WO2015079632A1

WO2015079632A1 - Atomic layer deposition device

Info

Publication number: WO2015079632A1
Application number: PCT/JP2014/005650
Authority: WO
Inventors: 昂陽堀内
Original assignee: 株式会社Ｊｏｌｅｄ
Priority date: 2013-11-28
Filing date: 2014-11-11
Publication date: 2015-06-04

Abstract

Provided is an atomic layer deposition device able to form a thin film with more uniform quality on a substrate. An atomic layer deposition device (10) is provided with the following: a film deposition container (20); a plate-shaped upper electrode disposed inside the film deposition container (20); a plate-shaped lower electrode that is disposed facing the upper electrode and that generates plasma with the upper electrode; a first frame disposed so as to surround the periphery of the upper electrode; a first anti-adhesion member disposed outside of the first frame; a second frame disposed so as to surround the periphery of the lower electrode; and a second anti-adhesion member disposed outside of the second frame. Portions of the first frame, the second frame, the first anti-adhesion member, and the second anti-adhesion member exposed to the inside of the film deposition container (20) are insulators.

Description

Atomic layer deposition equipment

The present disclosure relates to an atomic layer deposition apparatus that forms a thin film on a substrate.

By flowing an organic metal gas as a source gas above a substrate disposed in the film formation space, the organic metal is adsorbed on the substrate, and the first gas that does not chemically react with the organic metal is used in the film formation space. After the plasma is generated and the first gas is exhausted, the oxidizing gas is introduced into the film formation space as the second gas, and the plasma is generated in the film formation space using the oxidation gas, so that the metal component of the organic metal is formed on the substrate. An atomic layer deposition method is disclosed in which a metal oxide film is oxidized to form a metal oxide film (see, for example, Patent Document 1).

JP 2013-26479 A

The present disclosure provides an atomic layer deposition apparatus capable of forming a thin film more uniformly on a substrate.

An atomic layer deposition apparatus according to the present disclosure includes a film formation container, a flat plate-like upper electrode disposed inside the film formation container, a flat plate that is disposed to face the upper electrode and generates plasma between the upper electrode. The lower electrode, the first frame disposed so as to surround the periphery of the upper electrode, the first deposition member disposed outside the first frame, and the first frame disposed so as to surround the periphery of the lower electrode Two frames, and a second deposition member disposed outside the second frame. In the first frame, the second frame, the first deposition member, and the second deposition member, a portion exposed to the inside of the film formation container is an insulator.

The atomic layer deposition apparatus according to the present disclosure is effective for forming a thin film more uniformly on a substrate.

Diagram showing an overview of atomic layer deposition equipment Diagram showing the outline of the deposition container Exploded perspective view showing relationship between upper electrode, first frame, second frame and lower electrode Diagram showing the state where plasma is generated in the deposition container Flow diagram showing one cycle of atomic layer deposition method The figure which shows the state (raw material gas supply) in which a thin film is formed on a board | substrate The figure which shows the state (purge gas supply) in which a thin film is formed on a board | substrate The figure which shows the state (reactive gas supply) in which a thin film is formed on a board | substrate The figure which shows the state (plasma processing) where a thin film is formed on a substrate The figure which shows the state (purge gas supply) in which a thin film is formed on a board | substrate

The embodiment will be described in detail below. The drawings are referred to as appropriate for the description of the embodiments. However, more detailed description than necessary may be omitted. For example, detailed descriptions of already well-known matters and overlapping descriptions of substantially the same configuration may be omitted. This is for avoiding redundant description and facilitating understanding by those skilled in the art.

The inventor provides the accompanying drawings and the following description so that those skilled in the art fully understand the present disclosure. The inventor does not intend the claimed subject matter to be limited by the present disclosure.

[1. Configuration of atomic layer deposition equipment]
[1. -1. Overall configuration of atomic layer deposition system]
In the atomic layer deposition apparatus 10 shown in FIG. 1, an organic metal source gas mainly composed of a metal constituting a thin film to be formed and a reactive gas are alternately placed on a substrate placed in a film forming container 20. To supply. In addition, the atomic layer deposition apparatus 10 generates plasma to increase the reaction activity, and forms an oxide film of the source gas on the substrate in units of atomic layers. The atomic layer deposition apparatus 10 forms a thin film having a predetermined thickness by repeating the processing a plurality of cycles, with the above processing as one cycle. At this time, depending on the stability of the generated plasma, the film quality of the formed thin film is affected.

In the following description, a technique for forming a thin film of alumina (Al ₂ O ₃ ) by using TMA (Tri-Methyl-Alminum) as a source gas and oxygen (O ₂ ) gas as a reaction gas is exemplified. . However, the present disclosure is not limited to this. For example, ozone (O ₃ ) gas may be used as the reaction gas. As another example, when forming a thin film containing silicon, TDAMAS (Tris (dimethylamino) silane) or the like may be used as a source gas.

As shown in FIG. 1, the raw material gas supply unit 70 supplies a raw material gas such as TMA to the film forming container 20 through the raw material gas supply port 72 provided in the film forming container 20. The source gas supply unit 70 and the source gas supply port 72 are connected by, for example, a stainless steel pipe. A mass flow controller may be disposed between the source gas supply unit 70 and the source gas supply port 72. The source gas supply unit 70 is electrically connected to the control unit 60. The timing at which the source gas supply unit 70 supplies the source gas is controlled by the control unit 60.

The reaction gas supply unit 80 supplies a reaction gas such as oxygen gas to the film formation container 20 via a reaction gas supply port 82 provided in the film formation container 20. The reactive gas supply unit 80 and the reactive gas supply port 82 are connected by, for example, a stainless steel pipe. A mass flow controller may be disposed between the reaction gas supply unit 80 and the reaction gas supply port 82. The reactive gas supply unit 80 is electrically connected to the control unit 60. The timing at which the reaction gas supply unit 80 supplies the reaction gas is controlled by the control unit 60.

Although not shown, the source gas supply unit 70 and the reaction gas supply unit 80 supply a purge gas such as nitrogen (N ₂ ) gas or argon (Ar) gas to the inside of the film forming container 20, respectively. It is configured to be able to.

The exhaust unit 40 exhausts the source gas, reaction gas, and purge gas supplied into the film forming container 20 through the exhaust pipe 42. The exhaust unit 40 is, for example, a dry pump. The exhaust unit 40 may further include a turbo molecular pump. The exhaust unit 40 exhausts the film formation container 20 so that the pressure in the film formation container 20 is maintained at about 1 Pa to 200 Pa even when the source gas, the reaction gas, and the purge gas are supplied into the film formation container 20. The The exhaust capacity of the exhaust unit 40 is designed in consideration of the capacity of the film forming container 20, the supply gas amount, the set pressure range, and the like.

The high frequency power supply 50 is electrically connected to the film forming container 20 via the matching unit 90. When the high frequency power supply 50 supplies a high frequency current having a predetermined frequency (for example, 13.56 to 135.6 MHz) to the film forming container 20, plasma is generated inside the film forming container 20.

The high frequency power supply 50 is electrically connected to the control unit 60. The timing at which the high frequency power supply 50 supplies the high frequency current to the film forming container 20 is controlled by the control unit 60.

The control unit 60 independently controls the timing at which the source gas supply unit 70 supplies the source gas, the timing at which the reaction gas supply unit 80 supplies the reaction gas, and the timing at which the high frequency power supply 50 supplies the high frequency current.

[1. -2. Structure of film formation container]
As shown in FIGS. 2 and 3, the film forming container 20 includes a flat plate-like upper electrode 221 disposed on the upper part of the film forming container 20 and a flat plate-shaped lower electrode disposed on the lower part of the film forming container 20. 321 is provided. The upper electrode 221 and the lower electrode 321 are disposed so as to face each other. The upper electrode 221 and the lower electrode 321 constitute a parallel plate electrode 200. That is, in the present embodiment, capacitively coupled plasma is generated. As an example, the upper electrode 221 and the lower electrode 321 are made of stainless steel.

The upper electrode 221 is fixed to the film forming container 20. The upper electrode 221 is electrically connected to the high frequency power supply 50 shown in FIG. A matching unit 90 provided between the upper electrode 221 and the high-frequency power source 50 adjusts the inductance of the inductor and the capacitance of the capacitor in the matching unit 90 so as to match the impedance of the parallel plate electrode 200.

The lower electrode 321 is fixed on the susceptor 32 disposed at the lower part of the film forming container 20. The lower electrode 321 is grounded. A heater 324 is provided inside the susceptor 32. For example, a resistance heater is used as the heater 324. The heater 324 keeps the temperature of the substrate 100 during the process at, for example, 50 ° C. or more and 100 ° C. or less.

The substrate 100 is supported by lift pins (not shown) from below the film forming container 20. The lift pins can be moved up and down by a lifting mechanism (not shown). With the lift pins supporting the substrate 100, the lifting mechanism moves the lift pins downward, so that the substrate 100 is placed on the upper surface of the lower electrode 321.

[1. -3. Configuration of first frame, second frame, first deposition member, second deposition member]
As shown in FIGS. 2 and 3, the first frame 222 is arranged so as to surround the periphery of the upper electrode 221. As shown in FIG. 3, the first frame 222 is configured in a frame shape as an example. The first frame 222 is configured such that a portion exposed to the inside of the film forming container 20 is an insulator. A first deposition member 223 is disposed outside the first frame 222. The first deposition member 223 may have a more complicated shape than the first frame 222 in order to match the inner shape of the film forming container 20. The first deposition preventing member 223 is configured such that a portion exposed to the inside of the film forming container 20 is an insulator.

The first frame 222 and the first deposition preventing member 223 are fixed to the film forming container 20 with a fixture. For example, the fixture is a bolt 230 configured such that a portion exposed to the inside of the film forming container 20 is an insulator.

2 and 3, the second frame 322 is disposed so as to surround the periphery of the lower electrode 321. As an example, the second frame 322 is configured in a frame shape. The second frame 322 is configured such that a portion exposed in the film forming container 20 is an insulator. A second deposition preventing member 323 is disposed outside the second frame 322. The second deposition member 323 may have a more complicated shape than the second frame 322 in order to match the shape of the susceptor 32. The second deposition member 323 is configured such that a portion exposed to the inside of the film forming container 20 is an insulator.

The second frame 322 and the second adhesion preventing member 323 are fixed to the susceptor 32 disposed in the film forming container 20 with a fixture. For example, the fixture is a bolt 230 configured such that a portion exposed to the inside of the film forming container 20 is an insulator. In the case where the film forming container 20 does not have the susceptor 32, the second frame 322 and the second adhesion preventing member 323 may be fixed to the film forming container 20.

As an example, the first frame 222 and the second frame 322 are made of ceramics. Specifically, the first frame 222 and the second frame 322 are made of Al ₂ O ₃ . The first frame 222 and the second frame 322 may be made of yttria (Y ₂ O ₃ ). Further, the first frame 222 and the second frame 322 may be made of a metal having a ceramic film. As an example, a configuration in which an iron member is coated with Al ₂ O ₃ can be given. The ceramic film is formed by, for example, a thermal spraying method.

As an example, the first deposition member 223 and the second deposition member 323 have a configuration in which the main component is aluminum and the surface is anodized.

Note that either one or both of the first deposition member 223 and the second deposition member 323 may be made of ceramics. Specifically, the first deposition member 223 and the second deposition member 323 may be made of Al ₂ O ₃ or Y ₂ O ₃ . Moreover, the 1st adhesion preventing member 223 and the 2nd adhesion preventing member 323 may be comprised with the metal which has a ceramic membrane | film | coat. As an example, a configuration in which an iron member is coated with Al ₂ O ₃ can be given.

As an example, the bolt 230 is made of ceramics. Specifically, the bolt 230 may be made of Al ₂ O ₃ or Y ₂ O ₃ . The bolt 230 may be made of a metal having a ceramic film. As an example, a configuration in which an iron member is coated with Al ₂ O ₃ can be given.

Note that the first frame 222, the second frame 322, the first attachment member 223, and the second attachment member 323 may be fixed by a method that does not use the bolt 230. As an example, the second frame 322 and the second adhesion preventing member 323 may be configured to be fitted to the susceptor 32.

[1. -4. Functions of first frame, second frame, first deposition member, and second deposition member]
As shown in FIG. 4, the deposition container 20 in the present embodiment has a function of generating plasma 106 between the upper electrode 221 and the lower electrode 321. The main function of the first frame 222 and the second frame 322 is to suppress the spread of the plasma 106 generated between the upper electrode 221 and the lower electrode 321. The first frame 222 is disposed around the upper electrode 221. The second frame 322 is disposed around the lower electrode 321. Further, the first frame 222 and the second frame 322 are made of an insulator in the portions exposed to the inside of the film forming container 20. Since the periphery of the upper electrode 221 and the lower electrode 321 is surrounded by a first frame 222 and a second frame 322 whose surfaces are made of an insulator, the plasma 106 is generated by the first frame 222 and the second frame 322. It is suppressed to extend beyond the unintended range beyond.

Further, since each of the first frame 222 and the second frame 322 is disposed at a location close to each of the upper electrode 221 and the lower electrode 321, it may be directly exposed to plasma. Considering the damage that the first frame 222 and the second frame 322 receive from plasma, it is more preferable that the whole is made of an insulator than the structure that only the surface is an insulator. This is because the lifetime of the first frame 222 and the second frame 322 is extended.

The main function of the first deposition member 223 and the second deposition member 323 is to suppress unnecessary films from adhering to the inside of the film forming container 20. If an unnecessary film adheres to the inside of the film forming container 20, it may be easily peeled off due to an increase in the film thickness or a change with time. The peeled film becomes a foreign substance and may deteriorate the yield and quality of the product. Adhesion of unnecessary films is suppressed in the portions covered by the first and

second deposition members

223 and 323. On the other hand, an unnecessary film adheres to the first deposition member 223 and the second deposition member 323. Accordingly, the first and second

anti-adhesive members

223 and 323 are periodically subjected to processing such as cleaning. This is for preventing unnecessary films from being peeled off from the first and

second deposition members

223 and 323.

The first deposition member 223 and the second deposition member 323 may be configured in a more complicated shape than the first frame 222 and the second frame 322. Specifically, it is a case where it matches with the shape of the film forming container 20 or the like. When forming a complicated shape, it is easier to process a metal material than to process a ceramic material. However, when the first deposition member 223 and the second deposition member 323 are made of a metal material, the plasma 106 generated between the upper electrode 221 and the lower electrode 321 is generated in the first frame 222 and the second frame 321. In some cases, it extends beyond two frames 322. Alternatively, an unintended discharge may occur from the plasma 106 to the first deposition member 223 and the second deposition member 323. If the control of the plasma 106 becomes unstable, it may adversely affect the formation of a homogeneous film. Further, the first and second

anti-adhesive members

223 and 323 are not directly exposed to the plasma 106 in a steady manner.

In consideration of these viewpoints, the first deposition member 223 and the second deposition member 323 are mainly composed of metal, and the portion exposed to the inside of the film formation container 20 is configured of an insulator. preferable. This is because it contributes to improving the controllability of the plasma 106 and facilitates processing when the first and second

anti-adhesive members

223 and 323 are manufactured.

In the configuration in which the first frame 222, the second frame 322, the first deposition member 223, and the second deposition member 323 are fixed by a fixture such as the bolt 230, the plasma 106 is generated when the bolt 230 is conductive. Sometimes an unintended discharge to the bolt 230 may occur. Therefore, it is preferable that the part exposed to the inside of the film forming container 20 is made of an insulator. This is because it contributes to improving the controllability of the plasma 106.

[2. Atomic layer deposition method]
According to the flow shown in FIG. 5, one cycle of the atomic layer deposition method is performed. In step 101, as shown in FIGS. 1 and 6A, first, the source gas supply unit 70 supplies TMA as the source gas 110 into the film forming container 20. At a timing controlled by the control unit 60, the source gas 110 is supplied from the source gas supply unit 70 into the film forming container 20. The source gas supply unit 70 supplies the source gas 110 into the film forming container 20 for 0.1 seconds, for example. By supplying the source gas 110 into the film forming container 20, the source gas 110 is adsorbed on the substrate 100. An adsorption layer 102 is formed on the substrate 100.

Next, in step 102, as shown in FIGS. 1 and 6B, the source gas supply unit 70 supplies N ₂ as the purge gas 112 into the film forming container 20. The source gas supply unit 70 supplies the purge gas 112 into the film forming container 20 for 0.1 seconds, for example. Further, the exhaust unit 40 exhausts the source gas 110 and the purge gas 112 inside the film forming container 20. The exhaust unit 40 exhausts the source gas 110 and the purge gas 112 inside the film forming container 20 for 2 seconds, for example. By supplying the purge gas 112 into the film formation container 20, the source gas 110 that is not adsorbed on the substrate 100 is purged from the film formation container 20.

Next, in step 103, as shown in FIGS. 1 and 6C, the reactive gas supply unit 80 supplies O ₂ as the reactive gas 114 into the film forming container 20. The reaction gas 114 is supplied from the reaction gas supply unit 80 into the film forming container 20 at a timing controlled by the control unit 60. The reactive gas supply unit 80 supplies the reactive gas 114 into the film forming container 20 for 1 second, for example. The adsorption layer 102 changes to the precursor layer 103 containing Al ₂ O ₃ by reacting with the reaction gas 114. The precursor layer 103 is a layer containing Al ₂ O ₃ , but unreacted molecules remain.

Next, in step 104, as shown in FIGS. 1, 2, and 6D, the high frequency power supply 50 supplies a high frequency current of a predetermined frequency to the upper electrode 221. A high frequency current is supplied from the high frequency power supply 50 to the upper electrode 221 at a timing controlled by the control unit 60. The high frequency power supply 50 supplies a high frequency current for 0.2 seconds, for example. At this time, plasma 106 is generated between the upper electrode 221 and the lower electrode 321. The precursor layer 103 is activated by the plasma 106. As the reaction of unreacted molecules proceeds, the precursor layer 103 changes to the thin film layer 104. In this way, plasma processing is performed.

Next, in step 105, as shown in FIGS. 1 and 6E, the reaction gas supply unit 80 supplies N ₂ as the purge gas 112 into the film forming container 20. The reactive gas supply unit 80 supplies the purge gas 112 to the inside of the film forming container 20 for 0.1 seconds, for example. The exhaust unit 40 exhausts the reaction gas 114 and the purge gas 112 inside the film formation container 20. By this step 105, the purge gas 112 is supplied into the film formation container 20, and the reaction gas 114 is purged from the film formation container 20.

Through the above steps 101 to 105, the thin film layer 104 for one atomic layer is formed on the substrate 100. That is, steps 101 to 105 are one cycle of the atomic layer deposition method. For example, in order to form a film thickness of 100 atomic layers, steps 101 to 105 may be repeated 100 cycles. By controlling the number of cycles, the thin film layer 104 having a desired thickness can be formed.

[3. Effect]
In order to form the homogeneous thin film layer 104, the stability of the plasma 106 generated between the upper electrode 221 and the lower electrode 321 is one factor.

More specifically, if the plasma 106 generated between the upper electrode 221 and the lower electrode 321 spreads to an unintended range or abnormal discharge occurs during plasma generation, the stability of the plasma 106 is impaired. May be. For example, a nonuniform distribution of plasma density may adversely affect the formation of the thin film layer 104.

The atomic layer deposition apparatus 10 according to the present disclosure includes a film formation container 20, a flat plate-like upper electrode 221 disposed inside the film formation container 20, an upper electrode 221, and an upper electrode 221. A flat lower electrode 321 for generating plasma, a first frame 222 disposed so as to surround the periphery of the upper electrode 221, a first deposition member 223 disposed outside the first frame 222, and a lower portion A second frame 322 disposed so as to surround the periphery of the electrode 321 and a second adhesion-preventing member 323 disposed outside the second frame 322 are provided. The first frame 222, the second frame 322, the first deposition member 223, and the second deposition member 323 are portions that are exposed to the inside of the film forming container 20.

According to the above configuration, the periphery of the upper electrode 221 and the lower electrode 321 is surrounded by the first frame 222 and the second frame 322, which are the portions exposed to the inside of the film forming container 20, which are insulators. Furthermore, since the exposed portions of the first deposition member 223 and the second deposition member 323 inside the film forming container 20 are made of an insulator, the plasma 106 spreads to an unintended range or abnormal discharge occurs. Occurrence is suppressed. Therefore, the atomic layer deposition apparatus 10 can generate a stable plasma 106. Therefore, the atomic layer deposition apparatus 10 can form a more uniform thin film layer 104 on the substrate 100.

Further, the first frame 222 and the second frame 322 may be made of ceramics.

Further, either of the first anti-adhesion member 223 and the second anti-adhesion member 323 may be configured such that the main material is aluminum and the surface thereof is anodized.

Further, a bolt 230 that is a fixture for fixing any one of the first frame 222, the second frame 322, the first deposition member 223, and the second deposition member 323 to the film forming container 20 may be further provided. The portion of the bolt 230 exposed inside the film forming container 20 is an insulator. Further, the bolt 230 may be made of ceramics.

The source gas supply unit 70 that supplies the source gas 110 to the film formation container 20, the reaction gas supply unit 80 that supplies the reaction gas 114 that reacts with the source gas 110 to the film formation container 20, and the inside of the film formation container 20 The source gas supply unit 70 and the reaction gas supply unit 80 are controlled so that a high frequency power source 50 for supplying a high frequency current for generating plasma 106 on the substrate, a source gas 110 and a reaction gas 114 are alternately supplied. And the control part 60 which controls the timing which the high frequency power supply 50 supplies a high frequency current may be provided.

As described above, the embodiment has been described as an example of the technique in the present disclosure. To that end, the accompanying drawings and detailed description have been provided.

Therefore, the constituent elements described in the accompanying drawings and the detailed description may include constituent elements that are not essential for solving the problem. This is to illustrate the above technique. The non-essential components are described in the accompanying drawings and the detailed description, so that the non-essential components should not be recognized as essential.

Further, the above-described embodiment is for illustrating the technique in the present disclosure. Therefore, various modifications, replacements, additions, omissions, and the like can be made within the scope of the claims or an equivalent scope thereof.

The technique of the present disclosure is useful for an atomic layer deposition apparatus or the like.

DESCRIPTION OF SYMBOLS 10 Atomic layer deposition apparatus 20 Film-forming container 32 Susceptor 40 Exhaust part 42 Exhaust pipe 50 High frequency power supply 60 Control part 70 Source gas supply part 72 Source gas supply port 80 Reaction gas supply part 82 Reaction gas supply port 90 Matching device 100 Substrate 102 Adsorption Layer 103 precursor layer 104 thin film layer 106 plasma 110 source gas 112 purge gas 114 reaction gas 200 parallel plate electrode 221 upper electrode 222 first frame 223 first adhesion member 230 bolt 321 lower electrode 322 second frame 323 second adhesion member 324 Heater

Claims

A deposition container;
A plate-like upper electrode disposed inside the film-forming container;
A flat lower electrode disposed opposite to the upper electrode and generating plasma between the upper electrode;
A first frame arranged to surround the periphery of the upper electrode;
A first deposition member disposed outside the first frame;
A second frame arranged to surround the periphery of the lower electrode;
A second anti-adhesion member disposed outside the second frame,
In the first frame, the second frame, the first deposition member, and the second deposition member, a portion exposed to the inside of the film formation container is an insulator.
Atomic layer deposition equipment.
The first frame and the second frame are made of ceramics.
The atomic layer deposition apparatus according to claim 1.
Either of the first deposition member and the second deposition member, the main material is composed of aluminum, the surface is anodized,
The atomic layer deposition apparatus according to claim 1.
A fixture for fixing any one of the first frame, the second frame, the first deposition member, and the second deposition member to the film formation container;
The fixing tool has an insulating portion exposed inside the film formation container.
The atomic layer deposition apparatus according to claim 1.
The fixture is made of ceramics,
The atomic layer deposition apparatus according to claim 4.
A source gas supply unit for supplying source gas to the film formation container;
A reaction gas supply unit that supplies a reaction gas that reacts with the source gas to the film formation container;
A high-frequency power source for supplying a high-frequency current for generating plasma in the film formation container;
A control unit that controls the source gas supply unit and the reaction gas supply unit so that the source gas and the reaction gas are alternately supplied, and controls the timing at which the high-frequency power supply supplies a high-frequency current. When,
With
The atomic layer deposition apparatus according to any one of claims 1 to 5.