KR20230011032A - Method for substrate processing apparatus and substrate processing method - Google Patents

Abstract

The present invention relates to a substrate processing device cleaning method and a substrate processing method including the same and, more specifically, to a substrate processing device cleaning method for cleaning thin films accumulated inside a process chamber and a substrate processing method including the same. As a cleaning method of a substrate processing device for removing a thin film formed inside a process chamber during a substrate processing process, the cleaning method of a substrate processing device comprises: a decomposition gas supply step (S10) of supplying decomposition gas that promotes decomposition of chemical bonds in the thin film to processing space; a cleaning gas supply step (S20) of supplying a cleaning gas that combines with the thin film whose chemical bonds have been decomposed through the decomposition gas and removes the thin film from the inside of the process chamber; and a process chamber exhaust step (S40) of exhausting the processing space. Accordingly, the cleaning efficiency of the substrate processing device can be increased.

Description

Substrate processing apparatus cleaning method and substrate processing method including the same {Method for substrate processing apparatus and substrate processing method}

The present invention relates to a substrate processing apparatus cleaning method and a substrate processing method including the same, and more particularly, to a substrate processing apparatus cleaning method for cleaning a thin film accumulated inside a process chamber and a substrate processing method including the same.

When various electronic devices such as semiconductor memories are manufactured on a substrate, various thin films are required, and various thin films are formed on the substrate for this purpose.

Methods for manufacturing thin films include physical and chemical methods, and recently, chemical vapor deposition (CVD: chemical vapor deposition) and atomic layer deposition, which form metal, dielectric, or insulator thin films on a substrate by chemical reaction of gas. (ALD: Atomic layer deposition) method is mainly used.

In particular, the atomic layer deposition method is gradually being actively used to deposit ultra-thin films according to the trend of miniaturization of devices, but since each of the four process steps must be strictly separated, the process takes a long time to improve productivity. There is this low issue.

On the other hand, thin film production is performed by introducing a gas for thin film production into a process chamber where a substrate is loaded and controlling the temperature of the substrate to react with the gas to form a thin film on the substrate. As the number of deposition processes increases, unwanted films or thin films are formed on the inner surface by various gases introduced into the process chamber.

At this time, the formed thin film is an impurity such as a particle, which adversely affects the thin film of the substrate to be manufactured. More specifically, during substrate processing, it is detached from the inside of the process chamber and contaminates the thin film of the substrate to be deposited. there is

In order to improve this problem, conventionally, the inside of a substrate processing apparatus on which a thin film is deposited is periodically cleaned, but in the case of the atomic layer deposition method, the cleaning time is added to the process step itself, so there is a problem in that productivity is greatly reduced.

More specifically, in the prior art, it takes 260 seconds or more to completely clean a thin film of 0.6 μm inside the process chamber, which increases the overall process time and lowers productivity.

On the other hand, when the cleaning time is reduced to less than a certain time to improve productivity, the cleaning of a specific position of the substrate processing apparatus cannot be completely performed. There is a problem that cannot be done.

An object of the present invention is to provide a substrate processing apparatus cleaning method capable of removing a thin film formed inside the substrate processing apparatus in a short time and a substrate processing method including the same in order to solve the above problems.

The present invention was created to achieve the object of the present invention as described above, and the present invention is a cleaning method of a substrate processing apparatus for removing a thin film formed inside a process chamber during a substrate processing process, chemical bonding of the thin film A decomposition gas supply step (S10) of supplying decomposition gas to promote decomposition into the processing space; a cleaning gas supplying step (S20) of supplying a cleaning gas that combines with the thin film whose chemical bonds have been decomposed through the decomposition gas and removes the thin film from the inside of the process chamber; Disclosed is a cleaning method of a substrate processing apparatus including a process chamber exhausting step (S40) of exhausting the processing space.

The decomposition gas supply step (S10) and the cleaning gas supply step (S20) may be performed simultaneously or sequentially.

The thin film is a SiO ₂ film, and in the decomposition gas supply step (S10), chemical bond decomposition between silicon and oxygen may be promoted through the decomposition gas.

The cracked gas may include NH ₃ .

The cleaning gas may include NF ₃ .

The cleaning gas may include a fluorine radical.

The cleaning gas supplying step (S20) may include a plasma processing step (S21) of plasma-processing the cleaning gas and a supplying step (S22) of supplying the plasma-treated cleaning gas to the processing space. .

A ratio of the decomposition gas to the cleaning gas may be 1/16 or less.

A ratio of the decomposition gas to the cleaning gas may be 1/80.

In the decomposition gas supply step (S10) and the cleaning gas supply step (S20), the temperature of the processing space of the process chamber may be 50 °C or more and 60 °C or less.

After the cleaning gas supplying step (S20), a purge gas supplying step (S30) of supplying a purge gas to the processing space may be further included.

In addition, the present invention, the cleaning step (S100) through the cleaning method of the substrate processing apparatus according to any one of claims 1 to 11 for performing cleaning of the inside of the process chamber; After the cleaning step (S100), a substrate processing method including a thin film deposition step (S300) of forming a thin film on the substrate is disclosed.

In the thin film deposition step (S300), a thin film may be formed on the substrate through an atomic layer deposition method (ALD).

Between the cleaning step (S100) and the thin film deposition step (S300), a seasoning step (S200) of forming a seasoning thin film on a portion exposed to the process gas inside the process chamber may be further included.

A substrate processing apparatus cleaning method and a substrate processing method including the same according to the present invention have an advantage in that the cleaning efficiency of the substrate processing apparatus is increased.

In particular, the substrate processing apparatus cleaning method and the substrate processing method including the substrate processing method according to the present invention promote a decomposition reaction of Si and O through NH ₃ when the SiO ₂ thin film is cleaned, thereby providing a more complete substrate processing apparatus. There is an advantage that thin film removal and cleaning are possible.

In addition, the substrate processing apparatus cleaning method and the substrate processing method including the same according to the present invention can reduce the cleaning time by removing the thin film in a short time for the same thin film thickness, thereby reducing the process time and improving productivity There are advantages that can be

1 is a flowchart showing a substrate processing method according to the present invention.
FIG. 2 is a flowchart illustrating a cleaning method of the substrate processing apparatus among the substrate processing methods according to FIG. 1 .
3 is a graph showing the effect of the cleaning method of the conventional substrate processing apparatus.
FIG. 4 is a graph showing the effect of the cleaning method of the substrate processing apparatus according to FIG. 2 , and a graph showing results of performing cleaning for 120 seconds while varying the ratio of NH ₃ to NF ₃ .
FIG. 5 is a graph showing the cleaning time reduction effect of the cleaning method of the substrate processing apparatus according to FIG. 2 .

Hereinafter, a substrate processing apparatus cleaning method and a substrate processing method including the substrate processing method according to the present invention will be described with reference to the accompanying drawings.

As shown in FIG. 1, the substrate processing method according to the present invention includes a cleaning step (S100) of cleaning the inside of the process chamber; After the cleaning step (S100), a thin film deposition step (S300) of forming a thin film on the substrate is included.

In addition, the substrate processing method according to the present invention, between the cleaning step (S100) and the thin film deposition step (S300), a seasoning step (S200) of forming a seasoning thin film on a portion exposed to the process gas inside the process chamber It further includes can do.

At this time, the substrate to be treated according to the present invention may be understood as including all substrates such as substrates used in display devices such as LED, LCD, and OLED, semiconductor substrates, solar cell substrates, and glass substrates.

In addition, here, the process chamber is a configuration in which a processing space is formed therein to perform substrate processing, such as depositing a thin film on a substrate, and various configurations are possible.

At this time, the inside of the process chamber is an object of cleaning and seasoning for the processing space, and is not limited to the inner surface of the process chamber, and includes the upper lid exposed to process gas during the substrate processing process, the inner wall surface of the chamber body, the substrate support, and the shower. It can be understood as a term including the surface of the head assembly and the like.

At this time, the process chamber may include a chamber body and an upper lid forming a processing space, a substrate support unit for supporting a substrate to be processed in the internal processing space, and a shower head for supplying various gases including process gas. assembly can be installed.

In addition, a plasma generator (RPG: Remote Plasma Generator) provided on the upper side of the process chamber to perform a plasma treatment on the cleaning gas described below may be additionally provided.

The cleaning step (S100) is a step of cleaning the inside of the process chamber, and may be performed by various methods.

That is, in the cleaning step (S100), a thin film may be deposited inside the process chamber in the process of depositing a thin film on the substrate through the thin film deposition step (S300), and the thin film may be removed and cleaned. there is.

At this time, since the thin film deposited inside the process chamber acts as a contaminant on the substrate to be processed and causes defects in the deposition process, it is essential to perform the cleaning step (S100), but conventionally, the time required to perform complete cleaning is 260 It is longer than a second, so there is a problem in that process efficiency is lowered and productivity is low.

Meanwhile, a detailed description of a cleaning method of the substrate processing apparatus for improving these problems will be described later.

The seasoning step (S200) is a step for creating an atmosphere in the process chamber suitable for the thin film deposition step (S300) after the cleaning step (S100), and can be performed by various methods.

For example, the seasoning step (S200) raises the growth rate of the thin film formed on the substrate in the thin film deposition step (S300) to a steady state, and removes particles remaining inside the process chamber even after cleaning and purging. It can be fixed in a state that does not easily come off from.

In particular, in the seasoning step (S200), by forming a seasoning thin film inside the process chamber before performing the thin film deposition step (S300), dropping of foreign substances inside the process chamber during the thin film deposition step (S300) is prevented in advance and the process Deposition of a thin film inside the chamber can be suppressed.

To this end, the seasoning step (S200) is a material that does not affect the thin film deposited on the substrate even if particles are generated in the thin film deposition step (S300), and is the same as the thin film deposited in the thin film deposition step (S300). may be made of matter.

The thin film deposition step (S300) is a step of forming a thin film on the substrate after the cleaning step (S100) and the seasoning step (S200), and may be performed by various methods.

In this case, the thin film to be deposited may be applied to an oxide-based thin film, and for example, SiO ₂ and TiO ₂ thin films may be deposited.

Meanwhile, the thin film deposition step (S300) may be performed through various deposition processes such as CVD, PECVD, ALD, and PEALD, and ALD may be applied as an example.

More specifically, in the thin film deposition step (S300), a source gas supply step for supplying a source gas, a purge step, a reaction gas supply step, and a purge step are repeatedly performed to deposit a thin film on the substrate.

In this case, low productivity is a problem due to the nature of the ALD process in which four steps must be repeatedly performed, and in addition to this, when the cleaning step (S100) has to be performed for a relatively long time, the entire process time is very long and the productivity is low. There is a problem.

In order to improve this problem, a cleaning method of the substrate processing apparatus applied to the cleaning step (S100) will be described.

As shown in FIG. 2, the cleaning method of the substrate processing apparatus according to the present invention includes a decomposition gas supply step (S10) of supplying a decomposition gas that promotes decomposition of the chemical bond of the thin film into the processing space; a cleaning gas supplying step (S20) of supplying a cleaning gas that combines with the thin film whose chemical bonds have been decomposed through the decomposition gas and removes the thin film from the inside of the process chamber; and a process chamber exhausting step (S40) of exhausting the processing space.

In addition, the cleaning method of the substrate processing apparatus according to the present invention may further include a purge gas supplying step (S30) of supplying a purge gas to the processing space after the cleaning gas supplying step (S20).

Meanwhile, the cleaning method of the substrate processing apparatus according to the present invention is for removing a thin film deposited inside a process chamber, and may be an in-situ cleaning method as a dry cleaning method.

The decomposition gas supply step (S10) is a step of supplying a decomposition gas that promotes decomposition of the chemical bond of the thin film into the processing space, and may be performed by various methods.

For example, in the decomposition gas supply step (S10), in order to promote the decomposition of the chemical bond between silicon (Si) and oxygen (O) of the SiO ₂ thin film deposited inside the process chamber, NH ₃ containing Decomposition gas can be supplied.

Through this, in the decomposition gas supply step (S10), the decomposition gas is a gas having an unstable unshared electron pair, and is highly reactive, and bonds to each of silicon (Si) and oxygen (O) of the deposited SiO 2 to decompose the bond between them. can do.

Thus, in the decomposition gas supply step (S10), an intermediate material may be generated together with a cleaning gas to be described later, and the thin film may be removed according to a reaction immediately following.

Meanwhile, as described above, the decomposition gas at this time may be NH3 gas.

The cleaning gas supply step (S20) is a step of supplying a cleaning gas for removing the thin film from the inside of the process chamber by combining with the thin film having chemical bonds decomposed through decomposition gas, and may be performed by various methods.

For example, the cleaning gas supplying step (S20) may include a plasma processing step (S21) of plasma-processing the cleaning gas and a supplying step (S22) of supplying the plasma-treated cleaning gas to the processing space. there is.

In this process, the plasma processing step (S21) may be activated by applying a preset frequency and RF power to the cleaning gas through a plasma generator.

At this time, the RF power may be supplied in various ways, frequencies, powers, etc., for example, VHF (Very High Frequency) of 20 MHz to 60 MHz band, HF (High Frequency) of 10 MHz to 20 MHz band, 250 KHz to 400 KHz band It may be applied with any one of LF (Low Frequency) or a combination and change thereof.

More specifically, the cleaning gas may be a gas containing a halogen element, and any cleaning gas may be applied as long as it is a conventionally disclosed gas for removing, etching, and etching the SiO ₂ thin film.

For example, a cleaning gas containing a fluorine (F) element may be applied to remove the SiO ₂ thin film, and for example, NF ₃ gas may be included.

Meanwhile, reactivity can be improved by including fluorine radicals through plasma treatment, whereby the SiO ₂ thin film deposited inside the process chamber can be removed by bonding with silicon (Si).

The decomposition gas supply step (S10) and the cleaning gas supply step (S20) described above may be performed sequentially in the order of the decomposition gas supply step (S10) and the cleaning gas supply step (S20). As another example, the decomposition gas supply step (S10) The supplying step (S10) and the cleaning gas supplying step (S20) may be performed simultaneously.

That is, the decomposition gas and the cleaning gas may be simultaneously supplied into the processing space, and more specifically, the plasma treatment step (S21) is performed first, and the supply step (S22) in which the cleaning gas is supplied to the processing space and the decomposition gas are processed The decomposition gas supply step (S10) supplied to the space may be performed at the same time.

Also, in the decomposition gas supply step (S10) and the cleaning gas supply step (S20), the cleaning gas and the decomposition gas may be supplied while maintaining a preset ratio or maintaining a ratio within a preset range.

For example, the ratio of the decomposition gas to the cleaning gas may have a value of 1/16 or less, and more specifically, the ratio of 1/80 may be maintained.

That is, as shown in FIG. 2 , when cleaning is performed by supplying the cleaning gas alone, a cleaning time of 260 seconds is required for complete cleaning, and the dry etch rate (DER) at this time may be 5555 Å and 120 When cleaning was performed with a cleaning time of seconds, the level of 3291Å was maintained, which was less than this.

On the other hand, when cleaning is performed for 120 seconds by supplying the cleaning gas and the decomposition gas together, as shown in FIG. It can be confirmed that it is 6082Å at 1/40, 5513Å at 1/16, and 5346Å at 3/40.

As a result, the time of 260 seconds required to completely perform cleaning can be reduced to less than half, 120 seconds, through the supply of NF ₃ cleaning gas alone _. There is a need.

However, even if the existing conventional time of 260 seconds is not up to 120 seconds, for the effect of simple time reduction such as 200 seconds, the effect can be achieved by introducing at least a portion of NH ₃ to the NF ₃ cleaning gas.

On the other hand, it was confirmed that the DER value decreased when the ratio exceeded 1/16, and this is because the decomposition gas of NH3, which is highly reactive as the flow rate of NH3 increases, reacts with fluorine (F) radicals to form HF. , leading to a decrease in fluorine (F) radicals, resulting in a significant reduction in cleaning gas.

The purge gas supply step (S30) is a step of supplying a purge gas to the processing space after the cleaning gas supply step (S20), and may be performed by various methods.

For example, in the purge gas supply step (S30), an inert gas may be supplied to the inside of the process chamber to remove particles inside the process chamber from the surface with the pressure of the physical purge gas, and the process space may be purged. .

The process chamber exhausting step (S40) is a step of exhausting the processing space, and gas in the processing space can be exhausted through a pump connected to the outside.

Thus, in the process chamber exhausting step (S40), the cleaning gas, decomposition gas, purge gas and other reactants, particles, etc. remaining inside the processing space can be exhausted to the outside, through which cleaning of the processing space can be completed. there is.

Meanwhile, a detailed description of the reaction mechanism according to the main embodiment of the present invention is as follows.

As an example, NH ₃ is used as the decomposition gas according to the present invention, and NF ₃ may be used as the cleaning gas.

At this time, the introduced NH ₃ dissociates the bond of Si-O through the bond between H and O, and promotes the reaction of SiF through the bond between the remaining Si and the F radical introduced through NF ₃ .

That is, the reaction mechanism according to the present invention may carry out the reaction according to the following reaction formula.

3SiO ₂ (S) + 4NH ₃ (g) + 4NF ₃ (g) → 3SiF ₄ (g) + 6H ₂ O (g) + 4N ₂ (g)

Since the above has only been described with respect to some of the preferred embodiments that can be implemented by the present invention, as noted, the scope of the present invention should not be construed as being limited to the above embodiments, and the scope of the present invention described above It will be said that the technical idea and the technical idea together with the root are all included in the scope of the present invention.

S10: decomposition gas supply step S20: cleaning gas supply step
S30: purge gas supply step S40: process chamber exhaust step

Claims (14)

As a cleaning method of a substrate processing apparatus for removing a thin film formed inside a process chamber during a substrate processing process,
a decomposition gas supply step (S10) of supplying a decomposition gas that promotes decomposition of the chemical bond of the thin film into the processing space;
a cleaning gas supplying step (S20) of supplying a cleaning gas that combines with the thin film whose chemical bond is decomposed through the decomposition gas and removes the thin film from the inside of the process chamber;
A cleaning method of a substrate processing apparatus comprising a process chamber exhausting step (S40) of exhausting the processing space. The method of claim 1,
The decomposition gas supply step (S10) and the cleaning gas supply step (S20),
A cleaning method of a substrate processing apparatus, characterized in that performed simultaneously or sequentially. The method of claim 1,
The thin film is a SiO ₂ film,
In the decomposition gas supply step (S10),
A cleaning method of a substrate processing apparatus, characterized in that promoting the decomposition of the chemical bond between silicon and oxygen through the decomposition gas. The method of claim 3,
The decomposition gas,
A cleaning method for a substrate processing apparatus comprising NH ₃ . The method of claim 3,
The cleaning gas is
A cleaning method for a substrate processing apparatus comprising NF ₃ . The method of claim 3,
The cleaning gas is
A cleaning method for a substrate processing apparatus comprising a fluorine radical. The method of claim 1,
In the cleaning gas supply step (S20),
A cleaning method for a substrate processing apparatus comprising a plasma treatment step (S21) of plasma-processing the cleaning gas and a supply step (S22) of supplying the plasma-treated cleaning gas to the processing space. The method of claim 1,
The cleaning method of the substrate processing apparatus, characterized in that the ratio of the decomposition gas to the cleaning gas is 1/16 or less. The method of claim 1,
The cleaning method of the substrate processing apparatus, characterized in that the ratio of the decomposition gas to the cleaning gas is 1/80. The method of claim 1,
The decomposition gas supply step (S10) and the cleaning gas supply step (S20),
The cleaning method of the substrate processing apparatus, characterized in that the temperature of the processing space of the process chamber is 50 ℃ or more and 60 ℃ or less. The method of claim 1,
The cleaning method of the substrate processing apparatus, characterized in that it further comprises a purge gas supply step (S30) of supplying a purge gas to the processing space after the cleaning gas supply step (S20). a cleaning step (S100) of cleaning the inside of the process chamber through the cleaning method of the substrate processing apparatus according to any one of claims 1 to 11;
After the cleaning step (S100), a substrate processing method comprising a thin film deposition step (S300) of forming a thin film on the substrate. The method of claim 12,
In the thin film deposition step (S300),
A substrate processing method characterized by forming a thin film on the substrate through an atomic layer deposition method (ALD). The method of claim 12,
A substrate processing method further comprising a seasoning step (S200) of forming a seasoning thin film on a portion exposed to process gas inside the process chamber between the cleaning step (S100) and the thin film deposition step (S300). .

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