KR20070070866A - Plasma treatment apparatus and method for cleaning the same - Google Patents

Abstract

A plasma process apparatus is provided to minimize contamination of the inside of a chamber by effectively eliminating bounding particles. A process gas supply part(20) supplies process gas to the inside of a process chamber(10). A purge gas supply part supplies purge gas to the process chamber to re-suspend the particles(P) generated after a wafer treatment using plasma. A wafer chuck on which a wafer is placed is installed in the process chamber wherein an AC voltage is applied to the wafer chuck to ionize the particles. The ionized particles are exhausted by a particle exhausting part including a particle exhausting line(60) and a vacuum pump(65) installed in the particle exhausting line. The particle exhausting part further includes a collection part for collecting the ionized particles.

Description

Plasma treatment apparatus and cleaning method thereof {PLASMA TREATMENT APPARATUS AND METHOD FOR CLEANING THE SAME}

1 is a schematic configuration diagram of a plasma processing apparatus according to an embodiment of the present invention.

FIG. 2 is a process block diagram showing a cleaning method of the plasma processing apparatus shown in FIG. 1.

3 is a schematic configuration diagram of a plasma processing apparatus according to another embodiment of the present invention.

4 is a process block diagram illustrating a cleaning method of the plasma processing apparatus shown in FIG. 3.

5 is a schematic structural diagram of a plasma processing apparatus according to another embodiment of the present invention.

The present invention relates to a plasma processing apparatus that performs etching and / or deposition using a plasma process and a cleaning method for removing particles generated in a process chamber of the apparatus.

In order to produce a semiconductor product requires a very precise semiconductor manufacturing process, as well as a semiconductor manufacturing equipment that performs the semiconductor manufacturing process, these semiconductor manufacturing equipment can be largely divided into a preceding semiconductor manufacturing equipment and a subsequent semiconductor manufacturing equipment.

First, the above-described semiconductor manufacturing equipment performs a photolithography process, which is a preceding process for forming a semiconductor thin film pattern on a pure silicon wafer, and the subsequent semiconductor manufacturing equipment provides predetermined characteristics to the wafer through a photoresist thin film patterned on the wafer. An ion implantation process for implanting impurities, an etching process for etching and patterning a previously formed semiconductor thin film, a deposition process for adding a predetermined thin film to a wafer, a metal process for connecting a fine thin film circuit pattern, and the like are performed.

Among these, the semiconductor manufacturing equipment that performs the etching process may be divided into a wet etching equipment and a dry etching equipment, and the dry etching equipment includes a plasma processing apparatus using plasma gas.

In general, the plasma processing apparatus includes a process chamber, a gas supply unit installed in the process chamber and supplying a source gas necessary to generate plasma gas into the process chamber, a cathode electrode on which the wafer is seated, and facing the electrode. And an electrode unit having an anode electrode provided to be viewed, and gas distribution means for uniformly injecting the source gas supplied from the gas supply unit toward the wafer.

In addition, RF power is applied to the anode electrode during the etching process using the plasma processing apparatus having the above-described configuration.

Therefore, a large amount of particles are generated inside the process chamber of a conventional plasma processing apparatus due to stress caused by RF power applied to the anode electrode, and the particles are formed on the inner wall of the process chamber or the surface of other components. Is deposited.

The particles are also introduced into the chamber through the source gas and are also generated from the wafer during the plasma processing process.

By the way, the particles should be cleaned periodically to prevent yield degradation due to contamination of the wafer.

Thus, after etching about 100 to 300 wafers conventionally, the chamber is cleaned by a wet cleaning process with the etching chamber open to the atmosphere.

Then, after wet cleaning, the chamber and its inner surface are pumped down for a long time to provide consistent chamber characteristics. In the pump down process, the chamber is pumped down to a high vacuum environment for 2-3 hours to evacuate moisture and other volatile species confined within the chamber during the wet clean process. Thereafter, a series of etching processes are performed and seasoned on the dummy wafer.

In the competitive semiconductor industry, the increased cost per wafer resulting from downtime of the etch chamber during the wet cleaning and seasoning process steps described above is undesirable. Usually, it takes 2-3 hours to complete the wet cleaning process. In addition, wet cleaning and seasoning processes often provide inconsistent and variable etching characteristics. In particular, since the wet cleaning process is performed manually by an operator, it often changes from session to session, resulting in changes in chamber surface properties and low reproducibility of the etching process.

Accordingly, an object of the present invention is to provide a plasma processing apparatus and a cleaning method thereof capable of effectively removing particles within a short time after the process is performed.

The present invention to achieve the above object,

Process chambers;

A process gas supply unit supplying a process gas into the process chamber;

A purge gas supply unit supplying a purge gas to the process chamber to resuspend particles generated after a wafer processing process using plasma;

A wafer chuck seating the wafer inside the process chamber and receiving an alternating voltage to ionize particles; And

Particle discharge unit for discharging the ionized particles to the outside of the chamber

It provides a plasma processing apparatus comprising a.

In the practice of the present invention, the particle discharge part comprises a particle discharge line and a vacuum pump installed on the line.

In addition, the particle discharge unit may further include a particle dust collection unit, and the particle dust collection unit may further include a mesh provided in the particle discharge line and electrically conductive with the opposite polarity to the ionized particles.

The mesh may be installed on the inner wall surface of the process chamber or may be installed around the wafer chuck.

In addition, a DC voltage is applied to the mesh to conduct the mesh in the opposite polarity to the ionized particles, and nitrogen gas is used as the purge gas.

Plasma processing apparatus of such a configuration,

Supplying a purge gas into the chamber to suspend the particles;

Ionizing the particles by applying an alternating voltage to a wafer chuck on which the wafer is seated; And

Discharging the ionized particles out of the chamber

It can wash | clean by the cleaning method of the plasma processing apparatus containing.

According to a preferred embodiment of the present invention, after the particles are ionized, the method may further include collecting particles into the mesh by using a mesh electrically conductive with the opposite polarity of the ionized particles.

The above cleaning process can be performed at every wafer treatment or at regular intervals.

Cleaning the plasma processing apparatus using such a cleaning process can increase the cleaning cycle using the wet cleaning process, thereby improving productivity.

In addition, particles generated after the etching process using plasma can be effectively removed from the process chamber, thereby minimizing contamination in the chamber.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 shows a schematic configuration diagram of a plasma processing apparatus according to an embodiment of the present invention, and FIG. 2 shows a process block diagram showing a cleaning method for cleaning the plasma processing apparatus of FIG. 1.

Hereinafter, the present invention will be described using a plasma etching apparatus as an example, but the present invention can also be used in a plasma deposition apparatus that performs a deposition process using a plasma process.

The plasma processing apparatus for etching using a plasma process includes a process chamber 10 defining a process area for processing a wafer.

Process chamber 10 has sidewalls and bottom walls made from one of a variety of materials including metals, ceramics, glass, polymers, and composite materials. Here, the process chamber 10 may be flat, or may be provided with a ceiling of a rectangular, arcuate, conical, dome, or the like.

Process gas is introduced into the chamber 10 through the process gas supply 20. The process gas supplier 20 may include a gas outlet disposed around the wafer W, or may include a shower head 30 mounted on the ceiling of the chamber 10 and having an outlet therein. At this time, the shower head 30 and the process gas supplier 20 are connected through a process gas supply line 35.

In addition, one or more process electrodes may be used to accelerate or energize plasma ions in the process chamber 10. This process electrode includes an anode electrode installed on the ceiling of the chamber 10. Here, the anode electrode may be the same as the shower head 30.

The anode electrode is capacitively coupled with the cathode electrode 40 under the wafer (W). For example, the cathode electrode 40 may be formed of an electrostatic chuck. An electrode power source supplies an RF potential that keeps the anode and cathode electrodes at different potentials.

When the etching process is performed using the etching apparatus having the above-described configuration, as mentioned above, the components P inside the chamber 10, for example, sidewalls and bottom walls of the chamber 10, may generate particles P generated during the etching process. ) Is deposited.

Thus, in order to effectively remove the particles (P), the present invention provides a cleaning method comprising a particle suspension step, a particle ionization step and a particle discharge step.

More specifically, the plasma processing apparatus is a purge gas supply line for supplying a purge gas, for example, nitrogen (N2) gas, to the process chamber 10 in order to resuspend particles generated after a wafer processing process using plasma. 50 is provided. Here, the purge gas supply line 50 may be connected to the process gas supply line 35.

In order to ionize the particles P, an alternating voltage is applied to the cathode electrode 40, for example, the electrostatic chuck, on which the wafer W is seated.

In addition, a particle discharge line 60 and a vacuum pump 65 are provided to discharge the ionized particles P. Of course, the particle discharge line (2) also acts as an exhaust line, and the vacuum pump 65 may be pumped down after the wet cleaning process.

Hereinafter, the cleaning method of the above-described plasma processing apparatus will be described.

When performing a cleaning process for removing particles P inside the chamber 10 at every wafer processing or after processing a certain number of wafers, the inside of the chamber 10 is first passed through the purge gas supply line 50. To supply nitrogen gas.

As such, when nitrogen gas is supplied to the chamber 10, the particles P are suspended.

Next, an alternating voltage is applied to the cathode electrode 40 on which the wafer W is seated.

When an alternating voltage is applied to the cathode electrode 40 in this manner, the particles P attached to the wafer W are charged by the alternating voltage and ionized.

Thereafter, the vacuum pump 65 is operated to evacuate the inside of the chamber 10, thereby discharging the ionized particles P to the outside of the chamber 10.

3 is a schematic configuration diagram of a plasma processing apparatus according to another embodiment of the present invention, and FIG. 4 is a process block diagram illustrating a cleaning method for cleaning the plasma processing apparatus of FIG. 3. In implementing the present invention, the same reference numerals are assigned to the same constituent elements as in the above-described embodiment of FIG. 1, and a detailed description thereof will be omitted.

The present embodiment further includes a dust collecting part for collecting the ionized particles to increase particle discharge efficiency.

The dust collecting part includes a metal mesh 70, and a DC voltage supply part 80 for applying a DC voltage is electrically connected to the mesh 70.

In addition, the mesh 70 is provided with an acrylic discharge tube 75 for discharging the ionized particles P collected in the mesh 70 to the outside of the chamber 10, and the discharge tube 75. A vacuum pump (not shown) is connected thereto. Of course, the discharge tube 75 may be connected to the vacuum pump 65.

According to such a structure, after particle | grains P are ionized, the DC voltage supply part 80 supplies a DC voltage to the mesh 70. FIG.

In this case, a voltage of opposite polarity to the ionized particle P is applied as the DC voltage.

In this way, the ionized particles P are attracted toward the mesh 70 of opposite polarity by the attraction force, and then outside the chamber 10 through the evacuation tube 75 evacuated by the vacuum pump. Is discharged.

The plasma processing apparatus having such a configuration collects the ionized particles P in the mesh 70 and then discharges them out of the chamber through the discharge tube 75, thereby improving particle discharge efficiency.

5 is a schematic configuration diagram of a plasma processing apparatus according to another embodiment of the present invention. The embodiment of the present invention differs from the above-described embodiment of FIG. 3 in that the mesh 70 is formed in a circular ring shape. The wafer W is disposed around the wafer W.

In addition, the mesh 70 is preferably installed to maintain the wafer chuck and the ground inclination 60 °.

In the plasma processing apparatus having such a structure, since the mesh 70 is disposed around the wafer W, the particle discharging efficiency can be further improved as compared with the embodiment of FIG. 3.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above embodiments, and various modifications can be made within the scope of the claims and the detailed description of the invention and the accompanying drawings. In addition, it is natural that it belongs to the scope of the present invention.

Embodiments of the present invention as described above can effectively remove particles generated inside the process chamber after the process.

As such, the present invention can effectively remove bounding particles, thereby minimizing contamination inside the chamber, thereby increasing the frequency of the wet cleaning process.

Therefore, it is possible to solve the problem of reduced productivity caused by the wet cleaning process.

In addition, since the DC power supply, the mesh and the discharge tube need only be installed in the existing plasma processing apparatus without complicated additional equipment, the installation cost is low and the installation is simple.

Claims (11)

Process chambers; A process gas supply unit supplying a process gas into the process chamber; A purge gas supply unit supplying a purge gas to the process chamber to resuspend particles generated after a wafer processing process using plasma; A wafer chuck seating the wafer inside the process chamber and receiving an alternating voltage to ionize particles; And Particle discharge unit for discharging the ionized particles Plasma processing apparatus comprising a. The method of claim 1, The particle discharge unit includes a particle discharge line and a vacuum pump installed in the line. The method of claim 2, The particle discharge unit further comprises a dust collector for collecting the ionized particles. The method of claim 3, wherein The dust collector includes a mesh electrically conductive to the opposite polarity of the ionized particles, and a DC voltage supply unit configured to apply a DC voltage for conducting the mesh. The method of claim 4, wherein And the mesh is installed on the sidewall of the process chamber. The method of claim 4, wherein And the mesh is installed around the wafer chuck. The method according to any one of claims 1 to 6, Nitrogen gas is used as the purge gas. In the plasma processing apparatus for processing a wafer by performing a plasma process, Supplying a purge gas into the chamber to suspend the particles; Ionizing the particles by applying an alternating voltage to a wafer chuck on which the wafer is seated; And Discharging the ionized particles out of the chamber Cleaning method of the plasma processing apparatus comprising a. The method of claim 8, And after ionizing the particles, collecting particles into the mesh using a mesh conductive with a polarity opposite to that of the particles. The method of claim 9, A cleaning method of a plasma processing apparatus for applying a DC voltage to the mesh. The method according to any one of claims 8 to 10, The cleaning method of the plasma processing apparatus using nitrogen gas as said purge gas.

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