JPH06304465A - Method for cleaning of chamber and apparatus therefor - Google Patents

Abstract

PURPOSE:To provide a method and an apparatus for cleaning wherein stain etc., adhering the inner wall of a chamber can be easily removed with no contact without requiring disassembling of the chamber. CONSTITUTION:Microwave 3 is introduced into a chamber 1 used under vacuum or ordinary pressure and stain 5 adhering the inner wall 2 of the chamber is removed by incineration caused by the action of the microwave 3.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chamber cleaning method and a cleaning apparatus, and more particularly to cleaning various chambers used for processing, transporting and storing semiconductor substrates, liquid crystal substrates and the like in a highly clean atmosphere. A method and a cleaning device.

[0002]

2. Description of the Related Art In the manufacturing process of semiconductors, liquid crystal display devices, etc., substrate processing, transportation, storage, etc. are carried out in a vacuum atmosphere or a gas atmosphere of high cleanliness.
Therefore, various chambers are used, for example, a vacuum tunnel for transferring wafers or the like in vacuum, a vacuum chamber for processes, a robot chamber, a load lock chamber chamber, a chamber for transferring wafers or the like under normal pressure, It is a chamber for a process which is used under pressure.

In a semiconductor manufacturing process or the like, in order to avoid a decrease in yield, whether under vacuum or under normal pressure,
A clean environment is required for the processing, transportation, and storage environment of semiconductor substrates and the like. However, as the above-mentioned various chambers that were initially clean are used for a long time, gas used in the various chambers or particles generated in the various chambers adhere to the inner wall of the chamber and contaminate the chamber. In addition, the inner wall of the chamber is contaminated due to the peeling of particles of silicon or silicon oxide adhering to the photoresist applied to the front surface of the wafer and the back surface of the wafer, and the particles of metal or organic substances generated when the valve of the equipment is opened and closed. To do. When dirt adheres to the inner wall of the chamber, particles of dirt on the inner wall of the chamber are peeled off, and dirt is adhered to a substrate to be processed such as a semiconductor wafer to be placed in a high clean environment, which leads to a reduction in manufacturing yield of semiconductor elements and the like. It will be.

In order to remove dirt on the inner wall of the chamber,
Each chamber is regularly cleaned. In the conventional method of cleaning the inner wall of the chamber, if the dirt is light, the worker sucks the contaminants with a vacuum cleaner or the like. If it is further contaminated, the chambers such as the transfer tunnel chamber, the process device, and the load lock chamber are disassembled, thoroughly cleaned, and then reassembled.

[0005]

In the conventional cleaning method, it takes time to disassemble the chamber, and a long cleaning time is required for disassembling the chamber or related manufacturing equipment. It was very unreasonable to stop such work.

In view of the above-mentioned problems of the prior art, the present invention provides a cleaning method and a cleaning apparatus that can easily remove dirt and the like adhering to the inner wall of the chamber without contacting the chamber without disassembling the chamber. With the goal.

[0007]

According to the present invention, microwaves are introduced into a chamber used under vacuum or normal pressure, and the contaminants adhering to the inner wall of the chamber are destroyed by the microwaves.
Alternatively, it is characterized in that it is activated by heating and peeled by an air flow, or is removed by ashing by irradiation with ultraviolet rays.

[0008]

Since the dirt adhered to the inner wall of the chamber is burned by the microwave, or the dirt is removed by ashing or ashing with the air flow, the inner wall of the chamber can be cleaned without contact. Therefore, an extremely clean cleaning method can be realized without requiring labor such as disassembling the chamber.

[0009]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is an explanatory view showing a chamber cleaning apparatus according to a first embodiment of the present invention. The chamber 1 is a vacuum tunnel for transfer, a vacuum chamber for process, a robot chamber, a load lock chamber, a chamber for transporting a wafer under normal pressure, a process chamber, and the like. Chamber 1
Is equipped with a microwave oscillator 3. An appropriate oscillation frequency of the microwave oscillator 3 is about 300 GHz to 300 MHz. When the inner wall 2 of the chamber is contaminated, that is, the contaminant 5 is attached, a microwave having a frequency that resonates with the natural frequency of the contaminant 5 is introduced into the chamber.
Raise the temperature of.

FIG. 2 is an explanatory view of a mechanism in which the temperature of the pollutant rises by the irradiation of microwaves. Atom 15 and atom 16
The outer electrons connecting with and generate natural vibration f1 unique to the substance between the atoms. When the pollutant 5 is irradiated with the microwave 17 that resonates with this natural frequency, the vibration of the bonding portion between the atoms 15 and 16 becomes violent, resulting in vibration f2, and the temperature of the pollutant 5 rises.

If the temperature rise of the pollutant 5 occurs, the pollutant 5 itself can be burnt and gasified depending on the kind of the pollutant. That is, if the chamber is used in a vacuum environment by gasification, the vacuum pump 13 attached to one of the chambers 1 evacuates to remove the contaminants 5 and cleans the chamber. In the case of a chamber used under normal pressure by burning out pollutants 5 into gas, clean nitrogen gas (N2) is made to flow as a gas flow from a valve 7 which is a gas introduction device, and the other side of chamber 1 is used. It is discharged to a valve 9 provided at the end of the. Thus, the inner wall 2 of the chamber 1 can be cleaned by removing the burned and gasified pollutants by the air flow. At this time, the gas generated by burning the pollutant 5 on the inner wall 2 of the chamber 1 is a harmful gas, which is detoxified by the detoxification device 11 and released into the atmosphere.

Depending on the type of pollutant 5, the burning temperature is high, and even if the burning cannot be done only by microwave irradiation,
The pollutants cause a temperature rise due to the mechanism described above. As the temperature of the contaminant 5 itself rises and is activated, the bonding force with the chamber inner wall 2 is weakened. That is, it is conceivable that the activation of the pollutant itself increases the distance from the inner wall of the chamber to which the pollutant adheres, and reduces the van der Waals force, which is the energy that adheres, and facilitates separation.

Generally, the van der Waals force when the particles adhere to a flat surface is inversely proportional to the square of the distance from the particles. Assuming that 0.1 μm SiO2 particles adhere to a stainless steel plate, the adhesion energy increases to 9.7 × 1 when the adhesion distance increases from 1 atom to 2 atoms.
Reduced from 0-4 dyn to 2.4 x 10-4 dyn, 340
Particles that did not separate even with the energy of the air flow of m / s can now be separated (please note that an air flow of 340 m / s is 0.1
The energy given to a μm particle is 7.1 × 10 −4 dyn). As described above, even the fine particles that have not been separated by the airflow are activated by the irradiation of the microwaves, whereby the contaminants are separated and removed by the airflow from the attached chamber inner wall 2. It is also possible to do.

FIG. 3 is an explanatory diagram of a chamber cleaning apparatus according to a second embodiment of the present invention. The chamber cleaning device includes a microwave oscillator 3 and an ultraviolet lamp 4 in the chamber. That is, the chamber 1 used under vacuum or normal pressure
A microwave generated by a microwave oscillator 3 is propagated inside the chamber 1, and the contaminant 5 attached to the chamber inner wall 2 is heated and activated by the microwave. Then, while irradiating the ultraviolet ray from the ultraviolet lamp 4, a gas of O2, O3, Cl2 or F2 is caused to flow from the valve 8 which is a gas introducing device to incinerate the pollutant 5. Then, ashed pollutants are discharged into the atmosphere by the N2 gas flow from the valve 7 or from the valve 9 by the vacuum pump 13 or the like.

Ultraviolet rays are oxygen (O2, O3), chlorine (Cl
2) By combining with fluorine (F2) gas, organic substances such as resist, inorganic substances such as silicon oxide and metal can be ashed. Oxygen (O2 or O3) gas generates radical oxygen (O) by irradiation of ultraviolet rays,
Ash organic substances such as resist. Chlorine (Cl2) gas generates radical chlorine (Cl) by irradiation with ultraviolet rays to form a halide, which halogenates and removes inorganic substances such as metal particles and silicon. When a combination of fluorine (F2) gas and hydrogen (H2) or argon (Ar) gas is used, radical fluorine (F) is generated by irradiation of ultraviolet rays to halogenate and remove silicon oxide and the like.

Such ashing and halogenation can be carried out more effectively by raising the temperature of the contaminant 5 and activating it. For example, in the case of ashing a photoresist, the combination of UV and O3 is 250 ° C.
6 when ashing at 150 ° C
The ashing can proceed at a speed as high as 10 times. Therefore, by irradiating the microwave, the temperature of the pollutant is raised and activated to irradiate the pollutant with ultraviolet rays to emit O2, O3,
By flowing Cl2 or F2 gas, pollutants can be effectively incinerated. However, fluorine (F2
) When flowing gas, argon (A
r) or hydrogen (H2) gas must flow simultaneously.

Next, the operation of the cleaning apparatus using the microwave combined with the ultraviolet lamp will be described. Chamber 1
When the vacuum pump 13 is attached to the valve 7, the valve 7 is closed. A microwave is oscillated by the microwave oscillator 3 and the temperature of the contaminant 5 is raised and activated by the irradiation of the microwave. Next, the valve 8 is opened, and a radical-generating gas corresponding to the type of contaminant is introduced into the chamber 1. Then, the ultraviolet lamp 4 is turned on to irradiate the contaminant 5 with ultraviolet rays. The ultraviolet lamp 4 may be permanently installed in the chamber, or may be installed in the chamber only when cleaning. When the chamber has a large volume or the chamber has a long vacuum tunnel type transport path, an apparatus capable of automatically transporting the ultraviolet lamp along the transport path may be provided in advance in the chamber.

The pollutants ashed and halogenated by the reaction with the radicals caused by the irradiation of the ultraviolet lamp are sucked by the vacuum pump 13, detoxified via the detoxifying device 11, and discharged outside the chamber 1. If the chamber 1 is to be used at normal pressure, nitrogen (N2) gas is supplied to the valve 7
From the chamber 1, the polluted substances ashed and halogenated by being carried on the air flow are detoxified via the abatement device 11 and discharged to the outside of the chamber 1.

Also in the first and second embodiments, the inner wall 2 of the chamber 1 is generally made of a metal surface, and a waveguide for transmitting microwaves from one side of the chamber to the other end. Plays the role of. That is, even in the case of cleaning a chamber such as a long vacuum tunnel for transferring semiconductor wafers between process devices, the microwave oscillator 3 provided at one location uses the entire long transfer path as a waveguide to generate microwaves. Propagation can be performed and cleaning can be performed to every corner of the chamber.

[0021]

As described above, according to the present invention, contaminants adhering to the inner wall of the chamber are burnt out by irradiation of microwaves, or activated to facilitate separation, and removed by being put on an air stream, or oxygen, It is removed by ashing and halogenating with chlorine and fluorine radicals. Therefore, according to the above-described method of cleaning the chamber using microwaves, the inner wall of the chamber can be thoroughly cleaned without contacting contaminants and without requiring labor such as disassembling the chamber.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a chamber cleaning apparatus according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a mechanism in which the temperature of pollutants rises.

FIG. 3 is an explanatory diagram of a chamber cleaning device according to a second embodiment of the present invention.

[Explanation of symbols]

 1 Chamber 2 Chamber Inner Wall 3 Microwave Oscillator 4 Ultraviolet Lamp 5 Contaminant 7,8,9 Valve 11 Harmful Equipment 13 Vacuum Pump

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Takeshi Yoshioka 4-2-1 Motofujisawa, Fujisawa-shi, Kanagawa Stock company EBARA Research Institute

Claims (8)

[Claims] 1. A chamber used under vacuum or atmospheric pressure,
A method of cleaning a chamber, characterized in that microwaves are introduced, and contaminants attached to the inner wall of the chamber are burned to be removed by the microwaves. 2. A chamber used under vacuum or atmospheric pressure,
A method of cleaning a chamber, characterized in that a microwave and an air flow are introduced, and the dirt attached to the inner wall of the chamber is heated and activated by the microwave to facilitate separation, and the contaminant is removed by the air flow. 3. In a chamber used under vacuum or atmospheric pressure,
A microwave source, a gas introduction device, and an ultraviolet irradiation device are provided, and the dirt adhering to the chamber inner wall is heated and activated by the microwave introduced from the microwave source, and ultraviolet rays are irradiated from the ultraviolet irradiation device, and O2,
A method for cleaning a chamber, characterized in that a gas of O3, Cl2 or F2 is passed to incinerate and remove the dirt. 4. The method for cleaning a chamber according to claim 1, wherein the chamber is a waveguide for the microwave to propagate the microwave. 5. A chamber used under vacuum or atmospheric pressure,
A chamber cleaning apparatus comprising a microwave source, wherein a microwave introduced from the microwave source burns off stains attached to the inner wall of the chamber. 6. A chamber used under vacuum or atmospheric pressure,
A microwave source and a gas flow passage are provided, and the microwave introduced by the microwave source heats and activates stains adhering to the inner wall of the chamber, facilitating the peeling, and the air flow in the gas flow passage removes the stains. A cleaning device for a chamber, characterized in that it is removed. 7. A chamber used under vacuum or atmospheric pressure,
A microwave source, an ultraviolet irradiation device, and a gas introduction device are provided, and the dirt adhering to the chamber inner wall is heated and activated by the microwave introduced by the microwave source, and the ultraviolet irradiation is performed from the ultraviolet irradiation device. A chamber cleaning device, characterized in that the dirt is ashed and removed by O2, O3, Cl2 or F2 gas from a gas introduction device. 8. The chamber cleaning apparatus according to claim 5, wherein the chamber inner wall serves as a waveguide for the microwave to propagate the microwave.