JP2007317699A - Surface-treating apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent the excessive treatment (loading effect) of the edge of a workpiece in an apparatus for performing surface treatment by spraying treatment gas to the workpiece from a treatment head and moving the treatment head to the workpiece relatively. <P>SOLUTION: A blowout port 52 and a suction opening 61 of treatment gas are formed on a lower surface 21 that should oppose the workpiece W in the treatment head 20 while being separated in the relative travelling direction. An inert gas blowing section 71 made of a porous member is provided at an outside-installation region 12 outside the edge of an installation region 11 of the workpiece W. A suction port 82 is formed between the end face of the inert gas blowing section 71 and the object W to be treated at the installation region 11. When the treatment head 20 opposes the inert gas blowing section 71, insert gas is mixed into a treatment gas flow F and gas having an amount equal to the amount of mixture is sucked from the suction port 82. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an apparatus and a method for performing a surface treatment such as etching, film formation, and surface modification by spraying a processing gas on an object to be processed such as a glass substrate or a semiconductor wafer.

As this type of surface processing apparatus, for example, there is a scanning type apparatus that relatively moves a processing object in one direction with respect to the processing head while blowing a processing gas from the outlet of the processing head to the processing object (for example, Patent Documents). 1). The processing gas flows through the processing space between the processing head and the object to be processed toward the suction port of the processing head. In this process, the reactive component in the processing gas reacts on the surface of the object to be processed, and the surface of the object to be processed is etched or other surface treatment. The treated gas and reaction by-products are sucked and exhausted from the suction port.
In Patent Document 1, an inert gas blowing portion is provided on the outer side of the suction port, and the processing region is surrounded by an inert atmosphere. Thereby, the efficiency of a process process and the improvement of a yield are aimed at.
JP 2002-151494 A

  When the processing head scans the center of the object to be processed, as the processing gas flows from the outlet side to the suction port side on the object to be processed, the reactive components in the processing gas are changed. Concentration gradually decreases due to the reaction. On the other hand, when the processing head relatively enters the end of the object to be processed from the outside or goes out from the end of the object to be processed, the outlet is outside the end of the object to be processed. There is a state in which the suction port is located on the end of the workpiece. In this state, until the processing gas blown out from the outlet reaches the end of the object to be processed, the reactive component is not consumed and the high concentration is maintained. Ingredient consumption begins. Therefore, the edge part of a to-be-processed object will be processed more excessively than a center part by the high concentration reactive component. This is called a loading effect. Therefore, the end of the object to be processed cannot be used as a product and must be discarded. If the distance between the blowout port and the suction port of the processing head is shortened, the width of the region where such a loading effect occurs can be narrowed. However, in this case, the time until the processing gas exits from the outlet and is sucked into the suction port is shortened, and is sucked into the suction port without sufficiently reacting on the surface of the workpiece. Therefore, the processing speed is reduced and the loss of the processing gas is increased. By creating a dummy for the object to be processed and adding it to the end of the object to be processed, the concentration distribution of the reactive component of the processing gas flow at the end of the object to be processed is the same as that at the center of the object to be processed. However, it is difficult to always prepare a dummy of the same quality as the workpiece.

The present invention has been made to solve the above problems,
An apparatus for processing a surface of the object to be processed by spraying a processing gas on the object to be processed,
A processing head having a surface on which a blowing port and a suction port for processing gas are formed, the suction port being arranged away from one side in one direction with respect to the blowing port;
The processing head is relative to the installation region in the one direction within a range including an area where the object to be processed is installed and an outer edge of the installation region opposite to the one side in the one direction. A moving mechanism to move,
The installation area is fixed to the object to be processed, and is disposed in an installation outside area having a width corresponding to the predetermined distance outward from the opposite edge of the installation area, and faces the processing head. An inert gas blowing section having an inert gas blowing hole for blowing the inert gas to the possible side;
It is provided with.
As a result, the reactive component concentration of the processing gas blown from the outlet can be diluted with an inert gas, and the processing gas is prevented from being introduced at a high concentration at the end of the object to be processed. Can do.

It is preferable that an end suction hole is formed in the non-installation region to suck the gas on the side that can face the processing head by an amount corresponding to the amount of the inert gas blown out.
This not only reduces the reactive component concentration of the processing gas introduced into the end of the object to be processed, but also prevents an increase in flow rate, and reliably reduces the amount of the reactive component that comes into contact with the end of the object to be processed. be able to. As a result, the processing rate at the end of the object to be processed can be reduced, and excessive processing (loading effect) at the end of the object to be processed can be suppressed. As a result, a sufficient distance between the blowout port and the suction port of the processing head can be secured, and the processing speed can be improved.

It is preferable that the amount of the inert gas blown from the inert gas blowout hole is substantially equal to the amount of suction from the suction hole.
As a result, the flow rate of the processing gas introduced into the workpiece can be kept constant.

It is preferable that the end suction hole is disposed at an edge on the installation area side in the non-installation area so as to be sandwiched between the inert gas blowing portion and the installation area.
Thereby, the immediate vicinity of the edge of the workpiece can be sucked.

  It is preferable that the end suction hole is defined by an end edge of the inert gas blowing portion facing the installation area and an end edge of the workpiece disposed in the installation area. This eliminates the need for a member only for forming the end suction hole, and simplifies the configuration.

It is preferable that a width along the one direction of the inert gas blowing portion is substantially equal to or larger than a predetermined distance between the blowing port and the suction port.
It is preferable that the inert gas blowing holes are dispersedly arranged in the width direction of the inert gas blowing portion or in the outside area.
More preferably, the width of the end suction hole along the one direction is so small that it can be ignored with respect to the width of the inert gas blowing portion along the one direction.
Thereby, the reactive component concentration of the processing gas introduced into the end of the object to be processed can be increased or decreased with the relative movement of the processing head, and the processing amount at the end of the object to be processed can be made uniform. . Moreover, the immediate vicinity of the edge of a to-be-processed object can be attracted | sucked locally. On the other hand, the inert gas supply amount of the entire inert gas blowing section can be made constant, and control can be easily performed.

It is preferable that the inert gas blowing amount per unit area in the inert gas blowing portion is changed along the one direction, and the inert gas blowing amount per unit area in the inert gas blowing portion. However, it is more preferable that it becomes larger as it approaches the region.
The distribution along the one direction of the inert gas blowing amount per unit area is the one of the processing amount (processing rate at a certain moment) when the processing head is stationary with respect to the object to be processed in the installation region. More preferably, it correlates with the distribution along the direction.
This makes it possible to form a gas state in which the processing rate distribution when processing the edge of the workpiece is correlated with the processing rate distribution when processing the central portion of the workpiece, thereby further uniformizing the processing. Can be achieved.
The inert gas blowing amount per unit area in the inert gas blowing part may be substantially uniform over the entire area of the inert gas blowing part.

It is preferable that the inert gas blowing portion includes a porous member having a large number of blowing holes.
Thereby, the structure of the inert gas blowing part can be facilitated. As the porous member, a porous material may be used, or a flat plate such as punching metal having a large number of holes or a net may be used.

It is preferable that the surface of the porous member forming the space is substantially flush with the workpiece on the region.
As a result, the processing gas can smoothly flow from the inert gas blowing portion onto the object to be processed.
It is preferable that the suction hole is defined by an end surface of the porous member facing the installation area and an edge of the workpiece on the installation area. Thereby, the immediate vicinity of the edge of the workpiece can be sucked. In addition, a member only for forming the end suction hole is not required, and the configuration can be simplified.

It is preferable that another suction port (second suction port) is formed on the surface of the processing head opposite to the suction port (first suction port) across the blowout port.
Thereby, the process gas blown out from the blowout port flows in two directions. In this case, the non-installation area (first installation area) on the opposite side of the installation area, and the inert gas blowing section and suction hole (first inert gas blowing section and first suction hole) of the first installation area. In addition to the one side of the installation area, the second installation outside has a width corresponding to a second predetermined distance between the blowout port and the second suction port on the outer side of the one side of the installation region. It is preferable to provide a second inert gas blowing portion having a second inert gas blowing hole for setting an area and blowing the inert gas on the side where the processing head can be opposed to the second installation outside area. A second end suction hole is formed in the second non-installation region to suck the gas on the side that can face the processing head by an amount corresponding to the amount of inert gas blown from the second inert gas blow-out portion. Is more preferable.

A method of processing a surface of the object to be processed by spraying a processing gas on the object to be processed,
A process gas distribution step of blowing out the process gas from a blow-out port and sucking it from a suction port separated in one direction with respect to the blow-out port;
A moving step of moving the outlet and the suction port relative to the object to be processed in the one direction;
A mixing step of mixing an inert gas into the processing gas from the outlet when the outlet is located outside the object to be processed in the one direction and the suction port is opposed to the end of the object to be processed. When,
A suction step of sucking the processing gas between the blowout port and the object to be processed separately from the suction port by an amount corresponding to the amount of the inert gas mixed;
It is characterized by performing.
As a result, the processing gas blown out from the outlet can be introduced into the end of the object to be processed while reducing the concentration and maintaining the flow rate substantially constant, thereby reducing the processing rate at the end of the object to be processed. be able to. As a result, excessive processing (loading effect) of the end portion of the workpiece can be suppressed. As a result, a sufficient distance between the blowout port and the suction port can be secured, and the processing speed can be improved.

  According to the present invention, it is possible to prevent a processing gas from being introduced at a high concentration at the end of an object to be processed while ensuring a sufficient distance between the blowout port and the suction port and ensuring a processing speed. Can do. As a result, the excessive process (loading effect) of the edge part of a to-be-processed object can be suppressed.

Embodiments of the present invention will be described below.
As shown in FIGS. 1 and 2, in this embodiment, for example, a glass substrate W having a square shape in plan view is used as an object to be processed, and an amorphous silicon film or the like coated on the upper surface of the substrate W is etched. As the surface treatment apparatus 1 for etching, a remote type plasma surface treatment apparatus 1 is used. The plasma surface treatment apparatus 1 includes a stage 10 and a treatment head 20.
The stage 10 and the processing head 20 of the apparatus 1 are almost bilaterally symmetrical. Hereinafter, when these left and right substantially symmetrical elements (including the processing gas flow F and the like which will be described later) are distinguished from each other, “L” is attached to the symbol on the left side, and “R” is assigned to the symbol on the right side. I will attach it.

  A substrate placement area 11 having the same size as the substrate W is provided on the upper surface of the stage 10. A substrate W to be processed is set in the installation area 11. Outside installation areas 12 are provided on the left and right outside of the installation area 11 of the stage 10. The left installation outside region 12L is in contact with the left edge of the installation region 11, has a width substantially equal to the distance DR between the blowout port 52 of the processing head 20 and the right suction port 61R, and extends in a belt shape in the front-rear direction. Yes. The right installation outside region 12R is in contact with the right edge of the installation region 11, has a width substantially equal to the distance DL between the blowout port 52 of the processing head 20 and the left suction port 61L, and extends in a belt shape in the front-rear direction. Yes.

  As shown in FIG. 1, a processing head 20 is disposed above the stage 10. A processing space 1 s is formed between the processing head 20 and the substrate W on the stage 10.

The processing head 20 is connected to the moving mechanism 40. By this moving mechanism 40, the processing head 20 is moved (scanned) in the left-right direction (one direction). This moving range includes an installation area 11 of the stage 10 and left and right installation outside areas 12L and 12R. The moving mechanism 40 may be electric or hydraulic or pneumatic.
The processing head 20 may be fixed, and the stage 10 and thus the substrate W may be moved. In this case, the moving mechanism 40 may be configured by a roller conveyor or a belt conveyor.
As shown by the two-dot chain line in FIG. 2, the processing head 20 extends long in the front-rear direction corresponding to the dimension of the substrate W in the front-rear direction (the direction orthogonal to the plane of FIG. 1).

  The processing head 20 houses a pair of left and right electrodes 31, 31. Each of these electrodes 31 and 31 extends long in the front-rear direction perpendicular to the paper surface of FIG. A power supply 30 is connected to one electrode 31, and the other electrode 31 is electrically grounded. A solid dielectric layer 32 is provided on the opposing surfaces of the electrodes 31 and 31. The solid dielectric layer 32 only needs to be provided on the facing surface of any one electrode 31.

An in-head gas supply path 51 is formed between the solid dielectric layer 32 of the pair of electrodes 31 and 31. As shown in FIG. 2, the in-head gas supply path 51 has a slit shape and extends long in the front-rear direction. As shown in FIG. 1, a processing gas supply source 50 is connected to the upper end portion of the in-head gas supply path 51. The processing gas supply source 50 is configured to uniformly introduce a processing gas having a predetermined flow rate in the longitudinal direction of the head gas supply path 51. As the processing gas material for etching, for example, a fluorine-based component such as CF ₄ and an oxygen-based component such as O ₂ are included.
By supplying a voltage from the power supply 30 to one electrode 31, an atmospheric pressure glow discharge is formed in the gas supply path 51 in the head. Thereby, the gas supply path 51 in the head becomes an atmospheric pressure plasma space, the processing gas is turned into plasma, and a fluorine-based or oxygen-based reactive component is generated.

  The lower end of the gas supply path 51 in the head reaches the lower surface 21 (surface to be opposed to the object to be processed) of the processing head 20 and opens to constitute a main outlet 52. The outlet 52 extends long in the front-rear direction (FIG. 2). A processing gas containing the reactive component is blown downward from the blowout port 52. As shown in FIG. 1, when the processing head 20 is positioned on the central portion of the substrate W, the processing gas F blown from the blowout port 52 moves left and right in the processing space 1S between the processing head 20 and the substrate W. It is designed to flow in the direction. A reactive component in the processing gas flow F in the processing space 1S comes into contact with the substrate W to cause a reaction, and a processing target film such as amorphous silicon is etched. By this reaction, the concentration of the reactive component in the processing gas stream F is gradually decreased toward the downstream.

  Therefore, as shown in the graph inserted in FIG. 1, the etching rate becomes maximum immediately below the blowout port 52, and gradually decreases from there toward the downstream of the processing gas flows FL and FR on both the left and right sides. Become.

In-head suction paths 62 and 62 are provided on the left and right sides of the processing head 20, respectively. The lower end portions of the in-head suction paths 62 and 62 are opened on the lower surface 21 of the processing head 20 (a surface to be opposed to the object to be processed) to constitute a main suction port 61. As shown in FIG. 2, the left and right in-head suction paths 62, 62 and thus the suction ports 61, 61 each have a slit shape and extend long in the front-rear direction. The left and right suction ports 61L and 61R are separated from the blowout port 52 by a predetermined distance DL and DR. The distances DL and DR are equal to each other, for example, about 50 mm.
The distances DL and DR may be different from each other.

  As shown in FIG. 1, the upper ends of the suction paths 62 and 62 in each head are connected to a main suction source 65 such as a vacuum pump via a main suction flow rate adjusting means 64. By this main suction source 65, the processed gas flows F, F are sucked from the suction ports 61, 61 and exhausted. The main suction flow rate adjusting means 64 is composed of a mass flow controller, a flow rate control valve, and the like, and adjusts the suction flow rate from the corresponding suction port 61. The suction flow rate at each suction port 61 is preferably set so that it is exactly one half of the blow-off flow rate from the blow-out port 52.

  On both the left and right sides of the processing head 20, extension portions 22 that are flush with the lower surface 21 are provided. The extension portion 22 prevents the processing gas from leaking outside the suction ports 61L and 61R.

As shown in FIGS. 1 and 2, the surface treatment apparatus 1 is further provided with a supply / discharge mechanism 2. The supply / discharge mechanism 2 includes an inert gas blowing mechanism 70 and an edge suction mechanism 80. The inert gas blowing mechanism 70 includes a pair of left and right inert gas blowing portions 71L and 71R provided on the upper surfaces of the left and right outside installation areas 12L and 12R of the stage 10, respectively. Blowing chambers 73L and 73R are formed in the lower portions of the blowing portions 71L and 71R in the left and right outside installation areas 12L and 12R of the stage 10, respectively, and these blowing chambers 73L and 73R are respectively inert gas blowing flow rate adjusting means. It is connected to an inert gas source 75 via 74L and 74R.
An air pressure source such as a compressor is used as the inert gas source 75. Thereby, the air as an inert gas is blown out from the blowing part 71.
The left and right flow rate adjusting means 74 and 74 are each composed of a mass flow controller, a flow rate control valve, and the like, and adjust the air blowing flow rate from the blowing portion 71.

  The inert gas blowing part 71 is constituted by a plate-like porous member having a large number of blowing holes 72. The porous member 71 is preferably made of a material having sufficient resistance to the plasma-ized processing gas, and is made of ceramic such as alumina. A metal mesh member such as a punching metal plated with gold may be used.

The inert gas blowing part 71 extends long in the front-rear direction. The front-rear length of the inert gas blow-out portion 71 is slightly larger than the front-rear dimension of the substrate W, and is substantially equal to the lengths of the blow-off port 52 and the suction port 61 of the processing head 20 in the front-rear direction. The left and right widths of the inert gas outlet 71 are substantially the same as or slightly larger than the distances DL and DR (about 50 mm) from the outlet 52 of the processing head 20 to the left and right suction ports 61L and 61R.
When the left and right distances DL and DR are different from each other, the width of the left inert gas blowing portion 71L is substantially the same as or larger than the right distance DR, and the width of the right inert gas blowing portion 72R is: It is preferable that the distance DL on the left side is substantially the same as or larger than that.

  As shown in FIG. 3, when the processing head 20 is positioned at the left portion within the relative movement range, the processing head 20 and the left blowing portion 71 </ b> L face each other, and a space 1 </ b> SL serving as a passage for processing gas or the like therebetween. Is to be formed.

  As shown in FIG. 9, when the processing head 20 is positioned on the right side within the relative movement range, the processing head 20 and the right blowing portion 71R face each other, and a space 1SR serving as a path for processing gas or the like therebetween. Is to be formed.

  As shown in FIG. 1, the upper surfaces of the inert gas blowing portions 71, 71 (surfaces that can face the processing head 20) are flush with the upper surface of the substrate W.

The blowing hole 72 of the blowing part 71 made of a porous member penetrates the blowing part 71 in the thickness direction, and the lower end is connected to the blowing chamber 73.
The blowout holes 72 are arranged in a substantially distributed manner (longitudinal direction and width direction) of the blowout portion 71. The sizes of the blowout holes 72 are different from each other according to the position in the left-right direction in the blowout portion 71, and the diameter closer to the installation region 11 is larger. As a result, the air (inert gas) blowing amount per unit area increases as the position of the blowing portion 71 is closer to the installation region 11.
In addition, the size of each blowout hole 72 of the blowout portion 71 and the distribution of the air blowout amount q per unit area in the left-right direction are determined when the processing head 20 is stationary with respect to the central portion of the substrate W in the installation region 11. Is set so as to correlate with the distribution in the horizontal direction of the etching amount E at the center of the substrate (the distribution in the horizontal direction of the etching rate at a certain moment).

That is, as shown in the inset graph of FIG. 1, the air blowing amount per unit area of the left blowing portion 71L is qL, the right end portion of the blowing portion 71L is the origin, and the x axis in the left-right direction (therefore on the blowing portion 71L). When the point is the minus part of the x-axis), the air blowing amount qL (−x) per unit area at a point left by a distance (−x) from the right end of the blowing portion 71L is
qL (−x) = k _L ER (x) (Formula 1)
The size of the hole 72 of the left blowing portion 71L is set so that Here, the k _L a proportionality constant, blow upon the concentration and blowing flow rate of the processing gas, amount of suction from the suction port 61R, defined by etching amount of the total. ER is a distribution on the right half of the origin of the static etching amount E (just below the blowout port 52). Therefore, ER (x) is the amount of static etching at a point that is a distance x from right below the outlet 52 to the right.

Similarly, when the amount of air blowing per unit area of the right blowing portion 71R is qR and the left end portion of the blowing portion 71R is the origin and the x-axis is taken in the right direction, the right end portion of the blowing portion 71L is moved to the right by a distance x. The air blowing amount qR (x) per unit area at a remote point is
qR (x) = k _R EL (−x) (Formula 2)
The size of the hole 72 of the right outlet 71R is set so that Here, _{k R} is a proportionality constant. Since this apparatus 1 is symmetrical, K _L = K _R. EL is a distribution on the left half (minus side of the x-axis) of the origin of the static etching amount E (just below the blowout port 52). Therefore, EL (−x) is the amount of static etching at a point left to the left by a distance (−x) from just below the outlet 52.

  It is preferable to measure the static etching amount E using a sample of the substrate W in advance and set the size corresponding to the position of the blowout hole 72 in the left-right direction based on this. Instead of changing the size of the blowout holes 72, as shown in FIG. 10, the arrangement interval of the blowout holes 72 of the same size may be changed according to the position in the left-right direction. A plurality of blowing portions 71 having different degrees of change may be prepared so that they can be replaced as appropriate.

  The edge suction mechanism 80 of the supply / discharge mechanism 2 has an edge suction source 85 that is a vacuum source that is separate from or common to the main suction source 65, and an edge suction path 83 extends from the edge suction source 85. ing. The edge suction path 83 branches into two, and edge suction flow rate adjusting means 84L and 84R are provided in the branch paths 83L and 83R, respectively. The flow rate adjusting means 84, 84 are configured by a mass flow controller, a flow rate control valve, or the like, and adjust the suction flow rate of the corresponding suction path 83. The set suction flow rate of the flow rate adjusting means 84L is equal to the air blowing amount from the left blowing portion 71L (the set flow rate of the blowing flow rate adjusting means 74L). The set suction flow rate of the flow rate adjusting means 84R is equal to the air blowing amount from the right blowing portion 71R (the set flow rate of the blowing flow rate adjusting means 74R).

  The tip of the suction path 83L provided with the flow rate adjusting means 84L reaches the upper surface of the edge on the installation area 11 side in the left installation outside area 12L of the stage 10, and is opened upward. As shown in FIG. 2, the tip opening of the suction path 83 </ b> L is branched into a large number of spot holes, and is arranged back and forth along the boundary between the regions 11 and 12 </ b> L. As shown in FIGS. 1 and 2, a slit-like gap 82 </ b> L extending in the front-rear direction is defined between the right end surface of the blowing portion 71 </ b> L and the substrate W on the installation region 11. The bottom of the gap 82L is continuous with the tip opening of the suction path 83L. The gap 82L constitutes the left suction hole of the edge suction mechanism 80. The width in the left-right direction of the suction hole 82L is extremely small and can be ignored as compared with the width in the left-right direction of the blowout portion 71L. As a result, the vicinity of the left edge of the substrate W is locally sucked.

  Similarly, the tip of the suction path 83R provided with the other flow rate adjusting means 84R reaches the upper surface of the edge on the installation area 11 side in the right installation outside area 12R of the stage 10 and is opened upward. The tip opening of the suction path 83R is branched into a large number of spot holes, and is lined up and down along the boundary between the regions 11 and 12R. A slit-shaped gap 82R extending in the front-rear direction is formed between the left end surface of the blowing portion 71R and the substrate W on the installation region 11. The bottom of the gap 82R is connected to the tip opening of the suction path 83R. This gap 82 </ b> R constitutes the right suction hole of the edge suction mechanism 80. The width in the left-right direction of the suction hole 82R is extremely small and can be ignored as compared with the width in the left-right direction of the blowout portion 71R. As a result, the vicinity of the right edge of the substrate W is locally sucked.

A method of etching the surface of the substrate W by the plasma surface processing apparatus 1 configured as described above will be described focusing on the processing of the left and right end portions of the substrate W.
As shown in FIG. 3, the substrate W to be processed is placed in the substrate placement area 11 of the stage 10 with the processing head 20 retracted, for example, to the left outside from the substrate placement area 11 of the stage 10.

  Next, as shown by the white arrow in the figure, the processing mechanism 20 is moved (scanned) in the right direction by the moving mechanism 40 (moving step). The processing head 20 is in a state of being applied to the left inert gas blowing portion 71L. Around this time, the processing gas is turned into plasma and blown out (processing gas distribution step). That is, the processing gas is introduced from the processing gas supply source 50 into the in-head gas supply path 51 of the processing head 20 and the power source 30 is driven to apply an electric field between the electrodes 31 and 31 to form an atmospheric pressure glow discharge. . Thereby, in the gas supply path 51 in the head, the processing gas is turned into plasma, and a reactive component is generated. A processing gas containing this reactive component is blown out from the blowout port 52. The blown gas is divided into left and right on the stage 10 or the inert gas blowout part 71L immediately below the blowout port 52, and left or right between the processing head 20 and the stage 10 or the inert gas blowout part 71L, respectively. It flows. The speed of the gas flow F is sufficiently larger than the scanning speed of the processing head 20. Further, the main suction source 65 starts sucking the suction paths 62L and 62R in the head. Accordingly, the gas flow FL in the left direction is sucked into the in-head suction path 62L from the left suction port 61L, and the gas flow FR in the right direction is sucked into the head suction path 62R from the right suction port 61R. Exhausted. At the same time, the left and right flow rate adjusting means 64L and 64R adjust the suction amount of each in-head suction path 62 so that it is exactly half of the processing gas supply amount.

Further, air blowing from the blowing portion 71L of the inert gas blowing mechanism 70 to the space 1SL is started (mixing process), and local suction from the suction hole 82L is started (suction process). At this time, the air flow rate adjusting means 74L adjusts the air blow amount so that it becomes a predetermined amount, and the suction flow rate adjusting means 84L adjusts the suction amount so that it is exactly equal to the air blow amount.
The processing gas flow F increases in flow rate and decreases in concentration of the reactive component as it goes downstream due to air mixing from the blow-out portion 71L.

  Eventually, as shown in FIG. 4, the outlet 52 of the processing head 20 is positioned above the left side of the inert gas outlet 71L, and the right suction port 61R is located at the left edge of the substrate W. The right gas flow FR comes into contact with the upper surface of the left edge of the substrate W, and etching of the film on the left edge of the substrate W is started by the reactive component in the gas flow R. . At this time, air is mixed from the blow-out portion 71L into a portion covering almost the entire length of the right direction gas flow FR, and the amount of air mixed into the right direction gas flow FR is maximized. Accordingly, the concentration of reactive components in the gas stream FR is minimized. As a result, it is possible to prevent the reactive component from being sent to the left edge of the substrate W with a high concentration. Further, the flow rate of the right direction gas flow FR is maximized on the right end portion of the blow-out portion 71L. Just before the right direction gas flow FR reaches the substrate W, an amount corresponding to the flow rate increase just from the suction hole 82L is obtained. Locally aspirated. Therefore, the flow rate of the right gas flow FR reaching the left edge of the substrate W is the same as the set flow rate when air is not mixed (just one-half of the blow flow rate from the blow outlet 52). This makes it possible to create a gas state (reactive component concentration change and flow rate) as if the process gas traveled on the substrate W by the distance DR while consuming the reactive component, and the left edge of the substrate W. The etching rate can be suppressed.

As shown in FIG. 5, as the processing head 20 scans to the right, the distance x1 from the outlet 52 to the right end of the outlet 71L becomes shorter, and the amount of air mixed into the right gas flow FR gradually decreases. . (The amount of air mixed into the left gas flow FR gradually increases accordingly.) Thereby, the reactive component concentration of the right gas flow FR gradually increases.
In addition, when the air blowing amount qL (−x) per unit area satisfies the above-described expression 1, the reactive component concentration of the gas flow FR that has reached the left edge of the substrate W after traveling the blowing portion 71L by the distance x1 is obtained. The size can be the same as if the distance x1 was advanced while consuming reactive components on the substrate W. The final flow rate of the gas flow FR is maintained at the set flow rate by suction from the suction hole 82L.

  The gas flow FR in this state flows from the left edge of the substrate W to the inside of the substrate by a substantially distance (DR-x1), and is sucked from the suction port 61R. As a result, a portion having a substantially width (DR-x1) including the left edge of the substrate W is etched at a suppressed rate. In addition, when the central portion of the substrate W is processed (FIG. 1), the etching is performed with an etching rate distribution (static etching amount distribution) substantially the same as the section of x = x1 to DR.

  As shown in FIG. 6, when the blowout port 52 of the processing head 20 reaches the left edge of the substrate W, the air from the blowout part 71L is mainly mixed in the leftward gas flow FL to the rightward gas flow FR. Is hardly mixed. Accordingly, the gas FR having a substantially set concentration enters the substrate from the left edge of the substrate W, and is sucked from the suction port 62R at a position advanced by the distance DR while consuming reactive components. Therefore, the width of the etched portion is approximately DR. A portion having a substantially width DR including the left end edge of the substrate W is defined as a left end portion WL of the substrate W. The etching rate distribution at the substrate left end WL at this time is substantially the same as the etching rate distribution in the right half (x = 0 to DR) immediately below the blowout port 52 when the central portion of the substrate W is processed (FIG. 1). .

After the blowout port 52 reaches the substrate W, the air blowout from the blowout hole 72L and the local suction from the suction hole 82L may be stopped.
Thereafter, the processing head 20 is further scanned in the right direction so that the gas flow FL in the left direction hits the substrate end WL. Eventually, the gas flow FL also moves to the right from the substrate end WL, and the etching for the substrate end WL is completed.

  As described above, when etching the substrate end WL, the etching rate can be suppressed by performing air blowing and local suction, and excessive etching (loading effect) can be prevented. In addition, when the air blowing amount satisfies Expression 1, the etching rate distribution can be set to the same state as that of the central portion of the substrate, and the same etching amount as that of the central portion of the substrate can be obtained. Therefore, it is possible to prevent the processing amount from becoming discontinuous between the substrate end WL and the inner portion.

  The processing head 20 is further scanned rightward. Then, as shown in FIG. 1, the processing head 20 is positioned on the central portion of the substrate W, and the central portion of the substrate W is etched.

  Before and after the processing head 20 reaches the upper side of the right end of the substrate W, air blowing from the right inert gas blowing hole 72R and local suction from the suction hole 82R are started. Eventually, the outlet 52 reaches the right edge of the substrate W as shown in FIG. At this time, almost all the air from the blowout part 71R is mixed in the rightward gas flow FR. The gas flow FL in the left direction enters the substrate from the right edge of the substrate W with substantially the set concentration, and is sucked from the suction port 62L at a position advanced by a distance DL while consuming reactive components. A portion having a substantially width DL including the right end edge of the substrate W is defined as a right end portion WR of the substrate W. The etching rate distribution of the substrate right end portion WR at this time is substantially the same as the etching rate distribution of the left half (x = −DL to 0) from directly below the blowout port 52 when the central portion of the substrate W is processed (FIG. 1). Become.

  As shown in FIG. 8, with the further rightward scan of the processing head 20, the leftward gas flow FL passes through the space 1SR on the right inert gas outlet 71R. Thereby, a part of the air from the blowing part 71R is mixed into the left gas flow FL, and it is possible to prevent the reactive component from being sent to the substrate end part WR with a high concentration. In addition, just before the leftward gas flow FL reaches the substrate end WR, the same amount of gas as the mixed air is locally sucked by the suction holes 82R, so that the flow rate of the gas flow FL sent to the substrate end WR is reduced. The set flow rate when air is not mixed (just one-half of the blow-off flow rate from the blow-out port 52) can be made the same. As a result, the etching rate at the substrate end WR can be suppressed, and excessive processing (loading effect) can be prevented.

  In addition, when the air blowing amount qR (x) per unit area from the blowing portion 71R satisfies the above equation 2, the reactivity of the gas flow FL that has reached the right end edge of the substrate W by proceeding by the distance x2 from the blowing port 52. The component concentration can be set to the same level as if the substrate x was advanced by the distance x2 while consuming reactive components.

  The gas flow FL in this state flows from the right edge of the substrate W to the inside of the substrate by a substantially distance (DL-x2), and is sucked from the suction port 61L. As a result, the portion having the substantially width (DL-x2) including the right edge of the substrate W is substantially the same as the section of x = (− x2) to (−DL) when the central portion of the substrate W is processed (FIG. 1). Etching can be performed with a similar etching rate distribution.

As shown in FIG. 9, when the left suction port 61L of the processing head 20 reaches the right edge of the substrate W, the processing gas hits only the right edge of the substrate W, and only the right edge of the substrate W is etched. Will be. At this time, air is mixed from the blowing portion 71R into a portion extending over almost the entire length of the left gas flow FL, and the concentration of the reactive component in the gas flow FL sent to the right edge of the substrate is minimized. The flow rate is kept constant by local suction from the suction hole 82R. As a result, the same gas state (reactive component concentration and flow rate) can be created as if the process gas traveled the distance DL while consuming the reactive component on the substrate W, and the etching rate is sufficiently reduced. And loading can be prevented.
Thereafter, the processing head 20 is further scanned rightward, thereby completing the etching for the substrate end WR.

Thus, when the right end portion WR of the substrate is etched, the etching rate can be suppressed by performing air blowing and local suction similarly to the left end portion WL, and excessive etching (loading effect) can be prevented. . In addition, when the air blowing amount satisfies Expression 2, the etching rate distribution can be made to be in the same state as the central portion of the substrate, and the same etching amount as that of the central portion of the substrate can be obtained. Therefore, it is possible to prevent the processing amount from becoming discontinuous between the substrate end portion WR and the inner portion thereof.
Thereby, the whole surface of the substrate W can be processed substantially uniformly. As a result, the usable area of the substrate W can be increased.

According to the surface treatment apparatus 1, it is not necessary to shorten the distance between the blowout port 52 of the processing head 20 and the suction ports 61 </ b> L and 61 </ b> R, and a sufficient distance can be secured to use up the reactive components. Thereby, the processing efficiency can be improved and the loss of the processing gas can be suppressed.
Since the amount of air mixed into the gas flows FL and FR on the side toward the substrate W can be changed by scanning the processing head 20, the entire air blowing amount in the gas blowing portions 71L and 71R should be kept constant. Good. Therefore, it is not necessary to change the operation amount of the air pressure source 75 and the flow rate adjusting means 74L with time, and the control is easy.

The present invention is not limited to the above embodiment, and various modifications can be made.
For example, the inert gas is not limited to air as long as it does not have reactivity with the object to be processed, and nitrogen or the like may be used.
The upper surfaces of the inert gas blowing parts 71L and 71R do not have to be flush with the upper surface of the substrate W, may protrude above the upper surface of the substrate W, and are lower than the upper surface of the substrate W. It may be retracted, may be the same height as the lower surface of the substrate W, or may be retracted below the lower surface of the substrate W.
The processing head 20 may be provided with only one of the left and right suction ports 61L and 61R. In this case, the inert gas blowing part 71 and the suction hole 82 should just be provided only in the opposite side to the side by which the said one suction port 61 is arrange | positioned with respect to the blowing port 52. FIG. In short, when only the left suction port 61L is provided in the processing head 20, only the right inert gas blowing portion 71R and the suction hole 82R among the left and right inert gas blowing portions 71L, 71R and the suction holes 82L, 82R. If there is. When only the right suction port 61R is provided in the processing head 20, only the left inert gas blowing portion 71L and the suction hole 82L are required.
The distance between the blowout port 52 and the left suction port 61L and the distance between the blowout port 52 and the right suction port 61R may be different from each other. In that case, it is preferable that the left and right widths of the left inert gas outlets 71L and 71R are approximately equal to or greater than the distance between the outlet 52 and the right suction port 61R. The left and right widths of the blowing portions 71L and 71R are preferably set to be substantially equal to or greater than the distance between the blowing port 52 and the left suction port 61L.
Depending on the relative position of the processing head 20, the inert gas blowing amount from the entire blowing portion 71 and the suction amount from the suction hole 82 may be variably adjusted.
The present invention is not limited to etching treatment, and can be applied to various surface treatments such as film formation, surface modification such as hydrophilicity and water repellency, ashing, and washing. The present invention is not limited to the plasma processing in which the processing gas is turned into plasma and applied to the substrate W, and can also be applied to a surface processing apparatus s other than the plasma processing such as a thermal CVD apparatus.

  The present invention can be applied to etching a silicon film on the surface, for example, in the manufacture of a flat panel glass such as a semiconductor wafer or a liquid crystal.

It is a front view which shows schematic structure of the plasma surface treatment apparatus which concerns on 1st Embodiment of this invention in the state which is processing the center part of a board | substrate. It is a top view of the stage of the said surface apparatus. It is a front view which shows the said apparatus in the state in which a process head is located in the left outer side of a board | substrate. It is a front view which shows the said apparatus in the state in which the blower outlet of a process head is located in the left outer side of a board | substrate, and the suction port of the right side is located just above the edge of the left side of a board | substrate. It is a front view which shows the said apparatus in the state which the blower outlet and right suction port of a process head are located in both sides on both sides of the left edge of a board | substrate. It is a front view which shows the said apparatus in the state in which the blower outlet of a process head is located substantially right above the left end edge of a board | substrate. It is a front view which shows the said apparatus in the state in which the blower outlet of a process head is located substantially right above the right end edge of a board | substrate. It is a front view which shows the said apparatus in the state which the suction port and blower outlet of the left side of a process head are located in both sides on both sides of the right end edge of a board | substrate. It is a front view which shows the said apparatus in the state in which the blower outlet of a process head is located in the right outer side of a board | substrate, and the left side suction port is located just above the right edge of a board | substrate. It is a top view which shows the modification of the blowing hole structure of an inert gas blowing part.

Explanation of symbols

W substrate (object to be processed)
DL, DR Predetermined distance between the blowout port and the suction port 1 Surface treatment device 1SL, 1SR Space on the side that can face the treatment head of the inert gas blowout part 2 Supply / exhaust mechanism 10 Stage 11 Installation region 12 ( 12L, 12R) Out-of-installation region 20 Processing head 21 Lower surface of processing head (surface on which blowout port and suction port are formed)
30 Power supply 31 Electrode 32 Solid dielectric layer 40 Moving mechanism 50 Processing gas supply source 51 Gas supply path 52 in the head Blowing port F (FL, FR) Processing gas flow 61 (61L, 61R) Suction port 62 (62L, 62R) Head Inner suction path 63 Head outer suction path 64 Main suction flow rate adjusting means 65 Main suction source 70 Inert gas blowing mechanism 71 (71L, 71R) Inert gas blowing section 72 (72L, 72R) Inert gas blowing hole 73 (73L, 73R) Blowing chamber 74 (74L, 74R) Inert gas blowing flow rate adjusting means 75 Air pressure source (inert gas source)
80 Edge suction mechanism 82 (82L, 82R) Suction hole 83 (83L, 83R) Suction passage 84 (84L, 84R) End suction flow rate adjusting means 85 End suction means

Claims (12)

An apparatus for processing a surface of the object to be processed by spraying a processing gas on the object to be processed,
A processing head having a surface on which a blowing port and a suction port for processing gas are formed, the suction port being arranged away from one side in one direction with respect to the blowing port;
The processing head is relative to the installation region in the one direction within a range including an area where the object to be processed is installed and an outer edge of the installation region opposite to the one side in the one direction. A moving mechanism to move,
The installation area is fixed to the object to be processed, and is disposed in an installation outside area having a width corresponding to the predetermined distance outward from the opposite edge of the installation area, and faces the processing head. An inert gas blowing section having an inert gas blowing hole for blowing the inert gas to the possible side;
A surface treatment apparatus comprising:   The end suction hole for sucking the gas on the side that can face the processing head by an amount corresponding to the blowing amount of the inert gas is formed in the non-installation area. Surface treatment equipment.   The surface treatment apparatus according to claim 2, wherein the amount of inert gas blown from the inert gas blowout hole is substantially equal to the amount of suction from the end suction hole.   The said end suction hole is arrange | positioned so that it may be pinched | interposed into the said inert gas blowing part and the said installation area | region by the edge by the side of the said installation area | region in the said non-installation area | region. The surface treatment apparatus described in 1.   The said end suction hole is defined by the edge by the side of the said installation area | region of the said inert gas blowing part, and the edge of the to-be-processed object arrange | positioned in the said installation area | region. The surface treatment apparatus as described. A width along the one direction of the inert gas blowing portion is substantially the same as or larger than the predetermined distance, and the inert gas blowing holes are distributed and arranged in the width direction of the inert gas blowing portion,
The surface treatment apparatus according to claim 4 or 5, wherein a width of the end suction hole along the one direction is so small as to be negligible with respect to a width of the inert gas blowing portion along the one direction.   The surface treatment apparatus according to claim 6, wherein the amount of inert gas blown out per unit area in the inert gas blowing unit increases as the area approaches the installation area.   The distribution along the one direction of the inert gas blowing amount per unit area correlates with the distribution along the one direction of the processing amount when the processing head is stationary with respect to the workpiece in the installation area. The surface treatment apparatus according to claim 7, wherein:   The surface treatment apparatus according to any one of claims 1 to 8, wherein the inert gas blowing section is formed of a porous member having a large number of holes serving as the inert gas blowing holes.   The surface treatment apparatus according to claim 9, wherein a surface of the porous member forming the space is substantially flush with an object to be processed on the region.   The surface treatment according to claim 1, wherein another suction port is formed on the opposite side of the suction port on the surface of the processing head from the suction port. apparatus. A method of processing a surface of the object to be processed by spraying a processing gas on the object to be processed,
A process gas distribution step of blowing out the process gas from a blow-out port and sucking it from a suction port separated in one direction with respect to the blow-out port;
A moving step of moving the outlet and the suction port relative to the object to be processed in the one direction;
A mixing step of mixing an inert gas into the processing gas from the outlet when the outlet is located outside the object to be processed in the one direction and the suction port is opposed to the end of the object to be processed. When,
A suction step of sucking the processing gas between the blowout port and the object to be processed separately from the suction port by an amount corresponding to the amount of the inert gas mixed;
The surface treatment method characterized by performing.

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