TWI462162B - Cleaning method of apparatus for depositing carbon containing film - Google Patents

Description

Cleaning method for depositing a device containing a carbon film

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a method of cleaning a device for fabricating a semiconductor, and more particularly to a method of dry cleaning of a reactor for depositing a device containing a carbon film.

Generally, semiconductor components are fabricated by using a plurality of unit processes, such as an ion implantation process, a film formation process, a diffusion process, a photolithography process, and etching. Etching process. In the above unit process, in order to increase the reproducibility and reliability of semiconductor device fabrication, it is necessary to improve the film formation process.

A film of a semiconductor element is formed on a wafer by using, for example, sputtering, evaporation, chemical vapor deposition (CVD), and atomic layer deposition (ALD). A film deposition apparatus for performing the above method generally includes a reactor, a gas line supplying various gases to the reactor, and a wafer block in which the wafer is placed.

However, when a film forming process is performed by using a film deposition apparatus, a reaction product generated during the film forming process is deposited (attached) to the surface of the semiconductor film and the inner wall of the reactor. A film deposition apparatus for performing semiconductor mass production processes a large number of wafers. Therefore, when the semiconductor process is continuously performed in a state where the reaction product adheres to the reactor, the film characteristics in the semiconductor process will change. Its most representative example is membrane electricity. The change in resistance or thickness and the resulting particles due to the shedding of the reaction product. These particles can cause defects and adhere to the wafer during the deposition process, which will result in degradation of the yield of the semiconductor device.

Therefore, in the conventional semiconductor manufacturing method, the film deposition device is stopped before the film is changed, that is, after the wafer deposition process is performed for a predetermined time or after depositing a predetermined number of wafers, and the reactor is exposed to the air, so that the reactor is exposed to the air. The reactor and the components of the reactor are separated from one another. After cleaning the foreign matter deposited on the reactor and the various components by using a volatile material such as alcohol, the separate reactors are recombined. Typically, this method of cleaning is referred to as ex-situ cleaning. In the ex-situ cleaning method, productivity is significantly reduced when manufacturing a semiconductor, and a change-point of the device is generated.

Another cleaning method of the film deposition apparatus is a so-called in-situ cleaning dry cleaning method by which the inside of the reactor can be removed by using a corrosive gas without stopping the operation of the film deposition apparatus. Deposition product. For example, a perfluorized compound gas such as CF ₄ , C ₂ F ₆ , C ₃ F ₈ , C ₄ F ₈ , CHF ₃ , SF ₆ or NF _{3 is} injected into the reactor as a cleaning gas to clean , silicon oxide (SiO _x) or silicon nitride (SiN _x), etc. the film deposition apparatus silicon (Si), and said film is removed.

In particular, as the degree of integration of semiconductor elements continues to increase, in order to reduce leakage current, attempts have been made to add carbon into the film, for example, to deposit a low dielectric constant (low-k) film such as SiOCH. The metal nitride film (e.g., TaN) may comprise 10-20% carbon. Therefore, in a device for depositing a film containing 5% or more of carbon, when dry cleaning is performed by using a conventional etching gas, it is produced. A by-product of a white powder based on carbon fluoride (CF*). Therefore, there is a need for an improved dry cleaning method for depositing a carbon containing film.

The present invention provides a dry cleaning method for depositing a carbon-containing film.

According to an aspect of the present invention, there is provided a dry cleaning method for depositing a carbonaceous film-containing apparatus, the method comprising cleaning an interior of a reactor of the apparatus, wherein cleaning the interior of the reactor of the apparatus comprises supplying a cleaning gas to the reactor, The cleaning gas includes a halogen activated by using a remote plasma generator and simultaneously supplies an unactivated carbon removal gas to the reactor.

In the present invention, the cleaning gas may be a gas selected from the group consisting of NF ₃ , C ₂ F ₆ , CF ₄ , CHF ₃ , F _{2 ,} and combinations thereof. The carbon removal gas may be a gas including oxygen (O) or hydrogen (H). The carbon removal gas may be a gas selected from the group consisting of O ₂ , N ₂ O, O ₃ , NH ₃ , H _{2 ,} and combinations thereof.

Prior to supplying the cleaning gas and the carbon removal gas, the method further includes an O ₂ treatment to pre-removal of carbon present on the surface of the by-products present inside the reactor. After cleaning the interior of the reactor, the method further includes removing the residue of the cleaning gas by treating the carbon-containing film with a hydrogen-containing gas. In this case, the hydrogen-containing gas may be a gas selected from the group consisting of H ₂ , NH ₃ , SiH ₄ , H ₂ O, and combinations thereof.

After cleaning the interior of the reactor, the method further includes aging the interior of the reactor by using a carbonaceous film.

The invention will now be described more fully hereinafter with reference to the appended claims, However, the present invention may be embodied in different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

First, the cleaning method according to the present invention can be used to clean the film deposition apparatus shown in Fig. 1.

The film deposition apparatus 1 of FIG. 1 includes a reactor 10 having an internal space, a wafer block 12 mounted in the internal space of the reactor 10 for lifting and placing the wafer W, and a shower head 11 for injecting gas, and the shower head 11 allows the film to be formed on the film Placed on the wafer W on the wafer block 12.

The device 1 is for depositing a carbon-containing film on a semiconductor wafer W, such as a germanium wafer or a liquid crystal display (LCD) glass substrate. The apparatus 1 further includes a gas supply unit 20 that supplies a source gas of a certain process and an inert gas to the reactor 10 via a gas line. In the cleaning method according to the present invention, the cleaning gas includes halogen, and the cleaning gas is activated and supplied to the reactor 10 by using the remote plasma generator 22.

The cleaning gas including halogen may be a cleaning gas selected from the group consisting of NF ₃ , C ₂ F ₆ , CF ₄ , CHF ₃ , F _{2 ,} and combinations thereof. The carbon removal gas may be a gas including oxygen or hydrogen. For example, the carbon removal gas may be a gas selected from the group consisting of O ₂ , N ₂ O, O ₃ , NH ₃ , H _{2 ,} and combinations thereof.

Next, a cleaning method of the reactor 10 of the apparatus 1 of Fig. 1 according to an embodiment of the present invention will be described.

First embodiment

2 is a flow chart of a cleaning method in accordance with a first embodiment of the present invention.

Referring to Figures 1 and 2, in operation S1 of Figure 2, the internal pressure of the reactor 10 of the apparatus 1 is adjusted to be suitable for cleaning. The pressure inside the reactor 10 is from 0.3 to 10 torr. As the internal pressure of the reactor 10 decreases, the cleaning efficiency increases. The internal pressure of the reactor 10 is maintained at 0.5-4 torr.

Next, in operation S2, by supplying a cleaning gas to the reactor 10, the cleaning gas includes a halogen activated by using the remote plasma generator 22, and simultaneously supplies an unactivated carbon removal gas to the reactor 10. The inside of the reactor 10 is cleaned without stopping the operation device 1. The time of the cleaning operation S2 varies depending on the degree of contamination of the reactor 10, and can vary depending on whether 1000 or 500 wafers are processed. The carbon-containing film is removed at a rate of about 1000 Å/min, although it varies depending on conditions. Therefore, when processing 1000 wafers having a film thickness of 200 Å, the cleaning is performed for 200 minutes.

When a film such as TaCN is deposited using the device 1, the cleaning gas including halogen may be NF ₃ and the carbon removal gas may be O ₂ . The cleaning efficiency can be further maximized by operating the remote plasma generator 22, plasmaizing the cleaning gas, and supplying the cleaning gas to the reactor 10. Argon (Ar) can be used as a base process gas for generating plasma.

When cleaning is performed using only the corrosive gas of a general dry cleaning gas, the carbon and fluoride present in the reactor react with each other to form fluoride carbon and produce by-products in solid form. therefore, Reactor 10 cannot be completely cleaned. In the present invention, by removing the metal by-product in the reactor 10 by using a cleaning gas including a halogen and adding a carbon removing gas to a cleaning gas including a halogen, it can be cleaned without producing a by-product of a solid form. Reactor 10. Therefore, after processing a predetermined number of wafers, in-situ cleaning is performed without stopping the operation of the film deposition apparatus, so that the productivity of the film deposition apparatus is maximized. In particular, the invention is achieved by a partially activated gas. The cleaning gas is used in an activated state, and the carbon removal gas is used without being activated.

When the cleaning gas and the carbon removal gas are simultaneously activated and supplied to the reactor, they react with each other and produce organic by-products such as Teflon. According to the experimental results conducted by the inventors, the respective fluxes of the cleaning gas and the carbon removal gas must be adjusted to a very narrow range to avoid the production of organic by-products. Accordingly, the present invention provides a method of maximizing cleaning efficiency by activating only a cleaning gas, and removing carbon without activating carbon removal gas while not producing organic by-products. In this method, it is not necessary to avoid the generation of organic by-products by finely adjusting the respective flows of the cleaning gas and the carbon removal gas. Therefore, the reproducibility of the reactor is excellent, and a wider cleaning process margin can be obtained.

When the reaction of the cleaning operation S2 is completed, the cleaning operation S3 of removing the gas remaining in the reactor 10 is performed. The reactor 10, gas line and remote plasma generator 22 are cleaned. This is because a cleaning gas or the like may remain in the reactor 10 and the gas line. When such a problem does not occur, the cleaning operation S3 may be omitted. In this regard, the purge gas may be an inert gas such as Ar or N ₂ .

Second embodiment

Figure 3 is a flow chart of a cleaning method in accordance with a second embodiment of the present invention.

The cleaning method according to the second embodiment of the present invention is similar to the cleaning method of Fig. 2, but differs from the cleaning method of Fig. 2 in that other operations are also included.

Referring to Figures 1 and 3, in operation S11 of Figure 3, the internal pressure of the reactor 10 is adjusted to be suitable for cleaning.

Next, in operation S12, O ₂ processing is performed. An O ₂ treatment (operation S12) is performed to oxidize carbon on the surface of the by-product inside the reactor 10, and carbon is previously removed.

Subsequently, in operation S13, by supplying a cleaning gas to the reactor 10, the cleaning gas includes a halogen activated by using the remote plasma generator 22, and simultaneously supplies an unactivated carbon removal gas to the reactor 10. The interior of the reactor 10 is cleaned.

When the cleaning operation S13 is completed, the operation S14 of removing the gas remaining in the reactor 10 is performed. Operation S3 in Fig. 2 can be performed as operation S14.

Next, in operation S15, the operation of the processing apparatus 1 is further performed by using a hydrogen-containing gas to remove the residual of the cleaning gas. In this case, the hydrogen-containing gas may be a gas selected from the group consisting of H ₂ , NH ₃ , SiH ₄ , H ₂ O, and combinations thereof. The hydrogen-containing gas can be simply washed or treated by generating a plasma in a hydrogen-containing gas.

Next, the operation inside the reactor 10 is seasoned by using a carbon-containing film, and the reactor 10 is most suitable for film deposition.

After the cleaning is completed, in order to perform film deposition by loading the wafer, it is necessary to combine the atmosphere in the reactor 10. This is because the problem that the film deposited for the first time after the cleaning is completed has a different property (for example, a decrease in film thickness) from the film deposited in the subsequent process. Therefore, as a final operation of the cleaning method, before the loading of the first wafer, the aging operation S16 is performed in advance, that is, the film to be deposited on the wafer is covered on the inner surface of the reactor 10.

Although the present invention has been particularly shown and described with respect to the exemplary embodiments thereof, those skilled in the art should understand that various forms can be carried out without departing from the spirit and scope of the invention as defined in the appended claims. And the details of the changes.

According to the present invention, a device for depositing a carbon-containing film can be effectively cleaned. By supplying a cleaning gas to the reactor, the cleaning gas includes a halogen activated by a remote plasma generator, and simultaneously supplies an unactivated carbon removal gas to the reactor to clean the metal by-products inside the reactor. The reactor can be cleaned without producing by-products in solid form. Therefore, after processing a predetermined number of wafers, in-situ cleaning is performed without stopping the operation of the device for depositing the carbon-containing film, so that the productivity of the device for depositing the carbon-containing film is maximized.

In particular, in a reactor cleaning method using a partial activation gas, the cleaning gas is used in an activated state, and the carbon removal gas is used without being activated. Therefore, in this method, the reproducibility of the reactor is excellent, and a wider cleaning process tolerance can be obtained.

As described above, the present invention provides an in-situ cleaning method for depositing a carbon-containing film. Generally, when cleaning is performed using only corrosive gases, A by-product in the form of a solid is produced in the reactor and thus the reactor cannot be completely cleaned. In the present invention, the reactor can be cleaned without producing by-products in a solid form by removing the metal by-products in the reactor by using a cleaning gas including a halogen and adding a carbon removal gas to a cleaning gas including a halogen. .

In particular, the present invention describes a reactor cleaning method that uses a partially activated gas. The cleaning gas is used in an activated state, and the carbon removal gas is used without being activated. In this method, the reproducibility of the reactor is excellent, and a wider cleaning process tolerance can be obtained.

1‧‧‧membrane deposition device

10‧‧‧Reactor

11‧‧‧ sprinkler

12‧‧‧ Wafer block

20‧‧‧ gas supply unit

22‧‧‧Remote plasma generator

W‧‧‧ wafer

S1, S2, S3‧‧‧ steps

S11, S12, S13, S14, S15, S16‧‧ steps

1 illustrates an apparatus for depositing a carbonaceous film for performing a cleaning method in accordance with an embodiment of the present invention.

2 is a flow chart of a cleaning method in accordance with a first embodiment of the present invention.

Figure 3 is a flow chart of a cleaning method in accordance with a second embodiment of the present invention.

S1, S2, S3‧‧‧ steps

Claims (7)

A dry cleaning method for depositing a device comprising a carbon film, the method comprising cleaning an interior of a reactor of the apparatus, wherein cleaning the interior of the reactor of the apparatus comprises supplying a cleaning gas to the reactor and Simultaneously supplying an unactivated carbon removal gas to the reactor, the cleaning gas comprising a halogen activated by using a remote plasma generator, performing O before supplying the cleaning gas and the carbon removal gas ₂ treatment to pre-removal of carbon present on the surface of by-products present inside the reactor. A dry cleaning method for depositing a carbon film-containing apparatus according to claim 1, wherein the cleaning gas is composed of NF ₃ , C ₂ F ₆ , CF ₄ , CHF ₃ , F _{2 ,} and combinations thereof. A gas selected in the group. A dry cleaning method for depositing a carbonaceous film-containing apparatus according to claim 1, wherein the carbon removal gas is a gas including oxygen or hydrogen. A dry cleaning method for depositing a carbon film-containing apparatus according to claim 1, wherein the carbon removal gas is composed of O ₂ , N ₂ O, O ₃ , NH ₃ , H _{2 ,} and combinations thereof. A gas selected in the group. A dry cleaning method for depositing a carbon-containing film according to claim 1, further comprising: after cleaning the interior of the reactor, treating the deposited carbon-containing film by using a hydrogen-containing gas To remove the residue of the cleaning gas. A dry cleaning method for depositing a carbon film-containing apparatus according to claim 5, wherein the hydrogen-containing gas is from a group consisting of H ₂ , NH ₃ , SiH ₄ , H ₂ O, and combinations thereof. A gas of choice. The apparatus for depositing a carbonaceous film as described in claim 1 of the patent application The dry cleaning method further includes aging the interior of the reactor by using the carbon-containing film after cleaning the interior of the reactor.