FIG. 3  is a partial plan view schematically illustrating an example of the base film formed at a lower surface side of the shower head according to the first embodiment. In the example of  FIG. 3 , the base film  51  is formed with adhesion property improvement grooves  52  having a lattice-shaped pattern at the lower surface side of the shower head, and a pattern radially extending from the center of the gas supply passage  42  and a concentric pattern about the gas flow channel  421  at the exhaust port  422  of the gas supply passage  42 . Preferably, each adhesion property improvement groove  52  has a depth of 10 μm to 20 μm and a width of 10 μm to 20 μm, and a pitch between adjacent adhesion property improvement grooves  52  is 50 μm to 100 μm. Furthermore, since it is preferable that these patterns are formed in the base film  51 , the depth of the base film  51  preferably has a depth of 20 μm or more, which is deeper than that of the pattern. 
     The base film  51  has a structure in which a first conductive film, a second conductive film, and a third conductive film are sequentially stacked on the base material  411 , and an anodic oxidation film is formed at a contact portion to the plasma protective film  53 . The first conductive film and the third conductive film are formed of a material such as aluminum (Al) or titanium (Ti), which can form an anodic oxidation film with a clear columnar structure, and the second conductive film is formed of a material with an etching rate lower than that of the first conductive film and the third conductive film at the time of a wet etching process. In the example of  FIGS. 2A and 2B , the base film  51  has a structure in which an Al film  511 , an Al—Si alloy film  512 , and an Al film  513  are sequentially stacked on the base material  411 , and an alumite film  513   a  is formed at a contact portion to the plasma protective film  53 . 
     In addition, when viewed from the sectional structure of the base film  51  of  FIG. 2B , an inner surface constituting the adhesion property improvement groove  52  is not formed with a continuous surface, and the Al—Si alloy film  512  with a low etching rate as compared with Al protrudes beyond the Al films  511  and  513 . In detail, in the adhesion property improvement grooves  52 , an opening of the upper surface of the Al film  511  is formed larger in diameter than an opening of the lower surface of the Al—Si alloy film  512 , and an opening of the lower surface of the Al film  513  is formed larger in diameter than an opening of the upper surface of the Al—Si alloy film  512 , resulting in an increase in the surface area of the base film  51  formed with the adhesion property improvement grooves  52  and an anchor effect due to the shape, and the improvement of adhesion property to the base film  51  of the plasma protective film  53  formed on the base film  51 . Furthermore, the Al films  511  and  513  being in contact with the plasma protective film  53  is provided with the alumite film  513   a.    
     In addition, an adhesion property improvement effect is basically achieved regardless of the type of the pattern of the adhesion property improvement groove  52 . However, it is preferable that a pattern formed on a surface constituting the exhaust port  422  of the gas supply passage  42  is a radial pattern.  FIG. 3  illustrates an example in which a radial pattern and a concentric pattern are formed on the surface constituting the exhaust port  422  of the gas supply passage  42 . However, only the radial pattern may be formed. 
     Next, a method for forming the protective film  50  to the shower head  41  will be described.  FIGS. 4A ,  4 B,  5 A,  5 B,  6 A,  6 B,  7 A,  7 B,  8 A,  8 B,  9 A,  9 B,  10 A, and  10 B are sectional views schematically illustrating an example of the procedure of a method for forming the protective film according to the first embodiment. Among these drawings,  FIGS. 4A ,  5 A,  6 A,  7 A,  8 A,  9 A, and  10 A are sectional views in the vicinity of the shower head, and  FIGS. 4B ,  5 B,  6 B,  7 B,  8 B,  9 B, and  10 B are enlarged sectional views of protective film forming positions. 
     First, as illustrated in  FIGS. 4A and 4B , for example, the gas supply passage  42  is formed in the base material  411  formed of aluminum. As described above, the gas supply passage  42  includes the gas flow channel  421  with a first diameter, and the exhaust port  422  with an opening diameter increasing in a tilted manner from one end portion of the gas flow channel  421  so as to be a second diameter which is larger than the first diameter. 
     Next, as illustrated in  FIGS. 5A and 5B , the base film  51  is formed on the surface of a plasma-exposed side of the base material  411 . Here, as the base film  51 , the Al film  511 , the Al—Si alloy film  512 , and the Al film  513  are formed on the base material  411  using a deposition method. The Al—Si alloy film  512  has an etching rate lower than those of the Al films  511  and  513  at the time of a subsequent wet etching process. Furthermore, the thicknesses of the Al film  511 , the Al—Si alloy film  512 , and the Al film  513 , for example, may be 7 μm. In addition, the base film  51  may be formed using methods other than the deposition method, for example, a sputtering method and so forth. However, in order to form the base film  51  on the surface of the gas flow channel  421  formed perpendicularly to the surface of the base material  411 , it is preferable to use a film forming method (e.g., a deposition method) having an excellent step coverage. 
     Then, as illustrated in  FIGS. 6A and 6B , resist  71  is patterned in a predetermined shape on the base film  51 . At this time, the resist  71  is formed to be embedded in the gas supply passage  42 .  FIGS. 11A and 11B  are diagrams illustrating an example of a pattern forming tool, wherein  FIG. 11A  illustrates a plan view thereof and  FIG. 11B  illustrates a partially enlarged sectional view thereof. A pattern forming tool  81  forms grooves with a lattice-shaped pattern in the resist  71  positioned at the formation surface side of the exhaust port of the base material  411 , and includes a pattern  811  capable of forming grooves with a pattern, which radially extends from the center of the exhaust port  422 , in the resist  71  on the exhaust port  422 , and a pattern arranged concentrically to the center of the exhaust port  422 . The pattern forming tool  81 , for example, is formed of an elastic material such as rubber. 
       FIG. 12  is a sectional view schematically illustrating an example of a method for forming a pattern in resist. As illustrated in  FIG. 12 , the pattern forming tool  81  is arranged above the exhaust port formation surface of the base material  411  coated with the resist  71  through positioning. Then, the rear surface of the pattern forming tool  81  is pressed by a pressing tool  82  and the resist is solidified, thereby forming a pattern in the resist  71 . The pressing tool  82  is provided with a protrusion part  821  corresponding to the shape of the exhaust port  422  at the formation position of the exhaust port  422  of the base material  411 , and is formed of a material (e.g., a metal) having stiffness. If the pattern forming tool  81  is pressed by the pressing tool  82 , since the pattern forming tool  81  is formed of an elastic material, the pattern forming tool  81  is deformed according to the shape of the base material  411 , so that a pattern with lattice-shaped grooves is formed in the resist  71  on the plane of the exhaust port formation side of the base material  411 , and a pattern with radial and concentric grooves is formed in the resist  71  on the exhaust port  422 . Here, the pattern (an area not coated with the resist  71 ) with the grooves is formed with a width of 10 μm to 20 μm and a pitch of 50 μm to 100 μm. So far, a pattern formation method using transfer has been described. However, the pattern may be formed using a photolithography method, a laser drawing method, an imprinting method and so forth. 
     Thereafter, as illustrated in  FIGS. 7A and 7B , the base film  51  is etched using the patterned resist  71  as a mask through a wet etching process, thereby forming the adhesion property improvement grooves  52  in the base film  51 . As an etchant, for example, it is possible to use an alkali solution and so forth, such as mixed acid formed of phosphoric acid, nitric acid, acetic acid and water, sodium hydroxide, potassium hydroxide, or TMAH (Tetramethylammonium hydroxide). Furthermore, an etching time is controlled such that the base material  411  is not etched. 
     First, the uppermost Al film  513  not coated with the resist  71  is isotropically etched. As the Al film  513  is etched, if the Al—Si alloy film  512  is exposed at the lower portion of the Al film  513 , the Al—Si alloy film  512  is isotropically etched. In addition, as the Al—Si alloy film  512  is etched, if the Al film  511  is exposed at the lower portion of the Al—Si alloy film  512 , the Al film  511  is isotropically etched. Since each film is isotropically etched until the depths of the adhesion property improvement grooves  52  reach a predetermined depth, the Al film  513  is side-etched. Furthermore, since the Al—Si alloy film  512  has a low etching rate as compared with the Al film  511 , the uppermost Al film  511  is also side-etched. As a consequence, the Al—Si alloy film  512  protrudes beyond the upper and lower Al films  513  and  511 . That is, an opening of the upper surface of the uppermost Al film  511  is formed larger in diameter than an opening of the lower surface of the Al—Si alloy film  512 , and an opening of the lower surface of the uppermost Al film  513  is formed larger in diameter than an opening of the upper surface of the Al—Si alloy film  512 . In this way, a concave-convex structure having an anchor shape is formed on the inner surface of the adhesion property improvement groove  52 , resulting in an increase of adhesion caused by an increase of a shape effect and a surface area. 
     After the resist  71  is stripped, an anodic oxidation process is performed on the Al films  511  and  513  of the base film  51  as illustrated in  FIGS. 8A and 8B . In this way, the alumite film  513   a  is formed in an area where the Al films  511  and  513  are exposed. At this time, the Al film  513  of the base film  51 , which is formed on the inner surface of the gas flow channel  421 , is also anodically oxidized, so that the upper surface of the Al film  513  becomes the alumite film  513   a.    
     Then, as illustrated in  FIGS. 9A and 9B , the plasma protective film  53  is formed on the inner surface of the exhaust port  422  and the base film  51  of the exhaust port formation surface of the base material  411 . As the plasma protective film  53 , an alumina film, an yttria film and so forth can be used. Furthermore, as a method for forming the plasma protective film  53 , for example, it is possible to use a spraying method, a CVD (Chemical Vapor Deposition) method, an aerosol deposition method, a cold spraying method, a gas deposition method, an electrostatic powder impact deposition method, an impact sintering method and so forth. Here, the plasma protective film  53  is also embedded in the adhesion property improvement grooves  52  formed in the base film  51 . Since the surface area of the adhesion property improvement grooves  52 , for example, is increased as compared with the case in which the base film  51  is formed using one layer of an Al film, adhesion property of the plasma protective film  53  to the base film  51  is increased by an anchor effect. With the above-mentioned processes, it is possible to obtain the shower head  41  in which the protective film  50  according to the first embodiment has been formed on the base material  411 . 
     In addition, if the shower head  41  formed in this way is used in the plasma treatment apparatus illustrated in  FIG. 1  for a long time, the protective film  50  may deteriorate due to plasma damage. Therefore, when the protective film  50  deteriorates, the protective film  50  is removed as illustrated in  FIGS. 10A and 10B . That is, the plasma protective film  53  and the base film  51  are stripped off using a lift-off method to expose the base material  411 . Then, the protective film  50  can be formed (re-coated) on the base material  411  again using the method illustrated in  FIGS. 5A ,  5 B,  6 A,  6 B,  7 A,  7 B,  8 A,  8 B,  9 A, and  9 B. In addition, in the method according to the first embodiment, since an etching process is controlled such that the adhesion property improvement grooves  52  illustrated in  FIGS. 7A and 7B  do not reach the base material  411 , the base material  411  is prevented from being damaged, and the protective film  50  is re-coated, so that the base material  411  can be repeatedly used and the lifespan of the shower head  41  can be extended. 
     So far, the example has been described, in which three layers of the Al film  511 , the Al—Si alloy film  512 , and the Al film  513  are stacked on the base material  411  as the base film  51 . However, the base film  51  may have a structure in which a plurality of Al films and a plurality of Al—Si alloy films are alternately stacked. Furthermore, the base film  51  may have a structure in which a single Al film  511  is formed on the base material  411 . 
     Hereinafter, the effect of the first embodiment will be described in comparison with a comparative example.  FIGS. 13A to 13C  are sectional views schematically illustrating the overview of the procedure of a general method for forming a protective film to a shower head. In general, in order to form the protective film  50  on the gas supply passages  42  of the shower head  41 , the surface of the base material  411  formed of Al is subject to an anodic oxidation process to from an alumite film  58  as illustrated in  FIG. 13A . Next, as illustrated in  FIG. 13B , the surface of the alumite film  58  is stripped off using a sandblasting method. As a consequence, the alumite film  58  is provided on the surface thereof with a concave-convex structure. Then, as illustrated in  FIG. 13C , the protective film  50  is formed on the surface of the base material  411  provided with the concave-convex structure. In this way, the protective film  50  is formed on the base material  411  provided with the concave-convex structure, resulting in an increase of adhesion strength of the protective film  50 . 
     However, it is difficult to uniformly roughen the surface of the exhaust port  422  with a tapered shape by using the sandblast method. Specifically, a smaller concave-convex structure is formed on the exhaust port  422 , which is near the gas flow channel  421 , as compared with the plane of the exhaust port formation side of the base material  411 . As a consequence, the protective film  50  formed on the exhaust port  422  in the vicinity of the gas flow channel  421  has poor adhesion property to the base material  411 . In such a state, if the protective film  50  is subject to plasma treatment, since a crack may be generated in corners  75  at the boundaries between the gas flow channel  421  and the exhaust port  422 , the protective film  50  may be stripped off and the stripped film may fall on a wafer to be subject to plasma treatment as dust. 
     Meanwhile, in the first embodiment, the adhesion property improvement grooves  52  are formed in the base film  51 , in which the Al film  511 , the Al—Si alloy film  512 , and the Al film  513  are stacked, which have been formed on the exhaust port  422  with a tapered shape of the gas supply passages  42  of the base material  411 , and the Al—Si alloy film  512  has a sectional structure in which the Al—Si alloy film  512  protrudes beyond the Al films  511  and  513 . Furthermore, since the adhesion property improvement grooves  52  are formed using a lithography technique and an etching technique, even when the adhesion property improvement grooves  52  are positioned on a plane of the exhaust port formation side of the base material  411  or positioned adjacent to the gas flow channel  421  of the exhaust port  422 , the depths of the grooves are approximately constant, resulting in the achievement of uniform roughness. Consequently, adhesion property between the base film  51  and the plasma protective film  53  formed on the base film  51  is improved by an anchor effect. As a consequence, even when heat is repeatedly applied through plasma treatment, the plasma protective film  53  formed in the vicinity of the gas flow channel  421  of the exhaust port  422  is hardly stripped off. 
     Furthermore, a pattern (the adhesion property improvement groove  52 ) may be directly formed on the base material  411  without forming the base film  51 , and the plasma protective film  53  may be formed on the pattern. However, in such a case, since the surface area of the adhesion property improvement grooves  52  is not increased different from the first embodiment, the plasma protective film  53  may be easily stripped off as compared with the first embodiment. Therefore, as described above, it is preferable to use the base film  51  in which a metal film (e.g., the Al film  511 /the Al—Si alloy film  512 /the Al film  513 ) for allowing an anodic oxidation film to be easily formed, and a material film, which is hardly etched as compared with the metal film at the time of an etching process, are stacked on the base material  411 . 
     Moreover, after the Al film  513  of the base film  51  formed in the gas flow channel  421  of the base material  411  is anodically oxidized to form the alumite film  513   a , the plasma protective film  53  is formed on the base film  51  formed on the surface, which constitutes the exhaust port  422 , and a main surface of the exhaust port formation surface side of the base material  411 . Consequently, it is possible to form a film having a plasma resistance on the inner surface of the gas flow channel  421  on which the plasma protective film  53  is hardly formed. Moreover, as with the comparative example, the base film  51  may not be removed, which has been formed on a formation area of the plasma protective film  53 , that is, the surface constituting the exhaust port  422 , and the main surface of the exhaust port formation surface side of the base material  411 . 
     Second Embodiment 
       FIGS. 14A and 14B  are partial sectional views schematically illustrating the structure of the shower head according a second embodiment, wherein  FIG. 14A  is a sectional view schematically illustrating the structure in the vicinity of the exhaust port, and  FIG. 14B  is a partially enlarged sectional view of a protective film forming position. The first embodiment uses the base film obtained by sequentially stacking the Al film, the Al—Si alloy film, and the Al film on the base material. However, in the second embodiment, since the base material  411  is made of a material including Al, the base film  51  is obtained by sequentially stacking the Al—Si alloy film  512  and the Al film  513  on the base material  411 . That is, the second embodiment has a structure in which the base material  411  is used as the lowermost Al film  511  of the base film  51  in the first embodiment. Therefore, the adhesion property improvement grooves  52  reach the base material  411  and the plasma protective film  53  makes contact with the base material  411 . In addition, the same reference numerals are used to designate the same elements as those of the first embodiment, detailed description thereof will not be repeated. 
       FIGS. 15A ,  15 B,  16 A,  16 B,  17 A,  17 B,  18 A,  18 B,  19 A,  19 B,  20 A, and  20 B are sectional views schematically illustrating an example of the procedure of a method for forming the protective film according to the second embodiment. Among these drawings,  FIGS. 15A ,  16 A,  17 A,  18 A,  19 A, and  20 A are sectional views in the vicinity of the shower head, and  FIGS. 15B ,  16 B,  17 B,  18 B,  19 B, and  20 B are enlarged sectional views of protective film forming positions. 
     First, as illustrated in  FIGS. 15A and 15B , for example, the gas supply passage  42  including the gas flow channel  421  and the exhaust port  422  connected to the gas flow channel  421  is formed in the base material  411  formed of aluminum. Next, as illustrated in  FIGS. 16A and 16B , the base film  51  is formed on the surface of a plasma-exposed side of the base material  411 . Here, as the base film  51 , the Al—Si alloy film  512  and the Al film  513  are formed on the base material  411  using a deposition method. The Al—Si alloy film  512  has an etching rate lower than that of the Al film  513  at the time of a subsequent wet etching process. Furthermore, the thicknesses of the Al—Si alloy film  512  and the Al film  513 , for example, may be 1 μm, which is thinner than the first embodiment. 
     Then, as illustrated in  FIGS. 17A and 17B , the resist  71  is patterned in a predetermined shape on the base film  51  in the same manner as the first embodiment. A pattern with lattice-shaped grooves is formed in the resist  71  on the exhaust port formation surface side of the base material  411 , and a pattern with radial and concentric grooves is formed in the resist  71  on the exhaust port  422 . Here, the pattern (an area not coated with the resist  71 ) with the grooves is formed with a width of 10 μm to 20 μm and a pitch of 50 μm to 100 μm. 
     Thereafter, as illustrated in  FIGS. 18A and 18B , the base film  51  is etched using the resist pattern as a mask through a wet etching process, thereby forming the adhesion property improvement grooves  52  in the base film  51 . As an etchant, for example, it is possible to use mixed acid, which is formed of phosphoric acid, nitric acid, acetic acid and water, and so forth similarly to the first embodiment. 
     First, the uppermost Al film  513  not coated with the resist  71  is isotropically etched. As the Al film  513  is etched, if the Al—Si alloy film  512  is exposed at the lower portion of the Al film  513 , the Al—Si alloy film  512  is isotropically etched. In addition, as the Al—Si alloy film  512  is etched, if the base material  411  formed of a material including Al is exposed at the lower portion of the Al—Si alloy film  512 , the base material  411  is isotropically etched. Since each film and the base material  411  are isotropically etched until the depths of the adhesion property improvement grooves  52  reach a predetermined depth, the Al film  513  is side-etched. Furthermore, since the Al—Si alloy film  512  has a lower etching rate as compared with Al, the base material  411  is also side-etched. As a consequence, the Al—Si alloy film  512  protrudes beyond the Al film  513  and the base material  411 . That is, an opening of the upper surface of the base material  411  is formed larger in diameter than an opening of the lower surface of the Al—Si alloy film  512 , and an opening of the lower surface of the uppermost Al film  513  is formed larger in diameter than an opening of the upper surface of the Al—Si alloy film  512 . In this way, a concave-convex structure having an anchor shape is formed on the inner surface of the adhesion property improvement groove  52 , resulting in an increase of adhesion caused by an increase of a shape effect and a surface area. Furthermore, the base film  51  which has been formed on the inner surface of the gas flow channel  421  having no resist  71 , and a part of the base material  411  is removed by the etching process. 
     After the resist  71  is stripped off, an anodic oxidation process is performed on the Al film  513  of the base film  51  and the base material  411  as illustrated in  FIGS. 19A and 19B . In this way, the alumite film  513   a  is formed in an area where the Al film  513  and the base material  411  are exposed. 
     Then, as illustrated in  FIGS. 20A and 20B , the plasma protective film  53  such as an alumina film or an yttria film is formed on the inner surface of the exhaust port  422  and the base film  51  of the exhaust port formation surface of the base material  411 . As a method for forming the plasma protective film  53 , for example, it is possible to use a spraying method, a CVD method, an aerosol deposition method, a cold spraying method, a gas deposition method, an electrostatic powder impact deposition method, an impact sintering method and so forth. The plasma protective film  53  is also embedded in the adhesion property improvement grooves  52 , resulting in an increase of adhesion property between the adhesion property improvement grooves  52  and the base film  51  by an anchor effect. With the above-mentioned processes, it is possible to obtain the shower head  41  in which the protective film  50  according to the second embodiment has been formed on the base material  411 . 
     Even in the second embodiment, similarly to the first embodiment, even when the plasma treatment is repeated and the plasma protective film  53  is exposed to plasma, it is possible to obtain the plasma protective film  53  which is hardly stripped off from the base material  411 . 
     Third Embodiment 
       FIGS. 21A and 21B  are partial sectional views schematically illustrating the structure of the shower head according a third embodiment, wherein  FIG. 21A  is a sectional view schematically illustrating the structure in the vicinity of the exhaust port, and  FIG. 21B  is a partially enlarged sectional view of a protective film forming position. Low melting point alloy crystal grains  541  formed of an alloy of Al and a low melting point metal and having a height of about 10 μm to about 20 μm are formed to be dispersed on the exhaust port formation surface of the base material  411  and the inner surface of the exhaust port  422 , which constitute the shower head  41 . 
     Furthermore, an alumite base film formed of an alumite film is formed on the surface of the low melting point alloy crystal grains  541  and the surface (includes the inner surface of the gas flow channel  421  of the base material  411 ) of the base material  411  with no low melting point alloy crystal grains  541  being formed. In addition, the plasma protective film  53  formed of alumina and yttria is formed on the exhaust port formation surface of the base material  411  and the alumite base film of the exhaust port  422 . 
     That is to say, in the third embodiment, the low melting point alloy crystal grains  541  are formed to be dispersed on the exhaust port formation surface of the base material  411  and the inner surface of the exhaust port  422 , resulting in an increase of the surface area of the base material  411 , and the achievement of an anchor effect for the plasma protective film  53  formed on the base material  411 . 
       FIGS. 22A ,  22 B,  23 A,  23 B,  24 A,  24 B,  25 A,  25 B,  26 A,  26 B,  27 A, and  27 B are sectional views schematically illustrating an example of the procedure of a method for forming the protective film according to the third embodiment. Among these drawings,  FIGS. 22A ,  23 A,  24 A,  25 A,  26 A, and  27 A are sectional views in the vicinity of the shower head, and  FIGS. 22B ,  23 B,  24 B,  25 B,  26 B, and  27 B are enlarged sectional views of protective film forming positions. 
     First, as illustrated in  FIGS. 22A and 22B , for example, the gas supply passage  42  including the gas flow channel  421  and the exhaust port  422  connected to the gas flow channel  421  is formed in the base material  411  formed of aluminum. Next, as illustrated in  FIGS. 23A and 23B , a seal material  72  is filled in the gas flow channel  421  of the gas supply passage  42 . The seal material  72  is filled only in the gas flow channel  421 , and is not embedded in the exhaust port  422 . Furthermore, as the seal material  72 , for example, resist can be used. 
     Then, an aluminum alloy film  54   a  having a low melting point of about 200° C. is deposited with a predetermined thickness (e.g., 20 μm) on the surface of the exhaust port formation surface side of the base material  411 , in detail, the exhaust port formation surface of the base material  411 , the inner surface of the exhaust port  422 , and the upper surface of the seal material  72 . As the aluminum alloy film  54   a , for example, Al—Sn, Al—Pb, Al—In and so forth can be used. The aluminum alloy film  54   a  is in an amorphous state immediately after being deposited. 
     Then, as illustrated in  FIGS. 24A and 24B , heat treatment is performed with respect to the base material  411  at the temperature of about 200° C. Thus, the aluminum alloy film  54   a  in the amorphous state is crystallized. If the aluminum alloy film  54   a  is crystallized, low melting point metal components (e.g., Sn, Pb, In and so forth) having a melting point of 350° C. or less are segregated, resulting in the formation of an aluminum alloy film  54  in which the low melting point alloy crystal grains  541  including low melting point metals are dispersed among Al crystal grains  542  including no low melting point metals. 
     Thereafter, as illustrated in  FIGS. 25A and 25B , a wet etching process is performed, so that crystal grains including no low melting point metals, that is, the Al crystal grains  542  are removed, and the low melting point alloy crystal grains  541  remain. An etchant uses chemical that dissolves the Al crystal grains  542  but does dot dissolve the low melting point alloy crystal grains  541 , and for example, may use mixed acid formed of phosphoric acid, nitric acid, acetic acid and water similarly to the first embodiment. In addition, in this wet etching process, the Al crystal grains  542  of the aluminum alloy film  54  may be removed. Through the etching process, the low melting point alloy crystal grains  541  with a height of 10 μm to 20 μm are randomly arranged on the lower surface of the base material  411  and the inner surface of the exhaust port  422 . In this way, the low melting point alloy crystal grains  541  are arranged on the base material  411 , so that a concave-convex structure is formed on the surface of the base material  411  serving as a base film of the plasma protective film  53 . In addition, the low melting point alloy crystal grains  541  on the seal material  72  are removed by lift-off when removing the seal material  72 . 
     Next, as illustrated in  FIGS. 26A and 26B , an anodic oxidation process is performed with respect to the base material  411  and the low melting point alloy crystal grains  541 . In this way, an alumite base film  55  is formed on exposed areas of the base material  411  and the low melting point alloy crystal grains  541 . At this time, the alumite base film  55  is formed on the inner surface of the gas flow channel  421  of the gas supply passage  42 , in which the plasma protective film  53  is hardly formed. 
     Thereafter, as illustrated in  FIGS. 27A and 27B , the plasma protective film  53  such as an alumina film or an yttria film is formed on the inner surface of the exhaust port  422 , on which the low melting point alloy crystal grains  541  have been formed, and the exhaust port formation surface of the base material  411 . As a method for forming the plasma protective film  53 , for example, it is possible to use a spraying method, a CVD method, an aerosol deposition method, a cold spraying method, a gas deposition method, an electrostatic powder impact deposition method, an impact sintering method and so forth. The plasma protective film  53  is formed to fill among the low melting point alloy crystal grains  541 . The plasma protective film  53  is formed on the base material  411  with a surface having a concave-convex structure by the low melting point alloy crystal grains  541 . Therefore, the plasma protective film  53  having improved adhesion property to a base by an anchor effect is formed. With the above-mentioned processes, it is possible to obtain the shower head  41  in which the protective film  50  according to the third embodiment has been formed on the base material  411 . 
     So far, in  FIGS. 25A and 25B , after the Al crystal grains  542  of the aluminum alloy film  54  are removed through the wet etching process, the wet etching process is stopped. However, the embodiment is not limited thereto.  FIG. 28  is a sectional view schematically illustrating another example of the procedure of a method for forming the protective film according to the third embodiment. As illustrated in  FIG. 28 , the wet etching process is not stopped at the time point at which the Al crystal grains  542  have been removed, and the base material  411  is also etched so that the adhesion property improvement grooves  52  may be formed in the base material  411 . In such a case, since the base material  411  formed of a material including Al is easily etched as compared with the low melting point alloy crystal grains  541 , the base material  411  is side-etched at the lower portion of edges of the low melting point alloy crystal grains  541 . In this way, the etching process is performed until the adhesion property improvement grooves  52  are formed in the base material  411 , resulting in a further increase of an anchor effect for the plasma protective film  53 . In addition, when the base material  411  is etched, an etching time may be controlled. 
     Even in the third embodiment, similarly to the first embodiment, even when the plasma treatment is repeated and the plasma protective film  53  is exposed to plasma, it is possible to obtain the plasma protective film  53  which is hardly stripped off from the base material  411 . Furthermore, the aluminum alloy film  54   a  is crystallized on the base material  411  to be divided into the low melting point alloy crystal grains  541  and the Al crystal grains  542 , and the Al crystal grains  542  are molten using chemical, resulting in the achievement of the low melting point alloy crystal grains  541  distributed in an island shape on the exhaust port formation surface of the base material  411  and the inner surface of the exhaust port  422 . Furthermore, the surface area of the base material  411  is increased by the low melting point alloy crystal grains  541 . As a consequence, similarly to the first and second embodiments, it is not necessary to form the base film  51  and perform a patterning process. 
     Fourth Embodiment 
       FIGS. 29A and 29B  are partial sectional views schematically illustrating the structure of the shower head according to a fourth embodiment, wherein  FIG. 29A  is a sectional view schematically illustrating the structure in the vicinity of the exhaust port, and  FIG. 29B  is a partially enlarged sectional view of a protective film forming position. A first alumite film  56  is formed by an anodic oxidation process on the exhaust port formation surface of the base material  411  and the inner surface of the gas supply passage  42 , which constitute the shower head  41 . Furthermore, a second alumite film  57  having a columnar structure of an irregular shape as compared with Al is formed on the first alumite film  56  on the exhaust port formation surface of the base material  411  and the inner surface of the exhaust port  422 . The second alumite film  57 , for example, may use a material, such as Al—Si, Al—W, Al—Mo, Al—Ti or Al—Ta, which is hardly subject to an anodic oxidation process. A base film is formed by the first alumite film  56  and the second alumite film  57 . Then, the plasma protective film  53  formed of alumina or yttria is formed on the second alumite film  57 . In this way, the protective film  50  includes the first alumite film  56 , the second alumite film  57 , and the plasma protective film  53 . 
     That is to say, in the fourth embodiment, the second alumite film  57  having the irregular columnar structure is formed on the exhaust port formation surface of the base material  411  and the inner surface of the exhaust port  422 , resulting in an increase of the surface area of the base film and thus the achievement of an anchor effect for the plasma protective film  53  formed on the second alumite film  57 . 
       FIGS. 30A ,  30 B,  31 A,  32 B,  33 A,  33 B,  34 A,  34 B,  35 A, and  35 B are sectional views schematically illustrating an example of the procedure of a method for forming the protective film according to the fourth embodiment. Among these drawings,  FIGS. 30A ,  31 A,  32 A,  33 A,  34 A, and  35 A are sectional views in the vicinity of the shower head, and  FIGS. 30B ,  31 B,  32 B,  33 B,  34 B, and  35 B are enlarged sectional views of protective film forming positions. 
     First, as illustrated in  FIGS. 30A and 30B , for example, the gas supply passage  42  including the gas flow channel  421  and the exhaust port  422  connected to the gas flow channel  421  is formed in the base material  411  formed of aluminum. Next, as illustrated in  FIGS. 31A and 31B , an anodic oxidation process is performed to form the first alumite film  56  on the surface of the base material  411 . In this way, a protective film including the first alumite film  56  is formed on the inner surface of the gas flow channel  421  on which the plasma protective film  53  is hardly formed. 
     Then, as illustrated in  FIGS. 32A and 32B , the gas flow channel  421  of the gas supply passage  42  is sealed by the seal material  72 . The seal material  72  is filled only in the gas flow channel  421 , and is not embedded in the exhaust port  422 . Furthermore, as the seal material  72 , for example, resist can be used. 
     Moreover, an aluminum alloy film  57   a , which includes a material for forming a hollow columnar anodic oxidation film of an irregular shape by an anodic oxidation process, is formed on the surface of the exhaust port formation surface side of the base material  411 , in detail, the exhaust port formation surface of the base material  411 , the inner surface of the exhaust port  422 , and the upper surface of the seal material  72  by using a film forming method such as a deposition method. As the aluminum alloy film  57   a , for example, Al—Si, Al—W, Al—Mo, Al—Ti, Al—Ta and so forth can be used. 
     Then, as illustrated in  FIGS. 33A and 33B , an anodic oxidation process is performed on the aluminum alloy film  57   a  to form the second alumite base film  57 . The aluminum alloy film  57   a  is anodically oxidized to have an irregular hollow columnar shape, other than a regular hollow columnar shape as with the case in which Al has been subject to the anodic oxidation process. As a result, the surface area of the second alumite base film  57  is increased. 
     Thereafter, as illustrated in  FIGS. 34A and 34B , the seal material  72  formed in the gas flow channel  421  is removed by a wet etching process. Then, as illustrated in  FIGS. 35A and 35B , the plasma protective film  53  such as an alumina film or a yttria film is formed on the inner surface of the exhaust port  422  and the exhaust port formation surface of the base material  411 , on which the second alumite base film  57  has been formed. As a method for forming the plasma protective film  53 , for example, it is possible to use a spraying method, a CVD method, an aerosol deposition method, a cold spraying method, a gas deposition method, an electrostatic powder impact deposition method, an impact sintering method and so forth. The plasma protective film  53  is formed to fill in holes formed in the second alumite base film  57 . A base film of the plasma protective film  53  is the second alumite base film  57  provided on the surface thereof with a concave-convex structure by the irregular holes, so that the adhesion property of the plasma protective film  53  formed on the base film is improved by an anchor effect. With the above-mentioned processes, it is possible to obtain the shower head  41  in which the protective film  50  according to the fourth embodiment has been formed on the base material  411 . 
     Even in the fourth embodiment, similarly to the first embodiment, even when the plasma treatment is repeated and the plasma protective film  53  is exposed to plasma, it is possible to obtain the plasma protective film  53  which is hardly stripped off from the base material  411 . Furthermore, the second alumite base film  57  having an irregular hollow columnar shape by the anodic oxidation process is provided, resulting in an increase of the surface area of the base film of the plasma protective film  53 . As a consequence, similarly to the first and second embodiments, it is not necessary to form the base film  51  and perform a patterning process. 
     In addition, the shower head  41  also functions as an upper electrode of the plasma treatment apparatus, and includes a ground line and connection parts (not illustrated). When forming the protective film  50  described in the above embodiment, since it is difficult to form the protective film  50  formed of an insulation material on the connection parts, a mask is applied to the connection parts using resist and so forth. 
     Fifth Embodiment 
     In a general plasma treatment apparatus, reaction products generated by an RIE process may be accumulated on the inner wall of the chamber  11 , be stripped off from the inner wall of the chamber  11  during plasma treatment (RIE process) if the amount of the accumulated reaction products reaches a certain degree, and may fall on the wafer  100  as dust. In the fifth embodiment, the protective film  50  capable of solving such a problem will be described. 
       FIG. 36  is a sectional view schematically illustrating the structure of the protective film according to the fifth embodiment. As illustrated in  FIG. 36 , the surface of the base material  111  of the chamber  11  and so forth has been planarized, and a roughened alumite film  59  as the protective film  50  is formed on the surface of the base material  111 . Preferably, the thickness of the alumite film  59  is about 10 μm to about 200 μm, and the surface of the alumite film  59  has a concave-convex structure of about 2 μm to about 100 μm in terms of arithmetic average roughness Ra. 
     In this way, the roughened alumite film  59  is formed on the surface of the base material  111 , thereby preventing the base material  111  from being corroded by active species generated during the plasma treatment. Furthermore, the reaction products generated during the plasma treatment are accumulated on the roughened base material  111 , resulting in an increase of the surface area of the alumite film  59  and an increase of an anchor effect due to the shape. Since reaction products formed on the alumite film  59  improve adhesion property to the alumite film  59 , the reaction products are hardly stripped off therefrom. 
     Next, a method for manufacturing the alumite film  59  will be described.  FIGS. 37A to 37E  are sectional views schematically illustrating an example of the procedure of a method for forming the protective film according to the fifth embodiment. First, as illustrated in  FIG. 37A , prepared is the base material  111  formed of aluminum and having a planarized surface. Next, as illustrated in  FIG. 37B , the alumite film  59  (an anodic oxidation film) having a hollow cell shape and a thickness of about 10 μm to about 200 μm is formed on the surface of the base material  111  by an anodic oxidation process using a sulfuric acid aqueous solution, a mixed aqueous solution of sulfuric acid and axalic acid, and so forth. In addition, a crack is hardly generated in an alumite film  59  formed by the anodic oxidation process using the mixed aqueous solution of sulfuric acid and axalic acid, as compared with an alumite film  59  formed by the anodic oxidation process using the sulfuric acid aqueous solution. In this regard, it is preferable to appropriately change an aqueous solution to be used in consideration of the probability of the generation of a crack at the formation position of the alumite film  59 . 
     Then, as illustrated in  FIG. 37C , the surface of the alumite film  59  is roughened by a method such as a sandblast method. At this time, the alumite film  59  is roughened such that the arithmetic average roughness Ra of the surface of the alumite film  59  is 2 μm to 100 μm. However, the roughening process is performed such that the concave structure does not reach the base material  111 . 
     For an alumite film  59  formed at a place where no sudden change occurs in the temperature during the plasma treatment or a place other than corner-edges, or an alumite film  59  formed by the anodic oxidation method capable of preventing the generation of a crack as described above, even when the plasma treatment is repeated, since a crack is hardly generated, the procedure for forming the roughened alumite film  59  may be completed with the processes of  FIGS. 37A to 37C . 
     Meanwhile, for an alumite film  59  formed at a place (e.g., a place in the vicinity of a plasma generation area) where a sudden change occurs in the temperature during the plasma treatment or a place (e.g., corner-edges) where stress is easily concentrated, or an alumite film  59  formed by an anodic oxidation method that allows the generation of a crack, when the plasma treatment is repeated, a crack is easily generated. In this regard, it is preferable to perform processes of  FIGS. 37D and 37E  as follows. 
     As illustrated in  FIG. 37D , a crack is generated in the formed alumite film  59 . As a process for generating the crack, for example, a process for heating and cooling the base material  111  is repeated a plurality of times, so that a crack  59   a  is generated in the alumite film  59  due to the thermal expansion coefficient difference between aluminum (the base material  111 ) and the alumite film  59 . For example, the crack  59   a  is generated by repeating a plurality of times a cycle of increasing the temperature of the base material  111  from the room temperature to the temperature (100° C. to 200° C.) slightly higher than the maximum achieving temperature at the time of the plasma treatment, and then cooling the base material  111  up to the room temperature. In this way, the crack  59   a  is generated, so that stress occurring in the alumite film  59  is attenuated. 
     Then, as illustrated in  FIG. 37E , a hole sealing process is performed to seal the crack  59   a  generated in the alumite film  59 . As the hole sealing process, for example, the oxidation of the alumite film  59  is promoted using water vapor and so forth, thereby sealing the crack  59   a . At this time, a hollow cell is also sealed. Consequently, the roughened alumite film  59  is formed. 
       FIG. 36  illustrates an example in which the roughened alumite film  59  is provided on the base material  111  having a planarized surface. However, the embodiment is not limited to the structure as illustrated in  FIG. 36  if the roughened alumite film  59  is provided.  FIG. 38  is a sectional view schematically illustrating another example of the structure of the protective film according the fifth embodiment.  FIG. 38  illustrates an example in which the alumite film  59  is provided on a roughened base material  111 . In such a case, preferably, the thickness of the alumite film  59  is about 10 μm to about 100 μm, and the surface of the alumite film  59  has a concave-convex structure of about 2 μm to about 100 μm in terms of arithmetic average roughness Ra. Even in such a structure, similarly to the example as illustrated in  FIG. 36 , reaction products accumulated on the surface of the alumite film  59  roughened during the plasma treatment is hardly stripped off because it makes close contact with the component by an anchor effect. 
     Next, a method for manufacturing the alumite film  59  will be described.  FIGS. 39A to 39E  are sectional views schematically illustrating another example of the procedure of a method for forming the protective film according to the fifth embodiment. First, as illustrated in  FIG. 39A , prepared is the base material  111  formed of aluminum and having a planarized surface. Next, as illustrated in  FIG. 39B , the surface of the base material  111  is roughened by a method such as a sandblast method. At this time, the surface of the base material  111  is roughened such that the arithmetic average roughness Ra of the surface after the alumite film  59  is formed is 2 μm to 100 μm. 
     Then, as illustrated in  FIG. 39C , the alumite film  59  (an anodic oxidation film) having a hollow cell shape and a thickness of about 10 μm to about 100 μm is formed on the surface of the roughened base material  111  by an anodic oxidation process using a sulfuric acid aqueous solution, a mixed aqueous solution of sulfuric acid and axalic acid, and so forth. Similarly to the example of  FIGS. 37A to 37C , when the alumite film  59  is formed at a place where a crack is hardly generated during the plasma treatment, or when the alumite film  59  is formed by the anodic oxidation method capable of preventing the generation of a crack as described above, the procedure for forming the roughened alumite film  59  may be completed with the processes of  FIGS. 39A to 39C . 
     Meanwhile, when the alumite film  59  is formed at a place where a crack is easily generated during the plasma treatment, or an alumite film  59  is formed by an anodic oxidation method that allows the generation of a crack, it is preferable to perform processes of  FIGS. 39D and 39E  as follows. 
     As illustrated in  FIG. 39D , a crack is generated in the formed alumite film. As a process for generating the crack, a method for repeating a plurality of times the heating and cooling of the base material  111  can be used similarly to the process illustrated in  FIG. 37D . As a consequence, the crack  59   a  is generated in the alumite film  59 . 
     Then, as illustrated in  FIG. 39E , a hole sealing process is performed to seal the crack  59   a  generated in the alumite film  59 . As the hole sealing process, for example, the oxidation of the alumite film  59  is promoted using water vapor and so forth, thereby sealing the crack  59   a . At this time, a hollow cell is also sealed. Consequently, the roughened alumite film  59  is formed. 
     In addition, the roughened alumite film  59  can be provided to the surface of a component in an area where reaction products are accumulated. For example, the roughened alumite film can be provided to the surface of a component having a side making contact with a plasma generation area and the surface of the component up to the vicinity of the gas exhaust port  14  of the gas exhaust chamber  63 . 
     In the fifth embodiment, after the surface of the component having the side making contact with the plasma generation area is roughened, the alumite film  59  is formed. Consequently, during the plasma treatment, due to the presence of the alumite film  59 , active species generated in the plasma treatment are prevented from directly making contact with the component, so that the component is prevented from being corroded. Furthermore, since reaction products accumulated on the surface of the component during the plasma treatment are accumulated on the surface of the roughened alumite film  59 , the reaction products are accumulated by making close contact with the component by an anchor effect. As a consequence, it is possible to prevent the reaction products from being stripped off from the component and falling on the wafer  100  during the plasma treatment. 
     Furthermore, in the above description, the RIE apparatus has been described as an example of the plasma treatment apparatus  10 . However, it is possible to apply the above-described embodiments to all processing apparatuses such as a resist stripping apparatus, CDE (chemical dry etching) apparatus or a CVD apparatus, and all semiconductor manufacturing apparatuses. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.