KR101027954B1 - Showerhead and atomic layer deposition apparatus - Google Patents

Abstract

Disclosed are an atomic layer deposition apparatus and a shower head including a diaphragm valve unit intermittently injecting a source gas into a shower head. The showerhead for an atomic layer deposition apparatus including a diaphragm valve unit capable of intermittently injecting source gas may include a first plate having a plurality of first injection ports through which a first source gas is injected, and the first injection port being accommodated. A second plate having a second injection port formed therein, the second plate for injecting a second source gas between the first injection port and the second injection port, and a valve provided at an upper portion of the second injection port to selectively open and close the second injection port; And an opening and closing part for opening and closing the valve part by applying an electrical signal to the valve part. Therefore, the diaphragm valve is provided at the upper portion of the injection port in the shower head to intermittently inject the source gas, and the diaphragm valve can be used to accurately control the injection of the source gas and to improve the response. .

Deposition, ALD, Solar Cells, Diaphragm Valves

Description

Shower head and atomic layer deposition apparatus having the same {SHOWERHEAD AND ATOMIC LAYER DEPOSITION APPARATUS}

The present invention relates to an atomic layer deposition apparatus, and to provide an atomic layer deposition apparatus including a shower head having a diaphragm valve for intermittently injecting a source gas for deposition of a thin film.

In general, in order to deposit a thin film having a predetermined thickness on a substrate such as a semiconductor substrate or glass, physical vapor deposition (PVD) using physical collision such as sputtering and chemical vapor deposition using chemical reaction thin film manufacturing method using (chemical vapor deposition, CVD) or the like is used.

The chemical vapor deposition method may include atmospheric pressure chemical vapor deposition (APCVD), low pressure chemical vapor deposition (LPCVD), plasma organic chemical vapor deposition (plasma enhanced CVD, PECVD), and the like. Plasma organic chemical vapor deposition has been widely used due to the advantages of being able to deposit and fast forming thin films.

However, as the design rule of the semiconductor device is drastically fine, a thin film of a fine pattern is required, and the step of the region where the thin film is formed is also very large. As a result, the use of an atomic layer deposition (ALD) method capable of forming a very fine pattern of atomic layer thickness very uniformly and having excellent step coverage is increasing.

The atomic layer deposition method (ALD) is similar to the conventional chemical vapor deposition method in that it uses chemical reactions between gas molecules. However, conventional chemical vapor deposition (CVD) methods inject a plurality of gas molecules into the process chamber at the same time to deposit reaction products generated above the substrate onto the substrate, whereas atomic layer deposition processes a single gaseous material. It is different in that it is injected into the chamber and then purged to leave only the physically adsorbed gas on top of the heated substrate, and then inject other gaseous materials to deposit chemical reaction products that occur only on the upper surface of the substrate.

The thin film implemented through such an atomic layer deposition method has a very good step coverage characteristics and has the advantage that it is possible to implement a pure thin film with a low impurity content, which is widely attracting attention.

Conventional atomic layer deposition apparatus is formed such that the susceptor or showerhead is rotatably formed with respect to each other, and the source gas is sequentially sprayed onto the substrate as the susceptor or showerhead is rotated, thereby simultaneously depositing atomic layers on a plurality of substrates. The process is carried out.

On the other hand, there is a valve control method as a method for providing a plurality of types of source gas in the conventional atomic layer deposition apparatus. However, the conventional valve control method requires a separate gas supply line and a valve for each type of source gas, which complicates the structure of the shower head and the atomic layer deposition apparatus, and the valve is repeatedly turned on and off. There is a problem that the life of the shortening. In addition, there is a problem that it is difficult to match the operation order and time of the electric signal device, pneumatic actuator and valve on / off device for driving the valve.

In addition, since the valve is repeatedly opened and closed in the deposition process, when one valve fails, the operation of the entire atomic layer deposition apparatus is stopped.

An object of the present invention is to provide an atomic layer deposition apparatus having a shower head capable of injecting a source gas in the form of a pulse to solve the above problems.

In addition, the present invention is to provide an atomic layer deposition apparatus that simplifies the structure of the valve for controlling the supply of the source gas.

In addition, the present invention is to provide an atomic layer deposition apparatus that is easy to simplify the structure for supplying the source gas and control the injection of the source gas.

According to the embodiments of the present invention for achieving the above object of the present invention, the showerhead for an atomic layer deposition apparatus having a diaphragm valve portion capable of intermittently injecting the source gas, a plurality of first source gas is injected A first plate having two first injection ports, a second injection port having the first injection port formed therein, and a second plate in which a second source gas is injected between the first injection port and the second injection port, and And a valve unit disposed above the second injection port to selectively open and close the second injection port, and an opening and closing unit to open and close the valve unit by applying an electrical signal to the valve unit.

In an embodiment, the first buffer part is formed on the first plate and becomes a flow path for supplying the first source gas to the first injection port, and is separated from the first buffer part by the first plate. A second buffer part is formed to be a flow path for supplying the second source gas to the second injection port, and the first injection port extends from the lower portion of the first plate to the second injection port through the second buffer part. Can be formed. In addition, the outer peripheral surface of the first injection port and the inner peripheral surface of the second injection port is formed so as to be spaced apart.

In one embodiment, the valve portion is formed to cover the upper portion of the second injection port and the diaphragm-shaped valve body formed to penetrate the first injection port and the outer peripheral surface of the first injection port and the valve body to the first 1 comprises a fixing part fixed to the injection port. The valve body is formed of a piezoelectric element. In addition, the valve body is provided to correspond to the plurality of second injection ports one-to-one. The fixing part may have a rim shape for tightly fixing a part of the valve body to an outer circumferential surface of the first injection port.

In an embodiment, the opening and closing part may include a power source electrically connected to the first plate and applying power, and a switch provided between the power source and the first plate to selectively cut off power to the first plate. Can be. In addition, the first plate is formed of a conductive material.

On the other hand, according to other embodiments of the present invention for achieving the above object of the present invention, the atomic layer deposition apparatus having a diaphragm valve unit for intermittently injecting the source gas is a substrate is accommodated deposition process is performed A process chamber, a susceptor accommodated in the process chamber, on which the substrate is seated, and disposed on the substrate and injecting a first source gas and a second source gas onto the substrate, wherein the first and second source gases And a plasma generating unit provided at an upper portion of the shower head and generating a plasma inside the first buffer unit to independently and spray the first and second buffer units. The shower head may include a first plate having a plurality of first injection ports through which a first source gas is injected, and a plurality of second injection ports through which a second source gas is injected independently of the first source gas. A valve plate including a second plate, a diaphragm-shaped valve body provided on each of the second injection ports to open and close the second injection port, and a fixing part provided on the first injection port to fix the valve body; and It includes an opening and closing unit for opening and closing the valve unit by applying an electrical signal to the valve unit.

In an embodiment, the shower head is configured to continuously inject the first source gas and to intermittently inject the second source gas as the valve part is opened and closed.

In an exemplary embodiment, the shower head may be configured such that the first injection port communicates with the first buffer part and the process chamber through the second buffer part and the second plate, and into the second injection port. Is extended. In addition, an end of the first injection port and an end of the second injection port may be disposed on a plane having a different height from the surface of the substrate.

According to the present invention, first, by providing a diaphragm-type valve portion that is opened by an electrical signal on the injection port of the source gas can be injected intermittently, the response speed of the valve portion to improve the quality of the thin film The deposition process time can be shortened.

Second, since the valve portion has a simple structure of opening and closing by electricity and closing the upper portion of the injection port, the structure of the showerhead and the atomic layer deposition apparatus is simplified.

Third, since the valve portion is provided on the injection port of the source gas, the injection of the source gas is intermittently controlled simultaneously with the on / off of the valve portion, the response time is short, and the injection of the source gas can be accurately and effectively controlled.

Although the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, the present invention is not limited or restricted by the embodiments.

1 is a longitudinal cross-sectional view illustrating an atomic layer deposition apparatus according to an embodiment of the present invention, FIG. 2 is a cross-sectional view illustrating a showerhead and a valve unit in the atomic layer deposition apparatus of FIG. 1, and FIG. 3 is FIG. 2. The main part of the showerhead is a perspective view. 4 is a block diagram illustrating an example of an opening and closing unit for explaining an opening and closing operation of the valve unit in the shower head of FIG. 2. 5 is a sectional view showing the main parts of the valve part of FIG. 2 in an open state, and FIG. 6 is a sectional view showing the main part of the valve part of FIG. 2 in a closed state.

Hereinafter, the atomic layer deposition apparatus 100 and the valve unit 133 according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6.

Referring to FIG. 1, an atomic layer deposition apparatus 100 is an apparatus for processing a substrate 10 to be processed by using a plasma P, and includes a process chamber 101, a susceptor 102, and a shower head 103. ), And a plasma generating unit 104 and a valve unit 133.

Here, the substrate 10 may be a silicon wafer to be a semiconductor substrate. However, the present invention is not limited thereto, and the substrate 10 may be a transparent substrate such as glass used in a flat panel display device such as an LCD and a PDP. In addition, the substrate 10 is not limited in shape and size by the drawings, and may have substantially various shapes and sizes, such as circular and rectangular plates.

The process chamber 101 accommodates the substrate 10 and provides a space for depositing a predetermined thin film on the surface of the substrate 10. Here, the atomic layer deposition apparatus 100 is a deposition apparatus for generating a plasma (P) to form a thin film, the plasma (P) is formed in a low pressure atmosphere close to the vacuum, so the process chamber 101 maintains a vacuum It can have a sealed structure.

The susceptor 102 is provided in the process chamber 101 to seat the substrate 10. For example, the susceptor 102 may be an electrostatic chuck that fixes the substrate 10 by an electrostatic force. In addition, a heater (not shown) for heating the substrate 10 may be provided inside or below the susceptor 102.

The shower head 103 is provided on the process chamber 101 and the source gas supply unit 105 is connected to inject the source gas into the process chamber 101 and the substrate 10.

The source gas is a gas containing a material constituting the thin film to be deposited on the substrate 10, the reaction gas excited in the plasma (P) state (hereinafter referred to as the first source gas (R)) and the The first source gas R is formed of a source gas (hereinafter referred to as a second source gas S) that reacts with the surface of the substrate 10 to form a thin film by using the reactivity of the excited plasma P.

Here, the type of the source gas may vary depending on the type of the substrate 10 or the type of thin film to be deposited. For example, in order to deposit a silicon thin film, the second source gas S is a gas of any one of silane (SiH 4), TEOS (tetraethoxy-silane), and silicon tetrafluoride (SiF 4) containing silicon. The first source gas (R) may be any one of nitrogen (N 2), oxygen (O 2), argon (Ar), helium (He), hydrogen (H 2), or a mixture of two or more gases. Can be used.

In the present embodiment, the source gas supply unit 105 supplies two different types of source gases, and the first supply line 151 and the second source gas S supplying the first source gas R. It is configured to include a second supply line 152 for supplying.

When the high frequency power is applied, the plasma generator 104 forms a predetermined electric field in the process chamber 101 to excite the source gas to the plasma P state. Here, the atomic layer deposition apparatus 100 may generate a plasma by an inductively coupled plasma (ICP) method. For example, the plasma generating unit 104 is provided above the shower head 103, and when a high frequency power is applied from the power supply unit 145, the plasma generating unit 104 generates an induction electric field inside the shower head 103. The plasma P may be generated inside the 103. That is, in the process chamber 101, a space in which the substrate 10 is accommodated by the shower head 103 and a deposition process is performed and a space in which the plasma P is generated are separated, and the shower head 103 is separated. The radical of the plasma P component is provided to the substrate 10 through the first injection port 312 (see FIG. 2).

However, the present invention is not limited thereto, and the plasma generator 104 may use a capacitively coupled plasma (CCP) method. That is, the plasma generating unit 104 is a flat plate type electrode, and a high frequency power source or a ground is connected to the shower head 103 to generate an electric field generated between the plasma generating unit 104 and the shower head 103. Plasma is generated.

Meanwhile, the first source gas R is continuously injected, but the second source gas S is intermittently injected. In order to spray the second source gas (S) in the pulse method, the shower head 103 is provided with the valve portion 133 in the form of a diaphragm, and the valve portion 133 is inside the shower head 103. In the second source gas (S) is provided on the flow path is intermittently opened and closed to spray the second source gas (S) in a pulsed manner.

Hereinafter, the structures of the shower head 103 and the valve unit 133 will be described in detail with reference to FIGS. 2 and 3.

The shower head 103 has a first buffer unit so that the first and second source gases R and S are supplied through independent flow paths so that the shower head 103 may be sprayed without being mixed in the shower head 103. 313 and the second buffer 323 is separated.

For example, the shower head 103 may include a housing 131 forming a main body and a plurality of first injection ports 312 provided in the housing 131 to which the first source gas R is injected. A first plate 311 and a second plate 321 having a plurality of second injection ports 322 through which the second source gas S is injected are formed. In addition, the first and second plates 311 and 321 are vertically coupled so that the first and second buffer parts 313 and 323 are independent of each other by the first and second plates 311 and 321. The first supply line 151 is connected to the first buffer unit 313, and the second supply line 152 is connected to the second buffer unit 323.

The first and second injection ports 312 and 322 may uniformly spray the first and second source gases R and S onto the substrate 10. It is arranged uniformly and densely in the plates 311 and 321.

Here, the first injection port 312 is the second buffer unit 323 so that the first and second source gases R and S may be injected independently from each other without being mixed in the shower head 103. Pass through) so as to communicate with the process chamber 101. In particular, the first injection port 312 extends a predetermined length downward from the first plate 311 and extends into the second injection port 322.

The second injection port 322 accommodates the first injection port 312 but is formed to have a diameter larger than an outer circumferential surface of the first injection port 312. That is, the second source gas S is injected between the outer circumferential surface of the first injection port 312 and the inner circumferential surface of the second injection port 322.

Here, the first injection port 312 and the second injection port 322, as shown in the figure, the ends thereof may be disposed on a different plane. For example, an end portion of the first injection port 312 may be connected to the second injection port 322 to increase the contact time of the first and second source gases R and S and to improve mixing and reactivity. It may be formed inside of. Alternatively, an end portion of the first injection port 312 and the second injection port 322 may be formed on the same plane, and an end of the first injection port 312 may be formed at the second injection port 322. It may also be formed to protrude beyond the end.

However, the size, shape and arrangement of the first and second injection ports 312 and 322 are not limited by the drawings, and holes having substantially various sizes and shapes may be used to maintain a constant injection amount of the source gas. It can be arranged in various ways.

The valve part 133 is provided inside the second buffer part 323 and is provided to open and close the second injection port 322. In detail, the valve part 133 includes a diaphragm-shaped valve body 331 for opening and closing the second injection port 322 and a fixing part 335 for fixing the valve body 331.

The valve body 331 is provided above the second injection port 322 to open and close the second injection port 322, and has a diaphragm shape that is bent to a predetermined radius of curvature so as to have good response. Here, since the first injection port 312 has a form extending into the second injection port 322, the valve body 331, the first injection port 312 is the valve body 331 The fixing part 335 has a shape of a rim mounted on an outer circumferential surface of the first injection port 312 to fix a portion of the valve body 331.

In addition, the valve unit 133 is provided to correspond to the second injection port 322 one-to-one to open and close each of the second injection port (322).

The free end, which is not fixed in the valve body 331, extends outward from the first injection port 312 to be in contact with the surface of the second plate 321. That is, the second plate 321 becomes a valve seat of the valve unit 133.

One side of the valve unit 133 is provided with an opening and closing portion 135 for controlling the opening and closing of the valve unit 133, and controls the opening and closing portion 135 to inject the second source gas (S) in a pulsed manner. The control unit 353 (see Fig. 4) is provided.

For example, the valve unit 133 is operated by an electrical signal, and the opening and closing unit 135 is composed of a power source 351 (see FIG. 4) and a switch 352 (see FIG. 4) and the first plate 311. Is electrically connected). That is, the first plate 311 is formed of a conductive material to electrically connect the valve body 331 and the opening / closing part 135. Therefore, since the valve part 133 is electrically connected to the opening and closing part 135 at the same time, the plurality of valve parts 133 provided in the second injection port 322 according to whether power is supplied from the opening and closing part 135. Will work simultaneously.

Since the valve unit 133 is operated by electricity, the valve body 331 is formed of a piezoelectric element to be opened and closed by electricity.

However, the shape of the valve body 331 and the fixing portion 335 is not limited by the drawings, the valve body 331 is not in the form of a disk any other flexible form and the transition between the open and closed positions It may have a form that can be, and the fixing portion 335 may include a variety of structures that can be fixed to the valve body 331.

Hereinafter, operations of the atomic layer deposition apparatus 100 and the valve unit 133 according to an embodiment of the present invention will be described with reference to FIGS. 4 to 6.

First, the substrate 10 to be processed is introduced into the process chamber 101. In addition, a suitable source gas is supplied into the process chamber 101 according to the type of surface treatment process to be performed on the substrate 10.

Here, the source gas is appropriately selected according to the surface treatment process, for example, the source gas is a reaction material between the first source gas (R) and the substrate 10 excited in the plasma (P) state It may include a second source gas (S) comprising a.

As the high frequency power is applied to the plasma generating unit 104 and a predetermined electric field is generated in the process chamber 101, the first source gas R supplied to the first buffer unit 313 is plasma ( In the P state, plasma P is generated, and radicals in the plasma P particles are provided to the substrate 10 through the first injection port 312. In addition, on the surface of the substrate 10, the second source gas S injected from the second injection port 322 by radicals injected from the first injection port 312 reacts with the surface of the substrate 10. While a predetermined thin film is formed.

On the other hand, as shown in Figure 4, the control unit 353 intermittently opening and closing the valve unit 133 by controlling the opening and closing unit 135 so that the second source gas (S) is injected in a predetermined pulse method. . For example, when power is applied, the valve body 331 is reversed as shown in FIG. 6 to be separated from the second plate 321 to open the second injection port 322, and the power is turned on. When released, it may be restored to operate to close the second injection port 322. Of course, it would be possible to work in reverse.

First, as shown in FIG. 5, when the control unit 353 turns off the switch 352 of the opening / closing unit 135, power is released to the first plate 311, and the valve body 331 is The second injection port 322 is closed because the second plate 321 is in contact with the second plate 321, so that the second source gas S is not injected, and the first source is supplied through the first injection port 312. Only gas R is injected.

As shown in FIG. 6, when the control unit 353 turns on the switch 352 of the opening / closing unit 135, power is applied to the first plate 311 and the valve body 331 is connected to the second. The second injection port 322 is opened while being separated from the plate 321, and the second source gas S in the second buffer part 323 flows into the valve body 331 to allow the second injection port 322 to open. A thin film is formed on the surface of the substrate 10 while being injected through the injection port 322. Therefore, whether the second source gas S is injected and whether the thin film is deposited may be controlled according to whether the valve body 331 is opened.

In this embodiment, the first source gas (R) is continuously injected and only the second source gas (S) is injected in a pulse method, this method is the first and second source gas (R, S) Compared with a method of spraying alternately in a pulse method, there is an advantage that the deposition rate can be improved without degrading the quality of the deposited thin film. In addition, since only one source gas is intermittently injected, the structure of the shower head 103 may be simplified, and the second source gas S may effectively cope with a short pulse interval. In particular, the diaphragm-shaped valve body 331 does not require a separate complicated structure and a driving unit, and is a structure that is operated by an electrical signal, thereby lowering the failure rate of the shower head 103 and the valve unit 133 and lifespan. And durability can be improved.

As described above, although described with reference to the preferred embodiment of the present invention, those skilled in the art various modifications and variations of the present invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

1 is a cross-sectional view for explaining an atomic layer deposition apparatus according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view illustrating main parts of the showerhead and the valve unit in the atomic layer deposition apparatus of FIG. 1; FIG.

3 is a perspective view of main parts of the showerhead of FIG. 2;

4 is a block diagram illustrating an operation of an opening and closing unit for opening and closing a valve unit in the shower head of FIG. 2;

FIG. 5 is a sectional view showing the main parts of a valve unit in an open state in the shower head of FIG. 2; FIG.

FIG. 6 is a cross-sectional view illustrating the main parts of the shower head of FIG.

<Description of the symbols for the main parts of the drawings>

10: substrate 100: atomic layer deposition apparatus

101: process chamber 102: susceptor

103: shower head 104: plasma generating unit

105: source gas supply unit 131: housing

133: valve portion 135: opening and closing portion

145: power supply unit 151, 152: supply line

311, 321: plate 312, 322: injection port

313 and 323: buffer part 331: valve element

335: fixing unit 351: power supply

352: switch 353: control unit

P: plasma R: first source gas

S: second source gas

Claims (13)

A showerhead for an atomic layer deposition apparatus, A first plate having a plurality of first injection ports through which the first source gas is injected; A second plate formed with a second injection port for receiving the first injection port and injecting a second source gas between the first injection port and the second injection port; A valve unit disposed on the second injection port to selectively open and close the second injection port; And An opening / closing part which opens and closes the valve part by applying an electrical signal to the valve part; Including, The valve unit, A diaphragm valve body formed to cover the second injection port and penetrating the first injection port; And A fixing part mounted to an outer circumferential surface of the first injection port and fixing the valve body to the first injection port; Shower head for an atomic layer deposition apparatus comprising a. The method of claim 1, A first buffer part formed on the first plate and serving as a flow path for supplying the first source gas to the first injection port; And A second buffer part formed separately from the first buffer part by the first plate and serving as a flow path for supplying the second source gas to the second injection port; Is formed, And the first injection port extends from the lower portion of the first plate to the second injection port through the second buffer part. The method of claim 2, And an outer circumferential surface of the first injection port and an inner circumferential surface of the second injection port are spaced apart from each other. delete The method of claim 1, And the valve body is formed of a piezoelectric element. The method of claim 1, The valve body is a showerhead for an atomic layer deposition apparatus, characterized in that provided in one to one corresponding to the plurality of second injection port. The method of claim 1, The fixing part has a rim (rim) shape for fixing a portion of the valve body in close contact with the outer peripheral surface of the first injection port characterized in that the shower head for an atomic layer deposition apparatus. The method of claim 1, The opening and closing portion, A power source electrically connected to the first plate and applying power; And A switch provided between the power source and the first plate to selectively block power to the first plate; Shower head for an atomic layer deposition apparatus comprising a. The method of claim 8, The first plate is a showerhead for an atomic layer deposition apparatus, characterized in that formed of a conductive material. A process chamber in which a substrate is accommodated and a deposition process is performed; A susceptor accommodated in the process chamber to seat the substrate; A shower head provided on the substrate and injecting a first source gas and a second source gas to the substrate, wherein first and second buffer parts are formed to inject the first and second source gases independently of each other; And A plasma generation unit provided above the shower head to generate a plasma inside the first buffer unit; Including, The shower head, A first plate having a plurality of first injection ports through which the first source gas is injected; A second plate having a plurality of second injection ports through which the second source gas is injected to be independent of the first source gas; A valve unit including a diaphragm-shaped valve body provided at each of the second injection ports to open and close the second injection port, and a fixing part provided at the first injection port to fix the valve body; And An opening / closing part which opens and closes the valve part by applying an electrical signal to the valve part; Including, The valve unit, A diaphragm valve body formed to cover the second injection port and penetrating the first injection port; And A fixing part mounted to an outer circumferential surface of the first injection port and fixing the valve body to the first injection port; Atomic layer deposition apparatus characterized in that comprises a. The method of claim 10, The showerhead is the atomic layer deposition apparatus characterized in that the first source gas is continuously injected and the second source gas is intermittently sprayed as the valve portion is opened and closed. The method of claim 10, The shower head may be formed such that the first injection port communicates with the first buffer part and the process chamber through the second buffer part and the second plate, and extends into the second injection port. An atomic layer vapor deposition apparatus. The method of claim 12, And an end portion of the first injection port and an end portion of the second injection port are disposed on a plane having a different height from the surface of the substrate.

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