JPH1190365A - Cleaning of parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promote peeling of a polymer deposit and to decrease the treating time to remove the polymer by using an ether liquid as a cleaning liquid which contains C4 F9 OCH3 having high permeability in the polymer deposit containing carbon and fluorine. SOLUTION: Polymers -(CF2 )n- containing carbon and fluorine produced by generation of plasma deposit on the surface of a ring member 10 where a semiconductor wafer 21 is mounted in an etching device 13 used to remove a silicon oxide film 21a of the semiconductor wafer 21. In order to remove the polymers depositing on the ring member, the ring member is dipped in an ether liquid containing C4 F9 OCH3 . The ether liquid permeates into the interface between the polymers and the ring member to be cleaned and peels the polymer from the surface of the ring member 10. By this method, the same cleaning effect can be obtd. by 1 week treatment which is about a half period of a conventional method, and the effect does not saturate even in the treatment over 1l week.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for cleaning components of a machine such as a semiconductor manufacturing apparatus, and more particularly, to a method for cleaning a machine device such as a semiconductor manufacturing apparatus.
A cleaning method for removing polymer deposits containing carbon and fluorine from a part.

[0002]

2. Description of the Related Art As a device used in a semiconductor device manufacturing process, there are a chemical vapor deposition (CVD) device for forming a thin film, an etching device for an etching process, and an ashing device for removing an etching mask. . Some of these devices utilize plasma in a gas environment containing carbon and fluorine.

In the above-described apparatus utilizing plasma in a gas environment containing carbon and fluorine, a polymer containing carbon and fluorine generated by the plasma reaction adheres to components in a reaction chamber. Since the deposit of the polymer causes contamination, it is necessary to periodically remove the polymer in the reaction chamber.

One of the methods for removing this polymer is (C
₃ F ₇₎ using a washing liquid consisting mainly of ₃ N, a method of immersing the component in the cleaning liquid. According to this conventional method, the cleaning liquid permeates the interface between the component and the polymer, thereby separating the polymer from the component to which the polymer has adhered, thereby removing the polymer from the component.

[0005]

However, in the conventional cleaning liquid, the permeability to the interface is low, and the time required to immerse the polymer in the cleaning liquid in order to remove the polymer from the component is as follows.
Extremely long processing times of over two weeks were required. Since such a long process causes a reduction in the operation rate of the apparatus, an efficient cleaning method has been desired.

[0006]

The present invention adopts the following constitution in order to solve the above points. <Construction> The present invention provides a C liquid having a higher property of penetrating into polymer deposits containing carbon and fluorine generated by the generation of plasma in a gas environment containing carbon and fluorine as compared with the conventional cleaning liquid. _An ether solution containing ₄ F ₉ OCH ₃ is used as a washing solution for the polymer.

<Effect> Since the above-mentioned ether liquid shows almost twice the penetrating power to the above-mentioned polymer containing carbon and fluorine as compared with the conventional cleaning liquid, the polymer is separated from the deposit. Is promoted. Therefore, the polymer can be removed in about half the processing time as compared with the conventional cleaning method using the cleaning liquid.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. <Structure of a specific example> FIG. 1 shows a specific example for carrying out the cleaning method according to the present invention. In the cleaning method according to the present invention, the component 10 to be cleaned is immersed in, for example, an ether liquid 12 containing C ₄ F ₉ OCH ₃ contained in a cylindrical container 11.

In the example shown in FIG. 1, the component 10 is a component of an etching apparatus used for manufacturing a semiconductor device. FIG. 2 is a sectional view schematically showing a parallel flat etching apparatus for reactive ion etching.

As shown in FIG. 2, a parallel flat type etching apparatus 13 includes, for example, CF containing carbon and fluorine.
A discharge tube 16 for defining a reaction chamber 15 into which a reactive gas such as ₄ is introduced via a gas introduction tube 14 is provided. Reaction chamber 1
5, a negative pressure is introduced through an exhaust pipe 17 extending from a negative pressure source (not shown), as is well known in the art.
The discharge tube 16 has a pair of electrodes 18 and 19 for turning the reactive gas introduced into the reaction chamber 15 into plasma.
Is arranged. Between these electrodes 18 and 19,
A high frequency voltage is applied by the high frequency power supply 20.

A workpiece 21 is placed on the lower electrode 19 via a removable quartz ring member 10. The workpiece 21 to be subjected to the etching process is, for example, a semiconductor wafer 21 made of silicon having a surface on which a silicon oxide film 21a to be etched is formed. The semiconductor wafer 21 is disposed on the ring member 10 with the silicon oxide film 21a facing the upper electrode 18 in order to remove the silicon oxide film 21a formed on the surface.

According to the etching apparatus 13, as is well known in the art, the semiconductor wafer on the ring member 10 is subjected to a chemical reaction of reactive ions contained in the plasma generated between the pair of electrodes 18 and 19. The silicon oxide film 21a of 21 is removed. The ring member 10 on which the semiconductor wafer 21 is mounted is used to enhance the uniformity of the etching by the reactive ions, and the surface of the ring member 10 includes carbon and fluorine due to the above-described generation of plasma. including, for example, as represented by the molecular formula of _{C 2 F 6, - (CF} 2) n- polymer adheres.
The adhesive force of this polymer becomes stronger as the carbon / fluorine ratio in the reaction gas increases.

In order to remove the polymer adhering to the ring member 10, the ring member 10 is immersed in the ether liquid 12 containing C ₄ F ₉ OCH ₃ as shown in FIG. The ether liquid 12 permeates the interface between the polymer and the ring member 10 which is a component to be cleaned, thereby separating the polymer from the surface of the ring member 10.

This peeled state was observed for the ring member 10 after the operation under the same conditions in the contact hole etching step using, for example, the etching apparatus 13 shown in FIG. The operating conditions of the etching apparatus 13 are as follows. As a reaction gas, a mixed gas of Ar / CHF3 / CF4 (flow ratio: 400/20/20 sccm) was used, the pressure in the reaction chamber 15 was maintained at 250 mTorr, and the power of the high frequency power supply 20 was maintained at 800 W. A 6-inch semiconductor wafer 21 was used as a workpiece, and the temperature of the lower electrode 19 was maintained at -10 ° C.

Under such etching operation conditions, the etching process is repeated for one etching time of 60 seconds, and after the total etching time reaches about 20 hours, the ring member 10 under the same condition is conventionally used. The method and the method of the present invention were compared.

In the conventional method, (C ₃ F ₇ )
Using a washing liquid consisting mainly of ₃ N, parts 1 to the washing liquid
0 while the ring member 10 is maintained approximately every 24 hours.
The state of peeling of the polymer from the surface was visually observed with a microscope having a magnification of 20 times. In this conventional cleaning method, it took about two weeks to remove the polymer by peeling, and when the treatment was carried out for more than that, a saturation phenomenon was observed in the cleaning effect, and a sufficient cleaning effect was not observed.

On the other hand, the above-mentioned C ₄ F ₉ OC
In the present cleaning method using the ether solution 12 containing H ₃ ,
According to the same observation as described above, a cleaning effect equivalent to the conventional one was observed in the treatment for one week, which is about half the processing time compared to the conventional one. Moreover, the cleaning effect did not saturate even after more than one week of treatment.

As described above, according to the cleaning method of the present invention, the polymer can be effectively removed in about half the conventional processing time. After the treatment with the cleaning liquid, the ring member 10 is washed with a rinsing liquid such as ethanol, acetone or isopropyl alcohol, and then dried and stored, as in the related art.

Ether liquid 1 for immersing component 10 to be cleaned
2 is desirably made of stainless steel. The polymer peeled off from the component 10 to be washed hardly adheres to the stainless steel container 11. Therefore, the washing operation of the container 11 can be performed easily and quickly, and the polymer adhered to the inner wall of the container 11 can be reliably prevented from re-adhering to the part 10 to be washed.

Further, in order to prevent the fluctuation of the components of the cleaning liquid or the deterioration of the cleaning effect due to the evaporation of the ether liquid 12 containing C ₄ F ₉ OCH ₃ from the container 11, the container 1
It is desirable to use a closed container as 1.

As a means for sealing the container 11, as shown in FIG.
At a height of several tens of mm. Ether liquid 12
Pure water 22 stretched on the liquid surface 12a of the
And effectively prevent evaporation of the ether solution.

Further, in order to promote the above-mentioned stripping action of the ether liquid 12 containing C ₄ F ₉ OCH ₃ , ultrasonic waves are applied to the ether liquid 12 in the container 11 using an ultrasonic cleaning device. Can be. The addition of the ultrasonic wave can further enhance the effect of removing the polymer from the component 10 to be cleaned. This addition of ultrasound, in particular,
As a finishing step of the treatment with the ether liquid 12, it is extremely effective in removing fine polymer residues that are likely to remain on the part 10 to be cleaned.

In the above description, an example in which the present invention is applied to the cleaning of the quartz ring member 10 which is a detachable part of the etching apparatus used for manufacturing the semiconductor device has been described. For example, the present invention can be applied to the cleaning of various removable parts which are contaminated with the polymer in a reaction chamber such as a discharge tube and a clamp member for holding a workpiece.

Further, the present invention is not limited to a semiconductor manufacturing apparatus other than a chemical vapor deposition (CVD) apparatus for forming a thin film or an ashing apparatus for removing an etching mask, and a gas environment containing carbon and fluorine. It can be applied to the cleaning of various parts to remove polymers of carbon and fluorine in an apparatus utilizing plasma below.

[0025]

According to the present invention, as described above, C ₄ F having a high permeability to a polymer containing carbon and fluorine generated by the generation of plasma in a gas environment containing carbon and fluorine. By using an ether solution containing ₉ OCH ₃ as a cleaning solution for the polymer, the polymer can be removed with a processing time of about half the conventional value, and the time required for the cleaning process can be greatly reduced. Become.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing a cleaning method according to the present invention.

FIG. 2 is a cross-sectional view schematically showing an etching apparatus in which components for receiving a cleaning method according to the present invention are incorporated.

[Description of Signs] 10 Parts to be cleaned (ring member) 12 Ether liquid containing C ₄ F ₉ OCH ₃

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C11D 7:28)

Claims (5)

[Claims] 1. A method for removing polymer deposits containing carbon and fluorine generated by generation of plasma in a gas environment containing carbon and fluorine from a part, wherein C ₄ F ₉ OCH ₃ is used as a cleaning liquid. A method for cleaning parts, comprising using an ether solution containing the same. 2. The cleaning method according to claim 1, wherein the ether solution is contained in a stainless steel container, and the component is immersed in the ether solution in the container. 3. The cleaning method according to claim 2, wherein the container is kept in a closed state. 4. The cleaning method according to claim 3, wherein pure water is applied to an upper surface of the ether solution in the container as a means for sealing the container. 5. The cleaning method according to claim 1, wherein ultrasonic waves are applied to the ether liquid while the parts are immersed in the ether liquid.