JP7203207B2 - Gas inlet system, atomic layer deposition apparatus and method - Google Patents

Description

FIELD OF THE DISCLOSURE This disclosure relates to the field of semiconductor manufacturing technology, and in particular to gas inlet systems, atomic layer deposition apparatus, and atomic layer deposition methods.

Atomic Layer Deposition (ALD) refers to a method of plating material onto the surface of a substrate in the form of monolayer-by-layer monolayers, which have a cyclical growth process, each preparation cycle generally Includes two self-limiting reactions. A first reaction precursor is introduced into the reaction chamber at a specific temperature such that molecules of the first reaction precursor are adsorbed onto the surface of the substrate (primarily through chemisorption) as active agents. . Chemisorption is complete when the adsorption of the first reaction precursor reaches saturation and self-limiting control of the reaction between the first reaction precursor and the surface of the substrate (first self-limiting reaction). is realized. After the first self-limiting reaction is complete, the first reaction precursor (generally along with reaction by-products between the first reaction precursor and the surface of the substrate) undergoes a particular purging method. after which a second reaction precursor is introduced; this second reaction precursor reacts with the activator (the first reaction precursor) and adsorbs onto the surface of the substrate. , producing a monolayer to-be-prepared film on the surface of the substrate and releasing gaseous by-products.

Taking SiH ₄ and WF ₆ as examples of two reaction precursors, as shown in FIG. 1, the gas inlet system is configured to introduce each of SiH ₄ and WF ₆ into the reaction chamber through the showerhead. two gas intake pipelines (A, B) connected to each other, each of these two gas intake pipelines (A, B) having a mass flow controller (MFC) configured to control the gas flow. I have. In addition, each of the two gas intake pipelines (A, B) has a connection or disconnection of the gas intake pipelines such that alternating introduction of the two reaction precursors into the reaction chamber is achieved. A fast switching valve (hereinafter referred to as an ALD valve) configured to achieve this is provided. Furthermore, in addition to that, the gas intake system comprises two exhaust pipelines (C , D), a foreline configured to exhaust residual gases or by-products, and two exhaust pipelines (C, D) each carrying two reaction precursors into the reaction chamber. An ALD valve is provided to exhaust through the foreline any reaction precursors not introduced into the reaction chamber during the alternating introduction.

Using the gas inlet system described above, the ALD valve is alternately opened and closed to allow rapid and alternating introduction of the two reaction precursors into the reaction chamber to complete the preparation of the ALD thin film. However, the gas intake system described above inevitably has the following problems in practical application.

First, closing the ALD valve can prevent reaction precursors from entering the reaction chamber, but causes an increase in pressure in the gas inlet pipeline in which the ALD valve is installed. Therefore, when the ALD valve is reopened, the reaction precursors will flow into the reaction chamber with a highly unstable pressure and it is difficult for the MFC to control the gas flow.

Second, over a period of time, as reaction precursors are also introduced into the foreline, the total amount of gas entering the reaction chamber decreases resulting in an unstable process pressure inside the chamber, resulting in , the total gas flow rate and the process pressure inside the chamber become difficult to stabilize and control accurately; is sufficient to increase the number of particles in the chamber, thereby affecting process performance, particularly film uniformity.

In view of the above, embodiments of the present disclosure provide gas intake systems and control methods applied to ALD processes.

According to one aspect of an embodiment of the present disclosure, a gas inlet on/off valve is provided in communication with a gas distribution device and configured to introduce reaction precursors into the reaction chamber through said gas distribution device. A gas intake system is provided, including a gas intake pipeline that includes a gas intake pipeline; and the gas intake system further comprises:
an exhaust pipeline in communication with both the gas distribution device and the reaction chamber and provided with an exhaust on/off valve;
including.

Optionally, said gas intake pipeline comprises at least two gas intake pipelines configured to introduce different reaction precursors into said reaction chamber through said gas distribution device, said at least two gas intake pipelines. are provided with said gas intake on/off valves.

Optionally, a buffer device capable of storing a predetermined volume of reaction precursor is located on said gas inlet pipeline and upstream of said gas inlet on-off valve.

Optionally, said buffer device comprises:
a tubular cavity having an inner diameter greater than the inner diameter of said gas intake pipeline;
including.

Optionally, the gas intake pipeline is further equipped with a mass flow controller.

Optionally, said gas intake on/off valve is a solenoid valve.

Optionally, said exhaust on/off valve is a solenoid valve.

Optionally, said gas inlet pipeline comprises two gas inlet pipelines configured to introduce SiH ₄ and WF ₆ into said reaction chamber through said gas distribution device.

According to another aspect of this disclosure, there is provided an ALD method of performing a deposition process by utilizing an ALD apparatus provided by this disclosure, said ALD method comprising:
opening the gas intake on-off valve and simultaneously closing the exhaust on-off valve such that reaction precursors are introduced into the reaction chamber through the gas distribution device in a deposition stage;
In a purge stage, the gas intake is such that the reaction precursors left in the gas distribution device are exhausted into the reaction chamber and then the reaction precursors are exhausted from the reaction chamber through the foreline. closing an on-off valve and simultaneously opening the exhaust on-off valve;
including.

Optionally, said gas intake pipeline comprises two gas intake pipelines, said two gas intake pipelines each introducing a first reaction precursor into said reaction chamber through said gas distribution device. and a second gas intake pipeline configured to introduce a second reaction precursor; an intake on-off valve, wherein the two gas intake on-off valves are respectively a first gas intake on-off valve disposed on the first gas intake pipeline and the first gas intake on-off valve; a second gas intake on-off valve located on the gas intake pipeline of 2;
The ALD method comprises:
In a first deposition stage, opening the first gas inlet on-off valve and simultaneously opening the second gas inlet so that the first reaction precursor is introduced into the reaction chamber through the gas distribution device. closing the gas intake on-off valve and the exhaust on-off valve of
In a first purge stage, the first reaction precursor remaining in the gas distribution device is evacuated into the reaction chamber, after which the first reaction precursor flows through the foreline into the reaction chamber. closing said first gas intake on-off valve and simultaneously opening said exhaust on-off valve so as to be exhausted from;
In a second deposition stage, opening the second gas inlet on-off valve and simultaneously opening the first gas inlet so that the second reaction precursor is introduced into the reaction chamber through the gas distribution device. closing the gas intake on-off valve and the exhaust on-off valve of
In a second purge stage, the second reaction precursor remaining in the gas distribution device is evacuated into the reaction chamber, after which the second reaction precursor flows through the foreline into the reaction chamber. closing said second gas intake on-off valve and simultaneously opening said exhaust on-off valve so as to be exhausted from;
performing at least one cycle of the first deposition stage, the first purge stage, the second deposition stage, and the second purge stage;
including.

In the technical solution of the gas intake system, the ALD apparatus and ALD method of this disclosure provides an exhaust pipeline communicating with the gas distribution device and the reaction chamber, thereby removing the reaction precursor left in the gas distribution device. , can flow into the reaction chamber when the gas intake on-off valve on the gas intake pipeline is closed, and is then exhausted through the reaction chamber foreline, but the foreline In light of the prior art, in which reaction precursors are discharged directly into as a result of which the stability of the process pressure inside the chamber can be improved and the control of the total flow of gases and the process pressure inside the chamber can be facilitated, whereby the fact that Additionally, particle generation due to pressure fluctuations or flow rate fluctuations during the process is reduced, improving film uniformity and film yield.

Additional aspects and advantages of embodiments of the disclosure will be apparent from the description thereof below, or may be learned from the practical application of the disclosure.

In order to more clearly illustrate the technical solutions in the embodiments of this disclosure or those in the prior art, the drawings used to describe the embodiments or the prior art are briefly introduced below. It is evident that the drawings described below are used only for illustration of some embodiments of this disclosure, and a person skilled in the art would, without creative work, Other drawings can be derived from the following drawings.

1 is a schematic structural diagram of a gas intake system used in the prior art; FIG. 1 is a schematic structural diagram of a gas intake system according to this disclosure; FIG. 4 is a flow chart of an ALD process performed by utilizing the gas intake system provided by this disclosure;

This disclosure will now be described more fully hereinafter with reference to the drawings to illustrate exemplary embodiments of the disclosure. The following clearly and completely describes the technical solutions in the embodiments of this disclosure with reference to the drawings. Apparently, the embodiments described herein are not all of the embodiments of this disclosure, but rather only some. Based on the embodiments described in this disclosure, all other embodiments derived by persons skilled in the art without creative work fall within the protection scope of this disclosure. The technical solution of this disclosure will be described from several aspects with reference to the drawings and embodiments.

For convenience of explanation, the terms "left", "right", "top" and "bottom" used hereinafter correspond to left, right, top and bottom in the drawings. The terms "first", "second", and these classes of terms used hereinafter are merely to distinguish between the elements in the description and have no other special meaning. not

As shown in FIG. 2, this disclosure provides a gas inlet system configured to provide process gas for reaction chamber 8 and applicable to ALD processes. Specifically, the gas intake system includes a gas intake pipeline in communication with the gas distribution device 7 and configured to introduce reaction precursors into the reaction chamber 8 through the gas distribution device 7, wherein the gas intake The pipeline includes a gas intake on/off valve configured to connect or disconnect the gas intake pipeline. The gas distribution device 7 is configured to distribute the gas and allows the gas to flow uniformly into the reaction chamber 8 . For ALD processes, gas distribution device 7 has the ability to separate at least two reaction precursors from each other. Specifically, the gas distribution device 7 can include at least two mutually independent gas intake channels and scattering chambers, wherein the at least two gas intake channels correspond one-to-one to at least two gas intake pipes. Communicating with the line and configured to uniformly deliver reaction precursors from the gas inlet pipeline into the reaction chamber 8 .

In this embodiment, as shown in FIG. 2, two gas intake pipelines, a first gas intake pipeline 1 and a second gas intake pipeline 2, react two different reaction precursors. arranged for introduction into the chamber 8 through a gas distribution device 7, for example a first gas intake pipeline 1 to deliver SiH ₄ and a second gas intake pipeline 2 to deliver WF ₆ , configured respectively. In addition, the first gas intake pipeline 1 is provided with a first gas intake on-off valve 3; A valve 5 is provided. By alternately opening the first gas inlet on-off valve 3 and the second gas inlet on-off valve 5, it is possible to alternately introduce the two reaction precursors into the reaction chamber 8. . Preferably, both the first gas intake on/off valve 3 and the second gas intake on/off valve 5 are fast switching valves such as electromagnetic valves. In this method, two reaction precursors can alternately and rapidly enter the reaction chamber to complete the preparation of the ALD thin film.

Optionally, the gas inlet pipeline is provided with a mass flow controller (MFC) configured to control gas flow within the gas inlet pipeline.

The gas intake system further includes an exhaust pipeline 4 communicating with both the gas distribution device 7 and the reaction chamber 8 . Specifically, the exhaust pipeline 4 is configured to provide communication between the scattering chamber of the gas distribution device 7 and the reaction chamber 8 . The exhaust pipeline 4 is provided with an exhaust on/off valve 10 configured to connect or disconnect the exhaust pipeline 4 .

Residual reaction precursors in the gas distribution device 7 are allowed to flow through the exhaust pipeline 4 into the reaction chamber 8 when the gas intake on-off valve on the gas intake pipeline is closed, and , which is then discharged through the foreline 9 of the reaction chamber 8, which in the light of the prior art discharges reaction precursors directly into the foreline 9 from the gas inlet pipeline into the reaction foreline. It is possible to avoid shunting caused by direct entry of the precursors and thereby avoid pressure build-up in the gas intake pipeline. On the other hand, it can be ensured that the total amount of gas entering the reaction chamber 8 does not change, so that the stability of the process pressure inside the reaction chamber 8 can be improved and the total flow of gas and the chamber Control of the internal process pressure can be facilitated, which effectively reduces particle generation due to pressure fluctuations or flow rate fluctuations during the process and improves membrane uniformity. and the film yield is improved.

Optionally, the exhaust on/off valve 10 is a fast switching valve, such as an electromagnetic valve, so that fast switching between the exhaust and intake pipelines can be achieved.

Taking as an example a gas intake system delivering two reaction precursors SiH ₄ and WF ₆ shown in FIG. 2, but as shown in FIG. 3, this ALD process:
The first gas inlet on-off valve 3 is opened and simultaneously the second gas inlet is turned on so that the first reaction precursor (SiH ₄ ) is introduced into the reaction chamber 8 through the gas distribution device 7 a first deposition phase in which the off valve 5 and the exhaust on/off valve 10 are closed;
A first gas inlet on/off valve so that the first reaction precursor remaining in the gas distribution device 7 is vented into the reaction chamber 8 and then out of the reaction chamber 8 through the foreline 9; 3 is closed and at the same time the exhaust on-off valve 10 is opened;
The second gas intake on/off valve 5 is opened and simultaneously the first gas intake on/off so that the second reaction precursor (WF ₆ ) is introduced into the reaction chamber through the gas distribution device 7 . a second deposition stage in which the off valve 3 and the exhaust on/off valve 10 are closed;
A second gas inlet on/off valve so that the second reaction precursor remaining in the gas distribution device 7 is vented into the reaction chamber 8 and then out of the reaction chamber 8 through the foreline 9. 5 is closed and at the same time the exhaust on-off valve 10 is opened;
including.

A cycle of these first deposition phase, first purge phase, second deposition phase, and second purge phase is performed at least once to complete the ALD process.

Optionally, a buffer device capable of storing a predetermined volume of reaction precursor is placed on the gas intake pipeline upstream of the gas intake on/off valve. In this embodiment, the first gas intake pipeline 1 has a first buffer device 11 and the second gas intake pipeline 2 has a second buffer device 12, as shown in FIG. are provided respectively. By storing a certain volume of reaction precursor in the buffer device when the gas intake on-off valve is closed, the gas intake pipeline when the gas intake on-off valve is reopened It is possible to avoid large flow fluctuations and large pressure fluctuations in . Since the different gas intake on/off valves are switched over to each other at very short intervals, the buffer device can effectively stabilize the pressure and flow rate of the reaction precursors, which is useful for controlling the MFC. has no impact at all.

Optionally, the buffer device includes a tubular cavity having an inner diameter greater than the inner diameter of the gas intake pipeline. Indeed, in practical applications, buffer devices are implemented as other structures or in other manners, so long as the pressure and flow rate of the reaction precursors can be effectively stabilized. Sometimes.

As another technical solution, this disclosure further provides an ALD apparatus. As shown in FIG. 2, the ALD apparatus includes a reaction chamber 8, a gas distribution device 7 located on top of the reaction chamber 8, a gas intake system as described above, and a foreline 9. .

By utilizing the gas inlet system described above, the ALD apparatus provided by this disclosure improves the stability of the process pressure inside the chamber and facilitates control of the total gas flow rate and process pressure inside the chamber. which effectively reduces particle generation due to pressure fluctuations or flow rate fluctuations during the process and improves film uniformity and film yield.

As another technical solution, this disclosure further provides an ALD method for performing a deposition process by utilizing the ALD apparatus provided by this disclosure above. This ALD method:
opening a gas intake on-off valve and simultaneously closing an exhaust on-off valve such that the reaction precursor is introduced into the reaction chamber through the gas distribution device in the deposition stage;
In the purge phase, the gas inlet on-off valve is closed and exhausted simultaneously so that the reaction precursors left in the gas distribution device are exhausted into the reaction chamber and then out of the reaction chamber through the foreline. opening an on/off valve;
including.

By utilizing the ALD apparatus described above to perform the deposition process, the ALD method provided by this disclosure improves the stability of the process pressure inside the reaction chamber, as well as the total flow rate of gases and the Control of process pressure can be facilitated, which effectively reduces particle generation due to pressure fluctuations or flow rate fluctuations during the process, improves film uniformity and yield is improved.

Specifically, taking as an example the gas intake system utilized by the ALD apparatus shown in FIG. A pipeline 2 is arranged to introduce a first reaction precursor and a second reaction precursor into a reaction chamber 8 through a gas distribution device 7; A first gas intake on-off valve 3 and a second gas intake on-off valve 5 are arranged on the first gas intake pipeline 1 and the second gas intake pipeline 2, respectively. .

This ALD method:
In the first deposition stage, the first gas inlet on-off valve 3 is opened so that the first reaction precursor (SiH ₄ ) is introduced into the reaction chamber 8 through the gas distribution device 7 and simultaneously closing the second gas intake on-off valve 5 and the exhaust on-off valve 10;
In a first purge stage, the first gas is purged such that the first reaction precursor remaining in the gas distribution device 7 is evacuated into the reaction chamber 8 and then out of the reaction chamber 8 through the foreline 9 . Closing the gas intake on-off valve 3 and simultaneously opening the exhaust on-off valve 10;
In the second deposition stage, open the second gas inlet on-off valve 5 and simultaneously open the second gas inlet on-off valve 5 so that the second reaction precursor (WF ₆ ) is introduced into the reaction chamber through the gas distribution device 7 . closing gas intake on-off valve 3 and exhaust on-off valve 10 of 1;
In a second purge stage, the second gas is removed so that the second reaction precursor remaining in the gas distribution device 7 is evacuated into the reaction chamber 8 and then out of the reaction chamber 8 through the foreline 9 . closing the gas intake on-off valve 5 and simultaneously opening the exhaust on-off valve 10;
performing at least one cycle consisting of a first deposition stage, a first purge stage, a second deposition stage, and a second purge stage to complete the ALD process;
including.

In summary, in a technical solution of a gas intake system, the ALD apparatus and ALD method of this disclosure provide an exhaust pipeline communicating with the gas distribution device and the reaction chamber, thereby reducing the reaction left in the gas distribution device. Precursors are allowed to flow into the reaction chamber when a gas intake on-off valve on the gas intake pipeline is closed, and then exhausted through the reaction chamber foreline. However, in light of the prior art, where the reaction precursors are discharged directly into the foreline, this avoids increasing the pressure in the gas inlet pipeline and does not change the total amount of gas entering the reaction chamber. can be guaranteed, and as a result, the stability of the process pressure inside the chamber can be improved, and the control of the total gas flow rate and the process pressure inside the chamber can be facilitated, This effectively reduces particle generation due to pressure fluctuations or flow rate fluctuations during the process, improving film uniformity and film yield.

Unless otherwise stated, if any of the above technical solutions of this disclosure disclose a numerical range, the disclosed numerical range is a preferred numerical range, and this Those skilled in the art will understand that the preferred numerical ranges merely cover values that lead to obvious technical effects, or values that are representative of many possible values. and Since there are many possible values and it is impossible to list all of them, some of them are disclosed here in the illustration of the technical solution of this disclosure. and the values listed above should not be considered as limiting the scope of protection of this disclosure.

On the other hand, unless otherwise stated, where this disclosure discloses or relates to components or structural members that are fixedly connected together, fixed connections are defined as removably fixed It can be interpreted as a connection (such as via bolts or screws) or as a permanently fixed connection (such as by riveting or welding). Alternatively, the fixed connections to each other may be replaced by a unitary structure (eg, integrally formed by a casting process) (unless it is clear that the integrally formed process cannot be employed).

In addition, unless otherwise stated, in any of the above technical solutions of this disclosure, the terms used to indicate a specific positional relationship or shape are similar, similar, or The state or shape of the approximation is also indicated. Any of the parts provided by this disclosure can be assembled by multiple independent components or be independent parts manufactured by an integral forming process.

The above embodiments are only intended to illustrate the technical solutions of this disclosure and do not limit them. Although this disclosure has been described in detail with reference to preferred embodiments, those skilled in the art will appreciate that modifications to the specific embodiments of this disclosure may be made or equivalent substitutions made for parts of the technical features. need to understand that it is possible. Those modifications and equivalent substitutions made without departing from the spirit of the technical solution of this disclosure shall be deemed to fall within the protection scope of the technical solution of this disclosure.

The description of this disclosure has been given for illustrative purposes and is not intended to be exhaustive or to limit this disclosure. Many modifications and variations will be apparent to those skilled in the art. The embodiments are provided to better illustrate the principles and practical applications of this disclosure, and to those of ordinary skill in the art, upon understanding of this disclosure, to make various specific-purpose embodiments, including various modifications. selected and described to enable design.

1 first gas intake pipeline 2 second gas intake pipeline 3 first gas intake on-off valve 4 exhaust pipeline 5 second gas intake on-off valve 7 gas distribution device 8 reaction chamber 9 Foreline 10 Exhaust on/off valve 11 First buffer device 12 Second buffer device

Claims (11)

A gas inlet system comprising a gas inlet pipeline in communication with a gas distribution device and configured to introduce reaction precursors into a reaction chamber through said gas distribution device and provided with a gas inlet on/off valve. hand,
comprising an exhaust pipeline with an inlet communicating with the gas distribution device, an outlet communicating with the reaction chamber, and an exhaust on/off valve ;
The gas inlet system , wherein the exhaust pipeline is configured to introduce residual reaction precursors in the gas distribution device into the reaction chamber when the gas inlet on/off valve is closed . The gas intake pipeline includes at least two gas intake pipelines configured to introduce different reaction precursors into the reaction chamber through the gas distribution device, each of the at least two gas intake pipelines comprising: 2. The gas intake system of claim 1, wherein the gas intake on/off valve is provided. 3. A buffer device capable of storing a predetermined volume of reaction precursor is arranged on said gas inlet pipeline and upstream of said gas inlet on-off valve. A gas intake system as described in . The buffer device is
a tubular cavity having an inner diameter greater than the inner diameter of said gas intake pipeline;
4. The gas intake system of claim 3, comprising: 3. A gas intake system according to claim 1 or 2, wherein the gas intake pipeline is further provided with a mass flow controller. 3. The gas intake system according to claim 1 or 2, wherein said gas intake on/off valve is an electromagnetic valve. 2. The gas intake system of claim 1, wherein said exhaust on/off valve is a solenoid valve. 3. The gas intake system of claim 2, wherein the gas intake pipeline comprises two gas intake pipelines configured to introduce SiH ₄ and WF ₆ into the reaction chamber through the gas distribution device. 9. A system comprising a reaction chamber, a gas distribution device arranged on top of said reaction chamber, a gas intake system and a foreline, wherein said gas intake system is according to any one of claims 1 to 8. Atomic layer deposition apparatus, wherein the gas inlet system of An atomic layer deposition method for performing a deposition process by utilizing an atomic layer deposition apparatus according to claim 9, comprising:
opening the gas intake on-off valve and simultaneously closing the exhaust on-off valve such that reaction precursors are introduced into the reaction chamber through the gas distribution device in a deposition stage;
In a purge stage, the gas intake is such that the reaction precursors left in the gas distribution device are exhausted into the reaction chamber and then the reaction precursors are exhausted from the reaction chamber through the foreline. closing an on-off valve and simultaneously opening the exhaust on-off valve;
A method of atomic layer deposition comprising: The gas intake pipeline includes two gas intake pipelines, each of the two gas intake pipelines configured to introduce a first reaction precursor into the reaction chamber through the gas distribution device. a first gas intake pipeline and a second gas intake pipeline configured to introduce a second reaction precursor; an off-valve, wherein the two gas intake on-off valves are respectively a first gas intake on-off valve disposed on the first gas intake pipeline and the second gas intake on-off valve; a second gas intake on-off valve located on the gas intake pipeline;
Said atomic layer deposition method is:
In a first deposition stage, opening the first gas inlet on-off valve and simultaneously opening the second gas inlet so that the first reaction precursor is introduced into the reaction chamber through the gas distribution device. closing the gas intake on-off valve and the exhaust on-off valve of
In a first purge stage, the first reaction precursor remaining in the gas distribution device is evacuated into the reaction chamber, after which the first reaction precursor flows through the foreline into the reaction chamber. closing said first gas intake on-off valve and simultaneously opening said exhaust on-off valve so as to be exhausted from;
In a second deposition stage, opening the second gas inlet on-off valve and simultaneously opening the first gas inlet so that the second reaction precursor is introduced into the reaction chamber through the gas distribution device. closing the gas intake on-off valve and the exhaust on-off valve of
In a second purge stage, the second reaction precursor remaining in the gas distribution device is evacuated into the reaction chamber, after which the second reaction precursor flows through the foreline into the reaction chamber. closing said second gas intake on-off valve and simultaneously opening said exhaust on-off valve so as to be exhausted from;
performing at least one cycle of the first deposition stage, the first purge stage, the second deposition stage, and the second purge stage;
11. The atomic layer deposition method of claim 10, comprising:

Images