Patent Publication Number: US-2010126532-A1

Title: Substrate processing apparatus and substrate processing method

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to a substrate processing apparatus and a substrate processing method for supplying a predetermined processing solution onto a substrate such as a semiconductor wafer, a glass substrate for liquid crystal display panel and a glass substrate for plasma display panel. 
     2. Description of the Background Art 
     In a developing operation of a semiconductor resist, a developer such as an alkaline solution is supplied onto a wafer to produce a development reaction for a predetermined time period, and then, pure water is discharged as a rinse water onto the wafer to finish the development reaction. 
     Conventionally, pure water is discharged with the leading edge of a pipe-like nozzle directed toward a surface of a wafer employing a method of rotating the wafer for spreading pure water across the wafer (first technique). 
     However, it has been found out that, when discharging pure water while rotating a wafer as described above, the rotation causes triboelectric charging of the wafer, which causes charged particles included in a solution to adhere to the wafer surface, resulting in post-develop defects. 
     Accordingly, a method has been considered in which pure water is supplied onto the entire surface of a wafer held stationary or almost stationary by allowing a nozzle having a slit-like discharge port to pass over the wafer (second technique; e.g., Japanese Patent Application Laid-Open No. 2003-100601). 
     This method, in which the wafer is held stationary or almost stationary, can avoid triboelectric charging of the wafer, which is therefore expected to reduce post-develop defects. 
     On the other hand, to prevent a charging phenomenon of a wafer, a method of using pure water with CO 2  gas dissolved therein as a rinse water is known (third technique; e.g., Japanese Patent Application Laid-Open No. 60-165726 (1985)). 
     However, studies by trial and error made by inventors of the present invention have revealed the following problems. 
     More specifically, it has been revealed that the above-mentioned second technique cannot perfectly avoid charging due to the flow of pure water, and thus cannot limit the occurrence of post-develop defects not to exceed a certain degree. 
     Further, it has been revealed that the third technique cannot supply a uniform amount of rinse water onto the entire surface of a wafer, and particularly, defects tend to occur in the vicinity of the wafer edge to which a relatively small amount of rinse water is supplied. 
     Furthermore, it has been revealed that, among a great many of resists for use in lithography, some tend to cause post-develop defects rather by employing the method of supplying pure water with CO 2  gas dissolved therein as described in JP 60-165726 mentioned above. According to the inventors&#39; studies, this is because a sudden mixture of an aqueous CO 2  solution, which is acid, into a developer, which is alkaline, results in neutralization to cause precipitation of a resist dissolved in the developer. 
     SUMMARY OF THE INVENTION 
     This invention is directed to a substrate processing apparatus or a substrate processing method for supplying a processing solution onto a substrate. 
     According to a first aspect of the present invention, the substrate processing apparatus for supplying a processing solution onto a main surface of a substrate includes a substrate holding element for holding the substrate almost in a horizontal position, a processing solution supply nozzle having a discharge port for discharging the processing solution in a discharge width substantially equal to or greater than a width of the substrate, a processing solution supply element for supplying an anti-static processing solution as the processing solution to the processing solution supply nozzle, and a nozzle moving element for moving the processing solution supply nozzle from one end to the opposite end of the semiconductor wafer so as to pass over the semiconductor wafer. 
     The processing solution supply nozzle having the discharge port for discharging the anti-static processing solution in a predetermined discharge width passes over the substrate, so that the anti-static processing solution is supplied onto the entire surface of the substrate almost uniformly without spinning the substrate. The prevention of charging of the substrate avoids the occurrence of defects. The processing solution supplied almost uniformly on the entire surface of the substrate also avoids the occurrence of defects. 
     According to a second aspect of the present invention, the substrate processing method of supplying a processing solution onto a main surface of a substrate includes the following steps (a) and (b). The step (a) is to discharge an anti-static processing solution in a discharge width substantially equal to or greater than a width of the substrate. The step (b) is to scan the substrate from one end to the opposite end, thereby supplying the anti-static processing solution onto the substrate. The steps (a) and (b) are performed concurrently. 
     The substrate is scanned from one end to the opposite end while discharging the anti-static processing solution onto the substrate in a discharge width substantially equal to or greater than the width of the substrate. This can make it possible to supply the anti-static processing solution onto the entire surface of the substrate almost uniformly without spinning the substrate. The prevention of charging of the substrate avoids the occurrence of defects. The processing solution supplied almost uniformly on the entire surface of the substrate also avoids the occurrence of defects. 
     According to a third aspect of the present invention, the substrate processing apparatus for supplying a processing solution onto a main surface of a substrate having undergone a developing operation includes a substrate holding element for holding the substrate almost in a horizontal position, a first processing solution supply nozzle having a discharge port for discharging a first processing solution in a discharge width substantially equal to or greater than a width of the substrate, a development stop liquid supply element for supplying a development stop liquid, as the first processing solution, for stopping a development reaction to the first processing solution supply nozzle, a nozzle moving element for moving the first processing solution supply nozzle from one end to the opposite end of the substrate so as to pass over the substrate, a second processing solution supply nozzle for discharging a second processing solution onto the substrate, and an anti-static cleaning solution supply element for supplying an anti-static cleaning solution to the second processing solution supply nozzle as the second processing solution. The anti-static cleaning solution is supplied from the second processing solution supply nozzle after the development stop liquid is supplied from the first processing solution supply nozzle. 
     The anti-static cleaning solution is supplied onto the substrate after the development stop liquid is supplied. Therefore, it is possible to avoid generation of reactants of the developer and anti-static cleaning solution, and thus avoid the occurrence of defects. 
     According to a fourth aspect of the present invention, the substrate processing method of supplying a processing solution onto a main surface of a substrate having undergone a developing operation includes the following steps (c) and (d). The step (c) is to supply a development stop liquid onto the substrate having undergone the developing operation. The step (d) is to supply an anti-static cleaning solution onto the substrate after the step (c). 
     The anti-static cleaning solution is supplied onto the substrate after supplying the development stop liquid onto the substrate having undergone the developing operation. Therefore, it is possible to avoid generation of reactant of the developer and anti-static cleaning solution, and thus avoid the occurrence of defects. 
     It is therefore an object of the present invention to reduce the occurrence of operating defects to a minimum when supplying a processing solution on to a substrate. 
     These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  s a plan view schematically showing a construction of a substrate processing apparatus according to a first preferred embodiment of the present invention; 
         FIG. 2  is a side view schematically showing the construction of the substrate processing apparatus according to the first preferred embodiment; 
         FIG. 3  is a sectional view taken along the line III-III of  FIG. 1 ; 
         FIG. 4  shows a discharge port provided for a developer supply nozzle; 
         FIGS. 5 and 6  are enlarged views of an essential part showing the developer supply nozzle and a processing solution supply nozzle; 
         FIG. 7  shows a developer supply system; 
         FIG. 8  shows a processing solution supply system; 
         FIG. 9  is a block diagram showing an electrical configuration of the substrate processing apparatus according to the first preferred embodiment; 
         FIG. 10  is a flow chart showing a series of steps of a developing operation performed by the substrate processing apparatus according to the first preferred embodiment; 
         FIG. 11  is an explanatory view showing the movement of the developer supply nozzle; 
         FIG. 12  is an explanatory view showing the movement of the processing solution supply nozzle; 
         FIG. 13  is an explanatory view showing a relative movement of the processing solution supply nozzle with respect to a semiconductor wafer; 
         FIG. 14  is an explanatory view showing a state of supplying a processing solution; 
         FIG. 15  is an explanatory view showing another state of supplying the processing solution; 
         FIG. 16  shows a processing solution supply system of a substrate processing apparatus according to a second preferred embodiment of the present invention; 
         FIG. 17  shows an anti-static cleaning solution supply system of the substrate processing apparatus according to the second preferred embodiment; 
         FIG. 18  is a flow chart showing a series of steps of a developing operation performed by the substrate processing apparatus according to the second preferred embodiment; 
         FIG. 19  shows a variant of a method of moving a processing solution supply nozzle; and 
         FIG. 20  shows another variant of the method of moving a processing solution supply nozzle. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     First Preferred Embodiment 
     A substrate processing apparatus and a substrate processing method according to a first preferred embodiment of the present invention will be discussed hereinbelow. This first preferred embodiment is directed to a substrate processing apparatus and a substrate processing method in which a developer is supplied onto a substrate to cause a development reaction for a certain time period, and then an anti-static processing solution is supplied using a so-called slit-scan technology. 
       FIG. 1  is a plan view schematically showing a construction of the substrate processing apparatus.  FIG. 2  is a side view schematically showing the construction of the substrate processing apparatus.  FIG. 3  is a sectional view taken along the line III-III of  FIG. 1 . In  FIG. 3 , a section for holding a substrate is also shown in cross section. 
     This substrate processing apparatus is an apparatus for developing a resist thin film formed on a surface of a semiconductor wafer SW which is a substrate. Prior to a developing operation performed by this apparatus, the resist thin film is exposed to light by an exposure apparatus so that a predetermined pattern is formed thereon. 
     The semiconductor wafer SW to be processed is a substantially circular plate, having a diameter of 200 mm or 300 mm, for example. Further, the semiconductor wafer SW has a notch NC or orientation flat partly formed on its outer periphery. 
     This substrate processing apparatus includes a wafer holding/rotating mechanism  10 , a developer supply nozzle  20 , a developer supply system (see  FIG. 7 ), a developer supply nozzle scanning mechanism  30 , a developer supply nozzle up-and-down mechanism  39 , a processing solution supply nozzle  40 , a processing solution supply system (see  FIG. 8 ), a processing solution supply nozzle pivoting mechanism  50 , a processing solution supply nozzle up-and-down mechanism  56  and final rinse water supply nozzles  70 . 
     The wafer holding/rotating mechanism  10  is a mechanism for holding the semiconductor wafer SW almost in a horizontal position as well as rotating the semiconductor wafer SW, and has a support shaft  11 , a spin chuck  12  provided on the upper end of the support shaft  11  and a spin motor  13  with a rotary shaft connected to the lower end of the support shaft  11 . 
     The spin chuck  12  is intended to hold the semiconductor wafer SW almost in a horizontal position, and is constructed from a vacuum chuck for holding the semiconductor wafer SW by suction. Alternatively, a mechanical chuck for holding the semiconductor wafer SW by its outer periphery may be employed as the spin chuck  12 . 
     The spin motor  13  is constructed from, for example, a servomotor, which is configured such that the rotation speed and the amount of rotation can be controlled variably in response to a signal (e.g., a pulse number signal) sent from a control section  60  which will be described later. The rotation of the spin motor  13  is transferred to the spin chuck  12  through the support shaft  11 . The rotation driving of the spin motor  13  allows the semiconductor wafer SW to rotate within a horizontal plane about the vertical axis. 
     An inner cup  16  of substantially circular shape in plan view is provided around the spin chuck  12  so as to surround the semiconductor wafer SW held by the spin chuck  12 . The inner cup  16  has an opening on its top side which gradually narrows in an upward direction, and is movable up and down by the action of an up-and-down mechanism such as an air cylinder such that the upper edge of the opening is moved between an up position defined around the outer periphery of the semiconductor wafer SW and a down position lower than the up position. 
     Further, an outer cup  17  of substantially rectangular shape in plan view is provided to surround the inner cup  16 . When supplying a developer or processing solution from the developer supply nozzle  20  or processing solution supply nozzle  40  onto the semiconductor wafer SW, the developer or processing solution as supplied off the semiconductor wafer SW is intended to flow down on the outer surface of the inner cup  16  or between the inner cup  16  and outer cup  17  to be guided toward the bottom of the outer cup  17 . 
     Furthermore, a waiting pot  18  is provided on one side outside the outer cup  17  in correspondence with a waiting position of the developer supply nozzle  20 . The waiting pot  18  is formed like a case with such an opening on its top side that the developer supply nozzle  20  can be housed from above. 
     The developer supply nozzle  20  has a discharge port  22  for discharging the developer in a discharge width substantially equal to or greater than the width (diameter) of the semiconductor wafer SW. 
       FIG. 4  shows the discharge port  22  provided for the developer supply nozzle  20 . As shown, the developer supply nozzle  20  has the slit-like discharge port  22  on one side face of a long nozzle body  21 . The discharge port  22  extends along the length of the nozzle body  21 . The developer is discharged uniformly like a curtain from the discharge port  22  throughout its whole width to be supplied onto the semiconductor wafer SW throughout its whole width. 
     In addition, a developer supply system is connected to this developer supply nozzle  20 . This developer supply system will be discussed later. 
     Referring back to  FIGS. 1 to 3 , the developer supply nozzle scanning mechanism  30  is a mechanism for moving the developer supply nozzle  20  horizontally so as to pass over the semiconductor wafer SW, and has a pair of support side plates  31   a,    31   b  on both sides of a support member  5  guide-supported slidably in a horizontal direction and a horizontal driving section  35  for moving the support side plate  31   a  on the one side back and forth in the horizontal direction. 
     The support side plate  31   a  on the one side is a long plate. The lower portion of the support side plate  31   a  is guide-supported by two linear guides  32  provided on the outer surface of the one side wall of the support member  5  so as to be slidable in the horizontal direction while the upper portion of the support side plate  31   a  extends upwardly with respect to the support member  5 . 
     The horizontal driving section  35  has a driving pulley  36  and a follower pulley  37  provided on the respective ends of the one side wall of the support member  5 , a developer supply nozzle scanning motor  36   a  for rotating the driving pulley  36  and a belt  38  wound around these pulleys  36  and  37 . The lower end of the support side plate  31   a  is fixed on the upper portion of the belt  38  running between the pulleys  36  and  37 . Rotating the driving pulley  36  by driving the developer supply nozzle scanning motor  36   a,  the belt  38  rotates, and with the rotation of the belt  38 , the support side plate  31   a  moves back and forth in the horizontal direction on the one side of the support member  5 . The developer supply nozzle scanning motor  36   a  is constructed from a stepping motor, for example, which is configured such that the amount of rotation in both forward and reverse directions and the rotation speed can be controlled in response to a signal (e.g., a pulse number signal) sent from the control section  60 . 
     A plurality of position sensors  34   a,    34   b,    34   c  and  34   d  for detecting shifted positions of the support side plate  31   a  to thereby detect shifted positions of the developer supply nozzle  20  are provided on the outer surface of the one side wall of the support member  5 . The position sensor  34   a  for detecting a processing solution supply position U 1 , the position sensor  34   b  for detecting a waiting position U 2 , the position sensor  34   c  for detecting a developer discharge start position U 3  and the position sensor  34   d  for detecting a developer discharge stop position U 4  are arranged in this order from the right side of  FIG. 2 . A sector  31   e  attached to the support side plate  31   a  is inserted into the respective position sensors  34   a  to  34   d,  so that the positions U 1  to U 4  are detected respectively. 
     The support side plate  31   b  on the other side is also a long plate. A guide rail  33  is fixed on another support member different from the support member  5 . The lower end of the support side plate  31   b  is supported so as to be movable back and forth in the horizontal direction along the guide rail  33  with a cam follower  33   a  interposed therebetween while the upper portion of the support side plate  31   b  extends upwardly with respect to the support member  5 . When the developer supply nozzle  20  is in an up position, the cam follower  33   a  and guide rail  33  are spaced apart from each other. 
     The developer supply nozzle  20  is fixedly supported in a manner straddling the upper ends of the support side plates  31   a  and  31   b.  The developer supply nozzle  20  is arranged almost in a horizontal position with the discharge port  22  directed downwardly such that the developer is discharged in a nearly directly downward direction. A bridge member  31   c  for reinforcement is provided on one side of the developer supply nozzle  20  in a manner straddling the upper ends of the support side plates  31   a  and  31   b.  It is preferable that the both support side plates  31   a,    31   b  and bridge member  31   c  be formed integrally by molding or the like. 
     Driving of the developer supply nozzle scanning mechanism  30  allows the developer supply nozzle  20  to pass over the semiconductor wafer SW, and while passing, the developer is discharged from the discharge port  22  so as to be supplied onto the main surface of the semiconductor wafer SW. 
     The support side plate  31   b  on the other side and the guide rail  33  for supporting the support side plate  31   b  may be omitted, and the developer supply nozzle  20  may be cantilevered. 
     The developer supply nozzle up-and-down mechanism  39  is a mechanism for moving the developer supply nozzle  20  up and down between a first position which allows the developer supply nozzle  20  to pass over the semiconductor wafer SW and a second position lower than the first position where the developer supply nozzle  20  can be housed in the waiting pot  18 , and has an air cylinder  39   a  and a developer supply nozzle up-and-down guide  39   b.    
     The developer supply nozzle up-and-down guide  39   b  guides the support member  5  so as to be movable up and down, and the air cylinder  39   a  moves the support member  5  up and down. The up-and-down of the support member  5  allows the respective components attached to the support member  5 , that is, the developer supply nozzle  20 , developer supply nozzle scanning mechanism  30 , processing solution supply nozzle  40  and processing solution supply nozzle pivoting mechanism  50  to move up and down. The above-mentioned wafer holding/rotating mechanism  10 , inner cup  16 , outer cup  17  and waiting pot  18  are supported by another support member different from the support member  5 . Therefore, the developer supply nozzle  20  and processing solution supply nozzle  40  move up and down relative to the semiconductor wafer SW held by the wafer holding/rotating mechanism  10 . 
     In place of the air cylinder  39   a,  a servomotor and a ball screw mechanism may be employed. In that case, there is an advantage that the height of the developer supply nozzle  20  can be adjusted freely. 
     The developer supply nozzle scanning mechanism  30  and developer supply nozzle up-and-down mechanism  39  constitute a moving mechanism for moving the developer supply nozzle  20 . 
     The processing solution supply nozzle  40  has a discharge port  42  for discharging the anti-static processing solution for preventing charging of the semiconductor wafer SW as well as stopping a development reaction in a discharge width substantially equal to or greater than the width (diameter) of the semiconductor wafer SW. 
     The processing solution supply nozzle  40  has the slit-like discharge port  42  on one side of a long nozzle body  41 , similarly to the developer supply nozzle  20 . The discharge port  42  extends along the length of the nozzle body  41 . The anti-static processing solution is discharged uniformly like a curtain from the discharge port  42  throughout its whole width to be supplied onto the semiconductor wafer SW throughout its whole width. 
     Then, as will be described later, the processing solution supply nozzle  40  passes over the semiconductor wafer SW, so that the anti-static processing solution is supplied onto the semiconductor wafer SW. The developer on the semiconductor wafer SW is diluted with the anti-static processing solution into such a concentration that the development reaction is stopped or below such concentration, or the developer is replaced by the anti-static processing solution, so that the development reaction on the semiconductor wafer SW is stopped. 
     In addition, a processing solution supply system for supplying the anti-static processing solution is connected to this processing solution supply nozzle  40 . This processing solution supply system will be discussed later. 
     The processing solution supply nozzle pivoting mechanism  50  is a mechanism for pivoting the processing solution supply nozzle  40  so as to pass over the semiconductor wafer SW, and has a processing solution supply nozzle pivoting motor  52  and a rotary shaft  54 . 
     The processing solution supply nozzle pivoting motor  52  is constructed from a stepping motor and the like, and is attached to a position close to one end of the developer supply nozzle  20  with a bracket  51  and the processing solution supply nozzle up-and-down mechanism  56  interposed therebetween. The rotation speed and the amount of rotation of the motor  52  are controlled variably in response to a signal (e.g., a pulse number signal) sent from the control section  60 . 
     The rotary shaft  54  is connected to a motor shaft of the processing solution supply nozzle pivoting motor  52 , and extends downwardly from the bottom surface of the bracket  51 . The rotary shaft  54  is configured to be rotatable about a vertex of an imaginary square S circumscribed with the outer edge of the semiconductor wafer SW held by the wafer holding/rotating mechanism  10  when the developer supply nozzle  20  is in the processing solution supply position U 1 . 
     One end of the processing solution supply nozzle  40  is fixedly connected to the lower end of the rotary shaft  54 , so that the processing solution supply nozzle  40  is cantilevered almost in a horizontal position above the support member  5 . The discharge port  42  of the processing solution supply nozzle  40  is designed to incline at an angle ranging from 15 to 16 degrees, for example, with respect to a horizontal plane in a reverse direction to a direction in which the processing solution supply nozzle  40  pivots while discharging the processing solution. The reason for such inclination is to prevent the anti-static processing solution from flowing out prior to the movement of the processing solution supply nozzle  40 . The rotation of the rotary shaft  54  by the driving of the processing solution supply nozzle pivoting motor  52  allows the processing solution supply nozzle  40  to pivot so as to pass over the semiconductor wafer SW. The processing solution supply nozzle  40  discharges the anti-static processing solution from the discharge port  42  while passing over the semiconductor wafer SW, so that the anti-static processing solution is supplied onto the main surface of the semiconductor wafer SW. 
     The processing solution supply nozzle  40  is attached to the bridge member  31   c  with the bracket  51 , processing solution supply nozzle pivoting motor  52 , processing solution supply nozzle up-and-down mechanism  56  and a cylinder-attaching bracket  31   d  which will be described later interposed therebetween. 
     A processing solution supply nozzle original position sensor  55   b  is attached to the bracket  51  with a sensor bracket  55   a  interposed therebetween. A sector  41   a  serving as a detected member is fixed to the nozzle body  41  of the processing solution supply nozzle  40 . The sector  41   a  is inserted into the sensor  55   b  with the processing solution supply nozzle  40  placed in an original position (here, a position substantially parallel to the developer supply nozzle  20 ). The sensor  55   b  thereby detects whether or not the processing solution supply nozzle  40  is placed in the original position. 
       FIGS. 5 and 6  are enlarged views of an essential part showing the developer supply nozzle  20  and processing solution supply nozzle  40 .  FIG. 5  shows the processing solution supply nozzle  40  in an up position, and  FIG. 6  shows the processing solution supply nozzle  40  in a down position. 
     More specifically, the processing solution supply nozzle up-and-down mechanism  56  has block members  56   a  and  56   b  connected to be slidable up and down relative to each other. The block member  56   a  is fixed on the side of the bracket  51  with a rod  56   c  interposed therebetween, and the block member  56   b  fixed on the side of the bridge member  31   c  with the cylinder-attaching bracket  31   d  interposed therebetween. The block member  56   a  is arranged to be slidable relative to the other block member  56   b  by air driving, for example. Accordingly, the up-and-down of the bracket  51  allows the processing solution supply nozzle  40  to move up and down together with the processing solution supply nozzle pivoting motor  52  and the like relative to the developer supply nozzle  20 . 
     In the present embodiment, the processing solution supply nozzle  40  is attached integrally to the developer supply nozzle  20 , however, these nozzles may be provided separately. 
     Referring back to  FIGS. 1 to 3 , the two final rinse water supply nozzles  70  are provided one each on the leading edge of a nozzle support arm  71  and on a relatively backward side of the leading edge. A rinse water is supplied to each of the final rinse water supply nozzles  70  through a pipe  72 . 
     As the rinse water to be supplied, an anti-static processing solution similar to that supplied from the above-described processing solution supply nozzle  40  or pure water may be employed. The use of pure water results in savings of chemical solution. 
     One of the final rinse water supply nozzles  70  on the leading edge is intended to supply the rinse water onto the central portion of the semiconductor wafer SW, and the other one of the final rinse water supply nozzles  70  provided on a relatively backward side is intended to supply the rinse water onto the peripheral portion of the semiconductor wafer SW. One end of the nozzle support arm  71  is attached pivotably in an area surrounding the semiconductor wafer SW, more specifically, in a position farther than the processing solution supply position U 1  from the semiconductor wafer SW. When supplying the developer or anti-static processing solution onto the semiconductor wafer SW, the nozzle support arm  71  is placed in a waiting position away from the semiconductor wafer SW in a lateral direction (see  FIG. 1 ). When cleaning the main surface of the semiconductor wafer SW after the anti-static processing solution is supplied onto the semiconductor wafer SW, a nozzle rotating mechanism including a final rinse water supply nozzle rotating motor  73  (see  FIG. 9 ) is driven to cause the nozzle support arm  71  to pivot such that the final rinse water supply nozzle  70  on the leading edge is placed above the semiconductor wafer SW, and then, the rinse water is discharged from the final rinse water supply nozzles  70  onto the central portion and peripheral portion of the semiconductor wafer SW. 
       FIG. 7  is a piping diagram showing the developer supply system. 
     The developer supply system includes a developer tank  80  for applying pressure, a first developer pipe  81  for connecting the developer tank  80  and another developer tank or a plant utility system serving as a predetermined developer source installed in a plant, a second developer pipe  82  for connecting a predetermined N 2  gas source and the developer tank  80  and a third developer pipe  83  for connecting the developer tank  80  and developer supply nozzle  20 . An air operation valve  81   a  is provided halfway in the first developer pipe  81 . A regulator  82   a  for controlling the flow rate of N 2  gas and an air operation valve  82   b  are provided halfway in the second developer pipe  82 . An air operation valve  83   a,  a flow meter  83   b  having a mechanism for measuring and controlling the flow rate of the developer flowing toward the developer supply nozzle  20 , and a filter  83   c  for removing foreign substances included in the developer are provided halfway in the third developer pipe  83 . Each one end of the first and second developer pipes  81  and  82  close to the developer tank  80  is open into an upper space of the developer tank  80  where the developer is not present. One end of the third developer pipe  83  close to the developer tank  80  extends toward the bottom of the developer tank  80 , with its opening immersed in the developer as stored. The opening and closing of the air operation valves  81   a,    82   b  and  83   a  is controlled by controlling the flow rate of gas such as N 2  gas, and the flow rate of gas for the open/close control is controlled by opening and closing a solenoid valve by the control section  60 . 
     For supplying the developer to the developer supply nozzle  20 , the developer is previously supplied into the developer tank  80 . When supplying the developer into the developer tank  80 , the air operation valve  81   a  is opened with the air operation valves  82   b  and  83   a  closed, so that the developer is supplied into the developer tank  80  through the first developer pipe  81 . Then, the developer is sufficiently stored in the developer tank  80 . When supplying the developer to the developer supply nozzle  20 , the air operation valves  82   b  and  83   a  are opened with the air operation valve  81   a  closed. The N 2  gas is guided into the developer tank  80  through the second developer pipe  82 , which increases an internal pressure of the developer tank  80 . The developer is pumped up under this internal pressure to be supplied to the developer supply nozzle  20  through the third developer pipe  83 . The flow rate of the developer supplied to the developer supply nozzle  20  through the third developer pipe  83  is controlled by the flow meter  83   b.    
       FIG. 8  is a piping diagram showing the processing solution supply system. 
     The processing solution supply system includes a processing solution tank  85  for applying pressure, a first processing solution pipe  86  for connecting the processing solution tank  85  and another solution storage tank or a plant utility system serving as a predetermined pure water source installed in a plant, a second processing solution pipe  87  for connecting a predetermined N 2  gas source and the processing solution tank  85  and a third processing solution pipe  88  for connecting the processing solution tank  85  and processing solution supply nozzle  40 . An air operation valve  86   a  is provided halfway in the first processing solution pipe  86 . A regulator  87   a  and an air operation valve  87   b  are provided halfway in the second processing solution pipe  87 . An air operation valve  88   a,  a filter  88   c  for removing foreign substances included in the processing solution, and a flow meter  88   b  having a mechanism for measuring and controlling the flow rate of the processing solution flowing toward the processing solution supply nozzle  40  are provided halfway in the third processing solution pipe  88 . 
     In short, the processing solution supply system has a similar construction to the above-described developer supply system except that the filter  88   c  and flow meter  88   b  are interchanged in position in the third processing solution pipe  88  and that a gas dissolving section  89  which will be described next is added, and supplies the anti-static processing solution to the processing solution supply nozzle  40  on similar operating principles. 
     The gas dissolving section  89  is provided halfway in the third processing solution pipe  88 , here, between the flow meter  88   b  and processing solution supply nozzle  40 . CO 2  gas is supplied from a CO 2  gas source not shown to this gas dissolving section  89 , where the supplied CO 2  gas is dissolved in pure water. For such gas dissolving section  89 , a structure for dissolving CO 2  gas in pure water using a diaphragm which does not pass water molecules but pass gas molecules only, a structure for dissolving CO 2  gas in pure water by spraying pure water into an atmosphere of CO 2  gas by an ultrasonic nozzle or the like may be employed. 
     As described, an aqueous CO 2  solution obtained by dissolving CO 2  gas in pure water, in which hydrogen ions and hydrogen carbonate ions are dissociated, has a small electrical resistivity. Therefore, such aqueous CO 2  solution, when supplied onto a substrate, serves as an anti-static processing solution for avoiding charging of the substrate. 
     For such anti-static processing solution, the above-described aqueous CO 2  solution or various types of processing solutions in which ions are dissociated in such a degree that charging of the substrate can be avoided may be employed. 
       FIG. 9  is a block diagram showing an electrical configuration of the substrate processing apparatus according to the present embodiment. 
     The control section  60  controls a series of operations which will be discussed later, and is constructed from a general microcomputer having CPU, ROM, RAM and the like for performing a predetermined computing operation under a previously stored software program. 
     To this control section  60 , the position sensors  34   a  to  34   d  for detecting shifted positions of the developer supply nozzle  20  and the processing solution supply nozzle original position sensor  55   b  are connected, so that respective detecting signals are input to the control section  60 . Further, a control panel  62  is connected to the control section  60 , so that a predetermined operating instruction is input to the control section  60  through the control panel  62 . 
     The spin motor  13  constructed from a servomotor and the like is also connected to the control section  60 . The control section  60  receives a detecting signal output from a rotation amount detecting mechanism and the like such as a rotary encoder on the side of the spin motor  13 , and performs feedback control on the amount of rotation of the spin motor  13  based on the detecting signal. 
     Further, the developer supply nozzle scanning motor  36   a,  air cylinder  39   a  for moving the developer supply nozzle  20  up and down, processing solution supply nozzle pivoting motor  52 , processing solution supply nozzle up-and-down mechanism (air cylinder)  56 , final rinse water supply nozzle rotating motor  73 , respective solenoid valves for the air operation valves  81   a,    82   b,    83   a,    86   a,    87   b  and  88   a  in the above-described developer supply system and processing solution supply system are also connected to the control section  60 , and their operations are controlled by the control section  60 . 
     Next, a developing operation of the semiconductor wafer SW by this substrate processing apparatus will be discussed. 
       FIG. 10  is a flow chart showing a series of steps of developing operation performed by the substrate processing apparatus.  FIG. 11  is an explanatory view showing a movement of the developer supply nozzle  20 , and  FIG. 12  is an explanatory view showing a movement of the processing solution supply nozzle  40 . 
     After the start of the operation, in step S 1 , the semiconductor wafer SW is first loaded onto the spin chuck  12  of the wafer holding/rotating mechanism  10  by a transfer robot. In an initial state, the inner cup  16  is in the down position. 
     Next, in step S 2 , the developer is supplied onto the semiconductor wafer SW. 
     More specifically, as shown in  FIG. 11 , in the initial state, the developer, supply nozzle  20  is housed within the waiting pot  18  in the waiting position U 2 . Then, after the start of step S 2 , the developer supply nozzle  20  moves up in the waiting position U 2  as indicated by an arrow (i) to go away from the waiting pot  18 . Subsequently, as indicated by an arrow (ii), the developer supply nozzle  20  moves horizontally at a constant speed toward the developer discharge start position U 3  at one end of the semiconductor wafer SW, and then moves down in the position U 3  as indicated by an arrow (iii) to start discharging the developer. Here, one end of the semiconductor wafer SW is in an arbitrary position on the periphery of the semiconductor wafer SW, and the opposite end is in a position facing the one end with respect to the center of the semiconductor wafer SW. Next, as indicated by an arrow (iv), the developer supply nozzle  20  supplies the developer onto the semiconductor wafer SW in a constant flow rate while moving horizontally at a constant speed from the position U 3  toward the developer discharge stop position U 4  on the other end of the semiconductor wafer SW. The developer thereby accumulates on the semiconductor wafer SW. 
     Next, as indicated by an arrow (v), the developer supply nozzle  20  moves up in the position U 4 . 
     In step S 2 , the processing solution supply nozzle  40  is in the up position, and moves along with the developer supply nozzle  20 . The semiconductor wafer SW remains at rest. 
     Next, in step S 3 , a still developing operation is conducted. 
     More specifically, the developing operation is conducted on the semiconductor wafer SW having undergone exposure with the semiconductor wafer SW held stationary. A time period of this still developing operation depends on the speed of dissolution of resist and a throughput of the apparatus, and is set within a range between 3 and 120 seconds. 
     After this still developing operation is finished, the developer supply nozzle  20  once returns to the waiting position U 2  to move down into the waiting pot  18 , as indicated by an arrow (vi). In a structure where the processing solution supply nozzle  40  and developer supply nozzle  20  are provided separately, the developer supply nozzle  20  may be designed to return to the waiting position U 2  after a substrate unloading step (step S 7 ) which will be described later, in other words, after the semiconductor wafer SW is taken out. 
     Next, as shown in step S 4 , the anti-static processing solution is supplied onto the semiconductor wafer SW. 
     First, as indicated by an arrow (vii), the developer supply nozzle  20  moves up, and moves toward the processing solution supply position U 1  away from the semiconductor wafer SW. The developer supply nozzle  20  remains at still in the up position. At this time, the processing solution supply nozzle  40  is positioned above one end of the semiconductor wafer SW. This position is slightly closer to the semiconductor wafer SW than the position where the developer supply nozzle  20  starts discharging the developer. 
     In this state, as indicated by an arrow a in  FIG. 12 , the processing solution supply nozzle  40  moves down relative to the developer supply nozzle  20 . Next, the discharge of the anti-static processing solution from the processing solution supply nozzle  40  is started. After the start of the discharge of the anti-static processing solution, a pivot of the processing solution supply nozzle  40  is started, and at the same time, a rotation of the semiconductor wafer SW is started. In a circumferential direction of the semiconductor wafer SW, the position where the processing solution is supplied and that where the developer is supplied are substantially the same. Then, the processing solution supply nozzle  40  is pivoted by π/2 rad (90 degrees) (see an arrow b in  FIG. 12 ), and at the same time, the semiconductor wafer SW is rotated by π/2 rad (90 degrees). 
     At this time, assuming that a line connecting the supply start point on the semiconductor wafer SW where the supply of the processing solution is started and the supply finish point on the semiconductor wafer SW on the opposite side of the supply start point with respect to the center of the semiconductor wafer SW extends in an imaginary scanning direction, it is preferable that the imaginary scanning direction and the extending direction of the processing solution supply nozzle  40  be orthogonal to each other to the extent possible. 
     Further, it is preferable that a component of velocity of the processing solution supply nozzle  40  on the semiconductor wafer SW in the imaginary scanning direction and a speed of the developer supply nozzle  20  be as equal to each other as possible. 
     To satisfy these two relationships to the extent possible, the rotation speed of the processing solution supply nozzle  40  and that of the semiconductor wafer SW are controlled as appropriate. 
     In this case, it is not necessary to spin the semiconductor wafer SW such that the rinse water supplied on the central portion of the semiconductor wafer SW is spread out over the wafer as in the conventional case. Therefore, the semiconductor wafer SW rotates at such low speeds that rotation does not cause excessive charging of the semiconductor wafer SW. 
     The anti-static processing solution is supplied onto the semiconductor wafer SW as described above, so that the development reaction on the semiconductor wafer SW is stopped. 
     Then, after pivoting over the semiconductor wafer SW, the processing solution supply nozzle  40  moves up relative to the developer supply nozzle  20  as indicated by an arrow c in  FIG. 12 , and returns to its original position in a reverse direction to the arrow b, as indicated by an arrow d. Then, as indicated by arrows (viii) and (ix), the developer supply nozzle  20  moves to the waiting position U 2  and is housed within the waiting pot  18 . 
     Next, in step S 5 , rinse water is finally supplied onto the semiconductor wafer SW. 
     More specifically, the inner cup  16  is moved up, and the rinse water (pure water) is supplied from the final rinse water supply nozzles  70  onto the semiconductor wafer SW while rotating the semiconductor wafer SW, so that development products are removed by cleaning. 
     The revolution per minute of the semiconductor wafer SW at this time ranges from 500 rpm to 1000 rpm, for example. 
     Next, in step S 6 , the semiconductor wafer SW is spun, so that the rinse water on the semiconductor wafer SW is spun off and dried. 
     The revolution per minute of the semiconductor wafer SW at this time ranges from 1500 rpm to 3000 rpm, for example. 
     Finally, in step S 7 , the inner cup  16  is moved down, and the holding of the semiconductor wafer SW by the spin chuck  12  by suction is released. Thereafter, the semiconductor wafer SW is unloaded by the transport robot. 
     According to the substrate processing apparatus having the above-described construction, the processing solution supply nozzle  40  having the discharge port  42  for discharging the anti-static processing solution in a predetermined discharge width passes over the semiconductor wafer SW, so that the anti-static processing solution is supplied almost uniformly onto the entire surface of the semiconductor wafer SW. 
     At this time, it is not necessary to spin the semiconductor wafer SW to spread the processing solution across the semiconductor wafer SW as in the conventional case, which can avoid charging of the semiconductor wafer SW. Further, the anti-static processing solution such as aqueous CO 2  solution supplied onto the semiconductor wafer SW can cancel charging occurred a little on the semiconductor wafer SW. Therefore, it is possible to achieve an improved effect of avoiding charging of the semiconductor wafer SW as well as to avoid the occurrence of post-develop defects. 
     Further, moving the slit-like discharge port  42  over the semiconductor wafer SW, a development stop liquid is supplied onto the semiconductor wafer SW, so that the concentration of the developer on the semiconductor wafer SW shows a relatively gentle change, causing the development reaction to stop gradually. This can avoid the occurrence of defects due to a rapid neutralization. 
     Furthermore, the anti-static processing solution is supplied almost uniformly on the entire surface of the semiconductor wafer SW by the processing solution supply nozzle  40  having the discharge port  42  of a predetermined discharge width, which can reduce an area where the anti-static processing solution is not supplied to a minimum. The occurrence of post-develop defects can be avoided for this reason as well. 
     Still further, according to the substrate processing apparatus, as shown in  FIG. 13 , the processing solution supply nozzle  40  moves over the semiconductor wafer SW in an imaginary scanning direction La non-linearly (for example, arcuately). Therefore, the anti-static processing solution can be supplied uniformly on the entire surface of the semiconductor wafer SW. 
     Detailed description will be given now in reference to  FIGS. 14 and 15 .  FIGS. 14 and 15  each show a state of supplying the anti-static processing solution onto the semiconductor wafer SW with a point P 1  from which the anti-static processing solution is not supplied present in a certain position in the extending direction of the processing solution supply nozzle  40 . In each of  FIGS. 14 and 15 , an area diagonally shaded up to the right indicates an area to which the anti-static processing solution is supplied at the stage shown in  FIG. 14 . In  FIG. 15 , an area diagonally shaded up to the left indicates an area to which the processing solution is supplied at the stage shown in  FIG. 15 . 
     As shown in  FIG. 14 , considering a state where the processing solution supply nozzle  40  has moved halfway in the imaginary scanning direction La over the semiconductor wafer SW, an area E 1  to which the processing solution is not supplied is present as a streak on the semiconductor wafer SW in a rear direction on the extension of the point P 1 . 
     Then, as shown in  FIG. 15 , the processing solution supply nozzle  40  moves over the semiconductor wafer SW arcuately, which means the processing solution supply nozzle  40  moves a distance Mx in the imaginary scanning direction La and a distance My in a direction substantially orthogonal to the imaginary scanning direction La. Therefore, the point P 1  of the discharge port  42  also moves a distance My in the direction substantially orthogonal to the imaginary scanning direction La from the position shown in  FIG. 14 , so that a portion (other than the point P 1 ) of the discharge port  42  that can supply the processing solution is placed in a position corresponding to the area E 1 . Then, in the state shown in  FIG. 15 , the processing solution discharged from the portion of the discharge port  42  that can supply the processing solution is supplied onto the area E 1 . 
     These operations are performed continuously as the processing solution supply nozzle  40  rotates and moves. Accordingly, it is possible to reduce an area where the anti-static processing solution is not supplied to zero. This achieves uniform development and avoids post-develop defects. 
     In the present embodiment, the method of finally supplying rinse water in the final rinse step (step S 5 ) is not limited to the above-described one. For instance, similarly to the processing solution supply nozzle  40 , a nozzle having a slit-like discharge port may be employed to supply the rinse water. Alternatively, the final rinse step (step S 5 ) itself may be omitted. 
     Second Preferred Embodiment 
     A substrate processing apparatus according to a second preferred embodiment of the present invention will be discussed. The description in this embodiment will be focused on differences from the first preferred embodiment, and similar components will be referred to using the same reference characters, repeated explanation of which is thus omitted here. 
     In the substrate processing apparatus according to the second preferred embodiment, a processing solution supply system shown in  FIG. 16  is connected to the processing solution supply nozzle  40  in place of the processing solution supply system according to the first preferred embodiment shown in  FIG. 8 . 
     The processing solution supply system shown in  FIG. 16  is a system for supplying a development stop liquid (e.g., pure water) for stopping a development reaction to the processing solution supply nozzle  40  as a first processing solution, and more specifically, has the same construction as that of the processing solution supply system shown in  FIG. 8  although the gas dissolving section  89  is omitted. 
     Further, in the substrate processing apparatus, an anti-static cleaning solution supply system for supplying an anti-static cleaning solution as a second processing solution is connected to the final rinse water supply nozzles  70 , serving as the second processing solution supply nozzles. 
     As shown in  FIG. 17 , this anti-static cleaning solution supply system has a processing solution tank  185  for applying pressure, a first anti-static cleaning solution pipe  186  for connecting the processing solution tank  185  and another solution storage tank or a plant utility system serving as a predetermined pure water source installed in a plant, a second anti-static cleaning solution pipe  187  for connecting a predetermined N 2  gas source and the processing solution tank  185  and a third anti-static cleaning solution pipe  188  for connecting the processing solution tank  185  and final rinse water supply nozzles  70 . An air operation valve  186   a  is provided halfway in the first anti-static cleaning solution pipe  186 . A regulator  187   a  and an air operation valve  187   b  for controlling the flow rate of N 2  gas are provided halfway in the second anti-static cleaning solution pipe  187 . An air operation valve  188   a,  a filter  188   c  for removing foreign substances included in the anti-static cleaning solution, and a flow meter  188   b  having a mechanism for measuring and controlling the flow rate of the anti-static cleaning solution flowing toward the final rinse water supply nozzles  70  are provided halfway in the third anti-static cleaning solution pipe  188 . 
     In short, the anti-static cleaning solution supply system has a similar construction to the processing solution supply system shown in  FIG. 8 , and supplies the anti-static cleaning solution to the final rinse water supply nozzles  70  on similar operating principles. 
     It is preferable that ions, i.e., CO 2  be dissolved in the anti-static cleaning solution supplied to the final rinse water supply nozzles  70  in such a concentration that no bubble is generated. 
     Next, a developing operation of the semiconductor wafer SW by this substrate processing apparatus will be discussed. 
       FIG. 18  is a flow chart showing a series of steps of developing operation performed by the substrate processing apparatus. 
     After the start of the operation, the semiconductor wafer SW is loaded (step S 11 ; substrate loading step), and then, the developer is supplied onto the semiconductor wafer SW (step S 12 ; developer supply step). Thereafter, a still developing operation is performed (step S 13 ; still development step). The steps S 11  to S 13  are the same as steps S 1  to S 3  as described above. 
     When the still developing operation is completed after a lapse of a predetermined time period after the supply of the developer, the development stop liquid is supplied onto the semiconductor wafer SW in step S 14 . 
     More specifically, after the start of discharge of the development stop liquid from the processing solution supply nozzle  40 , a rotation of the semiconductor wafer SW is started at the same time a pivot of the processing solution supply nozzle  40  is started. 
     Accordingly, the development stop liquid is supplied onto the semiconductor wafer SW in a similar manner of supplying the anti-static processing solution is supplied onto the semiconductor wafer SW as described in the first preferred embodiment. The development stop liquid supplied onto the semiconductor wafer SW as described stops the development reaction on the semiconductor wafer SW. 
     At this time, the developer is supplied from the processing solution supply nozzle  40  in such an amount and a manner that the developer on the semiconductor wafer SW can be brought into a predetermined concentration (such that the development reaction is stopped) or below such concentration. Accordingly, products by the developing operation and the like remain on the semiconductor wafer SW just after step S 14 . 
     Next, in step S 15 , rinse water is finally supplied onto the semiconductor wafer SW. 
     More specifically, the final rinse water supply nozzles  70  are moved above the semiconductor wafer SW, and the anti-static cleaning solution is supplied onto the semiconductor wafer SW from the final rinse water supply nozzles  70  while rotating the semiconductor wafer SW. Then, the anti-static cleaning solution is supplied in such an amount and a manner that the developer on the semiconductor wafer SW is replaced and removed by the anti-static cleaning solution and that development products are removed by cleaning. 
     The anti-static cleaning solution supplied onto the semiconductor wafer SW avoids frictional charging of the semiconductor wafer SW due to spinning even in the case of spinning the semiconductor wafer SW. 
     The operation of the processing solution supply nozzle  40  and the like in steps S 14  and S 15  are almost the same as the operations in steps S 4  and S 5  described in the first preferred embodiment. 
     Next, similarly to steps S 6  and S 7  as described above, in step S 16 , the semiconductor wafer SW is spun, so that the rinse water on the semiconductor wafer SW is spun off and dried. Finally, in step S 17 , the semiconductor wafer SW is unloaded by the transport robot. 
     According to the substrate processing apparatus and substrate processing method as above described, the anti-static cleaning solution is supplied onto the semiconductor wafer SW after the development stop liquid is supplied, which can prevent generation of reactants of the developer and anti-static cleaning solution. This can avoid the occurrence of defects. 
     Further, moving the slit-like discharge port  42  over the semiconductor wafer SW, a development stop liquid is supplied onto the semiconductor wafer SW, so that the concentration of the developer on the semiconductor wafer shows a relatively gentle change, causing the development reaction to stop gradually. This can avoid the occurrence of defects due to a rapid neutralization. 
     Furthermore, subsequently to the supply of the development stop liquid, the anti-static cleaning solution is supplied in order to remove and clean the developer and products on the semiconductor wafer SW, which avoids charging of the semiconductor wafer SW in the cleaning step after the stop of development. Therefore, it is possible to avoid the occurrence of post-develop defects resulting from adhesion of charged particles included in the solution on the semiconductor wafer SW to the surface of the semiconductor wafer SW. 
     Particularly, the use of a solution with ions such as carbonate ions dissolved therein as the anti-static cleaning solution in such a concentration that no bubble is generated can prevent pattern fall resulting from bubbles and the like. 
     In the present embodiment, the construction of supplying the anti-static cleaning solution is not limited to the above-described one. For instance, similarly to the processing solution supply nozzle  40 , a nozzle having a slit-like discharge port may be used to supply the anti-static cleaning solution. 
     Variant 
     The above-described preferred embodiments have been directed to the case of rotating both the processing solution supply nozzle  40  and semiconductor wafer SW, however, as shown in  FIG. 19 , the processing solution supply nozzle  40  may be moved linearly from one end to the opposite end of the semiconductor wafer SW being held stationary. 
     Further, as shown in  FIG. 20 , the processing solution supply nozzle  40  may be moved linearly along a line tilted relative to a line connecting the one end and the opposite end of the semiconductor wafer SW being held stationary. In this case, the processing solution supply nozzle  40  is moved in such a position that the moving direction and extending direction of the processing solution supply nozzle  40  keep a constant angle. 
     Furthermore, similarly to the processing solution supply nozzle  40 , both the developer supply nozzle  20  and semiconductor wafer SW may be rotated when supplying the developer. 
     While the invention has been shown and described in detail, the foregoing description is in all aspects illustrative and not restrictive. It is therefore understood that numerous modifications and variations can be devised without departing from the scope of the invention.