JP3697139B2 - Substrate processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a substrate processing apparatus for processing a substrate such as a semiconductor substrate or a glass substrate for liquid crystal.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a substrate processing apparatus for processing a substrate such as a semiconductor substrate by immersing it in a processing solution in a processing tank is known. As such an apparatus, for example, an apparatus disclosed in Japanese Patent No. 2739419 is known. is there.
[0003]
This apparatus is provided with a water supply pipe for supplying pure water into the treatment tank, and a plurality of chemical liquid supply pipes respectively connected to different chemical liquid tanks are joined to the water supply pipe. During the treatment, the chemical solution is alternatively supplied to (combined with) the pure water in the water supply pipe through the chemical solution supply pipe and supplied to the treatment tank while preparing the chemical solution with a predetermined concentration, or the supply of the chemical solution is stopped. By supplying only pure water to the processing tank, the chemical liquid and pure water (hereinafter referred to as processing liquid) are overflowed while being stored in the processing tank.
[0004]
In this apparatus, as described above, the chemical solution is supplied to pure water to prepare a chemical solution with a predetermined concentration. Therefore, if the flow rate of pure water is unstable, a chemical solution with a desired concentration cannot be prepared, and stable treatment can be expected. Absent. In addition, when the flow rate of pure water varies, the flow rate of the treatment liquid in the treatment tank varies, which may adversely affect the in-plane uniformity of the substrate.
[0005]
For this reason, normally, a flow rate adjusting valve is provided in the water supply pipe upstream of the joint portion of the chemical liquid supply pipe, so that the flow rate of pure water supplied through the water supply pipe is kept constant.
[0006]
[Problems to be solved by the invention]
By the way, the substrate processing conditions differ depending on the type of substrate, and there are cases where it is desired to change the flow rate of pure water if the type of substrate is different. For example, depending on the type of substrate, the flow rate of the processing liquid may affect the processing speed. In such a case, the flow rate of the processing liquid in the processing tank is changed by changing the flow rate of pure water for each substrate. It is desirable to have a speed suitable for the substrate. In some cases, pure water with different temperatures may be selectively supplied depending on the type of substrate. In such a case, it is necessary to change the flow rate according to the temperature of the supplied pure water. There is.
[0007]
Therefore, in order to meet such a demand, for example, a plurality of parallel branch passages are provided in the water supply pipe upstream of the joint portion of the chemical solution supply pipe, and an opening / closing valve and a flow rate adjusting valve are provided in each branch passage. At the same time, it is conceivable to set the flow rate set by the flow rate adjusting valve to a different flow rate for each branch path and to change the flow rate by passing pure water selectively through the branch path.
[0008]
However, in this configuration, the water supply pipe, which is the main pipe of the treatment liquid supply system, needs to have a branch structure, and each branch path must be provided with a flow control valve, etc. It is disadvantageous. In particular, in an apparatus that includes a plurality of treatment tanks and branches a water supply pipe to connect to each treatment tank, the configuration for adjusting the flow rate as described above is required for each treatment tank. There is a problem that the liquid supply system becomes more complicated and the occupied space increases.
[0009]
The present invention has been made to solve the above problems, and while supplying the flow rate of the processing liquid supplied through the processing liquid supply pipe at a set constant flow rate, the set flow rate is simple, and An object of the present invention is to provide a substrate processing apparatus that can be changed with an inexpensive configuration.
[0010]
[Means for Solving the Problems]
In order to solve the above-described problems, the present invention provides a substrate processing unit that includes a substrate processing unit for processing a substrate and a processing liquid supply pipe that is connected to a processing liquid supply source and supplies the processing liquid to the substrate processing unit. In the apparatus, the processing liquid supply pipe is provided with a flow rate adjusting valve for adjusting the flow rate of the processing liquid in accordance with the pilot pressure given through the pilot pipe, and adjusting means for adjusting the pilot pressure in the pilot pipe. Further, as this adjusting means, a plurality of branch portions parallel to the pilot pipe are provided, and on each branch portion, an on-off valve and a pressure adjusting valve capable of adjusting the pilot pressure to a constant pressure are provided. The adjustment pressure value by the pressure adjustment valve at the branching portion is set to a different value (claim 1).
[0011]
According to this apparatus, when the opening / closing valve of each branching portion is selectively opened, the pilot pressure adjusted by the pressure adjusting valve of the corresponding branching portion of the opening / closing valve is adjusted to the flow rate adjustment of the processing liquid supply pipe. Given to the valve. Then, the flow rate of the processing liquid is changed according to the adjustment of the pilot pressure applied to the flow rate adjusting valve. After the change, the flow rate is maintained and the stable supply of the processing liquid is performed. For this reason, the processing liquid supply pipe can be changed in flow rate with a simple configuration in which a flow rate adjusting valve is interposed.
[0016]
In addition, for example, in an apparatus of a type that stores a processing liquid in a processing tank and performs processing while overflowing the processing liquid in a state where the substrate is immersed therein, the temperature of the processing liquid is changed depending on the type of the substrate. In this case, it may be preferable to change the flow rate of the processing liquid in the processing tank according to the temperature of the processing liquid. Therefore, in such a case, the adjusting means is configured so that the pilot pressure can be adjusted to a plurality of pressure values corresponding to the temperature of the processing liquid (claim 2 ), thereby changing the flow rate. The flow rate of the processing liquid in the processing tank may be adjusted according to the temperature of the processing liquid.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0018]
FIG. 1 schematically shows an embodiment of a substrate processing apparatus according to the present invention. The substrate processing apparatus 10 shown in this figure is a so-called one-bath type substrate that performs surface treatment by immersing a substrate such as a semiconductor wafer in this processing solution while sequentially storing various chemical solutions and pure water in a single processing tank. The processing apparatus includes a processing tank 12 as a substrate processing unit and a processing liquid supply / discharge system for the processing tank 12.
[0019]
The processing tank 12 is formed in a box shape having a rectangular cross section, for example, and a liquid receiving portion 12a is provided around the opening, and the whole is made of, for example, PTFE (polytetrafluoroethylene), PVDF (vinylidene fluoride), or the like. Consists of materials with excellent erosion resistance.
[0020]
A water supply pipe 14 (treatment liquid supply pipe) and a drainage pipe 16 constituting a treatment liquid supply / discharge system are connected to the treatment tank 12, respectively.
[0021]
Although the illustration of the water supply pipe 14 is omitted, for example, the upstream end side of the water supply pipe 14 is branched into two via a switching valve, and each is connected to a separate pure water storage tank (treatment liquid supply source) via a mechanical pump. ing. Each storage tank stores pure water at different temperatures, for example, room temperature and slightly higher temperature pure water, and is configured to supply either one of the pure water according to the operation of the switching valve. ing.
[0022]
On the other hand, the downstream end side of the water supply pipe 14 is connected to the bottom of the processing tank 12 and communicates with the processing tank 12, and on the downstream side of the switching valve, a flow rate adjusting valve 20, a flow meter 22 and a three-way valve. 24 is provided in order from the upstream side. Moreover, between the flowmeter 22 and the three-way valve 24, the chemical solution supply pipes 28a to 28c are connected to the water supply pipe 14 in a state where they are arranged in a line. The chemical liquid supply pipes 28a to 28c reach the chemical liquid tanks 26a to 26c storing different types of chemical liquids on the upstream end sides, respectively, and open / close valves 29a to 29c are interposed in the middle thereof. That is, when one of the opening / closing valves 29a to 29c is alternatively opened or a plurality of required ones are simultaneously opened, the chemical solution is mixed into the pure water fed through the water supply pipe 14, and the chemical solution with a predetermined concentration is supplied. While being prepared and fed to the treatment tank 12, when all the open / close valves 29 a to 29 c are closed, only pure water is fed to the treatment tank 12.
[0023]
In the present embodiment, the flow rate adjusting valve 20 is a pilot pressure type flow rate adjusting valve using air pressure, and the upstream side (hereinafter referred to as the primary side) pressure fluctuation or the like connected to the pure water storage tank. The flow rate of pure water supplied through the water supply pipe 14 is maintained at a constant flow rate corresponding to the pilot pressure.
[0024]
The pilot pressure supply system for the flow rate adjusting valve 20 has a pilot pipe 30 whose upstream side is connected to a compressor (not shown) as shown by a broken line in FIG. In the middle of the pilot pipe 30, branch portions 32a and 32b are provided in parallel as shown in the figure, and regulators (pressure reducing valves) 34a and 34b are provided in the branch portions 32a and 32b in order from the upstream side. Pressure gauges 36a and 36b and on-off valves 38a and 38b are interposed.
[0025]
The pressure reduction values by the regulators 34a and 34b are set to different values, and the pilot pressure applied to the flow rate adjusting valve 20 is switched by selectively opening and closing the on-off valves 38a and 38b. Yes. In addition, the pressure reduction value by each regulator 34a, 34b is set to the value corresponding to the temperature of pure water. That is, it is set so that pure water is supplied at a predetermined flow rate preset for each temperature.
[0026]
Here, the configuration of the flow rate adjustment valve 20 interposed in the water supply pipe 14 will be described.
[0027]
FIG. 2 is a schematic cross-sectional view showing the flow rate adjusting valve 20. The flow rate adjusting valve 20 shown in this figure is a general pilot pressure type flow rate adjusting valve, and has a pure water flow path 42 extending in the vertical direction (up and down in the figure), and communicates with the flow path 42. The ports 44 and 46 on the inlet side and the outlet side that are offset vertically are provided on both the left and right sides (left and right in the figure), and the water supply pipe 14 is connected to these ports 44 and 46.
[0028]
As will be described later, a valve body 48 is supported in the flow path 42 so as to be displaceable in the vertical direction, and has a circular cross section formed in the middle of the conical portion 48 c formed in the valve body 48 and the flow path 42. An orifice 56 is formed by the throttle portion 42c.
[0029]
Further, a valve body lower housing chamber 42a that houses the lower part 48a of the valve body 48 is formed below the flow path 42, and a valve body upper part housing the upper part 48b of the valve body 48 is placed above the flow path 42. A chamber 42b is formed. The lower portion 48a of the valve body 48 is supported by the lower diaphragm 50a in a flange-supporting manner in the valve-body lower housing chamber 42a, while the upper portion 48b is supported in the valve-body upper housing chamber 42b by the upper diaphragm 50b in a flange-supporting manner. It is supported. Thereby, the valve body 48 is supported in the flow path 42 so as to be displaceable in the vertical direction.
[0030]
The lower diaphragm 50a divides the valve body lower housing chamber 42a up and down to form an inlet-side fluid pressure acting space 51a that faces the flow path 42 above the diaphragm 50a, while the lower diaphragm 50a has a lower portion below the diaphragm 50a. A lower pilot pressure acting space 52a communicating with the pilot pipe 30 through the port 54a is formed. Further, the upper diaphragm 50b also divides the valve body upper accommodating chamber 42b vertically, and forms an outlet side fluid pressure acting space 51b facing the flow path 42 below the diaphragm 50b, while the upper port is located above the diaphragm 50b. An upper pilot pressure acting space 52b communicating with the pilot pipe 30 via 54b is formed.
[0031]
Then, as shown in FIG. 2, the upper valve body accommodating chamber 42b is formed wider (larger in diameter) than the lower valve body accommodating chamber 42a, whereby the upper diaphragm 50b and the valve body 48 in the upper pilot pressure acting space 52b. The air pressure receiving area is configured to be larger than the air pressure receiving area of the lower diaphragm 50a and the valve body 48 in the lower pilot pressure acting space 52a, and the upper side in the outlet side fluid pressure acting space 51b. The pressure-receiving area of the pure water of the diaphragm 50b and the valve body 48 is configured to be larger than the pressure-receiving area of the pure water of the lower diaphragm 50a and the valve body 48 in the inlet-side fluid pressure acting space 51a.
[0032]
In this configuration, when pure water is supplied through the inlet side port 44 and air pressure is applied through both ports 54a and 54b, the force that pushes down the valve body 48 by the pressure of pure water before passing through the orifice 56, after passing through the orifice 56 net force pushing up the valve body 48 by the pressure of the water, the force to push up the valve body 48 by the air pressure supplied to the lower side of the pilot pressure acting space 52a, the valve by the air pressure supplied to the upper side of the pilot pressure acting space 52b of force pushing down the body 48, both diaphragms 50a and its own weight and the elastic deformation of the valve body 48, but the restoring force of 50b acts on the valve body 48, the upper side of the pressure receiving area of the air pressure, such as lower diaphragm 50a as described above Since the pressure receiving area of the air pressure of the diaphragm 50b or the like is set larger, this can be achieved with pure water and air pressure applied. Increasing the air pressure gradually, the force pushing down the valve body 48 increases with increasing air pressure, and as a result, the valve element 48 is balanced at a predetermined position displaced downward.
[0033]
In other words, when the air pressure is gradually increased, the area of the orifice gradually increases and the flow rate of pure water from the port 46 on the outlet side increases, so the air pressure at the time when the required flow rate is obtained is set as a predetermined pilot pressure. Keep it.
[0034]
If the predetermined pilot pressure is applied in this way, even if the pressure fluctuation occurs in the pure water on the primary side thereafter, the flow rate control valve 20 operates as follows to maintain the flow rate constant. That is, for example, when the pressure on the primary side increases, as described above, the upper diaphragm 50b or the like in the outlet side fluid pressure acting space 51b has a larger pressure receiving area than the pure water in the lower diaphragm 50 or the like in the inlet side fluid pressure acting space 51a. Due to the large pressure receiving area of pure water, an increase in force that displaces the valve body 48 upward in the outlet-side fluid pressure acting space 51b displaces the valve body 48 downward in the inlet-side fluid pressure acting space 51a. As a result, the valve body 48 is displaced upward, the area of the orifice 56 is reduced, and the pure water flow rate at the outlet port 46 is maintained at a constant flow rate corresponding to the pilot pressure. Will be. On the other hand, when the pressure on the primary side decreases, the valve body 48 is displaced downward to enlarge the area of the orifice 56, and the pure water flow rate at the outlet side port 46 is maintained at a constant flow rate corresponding to the pilot pressure. Will be.
[0035]
The pilot pressure is set for each desired flow rate, so that the pilot pressure corresponding to each flow rate can be set.
[0036]
On the other hand, as shown in FIG. 1, the upstream end side of the drain pipe 16 is connected to the liquid receiving part 12a of the processing tank 12, while the downstream end side thereof is connected to a waste liquid tank not shown. Further, the drain pipe 16 is provided with a branch pipe 16 a in the middle thereof, and this branch pipe 16 a is connected to the three-way valve 24 of the water supply pipe 14. That is, while introducing pure water overflowing from the processing tank 12 to the liquid receiving portion 12a or chemical liquid (hereinafter referred to as processing liquid unless otherwise specified) into the waste liquid tank through the drain pipe 16, for example, the processing tank 12 When it is necessary to discharge all of the processing liquid in the wastewater, the processing liquid in the processing tank 12 is drained through the water supply pipe 14, the three-way valve 24, the branch pipe 16a and the drain pipe 16 by switching the three-way valve 24. It is designed to be introduced into the tank.
[0037]
In the substrate processing apparatus 10 configured as described above, for example, all the open / close valves 29a to 29c are first closed, and only the pure water is fed to the treatment tank 12 through the water supply pipe 14 and overflowed to the liquid receiving portion 12a. It is done. As a result, an upward flow of pure water is formed in the processing bath 12, and the substrate W is immersed in the processing bath 12 in this state, whereby the substrate W is subjected to a water washing process. At this time, the switching valve of the water supply pipe 14 is operated according to the type of the substrate W, and pure water having a temperature suitable for the substrate W is supplied through the water supply pipe 14. Further, the corresponding one of the on-off valve 38a and the on-off valve 23b of the pilot pipe 30 is opened so that the supplied pure water has a flow rate corresponding to the temperature of the pure water. As a result, a pilot pressure corresponding to the temperature of the pure water supplied is applied to the flow rate adjusting valve 20, and the pure water is supplied to the treatment tank 12 at a constant flow rate corresponding to the temperature of the pure water.
[0038]
After the water washing process is performed for a certain time in this way, next, one of the opening / closing valves 29a to 29c of the opening / closing valves 29a to 29c is opened, and the chemical solution is introduced into the water supply pipe 14 to prepare a chemical solution with a predetermined concentration. It is fed to the treatment tank 12. As a result, the substrate W is treated with the chemical solution. At this time, the concentration of the chemical solution is maintained at a predetermined concentration by keeping the flow rate of pure water constant by the action of the flow rate adjusting valve 20.
[0039]
Thus, thereafter, the opening / closing valves 29a to 29c are alternately opened sequentially, whereby different processing liquids are supplied into the processing tank 12, whereby the substrate W is sequentially processed with a plurality of types of processing liquids. The At this time, the chemical solution is continuously supplied to the processing tank 12 and overflows to the liquid receiving portion 12a, so that the processing residue is led out of the processing tank 12.
[0040]
When the processing with all the processing liquids is completed, only pure water is again supplied to the processing tank 12 and the substrate W is subjected to the water cleaning process. When the water cleaning process is performed for a certain time, the pure water to the processing tank 12 is purified. The supply of water is stopped, the substrate W is taken out of the processing tank 12, and the processing of the substrate W by the substrate processing apparatus 10 is completed.
[0041]
According to the substrate processing apparatus 10 described above, the flow rate of pure water supplied through the water supply pipe 14 is maintained at a constant flow rate set by the flow rate adjusting valve 20, so that it is supplied to the processing tank 12. In addition, it is possible to stably supply pure water by preventing fluctuations in the flow rate of pure water, and to change the set flow rate by the flow rate adjusting valve 20 in accordance with the temperature of the supplied pure water. Therefore, pure water can be supplied at an optimum flow rate corresponding to the temperature for processing.
[0042]
Moreover, since the flow rate of the pure water is changed by switching the pilot pressure applied to the flow rate adjusting valve 20 as described above, the configuration of the water supply pipe 14 itself that is the main pipe of the treatment liquid supply system is not complicated. The flow rate of pure water can be changed. Therefore, the occupied space of the processing liquid supply / discharge system is not increased, and the flow rate of pure water can be changed with an inexpensive configuration.
[0043]
In the configuration of the substrate processing apparatus 10, the flow rate of pure water can be changed with the simple configuration of the water supply pipe 14 as described above, but the pressure change is applied to the pilot pressure supply system for the flow rate adjustment valve 20. In order to incorporate the configuration for enabling, there is a concern that the configuration of the supply system becomes complicated, resulting in an increase in occupied space and an increase in cost. However, the pilot pressure supply system has a very small pipe diameter compared to the pure water supply system, and the valves and the like can be accommodated with a small size, so the pilot pressure supply system has a slightly more complicated configuration. However, for example, the configuration described in the prior art, that is, a plurality of parallel branch passages are provided in the water supply pipe, and an open / close valve and a flow rate adjustment valve are provided in each branch passage, so that the branch passage is alternatively selected. Compared to a configuration in which the flow rate is changed by passing pure water, the influence in terms of occupied space and cost is extremely small.
[0044]
By the way, the substrate processing apparatus 10 is an embodiment of the substrate processing apparatus according to the present invention, and its specific configuration can be appropriately changed without departing from the gist of the present invention.
[0045]
For example, in the substrate processing apparatus 10, as adjustment means according to the present invention, branch portions 32 a and 32 b parallel to the pilot pipe 30 are provided, and regulators 34 a and 34 b and on-off valves 38 a and 38 b are provided in these branch portions 32 a and 32 b, respectively. 38b is provided, and the pilot pressure is switched between two types of pressure by selectively opening and closing the on-off valves 38a and 38b according to the temperature of the pure water to be supplied. When there are three or more types of water temperature, a branch portion may be further added to the pilot pipe 30 so that more different pressures can be set.
[0047]
Furthermore, in the said substrate processing apparatus 10, although the structure of this invention is employ | adopted only about the supply system of a pure water, you may make it employ | adopt this invention also about the supply system of a chemical | medical solution, for example. That is, a pilot pressure type flow rate adjusting valve may be further provided in the chemical solution supply pipes 28a to 28c so that the pilot pressure for each flow rate adjusting valve can be changed. In this way, the flow rate of the chemical solution when the chemical solution is continuously supplied can be kept constant, and when the chemical solution concentration needs to be changed according to the type of the substrate W, the flow rate adjustment valve The flow rate of the chemical solution can be changed by changing the pilot pressure applied to the.
[0048]
Further, the flow rate adjusting valve 20 is not necessarily configured as shown in FIG. 2 as long as the flow rate of the pure water is set to a constant flow rate corresponding to the pilot pressure. You may make it employ | adopt a flow regulating valve. Moreover, you may employ | adopt the valve | bulb which uses hydraulic pressure as pilot pressure.
[0049]
In the above embodiment, the present invention is applied to a so-called one-bus type substrate processing apparatus that performs surface treatment by immersing the substrate W in a processing solution, but the present invention transports the substrate W. However, the present invention can also be applied to a so-called spray-type substrate processing apparatus that performs a surface treatment by spraying a processing liquid on the substrate W.
[0050]
【The invention's effect】
As described above, according to the present invention, in an apparatus for processing a substrate while supplying a processing liquid to a substrate processing unit through the processing liquid supply pipe, the processing liquid supply pipe is responsive to a pilot pressure applied via the pilot pipe. In addition, a flow rate adjusting valve for adjusting the flow rate of the processing liquid is provided, an adjusting means for adjusting the pilot pressure in the pilot pipe is provided, and a plurality of branches parallel to the pilot pipe are provided as the adjusting means. In each branch section, an on-off valve and a pressure adjustment valve capable of adjusting the pilot pressure to a constant pressure are provided, and the adjustment pressure value by the pressure adjustment valve in each branch section is set to a different value. Therefore, the set flow rate can be changed while supplying the flow rate of the process liquid supplied through the process liquid supply pipe at a set constant flow rate, and the structure of the simple process liquid supply pipe can be changed. In can be the flow rate change such processing liquid. Therefore, the occupied space of the processing liquid supply / discharge system is not increased, and the flow rate of the processing liquid can be changed with an inexpensive configuration.
[0052]
In the substrate processing apparatus, there is a case where it is desired to change the flow rate according to the temperature of the supplied processing liquid. In this case, the pilot pressure can be adjusted to a plurality of pressure values according to the temperature of the processing liquid. If the adjustment means is configured, the flow rate can be set according to the temperature of the processing liquid.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an embodiment of a substrate processing apparatus according to the present invention.
FIG. 2 is a cross-sectional view showing a configuration of a flow rate adjustment valve.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Substrate processing apparatus 12 Processing tank 14 Water supply pipe 16 Drainage pipe 20 Flow control valve 22 Flowmeter 24 Three-way valve 26a, 26b, 26c Chemical liquid tank 28a, 28b, 28c Chemical liquid supply pipe 29a, 29b, 29c Open / close valve 30 Pilot pipe 32a , 32b Branch portions 34a, 34b Regulators 36a, 36b Pressure gauges 38a, 38b On-off valve W Substrate

Claims (2)

In a substrate processing apparatus comprising a substrate processing section for processing a substrate and a processing liquid supply pipe connected to a processing liquid supply source for supplying the processing liquid to the substrate processing section, a pilot is connected to the processing liquid supply pipe. interposed the adjustment means allowing adjustment of the pilot pressure in the pilot pipe as well as interposed a flow regulating valve for regulating the flow rate of the treatment liquid in accordance with the pilot pressure supplied through the pipe, further as the adjusting means A plurality of branch portions parallel to the pilot pipe are provided, and an on-off valve and a pressure adjustment valve capable of adjusting the pilot pressure to a constant pressure are provided in each branch portion, and the adjustment pressure by the pressure adjustment valve of each branch portion A substrate processing apparatus characterized in that values are set to different values . 2. The substrate processing apparatus according to claim 1, wherein the adjusting means is configured so that the pilot pressure can be adjusted to a plurality of pressure values according to the temperature of the processing liquid .

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