JP3946123B2 - 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 a developing solution, a rinsing solution or pure water to a substrate such as a semiconductor wafer or a glass substrate for a liquid crystal display, and in particular, a technique for controlling the flow rate of the processing solution. About.
[0002]
[Prior art]
In such a substrate processing apparatus, for example, the time required for the developer to reach a predetermined flow rate when starting the discharge of the developer (that is, the time until the valve body of the flow rate adjustment valve of the developer reaches a predetermined opening) ) And the time required for stopping the supply of the developing solution (that is, the time until the valve element is fully closed from the predetermined opening), or the supply flow rate of the processing solution is adjusted. There is a need.
[0003]
Therefore, conventionally, as shown in the block diagram of the flow rate adjusting mechanism in FIG. 5, a flow rate adjusting valve 02 is provided at a midpoint of the processing liquid supply pipe 01.
The flow regulating valve 02 urges the piston 04 of the valve body 03 to be displaced to the fully closed side by the compression coil spring 05, and supplies air through the air supply pipe 06, thereby urging the compression coil spring 05. It is comprised with what is called a single action type air cylinder so that the valve body 03 may open against this.
[0004]
The air supply pipe 06 is provided with a valve opening speed adjustment circuit 09 provided with a first one valve 07 and a first throttle valve 08, and a valve provided with a second one valve 010 and a second throttle valve 011. A closing speed adjustment circuit 012 is interposed, and by adjusting the throttle amounts of the first and second throttle valves 08 and 011, the time until the predetermined opening degree (valve opening speed), and the predetermined opening degree The time until the valve is fully closed (valve closing speed) is adjusted. Further, a stopper bolt 013 for adjusting the maximum opening degree of the valve body 03 in contact with the piston 04 is provided to adjust the supply flow rate of the processing liquid.
[0005]
[Problems to be solved by the invention]
However, conventionally, the adjustment of the throttle amount of the first and second throttle valves 08 and 011 and the adjustment of the stopper bolt 013 are artificially performed, which is troublesome and difficult to adjust accurately. There was a problem.
[0006]
Further, when adjusting the supply flow rate of the processing liquid, it is performed while looking at the indicated value of a flow meter (not shown) provided in the processing liquid supply pipe 01, but in recent years, with the increase in the number of spin heads, As the number of processing liquid supply pipes 01 increases, the position of the stopper bolt 013 and the position of the flowmeter tend to be separated, which takes time to check the indicated value of the flowmeter, and it takes time to adjust the supply flow rate of the processing liquid. There was a drawback.
[0007]
Further, since the stopper bolt 013 is fixed in the middle of the processing, when the pressure varies at the processing liquid supply source and the flow rate changes due to this, there is a disadvantage that the processing liquid supply flow rate also varies. there were.
[0008]
The present invention has been made in view of the above points, and a main object of the present invention is to make it possible to accurately adjust the supply amount of the processing liquid with a simple operation.
[0009]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration.
That is, the invention described in claim 1 is a substrate holding means for holding a substrate, a nozzle for supplying a processing liquid to the substrate held by the substrate holding means, a processing liquid supply pipe connected to the nozzle, In the substrate processing apparatus provided with a flow rate adjusting valve that is provided in the processing liquid supply pipe and adjusts the flow rate of the processing liquid, the flow rate adjusting valve is coupled to the valve body that opens and closes the processing liquid supply path. And a control means for controlling the flow rate of the processing liquid by adjusting the opening degree and the opening / closing speed of the valve body by operating the electric motor . The processing solution is a developing solution, and the control means reduces the flow rate of the developing solution when the photoresist applied to the substrate has good wettability with the developing solution, and the photoresist is used as the developing solution. Develop if the dullness is poor To increase the flow rate, and controlling the flow rate of the developing solution according to the type of photoresist that is attached coating to the substrate.
[0010]
(Action / Effect)
According to the first aspect of the invention, the flow rate of the processing liquid can be arbitrarily set by adjusting the opening degree of the valve body by opening and closing the valve body by the electric motor. Moreover, by adjusting the opening / closing speed of the valve body by operating the electric motor by the control means, the time for opening the valve body from the fully closed state to the predetermined opening degree, and from the predetermined opening degree to the fully closed state The time can be adjusted arbitrarily.
Therefore, adjustment of the supply flow rate of the processing liquid can be carried out by setting it appropriately with little effort and without manually checking it with a flow meter. The supply amount can be adjusted with a simple operation with high accuracy.
In addition, it is possible to easily adjust the time from the predetermined opening to the fully closed state to be longer than the time to open from the fully closed state to the predetermined opening. It is possible to avoid the backflow of air at the tip and improve the processing quality of the substrate.
[0011]
By the way, when various photoresists are applied to the substrate and developed, development failure may occur depending on the type of photoresist, or particles ( There may be a problem that a small residue of photoresist) adheres. The present inventors have studied these causes, and have found that these causes are due to the difference in wettability between the photoresist and the developer. That is, in the case of a photoresist having poor wetting with the developer, the developer is repelled, resulting in insufficient development amount due to insufficient supply of the developer to the photoresist. Conversely, in the case of a photoresist with good wettability, the developer moves on the photoresist ahead of the nozzle when the nozzle is moved close to the substrate and the developer is deposited on the substrate. It will be in a flowing state. The photoresist was dissolved by the preceding developing solution, and the residue of the photoresist generated at that time adhered to the subsequent nozzle, resulting in contamination of the substrate.
[0013]
According to the invention of 請 Motomeko 1, based on the elaboration result of the above, according to the type of photoresist, the control unit operates the electric motor, when the photoresist is a good wettability with the developer The flow rate of the developing solution is controlled so that the flow rate of the developing solution is decreased and the flow rate of the developing solution is increased when the photoresist has poor wettability with the developing solution. As a result, regardless of the type of photoresist, the development process can be performed satisfactorily.
[0014]
The invention according to claim 2, in the substrate processing apparatus according to claim 1, the substrate is a circular substrate, and that the nozzle is moved in the substrate diameter direction along the surface of the circular of the substrate The control means reduces the flow rate of the processing liquid when the nozzle is away from the center of the circle of the substrate, and increases the flow rate of the processing liquid when the nozzle is near the center of the circle of the substrate. In addition, the flow rate of the developer is controlled in accordance with the position of the nozzle.
[0015]
(Action / Effect)
When supplying the processing liquid by moving the nozzle in the diametrical direction along the surface of the circular substrate, the surface area away from the center of the circle is narrower than the center of the circle of the substrate. Relatively few. The invention according to claim 2 pays attention to this point. When the nozzle is away from the center of the circle of the substrate, the flow rate of the processing liquid is reduced, and when the nozzle is near the center of the circle of the substrate. By controlling the flow rate of the processing liquid according to the position of the nozzle so as to increase the flow rate of the processing liquid, the amount of the processing liquid that flows out of the substrate without being subjected to the processing can be reduced as much as possible. Therefore, wasteful supply of the processing liquid can be avoided to reduce the consumption amount, and the economy can be improved.
[0016]
The invention according to claim 3 is the substrate processing apparatus according to claim 1 or 2 , further comprising a flow rate measuring unit provided in the processing solution supply pipe for measuring a processing solution flow rate, and the control unit includes The feedback control means operates the electric motor so that the treatment liquid flow rate measured by the flow rate measurement means becomes a target flow rate.
[0017]
(Action / Effect)
According to the third aspect of the present invention, the processing liquid flow rate can be automatically adjusted while confirming whether the actual processing liquid flow rate is the target flow rate. Therefore, even if pressure fluctuation occurs at the supply source of the processing liquid, the supply flow rate of the processing liquid can be accurately maintained at the target flow rate, and the processing quality of the substrate can be improved in a stable state.
[0018]
The present specification also discloses means for solving the following problems.
(1) In a development processing method in which a developing solution is deposited on a substrate and the developing treatment is performed, when the photoresist applied to the substrate is good in terms of wettability with the developing solution, the flow rate of the developing solution is reduced, A developing method characterized in that the flow rate of the developing solution is increased when the photoresist has poor wettability with the developing solution.
[0019]
(Action / Effect)
According to the invention of (1), in the case where the photoresist has good wettability with the developer, it is possible to avoid the disadvantage that the residue of the photoresist adheres to the nozzle and contaminates the substrate, If the photoresist has poor wetting with the developer, it is possible to avoid problems such as insufficient supply of the developer and poor development, and the development process is improved regardless of the type of photoresist. It can be carried out.
[0020]
(2) In a substrate processing method for supplying a processing liquid onto a substrate and performing a desired processing on the substrate by moving a nozzle for supplying the processing liquid in the substrate diameter direction along the surface of the circular substrate, the nozzle is the substrate. A substrate processing method characterized in that the flow rate of the processing liquid is reduced when it is far from the center of the circle, and the flow rate of the processing liquid is increased when the nozzle is near the center of the circle of the substrate.
[0021]
According to the invention (2), by changing the flow rate of the processing liquid according to the position of the nozzle, the amount of the processing liquid that flows out of the substrate without being subjected to the processing can be reduced as much as possible. Therefore, wasteful supply of the processing liquid can be avoided to reduce the consumption amount, and the economy can be improved.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is an overall configuration diagram showing an embodiment of a substrate processing apparatus according to the present invention. In this embodiment, a description will be given by taking as an example a development processing apparatus that performs development processing on a substrate by supplying the developer on the substrate and depositing the developer on the substrate.
[0023]
In FIG. 1, reference numeral 1 denotes a circular substrate, for example, a semiconductor wafer. The substrate 1 is sucked and held on a substrate mounting table 2 as a substrate holding means. The drive shaft of the electric motor 3 is interlocked and connected to the center of the lower surface of the substrate platform 2 so that the substrate 1 can be rotated in a horizontal posture.
[0024]
A nozzle 4 for supplying a developing solution as a processing solution to the substrate 1 is provided above the substrate 1 held on the substrate mounting table 2. As shown in the plan view of FIG. 2, the nozzle 4 is formed in a rectangular shape, and a slit 5 for discharging the developer is provided on the lower surface thereof. This nozzle 4 is. It is configured to be movable in the diameter direction of the substrate along the surface of the circular substrate 1.
[0025]
A processing liquid supply pipe 6 connected to a developer tank (not shown) is connected to the nozzle 4. The processing liquid supply pipe 6 is provided with a filter 7, a flow meter 8 as a flow rate measuring means, and a flow rate adjusting valve 9.
[0026]
As shown in the longitudinal sectional view of FIG. 3, the flow rate adjusting valve 9 is configured by providing a valve body 11 that opens and closes a supply flow path in a valve box 10 that forms a supply flow path for a developer. A valve rod 12 having a hollow shape and a square cross section is integrally connected to the valve body 11, and a nut 13 is connected to the tip of the valve rod 12. A screw shaft 15 driven and rotated by an electric motor 14 is screwed onto the nut 13, and the valve body 11 is driven to open and close by forward and reverse rotation of the electric motor 14, and the opening degree and opening / closing speed can be arbitrarily adjusted. Has been. The electric motor 14 is composed of, for example, a stepping motor.
[0027]
A controller 16 serving as a control means (specifically a feedback control means) is connected to the flow rate adjusting valve 9. The controller 16 is given a change pattern of the developer flow rate with time as a target value from the main controller 17. Further, the controller 16 is supplied with the measured flow rate of the developer from the flow meter 8 and operates the electric motor 14 of the flow rate adjusting valve 9 so that the measured flow rate matches the target value. The flow rate of the developer is controlled by adjusting the opening / closing speed.
[0028]
The target value of the developer flow rate given from the main controller 17 to the controller 16 will be described. As shown in FIG. 4, the target value of the developer flow rate is given as a change pattern of the developer flow rate over time. In this embodiment, two types of target values for the developer flow rate are prepared. One is a target value A that is set when the photoresist applied to the substrate 1 has a relatively good wettability with the developer. The other is a target value B that is set when the photoresist applied to the substrate 1 has relatively poor wetting with the developer. The target value A is set with a relatively small flow rate of the developing solution, and the target value B is set with a relatively high flow rate of the developing solution.
[0029]
When the wettability between the photoresist and the developer is good, when the developer is discharged while moving the nozzle 4 along the substrate surface in the state of being close to the surface of the substrate 1, the developer comes before the nozzle 4. There is a tendency to spread on the substrate surface. The photoresist is dissolved by the developer that has spread before the nozzle 4. The residue of the photoresist generated at that time may adhere to the subsequent nozzle 4 and contaminate the surface of the substrate 1. In this way, in the case of a photoresist having a good wettability with respect to the developing solution, the phenomenon that the developing solution spreads before the nozzle 4 is suppressed by relatively reducing the supply amount of the developing solution, Contamination of the substrate 1 can be prevented.
[0030]
On the other hand, when the wettability between the photoresist and the developer is poor, the developer discharged from the nozzle 4 is difficult to spread on the surface of the substrate. As a result, the developer supplied to the photoresist is insufficient and development failure occurs. Sometimes. In this way, in the case of a photoresist having poor wetting with respect to the developer, by increasing the supply amount of the developer, the spread of the developer can be promoted and development failure can be prevented.
[0031]
In this embodiment, two types of target values of the developer flow rate are used. However, if more target values are prepared according to the type of resist, the substrate processing quality can be further improved.
[0032]
Further, another feature of the target values A and B set in this embodiment is that when the nozzle 4 is away from the center of the circle of the substrate 1, the flow rate of the developer is reduced, and the nozzle 4 becomes a circle of the substrate 1. In the case of being near the center, the target flow rate of the developer is changed in accordance with the position of the nozzle 4 so as to increase the flow rate of the developer. Specifically, the target flow rate gradually increases as the nozzle 4 approaches the center from the end of the substrate 1, and the target flow rate gradually decreases as the nozzle 4 moves away from the center of the substrate 1.
[0033]
The reason why the flow rate target value is changed according to the position of the nozzle 4 in this way is as follows. When the nozzle 4 faces the end of the circular substrate, the area of the substrate portion that is to be supplied with the developer from the nozzle 4 is small. On the other hand, when the nozzle 4 is opposed to the central portion of the circular substrate, the area of the substrate portion to be supplied with the developer from the nozzle 4 is large. Therefore, if the flow rate target value is kept constant regardless of the position of the nozzle 4, it is necessary to set the target value to a larger flow rate value in accordance with the central portion of the substrate having a large area. At the end, the amount of developer that is not used for substrate processing and is wasted is increased. In this embodiment, in order to eliminate such waste of the developing solution, the flow rate target value is set to be smaller as it is closer to the edge of the substrate.
[0034]
Another feature of the target values A and B set in this embodiment is that the time T _O required for the developer to reach a predetermined flow rate at the start of the discharge of the developer (that is, the valve of the flow rate adjusting valve 9). The time until the body 11 reaches a predetermined opening) and the time T _C required for stopping the supply of the developer (that is, the time until the valve body 11 is fully closed from the predetermined opening) are set. In the point. For example, carried out rapidly stop the supply of the developing solution and (suddenly closing the valve body 11), so far discharged but the developer or to be stored in the nozzle 4 by the discharge force of the developing solution, it and reverses the functions of When air enters the nozzle 4 and is mixed with the developer during the next substrate development process, bubbles are ejected, and the bubbles adhere to the substrate surface, which may cause development failure. Slow the time T _C required for the supply stop of the developer in the present embodiment (for example, while the time T _O required for ejection start is 0.5 ± 0.1 seconds, the time T _C required for outage The above-mentioned inconvenience is avoided by setting (1.2 ± 0.1 seconds).
[0035]
Next, the operation of the embodiment apparatus having the above-described configuration will be described.
The main controller 17 selects a change pattern of the flow rate target value of the developer according to the type of the photoresist applied to the substrate 1. In this embodiment, one of the change patterns of the target values A and B shown in FIG. 4 is selected. The main controller 17 refers to the selected target value change pattern, and sequentially gives the target flow rate value every moment from the start of the discharge of the developer to the stop of the supply to the controller 16. The controller 16 operates the electric motor 14 of the flow rate control valve 9 so that the flow rate of the developer measured by the flow meter 8 matches the flow rate target value given every moment. Adjust the opening and closing speed.
[0036]
Specifically, according to any one of the target values A and B shown in FIG. 4, the valve body 11 is opened at a predetermined speed until the predetermined flow rate is reached when the discharge of the developer is started. After the predetermined flow rate is reached, the flow rate of the developer gradually increases as the nozzle 4 gradually opens as the nozzle 4 moves from the substrate end toward the center of the substrate. When the nozzle 4 is at the center of the substrate, the valve body 11 is maintained at a constant opening, so that the flow rate of the developer is maintained at a constant value. As the nozzle 4 is moved away from the center of the substrate, the valve body 11 is closed, whereby the flow rate of the developing solution is gradually reduced. When the predetermined flow rate is reached, the valve body 11 is slowly closed and the supply of the developer is stopped.
[0037]
The above developer flow rate control is feedback control in which the electric motor is operated so that the developer flow rate measured by the flow meter 8 matches the flow rate target value set from the main controller 17 every moment. Even if a pressure fluctuation occurs at the developer supply source, the supply flow rate of the processing solution can be accurately maintained at the target value.
[0038]
In the above-described embodiments, the development processing apparatus has been described as an example. However, the present invention can be applied to various substrate processing apparatuses that perform processing by supplying a processing liquid such as a chemical solution to the substrate.
[0039]
The present invention is not limited to the substrate processing apparatus provided with the nozzle 4 provided with the slit 5, and can be applied to a substrate processing apparatus provided with various nozzles such as a nozzle provided with a circular hole.
[0040]
【The invention's effect】
As described above, according to the present invention, the flow rate of the processing liquid can be arbitrarily set by opening and closing the valve body by the electric motor and adjusting the opening degree of the valve body. Moreover, by adjusting the opening / closing speed of the valve body by operating the electric motor by the control means, the time for opening the valve body from the fully closed state to the predetermined opening degree, and from the predetermined opening degree to the fully closed state The time can be adjusted arbitrarily. Therefore, adjustment of the supply flow rate of the processing liquid can be carried out by setting it appropriately with little effort and without manually checking it with a flow meter. The supply amount can be adjusted with a simple operation with high accuracy. In addition, it is possible to easily adjust the time from the predetermined opening to the fully closed state to be longer than the time to open from the fully closed state to the predetermined opening. It is possible to avoid the backflow of air at the tip and improve the processing quality of the substrate.
[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 plan view of a main part of the embodiment device.
FIG. 3 is a longitudinal sectional view of a flow rate adjusting valve.
FIG. 4 is a graph showing a change with time of a flow rate target value of a phenomenon liquid.
FIG. 5 is a configuration diagram of a conventional flow rate adjusting mechanism.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Board | substrate 2 ... Board | substrate mounting base (board | substrate holding means)
4 ... Nozzle 6 ... Processing liquid supply pipe 8 ... Flow meter (flow rate measuring means)
DESCRIPTION OF SYMBOLS 9 ... Flow control valve 11 ... Valve body 14 ... Electric motor 16 ... Controller (control means)
17 ... Main controller

Claims (3)

Substrate holding means for holding the substrate;
A nozzle for supplying a processing liquid to the substrate held by the substrate holding means;
A treatment liquid supply pipe connected to the nozzle;
A substrate processing apparatus provided with a flow rate adjusting valve provided in the processing liquid supply pipe for adjusting a flow rate of the processing liquid;
The flow rate adjustment valve includes a valve body that opens and closes a processing liquid supply path, and an electric motor that is linked to the valve body and drives the valve body to open and close,
And a control means for controlling the flow rate of the processing liquid by adjusting the opening degree and the opening / closing speed of the valve body by operating the electric motor ,
The processing solution is a developer;
The control means reduces the flow rate of the developer when the photoresist applied to the substrate has good repellency with the developer, and when the photoresist has poor repellency with the developer. A substrate processing apparatus for controlling a flow rate of a developing solution in accordance with a kind of a photoresist applied to a substrate so as to increase a flow rate of the developing solution . The substrate processing apparatus according to claim 1 ,
The substrate is a circular substrate, and the nozzle moves in the substrate diameter direction along the surface of the circular substrate;
The control means reduces the flow rate of the treatment liquid when the nozzle is away from the center of the circle of the substrate, and increases the flow rate of the treatment liquid when the nozzle is near the circle center of the substrate. The substrate processing apparatus which controls the flow volume of a developing solution according to the position. The substrate processing apparatus according to claim 1 or 2 ,
Provided with a flow rate measuring means for measuring the flow rate of the processing liquid provided in the processing liquid supply pipe,
And the said control means is a substrate processing apparatus which is a feedback control means which operates the said electric motor so that the process liquid flow volume measured by the said flow volume measurement means may turn into a target flow volume.

Images