JPH04196517A - Liquid treating method - Google Patents

Abstract

PURPOSE:To obtain a liquid treating method wherein air bubbles mixing in treating liquid to be supplied are eliminated and coating irregularities are prevented, by a method wherein, when a specified amount of liquid for treating an object to be treated is supplied via a filter, air is removed from the filter before the liquid passes the filter, and then the liquid is made to flow in the state that deserting is stopped. CONSTITUTION:Resist is sent from an accommodation vessel 13 to a liquid amount detector 11 through resist supply piping 12. The air permeating into the piping 12 between the vessel 13 and the detector 11 is introduced from the upper part of the detector 11 to piping 16 for deserting, and discharged into a drain vessel 23 via an air operating valve 22. The resist passes the piping 12 and progresses as far as a filter 10. The air permeating into the piping 12 between the detector 11 and the filter 10 is discharged from the filter. By the same operation, the air between the filter 10 and a filter 8 is discharged. In this manner, the air in the piping 12 are all eliminated, and the resist whose air bubbles are removed can be uniformly spread on a semiconductor wafer 2.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a liquid treatment method.

[Prior Art] Generally, semiconductor manufacturing processes include a photolithography process in which a pattern is formed on a thin film stacked on a semiconductor wafer. In the photolithography process, a resist is applied to a semiconductor wafer, exposed through a patterned mask, developed, and etched to form a thin film into a patterned shape. A resist coating device or a developing device used for resist coating or development drops a certain amount of resist solution or developer stored in a storage container from a nozzle onto a semiconductor wafer that is vacuum-adsorbed onto a chuck. By rotating at high speed, the resist or developer dropped onto the semiconductor wafer is uniformly applied over the entire surface.

[Problems to be Solved by the Invention] However, as integrated circuits become extremely highly integrated, coating unevenness greatly affects yield.

One of the major causes of uneven coating is air bubbles contained in the high clay resist solution or developer. The mixed air bubbles are difficult to remove, and even if the resist or developer containing the air bubbles is dropped onto a semiconductor wafer and spin-coded, the air bubbles will not disappear, resulting in uneven coating film thickness. Therefore, efforts are being made to remove air bubbles, but
Gas easily got mixed into the resist or developer. In particular, when replacing the storage container for resist solution or developer, air enters the piping, and it takes time to remove the air that has entered at the start of processing, and the resist or developer is wasted by being discarded. There was a drawback.

The present invention has been made in order to eliminate the above-mentioned drawbacks, and an object of the present invention is to provide a liquid processing method that can remove air bubbles mixed in a liquid such as a processing liquid, such as a resist liquid or a developer liquid, to be supplied. shall be.

[Means for Solving the Problem] In order to achieve the above object, the liquid treatment method of the present invention includes the following:
When supplying a predetermined amount of liquid to treat an object through a filter, air in the filter is degassed before the liquid passes through the filter, and the liquid is circulated while degassing is stopped. This is how it was done.

[Operation] A liquid processing method in which a predetermined amount of processing liquid is supplied to the object to be processed through a filter is to deaerate the air in the filter before the processing liquid passes through the filter, and remove the processing liquid with the degassing stopped. Since the process liquid was made to circulate, it was possible to reduce the amount of air mixed into the processing liquid.

[Embodiment] An embodiment of a resist coating apparatus for manufacturing semiconductor wafers to which the liquid processing method of the present invention is applied will be described with reference to the drawings.

A resist coating apparatus 1 shown in FIG. 1 includes a chuck 4 on which a semiconductor wafer 2, which is an object to be processed, is placed and connected to a rotational drive mechanism 3. A nozzle 5 is provided above the center of the semiconductor wafer 2 on the chuck 4 for dropping resist.

When the nozzle 5 restarts processing, the resist remaining in the nozzle 5 is discharged after being exposed to air and solidified.
It is connected to a horizontal movement device (not shown) so that it can be evacuated from above the semiconductor wafer. The nozzle 5 is connected to a storage container 13 for resist R, which is a liquid, through a resist supply pipe 12 that includes a suckback 6, a valve 7, a filter 8, a bellows pump 9, a filter 10, and a liquid amount detector 11.

The filters 8 and 10 are made of, for example, a transparent resin plate so that the inside thereof can be visually seen, and are connected to air bubble removal pipes 14 and 15, respectively. The flow rate detector 11 is equipped with a liquid level sensor (not shown) and is capable of measuring the amount of liquid in the storage container 13 from the liquid level position of the resist delivered from the storage container 13. Connected. Check valves 17, 18 and 19 and air operated valves 20, 21 and 22, which are deaerators, are inserted into these air bubble removal pipes 14, 15 and 16, respectively, and are connected to the drain container 23, respectively. Air operated valve 20.21
and 22 are normally closed and opened by connected air solenoids 24, 25 and 26, respectively. The air solenoids 24, 25, 26 are connected to the control device 27 to be activated at predetermined times. The control device 27 has timers 27-24, 27-25, as shown in FIG.
．． 27-26.27-29, these timers 2
7-24.27-25.27-26.27-29, the air solenoid 24.
25, 26 and 29.

On the other hand, a pressurizing pipe 28 is connected to the storage container 13, and is connected to a pressurized gas, for example, a nitrogen gas supply system 32, via an air operated valve 30 and a regulator 31 operated by an air solenoid 29 driven by a control device 27.

The operation of the resist coating apparatus configured as above will be explained. A pressurizing pipe 28 and a resist supply plumber 2 are connected and installed in the storage container 13 filled with resist. Timer 27-29.27-26.27-25 of control device 27.
27-24 to a predetermined time. That is, it is set based on the time required for the resist to be fed under pressure by the nitrogen gas fed by the nitrogen gas supply system 32 through the pressurizing pipe 28 to the storage container 13 . As shown in FIG. 3, the timer 27-26 is set after the time T1 required for the resist to reach the liquid amount detecting device 11 from the storage container 13 and reach a predetermined level of the liquid amount detecting device 11 from the start of processing. Set by. In addition, the resist is transferred from the liquid amount detection device 11 to the filter 10 after T1 time has elapsed since the timer 27-25 started processing.
Set the time required to reach 19 hours. In addition, the timer 27=26 is set from T1+72 hours after the start of the process to Ts, which is the time required for the resist to reach the filter 8 from the filter 10. Furthermore, the timers 27-29 are set to T, + T2 from the start of processing.
+T Set by a time later. After setting the timer in this way, nitrogen gas supply from the nitrogen gas supply system 32 is started. At this time, the air solenoids 29 and 26 are driven by the timer setting of the control device 27, and the air operated valve 30 is activated.
and 22 are opened. And the resist is storage container 1
3, the liquid is sent to the liquid amount detector 11 through the resist supply plumber 2. At this time, the air that has entered the resist supply pipe 12 between the storage container 13 and the liquid level detector 11 is introduced into the air-bleeding plumber 6 from the upper part of the liquid level detector 11 before the resist is pressure-fed, and is introduced into the air-bleeding plumber 6 through the air operation valve 22. The water is exhausted through the drain container 23.

After T1 hours have elapsed after the start of the process, when the tip of the resist reaches a predetermined level on the liquid level detector 11, the air solenoid 26 is stopped and the air operated valve 22 is closed.

At the same time, the air solenoid 25 is driven by the control device 27, and the air operated valve 21 is opened. The resist further advances through the resist supply pipe 12 to the filter 10 by the nitrogen gas supplied from the nitrogen gas supply system 32. At this time, the air that has entered the resist supply pipe 12 between the liquid amount detector 11 and the filter 10 is introduced from the filter 10 to the bubble removal plumber 5 before reaching the resist.
The air is exhausted to the drain container 23 through the air operated valve 21. When the tip of the resist reaches the filter 10 after T, +T* elapses after the start of processing, the air solenoid 25 is stopped, and the air operated valve 21 is closed, and at the same time, the air solenoid 24 is driven and the air operated valve 20 is opened. By the same operation, the air between the filter 10 and the filter 8 is exhausted after T 1 + T 2 + T s at the start of processing, and the air solenoid 24 is activated by the control device 27.
and 29 are stopped, and air operated valves 20 and 30 are closed. In this state, the air in the resist supply plumber 2 between the storage container 13 and the filter 8 is removed, and then, if dummy dispensing is performed from the nozzle 5 that has been evacuated from above the semiconductor wafer 2, the air in the resist supply plumber 2 is removed. All will be removed.

In this manner, the resist from which air bubbles have been removed is dropped from the nozzle 5 onto the semiconductor wafer 2 on the chuck 4, and is rotated at high speed by the rotation drive mechanism 3 to perform spin coding. By doing so, a thin and uniform resist film can be applied onto the semiconductor wafer 2.

The above description is a description of one embodiment of the present invention, and the present invention is not limited thereto, but can be applied to a developing device, a rinsing device, etc.

[Effects of the Invention] As is clear from the above description, the liquid treatment method of the present invention automatically bleeds out the air accumulated in the filter that filters the liquid in sequence according to the time required for the liquid to pass through the piping. This reduces air bubbles and allows liquid treatment to be performed.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment to which the liquid treatment method of the present invention is applied, FIG. 2 is a diagram showing the main parts of the embodiment shown in FIG. 1,
FIG. 3 is a diagram showing the operation using the embodiment shown in FIG. 1. 1...Resist coating device 2...Semiconductor wafer (object to be processed) 8.1o...
... Filter 12 ... Resist supply piping (piping) 20.21
．． 22...Air operated valve (deaerator) 27...Control device R...Resist (liquid) Agent Patent attorney Moritani -O'@2 Figure 3 Figure Haruma

Claims (1)

[Claims] When supplying a predetermined amount of liquid to treat an object through a filter, air in the filter is degassed before the liquid passes through the filter, and the liquid is circulated while degassing is stopped. A liquid processing method characterized by: