JPH05102023A - Treatment apparatus - Google Patents

Abstract

PURPOSE:To provide a treatment apparatus wherein the concentration of a treatment-liquid gas which is supplied to an object to be treated can be controlled surely and accurately. CONSTITUTION:An ultrasonic oscillator 10 is installed in a treatment-liquid gasification part. An HMDS liquid 12 is dropped, as liquid drops, onto the ultrasonic oscillator 10 by using a dropping nozzle 17; a pulse signal generated by a dropping shock from the terminal of the ultrasonic oscillator 10 is detected by using a liquid-amount detector 15. Thereby, a liquid amount is detected; its detection signal is transmitted to a control part 18; an opening and shutting valve 16 is controlled. While the supply amount of the HMDS liquid 12 is being monitored, it is controlled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a processing apparatus, and more particularly to a processing apparatus for processing a surface of a semiconductor wafer by supplying a processing gas to a processing portion of an object to be processed such as a semiconductor wafer. Is.

[0002]

2. Description of the Related Art Generally, when a photoresist layer or the like is formed on the surface of an object to be processed such as a semiconductor wafer, the surface of the semiconductor wafer is treated with hexamethyldisilazane (hereinafter referred to as HMDS) in order to improve the adhesion thereof. Processing is performed. During this pretreatment, the treatment liquid in the treatment liquid storage unit is vaporized by the vaporizer and supplied as a vapor phase to the treatment unit for storing the semiconductor wafer, where it adheres to the surface of the semiconductor wafer.

In a conventional processing apparatus of this type, as shown in FIG. 5, for example, an N2 gas supply pipe c for supplying a nitrogen (N2) gas as a carrier gas and a supply pipe d for supplying a processing gas to a processing chamber e. A bubbler b in the processing liquid storage portion a for connecting with
It has a structure in which In the processing apparatus configured as described above, HMDS gas is generated by the N2 bubbles generated by the bubbler b, and the HMDS gas is supplied to the processing chamber e through the supply pipe d. Then, the diffusion hole h of the diffusion plate g is guided by the guide passage f in the processing chamber e.
Is sprayed onto the wafer W on the heating table i. In this case, the processing chamber e is connected to the ejector k via the exhaust pipe j, and by supplying driving pressure air from the driving air supply pipe m to the ejector k, the inside of the processing chamber e is maintained at a negative pressure. It is like this. In FIG. 5, n and o are open / close valves.

By the way, in the conventional processing apparatus of this type, when N2 bubbles are blown off at the liquid surface in the processing liquid container a, droplets are generated, and a supply pipe leading from the processing liquid container a to the processing chamber e. There was a problem that dew condensation occurred in d.

Therefore, in order to prevent this, conventionally, a supply pipe d connecting the processing liquid accommodating portion a and the processing chamber e.
A separate N2 supply pipe p is connected to this to dilute the HMDS gas in the supply pipe d to prevent dew condensation in the supply pipe d.

Further, conventionally, the HM supplied to the processing chamber
A micro dispenser or mass flow controller is used to control the concentration of the DS gas.

[0007]

However, in the conventional processing apparatus of this type, it is necessary to separately connect the N2 gas supply pipe p to the supply pipe d, and the supply amount of the N2 gas and the HMDS gas Since it is necessary to control the amount and the like, there has been a problem that a piping structure, a control device and the like are required in a complicated manner and a large amount of them are required, and moreover, sufficient dew condensation cannot be prevented. Further, when the condensed liquid droplets enter the processing chamber e, they adhere to the wafer W, which causes a problem that the quality of the wafer W is deteriorated. Further, in a device in which the amount of the processing liquid is controlled by a micro dispenser, a mass flow controller, or the like, there is a problem that the device becomes complicated and expensive.

The present invention has been made in view of the above circumstances, and provides a processing apparatus in which the piping structure is simplified and the concentration of the processing liquid gas supplied to the processing chamber for the object to be processed can be accurately and reliably controlled. The purpose is that.

[0009]

In order to achieve the above-mentioned object, the processing apparatus of the present invention is a processing apparatus comprising a processing part for processing an object, a processing liquid storage part, and a processing liquid vaporizing part. An ultrasonic vibrator is provided in the processing liquid vaporization section, and a processing liquid supply means for supplying a predetermined amount of processing liquid to the ultrasonic vibrator is provided, and a liquid amount detecting means is connected to the ultrasonic vibrator. It is characterized in that the processing liquid supply of the processing liquid supply means is controlled by the output of the liquid amount detection means.

In the present invention, the ultrasonic transducer is
By utilizing the property of being a reversible converter of electric signal → vibration and vibration → electric signal, the vaporizing means is made to have the function of a sensor. In this case, the ultrasonic vibrator generates vibration by being driven by an electric signal and also generates an electric signal by a force or a shock applied to the vibrator, and can be formed by, for example, a piezoelectric element.
A magnetostrictive element can also be used depending on the case.

The treatment liquid supply means may be any one as long as it supplies a predetermined amount of treatment liquid to the ultrasonic vibrator. For example, the treatment liquid supply means has a dropping nozzle having a predetermined diameter and drops from this nozzle. It is possible to use one having an on-off valve for controlling the supply of the processing liquid. Utilizing the property that the size of the liquid drop dropped from a nozzle with a predetermined diameter is almost constant, the liquid amount detection means should be formed by a counter that counts the pulse signal generated from the ultrasonic transducer by the liquid drop. You can The amount of processing liquid supplied can be controlled by opening and closing the valve provided in the processing liquid supply means based on the count value of this counter.

[0012]

According to the processing apparatus of the present invention configured as described above, the processing liquid in the processing liquid storage device is dripped onto the ultrasonic vibrator through the dropping nozzle. This drop of droplets
It can be detected by monitoring the terminal voltage of the vibrator. The pulse signal generated by the impact of the dropping is counted to detect the number of droplets, and when the desired number is counted, the valve is closed to obtain the desired processing liquid supply amount.

The ultrasonic vibrator vibrates according to the supplied electric signal, and makes the dropped treatment liquid into fine droplets. The finer the droplets, the larger the surface area ratio (the size of the surface area per amount of liquid), and the treatment liquid is more likely to evaporate.
In addition, fine droplets are less likely to be condensed in the pipe. The evaporated processing liquid is supplied into the processing chamber of the object to be processed at a desired concentration through the supply pipe, and is used for processing the surface of the object to be processed.

[0014]

Embodiments of the present invention will be described in detail below. In this embodiment, a case where the processing apparatus of the present invention is applied to a semiconductor wafer preprocessing apparatus will be described.

FIG. 1 is a schematic block diagram of a semiconductor wafer pretreatment apparatus to which the treatment apparatus of the present invention is applied.

The semiconductor wafer pretreatment apparatus includes an object-to-be-processed portion 1 for accommodating an object to be processed, for example, a semiconductor wafer W (hereinafter referred to as a wafer), and a processing liquid vaporizer 2 which is a processing liquid vaporization portion.
Are connected via a supply pipe 3, and the processing liquid vaporizer 2
Supply pipe 3 for the process gas vaporized in step 1, that is, HMDS gas
It is configured to be supplied into the processing unit 1 and to perform the pretreatment of the surface of the wafer W as a pretreatment of other treatment.

In this case, the wafer W is placed and accommodated in the chamber 1a of the processing unit 1 on the mounting table 4 having a heating mechanism (not shown) built therein.
A diffusion plate 6 provided with a large number of diffusion holes 5 and a guide passage 7 for the HMDS gas having, for example, a cone shape are provided. A lid 1b that can be opened and closed is attached to the upper portion of the chamber 1a, and the opening and closing of the lid 1b allows the wafer W to be taken in and out of the chamber 1a. Further, an exhaust pipe 20 for exhausting the inside of the chamber 1a and exhausting the processed gas is connected to the bottom of the processing unit 1. The exhaust pipe 20 is provided with an ejector 21 (pneumatic vacuum device) for sucking the inside of the chamber 1a to a negative pressure, and the ejector 21 is connected to a drive air supply pipe 22 for supplying pressurized air for driving. ing. The exhaust pipe 20 and the drive air supply pipe 22 are provided with open / close valves 23 and 24, respectively. Further, the HMDS gas supply pipe 3 is connected to the supply pipe 3
A switching valve 25 is provided for switching and connecting to the intake system.

On the other hand, the treatment liquid vaporizer 2 includes the above-mentioned supply pipe 3
And an ultrasonic oscillator 10 as a processing liquid vaporizing means arranged in a vaporization chamber 9 connecting the N2 gas supply pipe 8 and a process for supplying a processing liquid (HMDS liquid) to the ultrasonic oscillator 10. HMDS connected via liquid supply pipe 11
And a processing liquid storage unit 13 that stores the liquid 12.
In this case, the ultrasonic transducer 10 is adapted to vibrate by driving a driver 14 (ultrasonic oscillator) arranged outside the vaporization chamber 9. In this case, the ultrasonic transducer 1
0 is formed of, for example, a piezoelectric element or a magnetostrictive element, can be driven by an electric signal from the driver 14, and its vibration output can be controlled by controlling the electric signal. In addition to the driver 14, a liquid amount detector 15, which is liquid amount detecting means, is connected to the connection terminal of the ultrasonic transducer 10. As shown in FIG. 2, the liquid amount detector 15 is
An amplifier 15a that amplifies a shockwave-shaped electric signal generated in the vibrator by the liquid droplets dropped on the ultrasonic vibrator 10,
Of the output voltage waveforms of the amplifier 15a, only those that exceed a certain voltage value are converted into pulse waveforms by a comparator 15b.
And a mono-multivibrator 1 for converting the pulse waveform group of the comparator 15b into one pulse waveform corresponding to one droplet.
5c and a counting counter 15 that counts the output signals of the mono multivibrator 15c and has a droplet number setting unit 15e.
It is composed of a driver 14 and an output unit 15f that sends a detection signal to the control unit 18, which will be described later.

A flow meter 8 is installed in the N2 gas supply pipe 8.
a is provided so that the supply amount of N2 gas can be controlled. Further, the temperature adjusting means 9a is provided on the outer periphery of the vaporization chamber 9.
Is provided and the temperature in the vaporization chamber 9 is maintained at 22 ° C., for example.

On the other hand, the ceiling portion of the vaporization chamber 9 above the ultrasonic transducer 10 is penetrated by a dropping nozzle 17 which is a processing liquid supply means connected to the processing liquid supply pipe 11 via an opening / closing valve 16. A predetermined amount of HMDS liquid is dripped onto the ultrasonic vibrator 10 from the dropping nozzle 17. In this case, the on-off valve 16 has the control unit 18
HMD from the dripping nozzle 17 by opening and closing according to commands from
The supply amount of the S liquid can be controlled. The control unit 18 receives the signal from the liquid amount detector 15 and transmits the command signal to the opening / closing valve 16.

In the semiconductor wafer pretreatment apparatus configured as described above, the ultrasonic oscillator 10 is vibrated by driving the driver 14, and the HMDS liquid 12 in the treatment liquid container 13 is ejected from the dropping nozzle 17 to the ultrasonic oscillator. When the HMDS liquid is dripped on 10, the HMDS liquid becomes fine liquid droplets due to the vibration and is vaporized in the vaporization chamber 9. And the vaporized HMD
The S gas flows through the supply pipe 3, passes through the diffusion holes 5 of the diffusion plate 6 in the guide passage 7 of the object-to-be-processed portion 1, and is uniformly diffused and applied to the surface of the wafer W. At this time, when the HMDS gas is supplied to the processing unit 1, the opening / closing valves 23 and 24 are opened to send driving pressure air from the drive air supply pipe 22 to the ejector 21, and the ejector 21 causes the chamber 1a of the processing unit 1 to be discharged. The atmosphere is sucked and exhausted to reduce the pressure. And
After the N2 gas mixed with HMDS is supplied to the processing unit 1, the opening / closing valve 24 is closed to stop the ejector 21,
The HMDS vaporized by the positive pressure of the gas is pressure-fed to obtain a normal HMDS processing state.

The vaporized HMDS supplied into the chamber 1a of the processing unit 1 is sprayed onto the heated wafer W, and the surface of the wafer W is hydrophobized. This allows
The adhesiveness / adhesiveness between the photoresist and the wafer W in the photoresist liquid application step described later is improved. Moreover,
Since the liquid droplets formed by the ultrasonic transducer are minute, dew condensation in the piping is less likely to occur and the liquid droplets of the processing liquid do not adhere to the surface of the object to be processed, resulting in deterioration of the quality of the object to be processed. It has an excellent effect such as no occurrence.

Further, from the droplet nozzle 17 to the ultrasonic transducer 1
When the amount of the supply liquid is detected from the phenomenon that occurs when the droplet of the HMDS liquid is dropped on the surface of 0, it can be detected as follows.

More specifically, referring to the timing charts of FIGS. 2 and 3, first, when the timer operates and the opening / closing valve 16 opens, the droplets of the HMDS liquid are dropped (FIGS. 3A, A ′, (See B), and a voltage is generated at a terminal (not shown) of the ultrasonic transducer 10 due to the impact. This voltage is amplified by the amplifier 15a, converted into a pulse waveform which becomes a logic "1" only when it is larger than the voltage designated by the comparator 15b (see FIGS. 3C and 3D), and then the droplets are generated by the mono-multivibrator 15c. It is converted into one pulse waveform corresponding to one pulse (see FIG. 3E). And the counting counter 1
The number of drops is counted by 5d, and the supply liquid amount is detected (see FIG. 3F). When it is detected that the predetermined supply amount has been reached, the signal α is sent to the control unit 18 and the driver 14, the on-off valve 16 is closed, and the supply of the HMDS liquid is stopped. Therefore, the supply amount of the HMDS liquid can be controlled. As described above, in order to detect the supply amount of the HMDS liquid, the driver 14 is stopped, but the driver 14 does not necessarily have to be stopped, and the supply liquid amount may be detected while the driver 14 is driven. it can. For example, by providing a filter (not shown) for removing frequencies near the ultrasonic signal for driving in the circuit of the liquid amount detector 15, the HM
It is possible to detect the electric signal generated by the droplet of the DS liquid. In addition to the above-mentioned supply amount of HMDS liquid,
For example, it can be detected by a method such as spectrum discrimination.

Specifically, the semiconductor wafer pretreatment apparatus configured as described above is used by being incorporated in a part of the semiconductor wafer treatment apparatus shown in FIG. That is, the processing apparatus is mainly composed of a processing mechanism unit 30 in which a processing mechanism for performing various processes on the wafer W is arranged, and a loading / unloading mechanism 31 for loading / unloading the wafer W into / from the processing mechanism unit 30. It is configured.

The carry-in / carry-out mechanism 31 is provided for the wafer W before processing.
A wafer carrier 32 for storing the wafer W, a wafer carrier 33 for storing the processed wafer W, an arm 34 for sucking and holding the wafer W, and an X for moving the arm 34 in the X direction, the Y direction, and the θ direction, respectively. Directional movement mechanism 3
5, a Y-direction moving mechanism 36, a θ-direction moving mechanism 37, and a mounting table 38 for transferring the wafer W to and from the processing mechanism unit 30. Further, the processing mechanism unit 30 includes a preprocessing mechanism 1 (specifically, an object processing part) which is a processing device of the present invention for performing a preprocessing for improving the adhesion between the wafer W and the resist film. , Coating mechanisms 39a and 39b for coating the resist liquid on the upper surface of the wafer W
Then, the cooling mechanism 40 for cooling the wafer W before the resist solution is coated by the coating mechanisms 39a and 39b to adjust the temperature to a predetermined temperature, and the solvent remaining in the resist film coated on the wafer W are evaporated. Is provided with a baking mechanism 41 for performing a heating process. In addition, the processing mechanism unit 30 includes the above-described processing mechanisms 1 and 39a.
An arm 42 for loading and unloading the wafer W into and from 41
A transport mechanism 42 having a is arranged so as to be movable along the transport path 43.

In the processing unit configured as described above, the wafer W loaded from the loading / unloading mechanism 31 is
After pretreatment by the pretreatment mechanism 1, cooling treatment and coating treatment are performed, and then heat treatment is performed by the bake mechanism 41, and then the wafer is conveyed to the carry-in / carry-out mechanism 31 and then the wafer carrier 33.
It is stored in.

In the above embodiment, the case where the processing apparatus of the present invention is applied to the wafer preprocessing apparatus has been described, but other than the preprocessing apparatus, for example, a coating apparatus, a developing apparatus,
Of course, it can be applied to a processing apparatus such as a CVD apparatus.

[0029]

As described above, according to the processing apparatus of the present invention, the processing gas of the processing gas is controlled by controlling the driving power of the ultrasonic vibrator or the supply liquid amount because the processing apparatus is configured as described above. The concentration can be controlled easily and reliably.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a semiconductor wafer pretreatment device to which a treatment device of the present invention is applied.

FIG. 2 is a schematic configuration diagram showing a liquid amount detecting means in the present invention.

FIG. 3 is a timing chart showing a liquid amount detection state in the present invention.

FIG. 4 is a schematic plan view showing a semiconductor wafer processing unit having the semiconductor wafer pretreatment apparatus of FIG.

FIG. 5 is a schematic configuration diagram showing a conventional processing apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing part to be processed 2 Treatment liquid vaporizer 3 Supply pipe 8 N2 gas supply pipe 9 Vaporization chamber 10 Ultrasonic transducer (treatment liquid vaporization part) 11 Treatment liquid supply pipe 12 HMDS liquid (treatment liquid) 13 Treatment liquid Storage part 15 Liquid amount detector (liquid amount detection means) 16 Opening / closing valve 17 Dropping nozzle (processing liquid supply means) 18 Control part W Semiconductor wafer (object to be processed)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location H04R 17/00 331 7350-5H

Claims (1)

[Claims] 1. A processing apparatus comprising a processing target object processing section, a processing liquid accommodating section, and a processing liquid vaporization section, wherein the processing liquid vaporization section is provided with an ultrasonic vibrator, and the ultrasonic vibrator is provided. A treatment liquid supply unit for supplying a predetermined amount of treatment liquid is provided, and a liquid amount detection unit is connected to the ultrasonic vibrator, and the treatment liquid supply of the treatment liquid supply unit is controlled by the output of the liquid amount detection unit. A processing device characterized by the above.