KR20070050569A - Apparatus for sensing position of coating liquid nozzle tip in semiconductor fabricating equipment - Google Patents

Abstract

Disclosed is a coating liquid nozzle tip sensing device in a semiconductor device manufacturing apparatus capable of preventing or minimizing a coating defect due to a poor position of a nozzle tip in a coating liquid discharging field for manufacturing a semiconductor device. The coating liquid nozzle tip sensing device in such a semiconductor device manufacturing apparatus includes a nozzle holder for holding the coating liquid nozzle tip; A position sensor attached to the nozzle holder to detect a holding state of the coating liquid nozzle tip; Fixing the tip of the nozzle by receiving a position sensing signal output from the position sensor and generating a warning control signal in case of a holding state error compared to a preset reference position sensing signal to perform an interlock of the equipment There is an advantage that the coating defect of the coating liquid caused by the defect is prevented or minimized.

Semiconductor manufacturing equipment, coating liquid discharge device, nozzle tip, coating liquid coating defect

Description

Apparatus for sensing position of coating liquid nozzle tip in semiconductor fabricating equipment

1 is a block diagram of a coating liquid discharge apparatus in a conventional semiconductor device manufacturing equipment

2 is a detailed cross-sectional view of the driving valve unit in FIG.

FIG. 3 is a view illustrating a coating liquid checkback process in a nozzle according to the operation of the checkback valve in FIG. 2.

FIG. 4 shows the types of lookback failures in the nozzle that may be generated by the lookback valve in FIG. 2. FIG.

5 is a structural diagram of a nozzle holder equipped with a position sensor according to an embodiment of the present invention;

6 is a circuit block diagram of a monitoring unit connected to the position sensor of FIG. 5.

FIG. 7 is a flowchart illustrating an operation in which nozzle tip position sensing is performed by the controller of FIG. 6.

The present invention relates to a semiconductor device manufacturing apparatus for manufacturing a semiconductor device, and more particularly to a coating liquid discharge apparatus for coating a coating liquid in the form of a chemical solution, such as photoresist on a wafer.

In recent years, with the rapid development of information processing apparatuses such as computers, PDAs, portable phones, and the like, semiconductor devices employed as components of information processing apparatuses have also become high-speed operation and large capacity. Accordingly, the manufacturing equipment for manufacturing the semiconductor device has also been remarkably advanced in the direction of improving the integration, operating speed, and reliability of the semiconductor device.

As is widely known, in the manufacturing process of a semiconductor device, after a resist coating treatment for forming a resist film on the surface of a semiconductor wafer is performed in a photolithography step, an exposure treatment is performed on a resist coated wafer. After that, development and etching are performed in turn.

In a photolithography process using a chemical reaction, a resist coating process is mainly achieved by coating a coating liquid such as photoresist on the surface of the wafer by spin coating. The coating liquid is supplied to the wafer through a nozzle of the coating liquid discharging device. A known example of the coating liquid discharging device is disclosed in US Pat. No. 5,968,268 to Kitano et al.

In such a coating liquid discharge apparatus, a poor holding or fixing state of the nozzle tip is one of the factors causing coating defects or development defects during the semiconductor device manufacturing process, and the countermeasure is urgently needed.

In the past, when the nozzle tip is fixed to the tip holder, a manual tightening method is used, the tightening state may be loosened due to minute vibration when the equipment is operated for a long time, or the position of the nozzle tip may deviate from the normal position, resulting in coating liquid coating defect. There have often been cases.

Therefore, there is a need for an improved technique capable of preventing or minimizing coating application or development failure of coating liquids caused by instability of nozzle tips.

Accordingly, an object of the present invention is to provide a semiconductor manufacturing equipment that can solve the above problems.

It is another object of the present invention to provide a coating liquid nozzle tip sensing device in a semiconductor device manufacturing apparatus capable of preventing or minimizing coating failure of a coating liquid due to a fixing failure of a nozzle tip.

Still another object of the present invention is to provide a coating liquid nozzle tip sensing device in a semiconductor device manufacturing apparatus capable of monitoring whether the position of the nozzle tip discharging the coating liquid is out of the normal position.

According to an embodiment embodiment of the present invention in order to achieve some of the above objects of the present invention, a coating liquid nozzle tip sensing device in a semiconductor device manufacturing equipment is: a nozzle holder for holding the coating liquid nozzle tip Wow; A position sensor attached to the nozzle holder to detect a holding state of the coating liquid nozzle tip; And a tip holding state monitoring unit configured to receive the position sensing signal output from the position sensor and generate an alarm control signal in case of a holding state error by comparing with a preset reference position sensing signal.

Preferably, the coating liquid dispensed from the coating liquid nozzle tip may be a photoresist,

The tip holding state monitoring unit:

A sensor interface for converting the position sensing signal into digital sensing data;

A read-only memory storing the reference position sensing signal as digital data and storing a program for controlling all operations related to tip holding state monitoring;

A controller configured to digitally compare the reference position sensing signal and the position sensing signal according to the program and output an alarm control signal according thereto;

A random access memory coupled to the controller and functioning as a main memory of the controller;

It may include an alarm driver connected to the control unit for receiving the alarm control signal and accordingly driving the alarm unit.

The control unit may be a microprocessor of AMD or Intel, which executes a program programmed with a programming language such as C language or the like, as shown in FIG. 7.

According to the configuration of the coating liquid nozzle tip detection apparatus of the present invention as described above, there is an advantage that the coating failure of the coating liquid due to the fixing of the nozzle tip is prevented or minimized.

Hereinafter, according to the present invention, a preferred embodiment of the coating liquid nozzle tip detection device in a semiconductor device manufacturing equipment will be described with reference to the accompanying drawings. Although each is shown in different figures, components having the same or similar functions are labeled with the same or similar reference numerals. While many specific details are set forth in the following examples, by way of example only, and with reference to the drawings, it should be noted that this has been described without the intent to help those skilled in the art to understand the invention. .

First, only with the intention of providing a thorough understanding of the coating liquid nozzle tip sensing structure of the present invention, the structure of a conventional coating liquid discharge apparatus and nozzle will be described by way of example.

1 is a schematic block diagram of a coating liquid discharge apparatus in a conventional semiconductor manufacturing equipment. Referring to the drawings, there is shown a coating liquid reservoir 110, a supply pump 120, a discharging pump 130, a drive valve unit 100, and a controller 140 that function as a chemical tank.

In FIG. 1, the coating liquid stored in the coating liquid storage unit 110 by the pumping operation of the supply pump 120 is sent to the connecting pipe 112, and then pumped out to the output connecting pipe 114 through the supply pump 120. do. The coating liquid pumped out to the connecting pipe 114 is discharged by the discharging pump 130 and provided to the connecting pipe 4. When the driving valve part 100 is opened, the coating liquid provided to the connecting pipe 4 is discharged (discharged or dispensed) with a constant pressure through a nozzle 3 installed at one end of the connecting pipe 5. . The coating liquid discharged onto the wafer W adsorbed on the wafer stage 1 spreads to the edge of the wafer W by centrifugal force generated as the wafer stage 1 rotates.

After discharging of the coating liquid through the nozzle 3 for a preset time, the controller 140 controls the air valves 122, 142, and 144 through control lines 140a, 140c, and 140d to control the nozzles. Allow discharging through (3) to be completed. At this time, the air valve 142 is controlled to close the opening / closing valve AV in the driving valve unit 100, and the air valve 144 is controlled to suck back the driving valve unit 100. The back valve SV forms a negative pressure with respect to the coating liquid contained in the nozzle 3.

Detailed operation of the drive valve unit 100 will be described below with reference to FIG. 2 is a detailed cross-sectional view of the driving valve unit 100 of FIG. 1.

The driving valve unit 100 is installed between the coating liquid connecting pipe 4 and the connecting pipe 5 and forms a negative pressure with respect to the coating liquid contained in the nozzle 3 attached to the connecting pipe 5 to form a nozzle. (4) the liquid coating pipe (4) is installed between the liquid coating valve (10) and the liquid coating pipe (4) and the liquid crystal valve (10) to allow the coating liquid to be sucked up to a predetermined height from the tip of (3) The coating liquid supplied to the coating liquid connecting pipe 4 by passing through the connecting pipe 5 or the coating liquid supplied to the coating liquid connecting pipe 4 by opening or closing the connection pipe 5 and the connecting pipe 5. And an on / off valve 20 for blocking passage to (5).

The checkback valve 10 is installed between the checkback valve body 11, the checkback valve body 11, and the connection pipe 5 having an internal space sealed to the outside and connected to the air line 104. And a diaphragm which forms a negative pressure with respect to the coating liquid contained in the connection pipe 5 according to the air pressure in the suction chamber 18 and the suction bag 18 having the suction port 16 for sucking the coating liquid. (15), the pressure is installed to the inside of the checkback valve body 11 and the operating range of the diaphragm 15 is adjusted to adjust the pressback height for the coating liquid contained in the nozzle (3) A key 13, a seatback height adjusting part 12 for adjusting the height of the pusher 13 from the outside, and a return spring 14 for maintaining a set height of the pusher 13.

The on-off valve 20 has an internal space sealed to the outside and is connected to the air line 102, the on-off valve body 21 is installed in the on-off valve body 21 and through the air line 120 When the applied air pressure rises, the coating liquid connecting pipe 4 is opened, and when the air pressure falls, the blocking rod 23 which blocks the coating liquid connecting pipe 4 as the rod tip 23a, and the blocking rod ( It includes a return spring 22 to maintain the blocking operation of the blocking rod 23 when 23 is blocking the coating liquid connecting pipe (4).

When the controller 140 of FIG. 1 controls the air valves 142 and 144 through the control lines 140c and 140d to perform coating liquid discharging, the air pressure applied to the air lines 102 and 104 of FIG. To rise. Accordingly, when the air pressure in the internal space in the on-off valve body 21 starts to rise and becomes greater than the restoring force of the return spring 22, the blocking rod 23 is moved in the vertically upward direction. Therefore, the rod tip 23a which was blocking the coating liquid connecting pipe 4 is lifted upward, and the coating liquid connecting pipe 4 is opened. Therefore, the coating liquid supplied to the connecting pipe 4 is passed to the connecting pipe 5. On the other hand, when the air pressure rises also in the internal space in the checkback valve body 11, the pusher 13 descends vertically downward. Thus, the diaphragm 15 is pressed to maintain the contracted state during the discharge operation of the coating liquid. The coating liquid passed to the connecting pipe 5 is discharged to the upper portion of the wafer W through the nozzle (3).

When an appropriate amount of coating liquid is discharged on the wafer W, the wafer W is rotated, and the controller 140 performs control to complete the coating liquid discharge operation. That is, when the controller 140 controls the air valves 142 and 144 through the control lines 140c and 140d to terminate the coating liquid discharging operation, the air pressure applied to the air lines 102 and 104 of FIG. This will descend. Accordingly, when the air pressure in the internal space in the on-off valve body 21 starts to fall and the lowered air pressure becomes less than or equal to the restoring force of the return spring 22, the blocking rod 23 is moved vertically downward. Thus, the coating liquid connecting tube 4 is closed by the rod tip 23a so that the coating liquid connecting tube 4 is closed. Therefore, the coating liquid supplied to the connecting pipe 4 is no longer passed to the connecting pipe 5 so that the discharge of the coating liquid is stopped.

On the other hand, when the air pressure decreases in the internal space in the checkback valve body 11, the pusher 13 is raised to the vertical upper portion by the restoring force of the return spring 14. As a result, the contracted diaphragm 15 is expanded to its original state, and the coating liquid contained in the connecting pipe 5 flows into the expanded space of the diaphragm 15. As a result, the coating liquid is sucked in the direction opposite to the discharging direction by the negative pressure caused by the operation of the diaphragm 15. Thus, the coating liquid in the connecting pipe 5 is received with a constant lookback height from the tip of the nozzle 3. If the coating liquid is located inside the nozzle 3, the coating liquid is not easily cured because the contact with the outside air is reduced.

FIG. 3 is a view illustrating a suckback process of the coating liquid according to the operation of the checkback valve of FIG. 2. 3a in the figure shows the first stage of the lookback operation. The first step is just before the knockback operation occurs, and the coating liquid 2 is discharged from the nozzle 3 and falls on the wafer W. As shown in FIG. In the first step, the on-off valve 20 and the checkback valve 10 are left open just before closing. 3b shows the second stage of the lookback operation, in which the on-off valve 20 is closed and the lookback valve 10 also proceeds in a closed state. In the second step, discharging of the coating liquid 2 is stopped so that the coating liquid 2 stays at the tip of the nozzle 3 without falling on the wafer W. 3c illustrates a third stage of the lookback operation, and illustrates a case in which the soundback valve 10 is completely closed and a negative pressure is generated according to the operation of the diaphragm 15. Here, the coating liquid 2 is received from the tip of the nozzle 3 in a state of having a constant rockback height such as about 4 millimeters (mm) in height.

When the checkback valve 10 is normally driven, the coating liquid should be managed as shown in the third step of FIG. 3. If the coating solution does not have a constant lookback height, the coating solution can be easily cured by contact with external air, or the coating solution flows down the top of the wafer, or the lookback height is too high. This is because problems may arise that the operation becomes unstable.

Figure 4 is a view showing the types of defects that may be caused by the checkback valve in Figure 2, 4a shows a case in which the flow down of the coating liquid is too low, and the back of the coating liquid 4b is a checkback The height H is too high to indicate a coating failure in the next operating cycle.

As in the case of FIG. 4A, in addition to a case where a coating defect in which the coating liquid leaks occurs, a coating defect or a defective defect may be caused even when a holding or fixing state of the nozzle tip occurs in the coating liquid discharge apparatus.

As a result, in the past, when the nozzle tip is fixed to the tip holder as described above, a manual tightening method is used, and thus, when the equipment is in operation, the tightening state may be loosened or the position of the nozzle tip may be out of the normal position. It has often been the case.

Therefore, in the exemplary embodiment of the present invention, the position sensor 60 is attached as shown in FIG. 5 to prevent or minimize coating defects or development defects of the coating liquid caused by the instability of the nozzle tip. A configuration is created that allows the block to monitor the position of the nozzle tip.

Hereinafter, an example of the structure and operation of the coating liquid nozzle tip sensing apparatus according to an embodiment of the present invention will be described with reference to FIGS. 5 to 7.

First, Figure 5 is a structural diagram of a nozzle holder equipped with a position sensor according to an embodiment of the present invention.

Referring to FIG. 5, a nozzle holder 59 for holding the coating liquid nozzle tip 4 and a position sensor 60 attached to the nozzle holder 59 to detect a holding state of the coating liquid nozzle tip 4 are provided. ) Is shown. In the drawings, reference numeral 50 denotes a supporting shaft, reference numerals 53 and 54 denote nozzle assembly fixing brackets, reference numeral 56 denotes a nozzle assembly body, and reference numeral 58 denotes a bottom body. Reference numeral 3 is a nozzle, reference numeral 4 is a nozzle tip, reference numeral 5 is an upper nozzle tube, and reference numeral 5-1 is a flexible nozzle tube.

In addition, FIG. 6 shows a circuit block diagram of a monitoring unit connected to the position sensor 60 of FIG. 5, which receives a position sensing signal output from the position sensor 60, compares it with a preset reference position sensing signal, and holds the same. It generates the alarm control signal in case of status error and plays the role of equipment interlock.

In Figure 6, the tip holding state monitoring unit,

A sensor interface 40 for converting the position sensing signal output from the position sensor 30 into digital sensing data, and a program for storing the reference position sensing signal as digital data and controlling all operations related to tip holding state monitoring. A control unit 50 for storing the read-only memory 45, the digitally comparing the reference position sensing signal and the position sensing signal according to the program, and outputting an alarm control signal according to the program; A random access memory 47 connected to 50 to serve as a main memory of the controller, and an alarm driver 57 connected to the controller 50 to receive the alarm control signal and drive the alarm 60 accordingly. ) May be included.

The controller may be implemented as a microprocessor of AMD or Intel, which executes a program programmed with a programming language such as a C language or the like, as shown in FIG. 7.

FIG. 7 is an operation control flowchart showing an example in which nozzle tip position sensing is performed by the controller of FIG. 6, and is shown from step S70 to step S76.

First, the controller 50 of FIG. 6 initializes various registers and flags in step S70 to allow the operation of the system to enter an initial state. In step S71, it is checked whether a sensing signal is input. Here, the sensing signal is a position sensing signal output from the position sensor 30, which is a signal converted into digital sensing data by the sensor interface 40. In step S72, it is checked whether the sensing signal is in the first state, and in the case of the first state, step S73 and step S74 are sequentially performed to generate an alarm control signal and to emit an alarm. Here, the first state may appear as a digital logic level high or low. For example, if the position sensor 30 composed of a photo coupler or the like outputs a logic low when the nozzle tip is positioned at a certain height, light may be emitted to the light receiving unit when the nozzle tip is distorted or loosened so that the height is out of position. Since this is not detected, a logic high is output. In this embodiment, for example, the first state is used as a signal that indicates a fixing failure of the nozzle tip. Here, the alarm may be an internal buzzer signal informing of a fixed failure state by an interlock signal or a sound indicating a stop of the equipment.

Step S75 is a step of checking whether it is in the second state, and the state in which the nozzle tip is normally held is checked here. In this case, since it is not a fixation failure, since the probability of coating failure occurring is small, the normal operation is controlled in step S76.

Meanwhile, the coating liquid dispensed from the coating liquid nozzle tip may be a photoresist used in a photolithography process.

According to the coating liquid nozzle tip detection apparatus of the present invention as described above, the coating failure of the coating liquid due to the fixing of the nozzle tip is prevented or minimized.

In the above description, the embodiments of the present invention have been described with reference to the drawings, for example. However, it will be apparent to those skilled in the art that the present invention may be variously modified or changed within the scope of the technical idea of the present invention. . For example, if the matter is different, the installation position or the monitoring method of the position sensor may be changed or modified in various forms without departing from the technical spirit of the present invention.

According to the coating liquid nozzle tip detection device of the present invention as described above, there is an effect to prevent or minimize the coating defect of the coating liquid due to the fixing failure of the nozzle tip. Therefore, there is an additional advantage of reducing the cost of the semiconductor device produced by reducing the process defect that can occur in the manufacturing process.

Claims (4)

In coating liquid nozzle tip detection device in semiconductor device manufacturing equipment: A nozzle holder for holding the coating liquid nozzle tip; A position sensor attached to the nozzle holder to detect a holding state of the coating liquid nozzle tip; And a tip holding state monitoring unit configured to receive a position sensing signal output from the position sensor and generate an alarm control signal in case of a holding state error by comparing with a preset reference position sensing signal to perform an equipment interlock. Coating liquid nozzle tip detector in manufacturing equipment. The coating liquid nozzle tip detection apparatus of claim 1, wherein the coating liquid dispensed from the coating liquid nozzle tip is a photoresist. The method of claim 2, wherein the tip holding state monitoring unit: A sensor interface for converting the position sensing signal into digital sensing data; A read-only memory storing the reference position sensing signal as digital data and storing a program for controlling all operations related to tip holding state monitoring; A controller configured to digitally compare the reference position sensing signal and the position sensing signal according to the program and output an alarm control signal according thereto; A random access memory coupled to the controller and functioning as a main memory of the controller; The coating liquid nozzle tip detection device in a semiconductor device manufacturing equipment, characterized in that it comprises an alarm driver connected to the control unit for receiving the alarm control signal and thereby driving the alarm. 4. The coating liquid nozzle tip sensing device of claim 3, wherein the control unit is a microprocessor.

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