JP3647664B2 - Substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing apparatus for supplying a processing solution such as an etching solution to a substrate such as a semiconductor wafer, a glass substrate for a photomask, a glass substrate for a liquid crystal, or an optical disc substrate and performing a predetermined process on the substrate.
[0002]
[Prior art]
In a series of processing steps of a substrate such as a semiconductor wafer, there are a plurality of film forming steps for forming a thin film such as a photoresist on the surface of the substrate. The film may also be formed on the part. However, in general, it is only the surface of the substrate that needs to be formed on the substrate. If the film is formed on the back surface or the end of the surface of the substrate, contact with other devices in the subsequent step of the film forming process The thin film formed on the back surface or the surface edge of the substrate may be peeled off, which may cause a decrease in yield and trouble in the substrate processing apparatus itself.
[0003]
Therefore, in order to remove the thin film formed on the back surface or the front edge of the substrate, the following removal method is employed in the conventional substrate processing apparatus.
[0004]
First, as a first method, a masking material for a photoresist or the like is applied to the surface of the substrate, and then an etching solution is supplied to perform an etching process, whereby a thin film formed on the back surface or the surface edge of the substrate. There is something to remove. As a second method, using a single wafer processing apparatus that performs processing while rotating the substrate, a processing solution such as pure water is supplied to the surface of the substrate on the one hand, and an etching solution is supplied to the back surface of the substrate on the other hand. Some supply and remove the thin film formed on the back or front edge of the substrate.
[0005]
[Problems to be solved by the invention]
However, the method employed in the conventional substrate processing apparatus has the following problems.
First, in the conventional substrate processing apparatus, when the thin film is removed by the first method described above, the masking material is applied before the etching process is performed by supplying the etching solution, and the masking is performed after the etching process is performed. It is necessary to individually remove the material. Therefore, there is a problem that the substrate processing time including the etching process by adding the masking material application process and the masking material removal process is increased and the cost of the substrate processing apparatus itself is increased.
[0006]
Further, in the conventional substrate processing apparatus, when the thin film is removed by the second method described above, pure water is supplied to the surface of the substrate and etching solution is supplied to the back surface of the substrate at the same time. And the etching solution are mixed. Therefore, there is a problem that it becomes impossible to collect and reuse the etching solution.
[0007]
The present invention has been made in view of such circumstances, and the substrate processing time including the etching process can be shortened, the etching solution can be recovered, and the substrate is surely formed on the back surface or the edge of the substrate. An object is to provide a substrate processing apparatus capable of removing a thin film.
[0008]
[Means for Solving the Problems]
The substrate processing apparatus according to claim 1 is a substrate processing apparatus for performing a predetermined process on a substrate, wherein the substrate holding means for holding a substrate having a thin film formed on a surface thereof in a horizontal posture, and the substrate holding means are rotated. A first driving means for rotating, a rotating member having a facing surface facing the surface of the substrate held by the substrate holding means, and rotatable in a state of being separated from the surface of the substrate by a predetermined distance, and the rotating member A second driving means for rotating; an etching liquid supplying means for supplying an etching liquid to the vicinity of the rotation center of the back surface of the substrate held by the substrate holding means; and supplying a gas to the surface of the substrate held by the substrate holding means a gas supply means for said first drive means, said second drive means, said comprising control means for controlling the etching liquid supply means and the gas supply means, wherein the control means, by said first driving means While by the second driving means while being opposed to the surface of the substrate which is then rolling by rotating the rotating member, the supply of gas begins on the surface of the substrate by the gas supply means, wherein the etching in this state The etching process is performed only on the back surface and the front surface edge of the substrate by supplying the etching solution to the back surface of the substrate by the liquid supply means.
[0009]
According to the substrate processing apparatus of claim 1, the substrate in which the etching solution supply unit is held by the substrate holding unit while the substrate holding unit holding the substrate having the thin film formed on the surface is rotated by the first driving unit. An etching solution is supplied to the back surface of the substrate. At this time,
When a rotating member having a facing surface facing the surface of the substrate and spaced apart from the surface of the substrate by a predetermined distance is rotated by the second driving means, the etching liquid is removed from the back surface of the substrate by the rotation of the substrate and the rotation of the rotating member. The thin film made of photoresist or the like is removed only at the back surface of the substrate and the front surface edge of the substrate.
[0012]
The substrate processing apparatus according to claim 2 is the substrate processing apparatus according to claim 1 , wherein the substrate holding means and the rotating member are relatively moved to be held by the substrate holding means. And a third driving means for varying the distance between the surface of the rotating member and the opposing surface of the rotating member.
[0013]
According to the substrate processing apparatus of the second aspect , the substrate holding unit and the rotating member are relatively moved by the third driving unit, and the surface of the substrate held by the substrate holding unit and the opposing surface of the rotating member are If the distance is made variable, the thin film on the back surface and the front edge of the substrate is surely removed regardless of other conditions such as the number of rotations of the substrate.
[0014]
The substrate processing apparatus according to claim 3 is the substrate processing apparatus according to claim 1 or 2 , wherein when the etching solution is supplied to the back surface of the substrate by the etching solution supply means, The distance between the surface of the substrate held by the substrate holding means and the facing surface of the rotating member is in the range of 0.5 mm to 10.0 mm.
[0015]
The substrate processing apparatus according to claim 3 , wherein when the etching solution is supplied to the back surface of the substrate by the etching solution supply unit, the distance between the surface of the substrate held by the substrate holding unit and the opposing surface of the plate-like member. Since the thickness is in the range of 0.5 mm to 10.0 mm, the thin film on the back surface of the substrate and the edge of the front surface of the substrate is more reliably removed.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a longitudinal sectional view showing the overall configuration of a substrate processing apparatus according to an embodiment of the present invention.
[0017]
The hollow rotating shaft 1 is conductively connected to the motor 10 and can rotate about the vertical axis. A disc-shaped spin base 2 as a base member is integrally connected to the upper end portion of the rotating shaft 1. Near the periphery of the spin base 2, there are provided holding members 3 that hold the outer peripheral edge of a wafer W, which is a kind of substrate, at three or more locations. The wafer W is held by the holding member 3 so as to be held in a horizontal posture at a predetermined distance from the surface of the spin base 2 and rotated about the vertical axis by the rotation drive of the motor 10. ing. An apparatus for holding the wafer W above the spin base 2 like this substrate processing apparatus usually has the surface of the wafer W facing up, that is, the upper surface of the wafer W shown in FIG. It is held in such a state that it becomes the back side. The control of the rotational drive of the motor 10 is performed by the control unit 11.
[0018]
In FIG. 1, an upper surface of the wafer W held by the holding member 3 is opposed to the surface of the wafer W, and the wafer W has a larger disk shape and is shielded from the atmosphere as a rotating member. A member 20 is arranged. The atmosphere shielding member 20 is provided with a cleaning liquid supply pipe 21, and the pure water as the cleaning liquid is supplied to the vicinity of the rotation center of the wafer W held by the holding member 3 with the tip of the cleaning liquid supply pipe 21 as the cleaning liquid discharge section 30. To do. The cleaning liquid supply pipe 21 communicates with the cleaning liquid supply source 22, and an opening / closing valve 23 is provided in the middle of the cleaning liquid supply pipe 21. This on-off valve 23 controls the amount of pure water supplied to the surface of the wafer W. In addition, the atmosphere shielding member 20 is provided with a gas supply path 31 coaxially with the cleaning liquid supply pipe 21 and on the outer periphery, and the wafer W held by the holding member 3 with the distal end portion of the gas supply path 31 serving as a gas ejection port 32. A gas that becomes a purge gas such as nitrogen gas is supplied in the vicinity of the rotation center. The gas supply path 31 communicates with a gas supply source 33, and an open / close valve 34 is provided in the middle of the gas supply path 31. The on-off valve 34 controls the amount of nitrogen gas supplied to the surface of the wafer W.
[0019]
The atmosphere shielding member 20 can be rotated around the vertical axis by the motor 12 in the same manner as the rotary shaft 1. An endless belt (not shown) is stretched between the rotating shaft of the motor 12 and the illustrated pulley provided on the outer periphery of the gas supply path 31, and the rotational drive of the motor 12 is transmitted to the pulley via the endless belt. Then, the atmosphere shielding member 20 rotates. Further, the atmosphere shielding member 20 moves up and down with respect to the wafer W held on the holding member 3 of the spin base 2 by the driving mechanism 13 as shown by an arrow A in FIG. And the surface of the wafer W can be changed. Note that the control of the rotation drive of the motor 12 and the drive control of the drive mechanism 13 are performed by the control unit 11.
[0020]
The hollow portion of the rotating shaft 1 is provided with a processing liquid supply pipe 5 coaxially with the rotating shaft 1 and on the inner periphery thereof. The processing liquid supply pipe 5 is further provided with an etching liquid supply pipe 5A and a cleaning liquid supply pipe 5B. It is branched to.
[0021]
The etching solution supply pipe 5A communicates with an etching solution supply source 41, and an opening / closing valve 42 is provided in the middle of the etching solution supply pipe 5A. The on-off valve 42 controls the amount of etching solution supplied to the back surface of the wafer W. The etching solution is supplied from the etching solution supply source 41 to the back surface of the wafer W from the processing solution discharge unit 6 through the etching solution supply pipe 5 </ b> A and the processing solution supply pipe 5.
[0022]
The cleaning liquid supply pipe 5B communicates with the cleaning liquid supply source 43, and an opening / closing valve 44 is provided in the middle of the cleaning liquid supply pipe 5B. The on-off valve 44 controls the supply amount of pure water as a cleaning liquid to the back surface of the wafer W. The pure water is supplied from the cleaning liquid supply source 43 to the back surface of the wafer W from the processing liquid discharge section 6 through the cleaning liquid supply pipe 5B and the processing liquid supply pipe 5. The opening / closing control of the opening / closing valve 42, that is, the control of discharging and stopping the etching liquid from the processing liquid discharge unit 6 to the back surface of the wafer W, and the opening / closing control of the opening / closing valve 44, that is, the control of the wafer W The control of the discharge of pure water to the back surface and the stop thereof is performed by the control unit 11.
[0023]
In addition, a gas supply path 7 is formed in a space between the inner peripheral surface of the hollow portion of the rotating shaft 1 and the processing liquid supply pipe 5, and a wafer held by the holding member 3 with the distal end portion serving as a gas outlet 8. A gas serving as a purge gas such as nitrogen gas is supplied to the space 9 between the back surface of W and the upper surface of the spin base 2. The gas supply path 7 communicates with a gas supply source 45, and an opening / closing valve 45 is provided in the middle of the gas supply path 5. The on-off valve 45 controls the amount of nitrogen gas jetted onto the back surface of the wafer W. Then, the nitrogen gas is supplied from the gas supply source 45 to the back surface of the wafer W from the gas ejection part 8 through the gas supply path 7. The controller 11 performs opening / closing control of the opening / closing valve 46, that is, adjustment control of the ejection amount from the gas ejection port 8.
[0024]
An umbrella-shaped blocking member 50 is detachably attached to the distal end portion of the processing liquid supply pipe 5, and a central portion of the upper end of the blocking member 50 serves as the processing liquid discharge unit 6. The blocking member 50 includes a flange portion 51 that covers the upper side of the gas ejection port 8, and the upper surface of the flange portion 51 is lowered from the peripheral portion of the processing liquid discharge portion 6 to the peripheral portion of the flange 51. It is inclined.
[0025]
The nitrogen gas ejected from the gas ejection port 8 is formed between the rear surface of the wafer W and the upper surface of the spin base 2 held by the retaining member 3 from the gap between the flange portion 51 of the blocking member 50 and the upper surface of the spin base 2. It is conceivable that the nitrogen gas is difficult to be supplied near the rotation center of the wafer W. Therefore, an adjustment hole (not shown) for adjusting the direction of nitrogen gas jetted from the gas jetting port 8 to the vicinity of the rotation center of the back surface of the wafer W is formed in the flange portion 51 of the blocking member 50. As a result, the nitrogen gas ejected from the gas ejection port 8 is supplied to the space 9 from the gap and the adjustment hole described above.
[0026]
The control unit 11 controls the motor 10, the motor 12, the drive mechanism 13, the on-off valves 23, 34, 42, 44, 46, etc., and etches, cleans and dries the wafer W as will be described later. Substrate processing including processing is performed.
[0027]
Next, a substrate processing operation including an etching process, a cleaning process, a drying process, and the like of the substrate processing apparatus according to an embodiment of the present invention will be described. FIG. 2 is a flowchart illustrating the substrate processing operation of the substrate processing apparatus.
[0028]
First, the holding member 3 holds the wafer by loading the wafer W into the substrate processing apparatus by a substrate transfer mechanism (not shown) and placing the wafer W on the holding member 3 (step S1). At this time, the atmosphere blocking member 20 is retracted above the spin base 2. Next, the control unit 11 controls the motor 10 to rotate the spin base 2 at a rotational speed of 100 rpm to 1500 rpm, thereby starting the rotation of the wafer W (step S2). As the wafer W rotates, the control unit 11 controls the drive mechanism 13 to lower the atmosphere shielding member 20 in the retracted state (step S3). 3A is a state when the atmosphere shielding member 20 is lowered, and the distance between the lower surface of the atmosphere shielding member 20 and the surface of the wafer W at this time is 0.5 mm to 10. Set to 0 mm. This is because if the distance is less than 0.5 mm, the lower surface of the atmosphere shielding member 20 is too close to the surface of the wafer W, adversely affecting the thin film on the surface of the wafer W, and if the distance is more than 10.0 mm, This is because the effect of the atmosphere shielding member 20 is lost.
[0029]
The control unit 10 controls the motor 12 to rotate the atmosphere shielding member 20 at a rotational speed in a range substantially the same as the rotational speed of the spin base 2, that is, a rotational speed of 100 rpm to 1500 rpm (step S4). Next, the controller 11 opens the on-off valve 34 provided in the gas supply path 31 and starts supplying nitrogen gas from the gas outlet 32 to the vicinity of the rotation center of the surface of the wafer W (step S5). . The supplied nitrogen gas flows from the vicinity of the rotation center of the wafer W between the lower surface of the atmosphere shielding member 20 and the surface of the wafer W to the outer peripheral end as the atmosphere shielding member 20 and the wafer W rotate. .
[0030]
In this state, the control unit 11 controls the on-off valve 42 to be in an open state, and performs an etching process by supplying an etching solution from the processing solution discharge unit 6 to the vicinity of the rotation center on the back surface of the wafer W (step S6). As the wafer W rotates, the supplied etching solution flows in the space 9 between the upper surface of the spin base 2 and the back surface of the wafer W from the vicinity of the rotation center of the back surface of the wafer W to the outer peripheral edge. Further, a part of the etching solution that has come out from the outer peripheral edge of the wafer W slightly rises from the position of the wafer W held by the holding member 3 as the spin base 2 rotates. However, since the atmosphere shielding member 20 is also rotating, and the nitrogen gas flows from the vicinity of the rotation center of the wafer W between the lower surface of the atmosphere shielding member 20 and the surface of the wafer W to the outer peripheral end, the etching solution Does not enter between the lower surface of the atmosphere shielding member 20 and the surface of the wafer W, and flows as shown by an arrow B in FIG. Only is removed. When the etching process is performed for a predetermined period, the control unit 11 closes the on-off valve 42 and ends the etching process.
[0031]
When the etching process for the wafer W is completed, the controller 11 opens the on-off valve 23 and the on-off valve 44 to perform the cleaning process on the front and back surfaces of the wafer W (step S7). First, when the on-off valve 23 is opened, pure water is supplied from the cleaning liquid discharge unit 30 to the vicinity of the rotation center of the surface of the wafer W. The supplied pure water flows from the vicinity of the rotation center of the wafer W between the lower surface of the atmosphere shielding member 20 and the surface of the wafer W to the outer peripheral end as the atmosphere shielding member 20 and the wafer W rotate. . Thereby, the surface of the wafer W is cleaned. Further, when the on-off valve 44 is opened, pure water is supplied from the processing liquid discharge port 6 to the vicinity of the rotation center on the back surface of the wafer W. The supplied pure water flows from the vicinity of the center of rotation of the wafer W in the space 9 between the upper surface of the spin base 2 and the back surface of the wafer W to the outer peripheral edge as the spin base 2 and the wafer W rotate. Go. Thereby, the cleaning process of the back surface of the wafer W is performed. When the cleaning process is performed for a predetermined period, the control unit 11 closes the on-off valve 23 and the on-off valve 44 and ends the cleaning process.
[0032]
When the cleaning process of the wafer W is completed, the control unit 11 opens the on-off valve 46 provided in the gas supply path 7 and opens the flange 51 and the spin base 2 from the gas outlet 8 to the vicinity of the rotation center on the back surface of the wafer W. Nitrogen gas is supplied through a gap with the upper surface of the substrate and an adjustment hole not shown. The supplied nitrogen gas flows from the vicinity of the rotation center of the wafer W between the lower surface of the atmosphere shielding member 20 and the surface of the wafer W to the outer peripheral end as the atmosphere shielding member 20 and the wafer W rotate. . At this time, since the nitrogen gas is continuously supplied to the vicinity of the rotation center of the front surface of the wafer W from step S5 described above, the nitrogen gas is supplied to the front and back surfaces of the wafer W, and the rotation of the wafer W is also performed. Along with this, drying processing of the front and back surfaces of the wafer W is performed (step S8). When the drying process is performed for a predetermined period, the control unit 11 closes the on-off valves 34 and 46 (step S9), and the wafer W drying process is completed.
[0033]
When the drying process of the wafer W is completed, the control unit 11 controls the motor 12 to stop the rotation of the atmosphere shielding member 20 (step S10). As the atmosphere shielding member 20 stops rotating, the control unit 11 controls the drive mechanism 13 to raise the atmosphere shielding member 20 (step S11). Next, the control unit 11 stops the rotation of the wafer W by controlling the motor 11 to stop the rotation of the spin base 2 (step S12). Finally, the wafer W held on the holding member 3 is carried out of the substrate processing apparatus by the substrate transfer mechanism (step S13). Thus, a series of substrate processing operations of the substrate processing apparatus is completed.
[0034]
In the substrate processing apparatus according to the present invention, when the etching solution is supplied to the vicinity of the rotation center of the back surface of the wafer W to perform the etching process, the etching solution that has come out from the outer peripheral edge of the wafer W As the base 2 rotates, it slightly rises from the position of the wafer W held by the holding member 3. However, since the atmosphere shielding member 20 is rotated simultaneously with the rotation of the spin base 2, the etching solution is shielded from the atmosphere. Without entering between the lower surface of the member 20 and the front surface of the wafer W, it is possible to remove only the thin film on the back surface of the wafer W and the front edge portion of the wafer W.
[0035]
Further, when performing the etching process, the nitrogen gas supplied from the gas outlet 32 to the vicinity of the rotation center of the surface of the wafer W causes the lower surface of the atmosphere shielding member 20 to move along with the rotation of the atmosphere shielding member 20 and the wafer W. Flows from the vicinity of the center of rotation of the wafer W to the outer peripheral edge. The flow of the nitrogen gas can prevent the etching solution from entering between the lower surface of the atmosphere shielding member 20 and the surface of the wafer W.
[0036]
Further, since the atmosphere shielding member 20 is movable in the vertical direction with respect to the wafer W held on the holding member 3 of the spin base 2 by the driving mechanism 13, other conditions such as a change in the number of rotations of the wafer W are changed. If the distance between the lower surface of the atmosphere shielding member 20 and the front surface of the wafer W is changed in accordance with the above, the thin film on the back surface and front surface edge of the wafer W can be surely removed regardless of the rotation speed of the wafer W. it can. In particular, if the distance between the lower surface of the atmosphere shielding member 20 and the surface of the wafer W during the etching process is set to 0.5 mm to 10.0 mm, the thin film on the back surface and the front edge of the wafer W is formed. Removal can be performed more reliably.
[0037]
Note that nitrogen gas is supplied from the gas outlet 32 to the center of the surface of the wafer W while the atmosphere shielding member 20 is rotated, and etching is performed by supplying an etching solution near the center of rotation of the back surface of the wafer W. The processing time required for the etching process can be shorter than that used in the conventional substrate processing apparatus.
[0038]
Also, the cleaning process for cleaning the wafer W step S7, since the etching process of removing a thin film of the back surface and the top surface and edge of the wafer W is carried out in separate steps as such step S6, and pure as a cleaning solution If separation and recovery from the etching solution is performed, the etching solution can be reused.
[0039]
In the embodiment described above, the rotation speed of the spin base 2 and the rotation speed of the atmosphere shielding member 20 are set in the range of 100 rpm to 1500 rpm, but the present invention is not limited to this range. Further, the rotation speed of the spin base 2 and the rotation speed of the atmosphere shielding member 20 may be changed in the etching process in step S6, the cleaning process in step S7, and the drying process in step S8, respectively.
[0040]
【The invention's effect】
According to the substrate processing apparatus of claim 1, when the etching solution supply unit supplies the etching solution to the back surface of the substrate held by the substrate holding unit, the rotating member is separated from the surface of the substrate by a predetermined distance. Since the etching liquid is supplied only to the back surface of the substrate and the front surface edge of the substrate, the thin film can be removed only from the back surface of the substrate and the front surface edge of the substrate. Further, the substrate processing time including the etching process can be shortened, the etching solution can be collected, and the thin film formed on the back surface or the end of the substrate can be surely removed.
[0042]
According to the substrate processing apparatus of the second aspect , the substrate holding unit and the rotating member are relatively moved by the third driving unit, and the surface of the substrate held by the substrate holding unit and the opposing surface of the rotating member are If the distance is made variable, the thin film on the back and front end portions of the substrate can be removed regardless of other conditions such as the number of rotations of the substrate.
[0043]
According to the substrate processing apparatus of the third aspect , when the etching solution is supplied to the back surface of the substrate by the etching solution supply unit, the surface of the substrate held by the substrate holding unit and the opposing surface of the rotating member Since the distance is in the range of 0.5 mm to 10.0 mm , it is possible to more reliably remove the thin film on the back surface of the substrate and the edge portion of the front surface of the substrate.
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view showing an overall configuration of a substrate processing apparatus according to an embodiment of the present invention.
FIG. 2 is a flowchart illustrating a substrate processing operation of the substrate processing apparatus.
FIG. 3 is a diagram for explaining a state of etching of a wafer in a substrate processing operation of the substrate processing apparatus.
[Explanation of symbols]
2 Spin base 3 Holding member 5 Processing liquid supply pipe 5A Etching liquid supply pipe 5B Cleaning liquid supply pipe 6 Processing liquid discharge part 10 Motor 12 Motor 13 Drive mechanism 20 Atmosphere shielding member 31 Gas supply pipe 32 Gas outlet 33 Gas supply pipe 34 Opening and closing Valve 41 Etching solution supply source 42 On-off valve W Wafer

Claims (3)

A substrate processing apparatus for performing predetermined processing on a substrate,
Substrate holding means for holding a substrate having a thin film formed on the surface in a horizontal posture;
First driving means for rotating the substrate holding means;
A rotating member having a facing surface facing the surface of the substrate held by the substrate holding means, and rotatable in a state spaced apart from the surface of the substrate by a predetermined distance;
Second driving means for rotating the rotating member;
An etchant supply means for supplying an etchant near the rotation center of the back surface of the substrate held by the substrate holding means;
Gas supply means for supplying gas to the surface of the substrate held by the substrate holding means;
Control means for controlling the first drive means, the second drive means, the etchant supply means, and the gas supply means;
With
The control means allows the gas supply means to gas the surface of the substrate while rotating the rotating member by the second driving means in a state of being opposed to the surface of the substrate being rotated by the first driving means. The substrate processing apparatus is characterized in that, in this state, the etching solution is supplied to the back surface of the substrate by the etching solution supplying means, so that only the back surface and the front surface edge of the substrate are etched. The substrate processing apparatus according to claim 1,
The apparatus further comprises third driving means for moving the substrate holding means and the rotating member relatively to vary the distance between the surface of the substrate held by the substrate holding means and the opposing surface of the rotating member. A substrate processing apparatus. The substrate processing apparatus according to claim 1 or 2, wherein
When the etching solution is supplied to the back surface of the substrate by the etching solution supply means, the distance between the surface of the substrate held by the substrate holding means and the facing surface of the rotating member is 0.5 mm to 10.0 mm. A substrate processing apparatus, characterized by being in the range.

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