Patent Document

CROSS-REFERENCE TO RELATED APPLICATION  
       [0001]    This application is a Continuation of International patent application Serial No. PCT/JP02/12469 filed Nov. 28, 2002, which was published in Japanese on Jul. 31, 2003 as WO 03/063222 A1, and Japanese Patent Application No. 2002-15919 filed Jan. 24, 2002 which is incorporated herein by reference in its entirety. 
     
    
     
       BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to an ozone processing device which discharges a processing gas containing at least ozone onto the surface of a substrate such as a semiconductor substrate or a liquid crystal substrate in order to form or to improve an oxide film on the substrate surface or to remove a resist film formed on the substrate surface.  
           [0003]    [0003]FIG. 7 and FIG. 8 show examples of conventional ozone processing devices. FIG. 7 is a cross-section drawing showing a portion of an ozone processing device based on a conventional technology and is a cross-section drawing along the E-E line in FIG. 8. FIG. 8 is a bottom-view drawing along the D-D line in FIG. 7.  
           [0004]    As FIG. 7 and FIG. 8 show, an ozone processing device  100  is equipped with: a mounting base  101  on which a substrate K is mounted; a gas supply head  102  disposed above the mounting base  101  so that it faces the substrate K. The mounting base  101  and the gas supply head  102  are disposed in a chamber (not illustrated) equipped with a closed space. The chamber (not illustrated) is formed with a suitable exhaust opening from which internal gasses are discharged to the outside.  
           [0005]    The mounting base  101  is equipped with an internal heating device (not illustrated) formed from a heater. The substrate K mounted on the upper surface is heated by this heating device (not illustrated). Also, the mounting base  101  can be raised and lowered by a raising/lowering device (not illustrated).  
           [0006]    The gas supply head  102  is formed from a nozzle module  103  and a cooling module  104 , both formed as block-shaped members that are stacked vertically and bonded. A cavity  105  is formed on the upper surface of the nozzle module  103 , i.e., the surface where it bonds with the cooling module  104 . Nozzles  106 , which communicate with the cavity  105  and open on the lower surface, are arranged in a plurality of rows in a staggered manner. Exhaust grooves  107 , which open on the side surfaces, are formed on the bottom surface between the rows of the nozzle  106 .  
           [0007]    The cooling module  104  is formed from an upper member  104   a  and a lower member  104   b , which are stacked vertically and bonded. A cooling fluid path  108  ( 108   a ,  108   b ) is formed on the bonding surface between the upper member  104   a  and the lower member  104   b  in a zigzag pattern extending from one side surface to the other side surface. The cooling fluid path  108  is connected by way of pipes  109 ,  110  to external cooling fluid supplying means  111 . In this manner, the cooling fluid path  108 , the pipes  109 ,  110 , and cooling fluid supplying means  111  form a circulation path for cooling fluid to allow the cooling fluid to circulate.  
           [0008]    The cooling module  104  is formed with a through-hole  112  that passes from the upper surface to the lower surface and communicates with the cavity  105 . This through-hole  112  is connected by way of a pipe  114  connected thereto to an external ozone gas generating device  113 . A predetermined concentration of ozone gas (processing gas) is supplied from ozone gas generating means  113  by way of the pipe  114  and the through-hole  112  to the cavity  105 , and is discharged toward the substrate K from the lower openings of the nozzle  106 .  
           [0009]    With the ozone processing device  100  described above, the substrate K is mounted on the mounting base  101 . The substrate K is mounted on heating means (not shown) and the mounting base  101  is raised by raising/lowering means (not shown) to a position, as shown in FIG. 7, where it is separated by a predetermined space from the gas supply head  102 .  
           [0010]    Then, the ozone gas is supplied from ozone gas generating device  113  to the cavity  105  by way of the pipe  114  and the through-hole  112 , and this is blown toward the substrate K from the lower openings of the nozzles  106 .  
           [0011]    The ozone gas flows discharged from the nozzles  106  in this manner run into the surface of the substrate K, flow along the surface, and run into each other to form a flow toward the discharge grooves  107 . During this flow, the ozone (O 3 ) is heated by the substrate K. This heating and the contact with the substrate K and the resist cause the gas to break down into oxygen (O 2 ) and active oxygen (O*). This active oxygen (O*) forms an oxide film on the surface of the substrate K, improves the oxide film on the surface of the substrate K, or removes the resist film formed on the surface of the substrate K by a thermochemical reaction with the active oxygen (O*).  
           [0012]    Then, the ozone gas that flows into the discharge grooves  107  after the processing it performs is discharged by way of the discharge grooves  107  from between the substrate K and the gas supply head  102 .  
           [0013]    In this ozone processing device  100 , the gas supply head  102  is cooled by a cooling fluid, and the ozone gas that flows through the through-hole  112 , the cavity  105 , and the nozzle  106  is cooled by the cooling fluid. Thus, the ozone gas flowing through the through-hole  112 , the cavity  105 , and the nozzle  106  is prevented from undergoing thermal decomposition due to increased temperature, thus preventing the ozone concentration from dropping due to thermal decomposition.  
           [0014]    Also, since the substrate K and the gas supply head  102  are brought close to each other so that the lower openings of the nozzles  106  can be near the substrate K, the ozone discharged from the nozzles  106  is prevented from being thermally decomposed before it reaches the substrate K and a thinner layer of ozone gas flowing on the substrate K is provided. This allows more ozone to contribute to the formation of the oxide film, the improvement of the oxide film, or the removal of the resist film.  
           [0015]    In this conventional ozone processing device  100 , the gas supply head  102  is positioned close to the substrate K as described above. This causes heat to transfer from the substrate K and the mounting base  101  to the gas supply head  102 , resulting in an increase in temperature in the gas supply head  102 .  
           [0016]    Because the volume (capacity) of the gas supply head  102  is high and is cooled with the cooling fluid described above, thermal equilibrium in the substrate K and the gas supply head  102  becomes difficult to achieve and takes a long time. As a result, the temperature of the substrate K does not stay constant over a long period of time, leading to unevenness in the ozone processing operation.  
           [0017]    Also, the processing gas discharged from the nozzles  106  flow into the discharge grooves  107 . The processing gas discharged from the nozzles  106  toward the center of the nozzle module  103  is discharged from the nozzles  106  disposed toward the ends because the gas discharged from the nozzles  106  flow into the exhaust grooves  107 . The gas flowing into the exhaust grooves  107  obstructs the flow within the exhaust grooves  107 , making it difficult for the gas discharged from the nozzles  106  toward the center from being discharged out between the substrate K and the gas supply head  102 .  
         OBJECTS AND SUMMARY OF THE INVENTION  
         [0018]    The object of the present invention is to overcome the problems described above and to provide an ozone processing device that allows easy management of the temperature of the substrate and that quickly discharges the gas from the upper surface of the substrate after the gas finishes performing ozone processing operations.  
           [0019]    The present invention relates to an ozone processing device including a mounting base upon which a substrate is mounted, heating device heating the substrate on the mounting base, a facing plate disposed facing the substrate on the mounting base and equipped with a plurality of discharge openings discharging a processing gas containing ozone toward the substrate and a through-hole disposed between the discharge openings and passing through the front and back surfaces, and a gas supplying device supplying and discharging the processing gas to the discharge openings of the facing plate.  
           [0020]    According to this invention, the processing gas containing ozone is supplied by gas supplying device and is discharged toward the substrate from the discharge openings on the facing plate disposed facing the substrate mounted on the mounting base. The substrate is heated by the heating device.  
           [0021]    The processing gas discharged in this manner collides with the substrate, forming a flow along the substrate. In this flow, the ozone (O 3 ) is heated. This heating and the contact with the substrate K and the resist causes it to break down into oxygen (O 2 ) and active oxygen (O*). This active oxygen (O*) results in the formation of oxide film on the substrate surface or improvement in oxide film on the substrate surface or removal of resist film formed on the substrate surface through thermochemical reaction.  
           [0022]    The processing gas discharged from the discharge openings and flowing along the substrate then collides with each other to form a flow toward the through-holes. This is then discharged toward the back side of the facing plate through the through-holes, i.e., is discharged from between the substrate and the facing plate. As a result, the processing gas that has completed its processing operation does not remain above the substrate surface and the processing gas discharged from the discharge openings can reach the substrate surface unobstructed. This allows effective processing such as the formation or improvement of oxide film or removal of resist film.  
           [0023]    The facing plate described above serves to control the thickness of the processing gas flow along the substrate surface. From this perspective, it would be preferable to have the facing plate disposed as close as possible to the substrate. This allows a thin gas flow layer over the substrate surface and allows more ozone to contribute to forming or improving oxide film or removing resist film, thus improving processing effectiveness.  
           [0024]    When the facing plate is brought close to the substrate, however, thermal transfer from the substrate to the facing plate takes place. If the volume is large, as in the gas supply head in the conventional technology, thermal equilibrium between the two elements becomes difficult and the temperature of the substrate does not stay constant over a long period of time, thus leading to unevenness in processing. In the facing plate according to the present invention, however, the volume of the gas supply head is smaller than that of the conventional example, so this problem is corrected.  
           [0025]    The through-holes are lined up to partition the facing plate into multiple regions, and a discharge opening is formed in each region partitioned by the through-holes.  
           [0026]    This allows the processing gas discharged from the discharge openings to be effectively discharged from between the substrate and the facing plate. If the regions are partitioned so they are the same size (area), the substrate surface can be processed without unevenness. The size of the regions can be set to suit the required processing speed.  
           [0027]    It would be preferable for the through-hole diameter to be at least 0.5 mm and no more than 3 mm. If the hole diameter exceeds 3 mm, unprocessed sections corresponding to the through-holes can remain on the substrate surface. If the diameter is less than 0.5 mm, the discharge efficiency of the processing gas is very poor, and the processing effectiveness is reduced.  
           [0028]    The through-holes can be formed as long, thin slits. In this case, it would be preferable, for the reasons described above, for the width of the slits to be at least 0.5 mm and no more than 3 mm.  
           [0029]    It is possible to have a plurality of facing plates, each equipped with a discharge opening. The plurality of facing plates can be arranged in a co-planar manner with gaps formed between adjacent facing plates. Advantages similar to those described above can be provided with this structure. In this case, if the facing plates are all made the same size (area), the substrate surface can be processed without unevenness. The sizes of the facing plates can be set to suit the required processing speed.  
           [0030]    In the present invention, an appropriate space must be maintained between the substrate and the facing plate, but the facing plate is heated by heat radiating from the heated substrate and the mounting base so that thermal deformation can tend to take place. For this reason, if a large substrate with a large area is to be processed, using a single-piece facing plate can prevent an appropriate gap from being maintained with the substrate.  
           [0031]    If the facing plates are formed from a suitable plurality of plates, the thermal deformation in each of the facing plates can be kept very small so that, as a result, the thermal deformation for the facing plates overall can be kept very small.  
           [0032]    Substrates have been getting larger and larger in recent years, but with this structure, the surface of a large substrate can be processed uniformly even if the size exceeds 1100 mm×1300 mm.  
           [0033]    Taking thermal deformation into account, it would be preferable for the thickness of the facing plate to be at least 0.1 mm, and more preferably at least 1 mm, in order to allow a good distance from the substrate to be maintained. Taking the time required to achieve thermal equilibrium in the facing plate, it would be preferable for the thickness to be no more than 5 mm, more preferably no more than 2 mm.  
           [0034]    It is preferable for the space to be within the range of at least 0.5 mm and no more than 3 mm. If the space exceeds 3 mm, unprocessed sections on the substrate surface corresponding to the gaps can remain. If the space is less than 0.5 mm, the exhaust efficiency of the processing gas is very poor and the processing effectiveness is reduced.  
           [0035]    Examples of materials for the facing plate include fluorinated resin, zirconia, mica, ceramic, stainless steel, silicon, aluminum, titanium, glass, and quartz. There are no restrictions on the shape, which can be triangular, rectangular, hexagonal, circular, and elliptical.  
           [0036]    The mounting base, heating device, and facing plate can be placed in a processing chamber forming a closed space with the substrate being processed in this processing chamber. In this case, the gasses in the processing chamber can be discharged outside by exhausting means. By discharging the gasses in the processing chamber, the exhaust of gasses from the through-holes and gaps can take place smoothly with no obstructions.  
           [0037]    The pressure in the processing chamber exhausted by exhausting means can be, in absolute pressure, at least 7 KPa. If the pressure in the processing chamber is less than 7 KPa, the exhaust speed at which gasses are discharged from the through-holes and the gaps becomes too fast, reducing the time during which the processing gas lingers between the facing plate and the substrate and reducing the reaction efficiency. A more preferable pressure for the inside of the processing chamber is at least 14 KPa.  
           [0038]    In terms of reaction efficiency, there are no restrictions to the upper limit of pressure inside the processing chamber, but in terms of the exhausting of product gas generated by the processing, it is be preferable for the pressure inside the processing chamber to be no more than the pressure (absolute pressure) of the processing gas supply source.  
           [0039]    With the present invention as described above, the facing plate controls the thickness of the layer of processing gas flowing along the substrate surface, and the processing gas after the processing is completed (after reactions) is exhausted from the through-holes and the gaps between the facing plates. This makes it possible to uniformly process the entire substrate surface while improving reaction efficiency and processing efficiency for the processing gas.  
           [0040]    The heating temperature of the substrate in the present invention can be in the range of 200°-500° C. Within this range, the processing described above can be performed while at the same time impurities contained in the substrate can be vaporized. Also, the processing gas can contain at least 14% by weight of ozone. A mixed gas of ozone and TEOS (Tetraethyl orthosilicate, Si(C 2 H 5 O) 4 ) can also be used.  
           [0041]    The above, and other objects, features and advantages of the present invention will become apparent from the following description read in conjunction with the accompanying drawings, in which like reference numerals designate the same elements.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0042]    [0042]FIG. 1 is a cross-section drawing showing the simplified structure of an ozone processing device according to an embodiment of the present invention, and is a cross-section drawing along the C-C line in FIG. 2.  
         [0043]    [0043]FIG. 2 is a cross-section drawing along the A-A line in FIG. 1.  
         [0044]    [0044]FIG. 3 is a cross-section drawing along the B-B line in FIG. 1.  
         [0045]    [0045]FIG. 4 through FIG. 6 are bottom-view drawings showing facing plates from other embodiments of the present invention.  
         [0046]    [0046]FIG. 7 is a cross-section drawing showing the simplified structure of an ozone processing device according to a conventional technology and is a cross-section drawing along the E-E line in FIG. 8.  
         [0047]    [0047]FIG. 8 is a bottom-view drawing along the D-D line in FIG. 7. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0048]    The present invention will be described in detail with references to the attached drawings.  
         [0049]    As shown in FIG. 1 and FIG. 2, an ozone processing device  1  according to this example is equipped with a processing chamber  10  having a predetermined internal volume, a mounting base  20  disposed in the processing chamber  10  and upon the upper surface thereof a substrate K is mounted, and a gas supply head  30  disposed above the mounting base  20 .  
         [0050]    The processing chamber  10  is a case having a predetermined inner volume and closed by a cover  11 . The processing chamber  10  is formed so that gasses therein are discharged outside by an exhaust device  70  by way of exhaust pipes  71 ,  72 , which are passed through and secured to side plates of the processing chamber  10 . The exhaust device  70  adjusts the internal pressure (absolute pressure) of the processing chamber  10  so that it is at least 7 KPa (preferably at least 14 KPa) and no more than the pressure of the ozone gas supply source.  
         [0051]    The mounting base  20  is equipped with internal heating means (not shown) formed from a heater or the like. This heating means (not shown) heats the substrate K mounted on the upper surface. The mounting base  20  can be raised and lowered by raising/lowering device  21 . This raising/lowering device  21  is equipped with a raising/lowering rod  22  that passes through the bottom surface of the processing chamber  10 . This raising/lowering rod  22  supports the mounting base  20 . The raising/lowering rod  22  supports the mounting base  20 . Raising/lowering device  21  is formed from, for example, a pneumatic cylinder, and an electric cylinder.  
         [0052]    Multiple support needles  23  formed with tapered ends are projected from the bottom surface of the processing chamber  10 , and the substrate K is loosely placed on the end surfaces. Support needles  23  are inserted through through-holes (not shown) formed on the mounting base  20  when the mounting base  20  is at its lowermost position, so that the ends project upward from the upper surface of the mounting base  20 . When the mounting base  20  is at its uppermost position, the support needles  23  are pulled out from the through-holes (not shown).  
         [0053]    The substrate K is loosely placed on the support needles  23  when the mounting base  20  is at its lowermost position. Then, the mounting base  20  is raised and the support needles  23  move down relative to the mounting base  20  so that the substrate K is mounted on the mounting base  20 .  
         [0054]    The gas supply head  30  is formed from a block-shaped main head unit  31  and multiple facing plates  40  disposed at a predetermined distance from the main head unit  31  and facing the substrate K on the mounting base  20 . The main head unit  31  is secured to the inner walls of the processing chamber  10  using securing members  12 .  
         [0055]    A cooling fluid flow path  32  passes through one side surface to the other side surface of he main head unit  31 . Cooling fluid circulating device  50  shown in FIG. 2 supplies cooling fluid to the cooling fluid flow path  32 , and this cooling fluid is circulated.  
         [0056]    Cooling fluid circulating device  50  is formed from pipe fittings  56 , pipes  57 , pipe fittings  58 , pipes  59 , cooling fluid supplying device  51 , a pipe  52 , a pipe fitting  53 , a pipe  54 , and a pipe fitting  55 , for example. The pipe fittings  56  are connected to one end of the cooling fluid flow path  32 , and the pipe fitting  55  is connected to the other end of the cooling fluid flow path  32 . The cooling fluid circulation path is formed in this manner from the pipe fittings  56 , the pipes  57 , the pipe fittings  58 , the pipes  59 , cooling fluid supplying means  51 , the pipe  52 , the pipe fitting  53 , the pipe  54 , the pipe fitting  55 , and the cooling fluid flow path  32 .  
         [0057]    The cooling fluid  32  is supplied from cooling fluid supplying device  51  to the cooling fluid flow path  32  by way of the pipe  52 , the pipe fitting  53 , the pipe  54 , and the pipe fitting  55 , in that order. After it passes through the cooling fluid flow path  32 , the supplied cooling fluid is circulated back to cooling fluid supplying device  51  by way of the pipe fittings  56 , the pipes  57 , the pipe fittings  58 , and the pipe  59 , in that order.  
         [0058]    Ozone gas flow path  33  is formed in the main head unit  31 opening to one of the side surfaces and gas conduction holes  34  opening to the lower surface and communicating with the ozone gas flow path  33 . The gas conduction holes  34  are equipped with through-holes  36  that extend from the upper surface to the lower surface and are connected to gas conduction pipes  35  extended toward the substrate K.  
         [0059]    Each facing plate  40  can be formed in a rectangular shape and is disposed in a co-planar manner so that predetermined gaps  41  are formed between adjacent facing plates  40 . The facing plates  40  are secured with bolts to support members  37 , which are secured to the lower surface of the main head unit  31 . If bolts are used for securing, counterbore holes  42  are formed on the facing plates  40  to prevent the bolt heads from projecting from the lower surfaces of the facing plates  40 . Examples of materials preferable for the facing plates  40  include fluorinated resin, zirconia, mica, ceramic, stainless steel, silicon, aluminum, titanium, glass, and quartz.  
         [0060]    Through-holes  43  passing from the upper surface to the lower surface are formed on the facing plates  40 , and the lower ends of the gas conduction pipes  35  are fitted to the through-holes  43 . Lower surface openings  43   a  of the through-holes  43  serve, together with the lower openings  36   a  of the gas conduction pipes  35 , as discharge openings for discharging ozone gas. Ozone gas supplied from ozone gas supplying device  60  shown in FIG. 2 to the ozone gas flow path  33 , the gas conduction holes  34 , and the through-holes  36  are discharged from these discharge openings  43   a  ( 36   a ) to the substrate K.  
         [0061]    Ozone gas supplying device  60  is formed from pipe fittings  65  connected to the ozone gas flow path  33 , pipes  64  connected to the pipe fittings  65 , pipe fittings  63  connected to the pipes  64 , pipes  62  connected to the pipe fittings  63 , an ozone gas generating device  61  connected to the pipes  62 , and the like. Ozone gas (processing gas) having a predetermined concentration is supplied from the ozone gas generating device  61  to the ozone gas flow path  33  by way of the pipes  62 , the pipe fittings  63 , the pipes  64 , and the pipe fittings  65 , in that order.  
         [0062]    In the ozone processing device  1  described above, the substrate K is mounted on the support needles  23  using suitable means. At this point, the mounting base  20  is at its lowermost position. The cooling fluid is supplied by cooling fluid supplying device  51  and is circulated through the cooling fluid circulation path  32  of the main head unit  31 . The main head unit  31  is cooled by this cooling fluid.  
         [0063]    Next, the pressure (absolute pressure) within the processing chamber  10  is adjusted by the exhaust device  70  to at least 7 KPa (preferably at least 14 KPa) and no more than the pressure of the gas supply source, and raising/lowering device  21  raises the mounting base  20 .  
         [0064]    When the mounting base  20  is raised, the support needles  23  are lowered relative to the mounting base  20 . The mounting plate K is mounted on the mounting base  20  and the mounting base  20  reaches its uppermost position. Also, the substrate K mounted on the mounting base  20  is heated by heating device (not shown).  
         [0065]    Then, ozone gas with a predetermined concentration is supplied from the ozone gas generating device  61  to the ozone gas flow path  33  of the main head unit  31  by way of the pipes  62 , the pipe fittings  63 , the pipes  64 , and the pipe fittings  65 , in that order. The gas passes through the gas conduction holes  34  and the through-holes  36  and is blown toward the substrate K from the discharge openings  43   a  ( 36   a ) of the facing plates  40 .  
         [0066]    The ozone gas discharged in this manner collides with the substrate K and forms a flow along it. In this flow, the ozone (O 3 ) is heated by the substrate K. This heating and the contact with the substrate K and the resist causes it to breaks down into oxygen (O 2 ) and active oxygen (O*). This active oxygen (O*) forms an oxide film on the surface of the substrate K or improves the oxide film on the surface of the substrate K or removes the resist film formed on the surface of the substrate K through a thermochemical reaction.  
         [0067]    The ozone gas discharged from the discharge openings  43   a  and flowing along the substrate K then collides with each other, forming a flow toward the gaps  41 . The gas flows from the gaps  41  to the back surfaces (upper surfaces) of the facing plates  41 , i.e., is discharged from between the substrate K and the facing plates  40 . As a result, the ozone gas which has completed its processing operation is prevented from lingering around the surface of the substrate K to obstruct the flow of ozone gas discharged from the discharge openings  43   a  ( 36   a ) to the surface of the substrate K. This allows the operations such as forming or improving oxide film or removing resist film to be performed effectively.  
         [0068]    The gaps  41  can be within the range of at least 0.5 mm and no more than 3 mm. If the gap  41  is less than 0.5 mm, the exhaust efficiency of the ozone gas is very poor and the processing effect of the ozone gas is reduced. If the gap exceeds 3 mm, unprocessed sections will remain at areas corresponding to the gaps  41 .  
         [0069]    By discharging the gas in the processing chamber  10 , the discharging from the gaps  41  can be performed smoothly. In this process, it is preferable for the pressure (absolute pressure) in the processing chamber  10  to be at least 7 KPa (more preferably at least 14 KPa) and no more than the pressure of the ozone gas supply source.  
         [0070]    If the pressure in the processing chamber  10  is less than 7 KPa, the discharging from the gaps  41  becomes too fast, shortening the time during which the ozone gas can linger between the facing plates  40  and the substrate K and reducing the effectiveness of the reaction. If the pressure within the processing chamber  10  exceeds the pressure of the ozone gas supply source, the discharge of the product gas generated by the processing does not take place smoothly.  
         [0071]    The facing plates  40  serve to control the thickness of the ozone gas flow layer flowing along the surface of the substrate K. From this perspective, it is preferable to have the facing plates  40  be as close as possible to the substrate K. By doing this, the thickness of the layer of ozone gas flow along the surface of the substrate K can be made thinner, allowing more ozone to contribute to the formation or improvement of the oxide film or the removal of resist film, thus improving the processing effectiveness.  
         [0072]    Thus, the space between the substrate K and the facing plates  40  must be maintained in an appropriate manner but the facing plates  40  are heated by radiated heat from the heated substrate K and the mounting base  20 , resulting in a tendency to thermally deform. As a result, when a substrate with a large area is to be processed, forming the facing plate  40  from a single plate may lead to thermal deformation that prevents the distance from the substrate K to be maintained appropriately.  
         [0073]    In this example, the facing plates  40  are formed from multiple plates so that thermal deformation of each individual plate  40  can be kept very small. As a result, an effective distance from the substrate K can be used.  
         [0074]    In recent years, substrates are becoming larger and larger, but with this arrangement, surfaces can be processed uniformly even for a large substrate K exceeding 1100 mm×1300 mm.  
         [0075]    Taking thermal deformation into account, the thickness t for the facing plates  40  that allows an effective distance from the substrate K to be maintained is at least 0.1 mm, and more preferably at least 1 mm. Taking into account the time required for thermal equilibrium to be achieved in the facing plates  40 , it would be preferable for the thickness t to be no more than 5 mm, more preferably no more than 2 mm.  
         [0076]    If the facing plates  40  all have the same size (area), the surface sections of the substrate K corresponding to the facing plates  40  can be processed without unevenness. Also, the size of the facing plates  40  can be set to suit the required processing speed.  
         [0077]    The atmospheric temperature within the processing chamber  10  is increased by the heating performed by heating means (not shown). The main head unit  31  is heated in this high-temperature atmosphere, but since the main head unit  31  is cooled by the cooling fluid flowing through the cooling fluid flow path  32 , the ozone gas flowing through the ozone gas flow path  33  is cooled by the cooling fluid and the temperature thereof is kept within a fixed range. As a result, the thermal breakdown of ozone accompanying a rise in temperature is prevented and the lowering of the ozone concentration in the ozone gas is prevented.  
         [0078]    The heating temperature of the substrate can be in the range 200°-500° C. Within this range, the operations described above can be performed while also vaporizing impurities contained in the substrate K. Also, the ozone gas can contain at least 14% by weight of ozone, or a mixed gas of ozone and TEOS (Tetraethyl orthosilicate, Si(C 2 H 5 5O) 4 ).  
         [0079]    With the ozone processing device  1  described in detail above, the thickness of the layer of ozone gas flowing along the surface of the substrate K is controlled by multiple facing plates  40  and the ozone gas that has completed processing operations (reactions) is discharged from the gaps  41  between the facing plates  40 . This improves the reaction efficiency and the processing efficiency of the ozone gas and allows uniform processing of the entire surface even for a large substrate K exceeding 1100 mm×1300 mm.  
         [0080]    The above description presents an embodiment of the present invention, but the implementations of the present invention are not restricted to this.  
         [0081]    For example, the shape of the facing plates  40  is not restricted to the rectangular shape described above. Besides the rectangular shape, it is possible to have gaps  77  formed so that the facing plates  75  with discharge openings  76  are formed hexagonally. Alternatively, as shown in FIG. 5, gaps  82  can be formed so that the facing plates  80  with discharge openings  81  are formed with triangular shapes. Also, facing plates with different shapes such as triangles and rectangles can be combined.  
         [0082]    As shown in FIG. 6, an embodiment has multiple facing plates  40  formed from a single facing plate  85 , with slit-shaped through-holes  87  formed on the facing plate  85  to partition the surface into multiple regions, each region being formed with a discharge opening  86 . Advantages similar to those described above can be obtained with this structure. In this case, taking into account the discharge efficiency of the through-holes  87 , it would be preferable for the slit width to be at least 0.5 mm and no more than 3 mm.  
         [0083]    The slit-shaped through-holes  87  can be replaced with multiple circular holes that are lined up. In this case, the inner diameter of each circular hole can be at least 0.5 mm and no more than 3 mm.  
         [0084]    As described above, the ozone processing device according to the present invention can be used effectively for forming oxide film on the surface of a substrate, e.g., a semiconductor substrate or a liquid crystal substrate, or improving oxide film formed on the substrate surface, or removing resist film formed on the substrate surface.  
         [0085]    Having described preferred embodiments of the invention with reference to the accompanying drawings, it is to be understood that the invention is not limited to those precise embodiments, and that various changes and modifications may be effected therein by one skilled in the art without departing from the scope or spirit of the invention as defined in the appended claims.

Technology Category: h