KR100930824B1 - Atomic layer deposition apparatus - Google Patents

Abstract

Disclosed is an atomic layer deposition apparatus having a reaction cell to adjust a gap between a susceptor and a showerhead. The atomic layer deposition apparatus includes a reaction cell along the periphery of the substrate. The reaction cell is formed to be in contact with the susceptor and the shower head, and is provided with a height adjusting member to adjust the gap between the susceptor and the shower head. Therefore, the atomic layer deposition apparatus may adjust the height of the reaction cell to adjust the distance between the susceptor and the showerhead. In addition, the space in which the actual deposition reaction occurs in the atomic layer deposition apparatus is limited to the inside of the reaction cell, thereby minimizing the reaction space. In addition, by minimizing the reaction space, the time required for supply and exhaust of the source gas is reduced, and the amount of the source gas is reduced. In addition, it is possible to minimize the area where contamination occurs due to reaction by-products generated in the deposition reaction.

Description

Atomic Layer Deposition Apparatus {ATOMIC LAYER DEPOSITION APPARATUS}

The present invention relates to an atomic layer deposition apparatus, and more particularly, is provided around the substrate in the atomic layer deposition apparatus can adjust the distance between the susceptor and the showerhead, atomic layer deposition apparatus to minimize the space for the deposition reaction occurs It is about.

Recently, as the degree of integration of semiconductor devices increases in the semiconductor manufacturing process, the demand for micromachining increases. That is, in order to form a fine pattern and to highly integrate cells on one chip, it is necessary to reduce the thickness of the thin film and develop a new material having a high dielectric constant. In particular, when a step is formed on the surface of the substrate, it is very important to secure step coverage, step coverage, and within wafer uniformity that smoothly cover the surface. In order to satisfy such requirements, an atomic layer deposition (ALD) method, which is a method of forming a thin film having a small thickness in atomic layer units, has been proposed.

The ALD process forms a monoatomic layer using chemical adsorption and desorption processes by surface saturation reaction of the reactants on the surface of the substrate. Possible thin film deposition methods.

The ALD process introduces two or more source gases alternately, and introduces an inert purge gas between the inflows of each source gas to prevent the source gases from mixing in the gas phase. In other words, one source gas is chemically adsorbed onto the surface of the substrate, and then another source gas is subsequently reacted to generate one atomic layer on the surface of the substrate. Then, this process is repeated at one cycle until a thin film having a desired thickness is formed.

On the other hand, the source gas should be suppressed so that chemical adsorption and chemical reaction occur only on the surface of the substrate so that no other surface reaction occurs until one atomic layer is completely formed.

However, even in the conventional ALD process, even if the purge gas is supplied to purge the residual source gas in the process chamber, a small amount of source gas remains in the process chamber, and such residual source gas and other source gas are mixed and Reacting particles can be generated. In addition, particles are included in the thin film formed on the substrate due to the generation of particles, and thus there is a problem that the quality of the thin film is degraded.

In addition, as the substrate gradually increases in size, the volume of the process chamber also increases. Therefore, in order to fill the process chamber, the amount of source gas consumed is increased, and the amount of unnecessary waste is also increased.

In addition, as the volume of the process chamber increases, the time required for supplying and replacing the source gas increases, thereby increasing the overall process time.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and to provide an atomic layer deposition apparatus capable of adjusting a distance between a showerhead and a susceptor.

In addition, the present invention is to provide an atomic layer deposition apparatus having a reaction cell that accommodates the substrate in the atomic layer deposition apparatus to minimize the reaction space in which the deposition reaction occurs.

In addition, the present invention is to provide an atomic layer deposition apparatus that minimizes the reaction space, and also minimizes contamination of the process chamber wall surface due to reaction by-products generated in the deposition process.

According to embodiments of the present invention for achieving the above object of the present invention, the atomic layer deposition apparatus that can easily adjust the volume of the reaction space, a process chamber in which a plurality of substrates are accommodated to perform the deposition process, the A showerhead provided above the substrate in the process chamber to inject a source gas to the substrate, and provided below the showerhead in the process chamber to support the substrate and to move up and down with respect to the showerhead; Coupled to any one of the susceptor, the showerhead or the susceptor and in contact with the other as the susceptor moves up and down to selectively seal the space in which the substrate is accommodated between the susceptor and the showerhead; Reaction having an elastic member so that the height is elastically adjustable in accordance with the lifting movement of the susceptor And it is provided on an inside of the reaction cell can comprise parts of an exhaust for discharging the exhaust gas inside the reaction cell.

In an embodiment, the reaction cell is formed to accommodate a plurality of substrates at the same time. For example, the reaction cell is formed along the outer periphery of the susceptor to accommodate the plurality of substrates at the same time.

In an embodiment, the reaction cell is a body forming an appearance, the height adjusting member and the height adjusting member that is retractable and inserted in the body and is elastically supported by the elastic member by the lifting movement of the susceptor. It may be configured to include an elastic member provided inside the body to apply an elastic force to the height adjustment member from the rear. Here, the body is coupled to either the showerhead or the susceptor. As the susceptor moves up and down, the height adjusting member is in close contact with the susceptor and the shower head to seal the reaction cell internal space.

In an embodiment, the extraction length of the height adjusting member is adjusted by the lifting movement of the susceptor so as to adjust the volume of the reaction cell.

In some embodiments, the exhaust part may include a first exhaust part provided in the shower head to exhaust the exhaust gas to the upper portion of the substrate. The exhaust part may include a second exhaust part formed around the substrate in the susceptor to discharge the exhaust gas through the lower portion of the substrate. Of course, the atomic layer deposition apparatus may include any one or both of the first exhaust unit and the second exhaust unit.

According to the present invention, first, the distance between the showerhead and the susceptor can be adjusted by adjusting the height of the reaction cell. In addition, the volume of the reaction space consisting of the reaction cell, the shower head and the susceptor can be adjusted. Therefore, by adjusting the volume of the reaction space, it is possible to change process factors such as the plasma density and the flow rate and flow type of the source gas in the reaction space.

Second, by providing a reaction cell at a position adjacent to the substrate, the volume of the reaction space is minimized because the reaction space of the actual source gas is limited to the inside of the reaction cell. Therefore, it is possible to increase the density of the source gas in the reaction space and to increase the generation density of the plasma.

In addition, by minimizing the volume of the reaction space, it is possible to quickly replace the source gas and to quickly exhaust the unreacted gas and the purge gas, it is possible to reduce the consumption of the source gas. Therefore, the time required to replace and exhaust the source gas in the deposition process can be reduced, thereby reducing the overall process time and improving the productivity.

Third, since a substantial reaction space is limited to the inside of the reaction cell, it is possible to prevent contamination by reaction by-products that may occur in the deposition process on the process chamber wall.

In addition, it is possible to minimize the area contaminated by the reaction by-products. In addition, impurities remaining in the thin film due to such contamination can be prevented from being degraded.

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.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, but the present invention is not limited or limited by the embodiments.

1 is a cross-sectional view illustrating an atomic layer deposition apparatus according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating another embodiment of the exhaust unit of FIG. 1. 3 is a perspective view for explaining a reaction cell according to an embodiment of the present invention, Figure 4 is a cross-sectional view for explaining the reaction cell of FIG.

Referring to Figures 1 to 4, the atomic layer deposition apparatus according to an embodiment of the present invention will be described.

Referring to FIG. 1, the atomic layer deposition apparatus 100 includes a process chamber 101, a shower head 110, a susceptor 130, an exhaust unit 150, and a reaction cell 120.

The process chamber 101 accommodates the substrate 10 to provide a space in which a thin film deposition process is performed on the substrate 10. For example, the process chamber 101 may have a shape corresponding to that of the susceptor 130 and may have a cylindrical shape surrounding the susceptor 130.

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 glass substrate for a flat panel display device such as an LCD and a PDP. In addition, the substrate 10 is not limited in shape or size by the drawings, and may have substantially various shapes and sizes, such as circular and rectangular plates.

In the present embodiment, the atomic layer deposition apparatus may use a semi batch atomic layer deposition apparatus capable of simultaneously processing a plurality of substrates 10 to increase productivity. Here, in the case of the semi-batch type, the deposition process may be performed on the plurality of substrates 10 at the same time, thereby improving throughput.

However, the present invention is not limited thereto, and the present invention may be applied to a deposition apparatus of substantially various types, including a sheet type apparatus for treating one substrate 10.

Hereinafter, in the present invention, a semi-batch type atomic layer deposition apparatus will be described as an example.

The susceptor 130 has a disk shape so that the plurality of substrates 10 may be arranged at equal intervals. However, the susceptor 130 may have various shapes and sizes depending on the shape of the substrate 10 and the number of substrates 10 that can be disposed.

The susceptor 130 supports the surface on which the thin film of the substrate 10 is to be deposited to be exposed to the top, but has a shape in which the plurality of substrates 10 may be disposed on the same plane.

In addition, the susceptor 130 is formed to be elevated in the vertical direction with respect to the shower head 110, the driving unit 135 is provided to provide a driving force for the lifting movement of the susceptor 130.

The shower head 110 is provided on the substrate 10 and has a shape corresponding to that of the susceptor 130. In addition, the shower head 110 injects a plurality of source gases for forming a thin film on the substrate 10 and a purge gas for purging the source gas (hereinafter, all referred to as source gas S). . The shower head 110 is formed with a plurality of injection holes (not shown) for injecting the source gas (S) to the substrate 10, the shower head 110 to the source gas (S) The source gas supply part 115 which supplies is connected.

The shower head 110 is provided with an exhaust unit 150 for exhausting the exhaust gas generated in the process chamber 101. The exhaust unit 150 is connected to an exhaust pump 251 to discharge the exhaust gas including the unreacted source gas or the reaction by-product generated during the thin film deposition process in the process chamber 101.

The exhaust part 150 includes an exhaust chamber 151 in which a plurality of exhaust holes 152 are formed, which communicate with the inside of the process chamber 101. In addition, an exhaust line 155 for discharging the exhaust gas inside the exhaust chamber 151 is connected to one side of the exhaust chamber 151. For example, the exhaust line 155 is a flow path connected to the central portion of the shower head 110, and one end of the exhaust pump 251 is connected. In addition, the exhaust pump 251 may be a vacuum pump.

The exhaust chamber 151 is provided at the central portion of the shower head 110 to uniformly provide a suction force in the process chamber 101 to discharge the exhaust gas in the process chamber 101 to the outside. .

The exhaust hole 152 is uniformly formed along the circumference of the exhaust chamber 151. In addition, the position of the exhaust hole 152 is located above a predetermined height above the upper surface of the substrate 10 so as to effectively suck the exhaust gas from the upper portion of the substrate 10. In addition, a plurality of exhaust holes 152 may be formed on the lower surface of the exhaust chamber 151 so that the exhaust gas may be effectively exhausted even under the exhaust unit 150. Therefore, when a negative pressure is formed in the exhaust chamber 151 through the exhaust line 155, the exhaust gas in the process chamber 101 is sucked through the exhaust hole 152, thereby It is discharged out of the process chamber 101.

On the other hand, as a modified embodiment of the exhaust unit described above, an exhaust unit (hereinafter referred to as a second exhaust unit 250) for exhausting the inside of the reaction cell 120 may be formed through the susceptor 130. It will be possible.

Referring to FIG. 2, the second exhaust part 250 is provided through the susceptor 130 so as to suck the exhaust gas downward from the periphery of the substrate 10. For example, the second exhaust part 250 includes a plurality of second exhaust holes 252 penetrating the susceptor 130, and a second exhaust line connected to the second exhaust holes 252. 255 extends a predetermined length below the susceptor 130.

The second exhaust hole 252 is formed in the vicinity of the substrate 10 to effectively discharge the unreacted source gas remaining on the substrate 10. In addition, the second exhaust hole 252 may have a plurality of holes uniformly disposed around the substrate 10 in order to effectively discharge the exhaust gas.

Meanwhile, only one of the exhaust unit 150 and the second exhaust unit 250 may be formed. As shown in FIG. 2, the shower head 110 may also discharge the exhaust gas to the upper portion of the substrate 10. An exhaust unit 150 may be formed in the shower head 110, and a second exhaust unit 250 may be formed in the susceptor 130.

A reaction cell 120 is provided along the periphery of the substrate 10.

The reaction cell 120 is provided between the susceptor 130 and the shower head 110 to adjust the distance between the susceptor 130 and the shower head 110.

In addition, the reaction cell 120 minimizes the reaction space in which the deposition process is performed by sealing the space in which the substrate 10 is accommodated. For example, the reaction cell 120 is provided on the lower surface of the shower head 110, and the upper surface of the susceptor 130 as the susceptor 130 moves up and down toward the shower head 110. Close to

The reaction cell 120 accommodates all of the substrate 10 and is formed to minimize the volume inside the reaction cell 120.

Referring to the drawings, the reaction cell 120 is composed of a body 121, the height adjusting member 123 and the elastic member 125.

The body 121 forms an appearance of the reaction cell 120 and accommodates the elastic member 125 and the height adjusting member 123.

The height adjusting member 123 is formed to be in contact with the susceptor 130. For example, the height adjusting member 123 is accommodated to protrude out of a predetermined length toward the end of the body 121.

In particular, when the height adjusting member 123 is in contact with the susceptor 130, in order to ensure the sealing of the inside of the reaction cell 120, the height adjusting member 123 into the body 121. It is provided to be movable a predetermined distance.

The elastic member 125 elastically supports the height adjusting member 123. For example, the elastic member 125 is provided so that the elastic force for restoring the height adjusting member 123 to the initial position. That is, when the height adjusting member 123 and the susceptor 130 contact, the elastic member 125 is compressed and presses the height adjusting member 123 against the susceptor 130. As the height adjusting member 123 is in pressure contact with the surface of the susceptor 130, the inside of the reaction cell 120 is sealed.

Here, the rate at which the source gas S is adsorbed to the substrate 10 in the atomic layer deposition process is proportional to the partial pressure of the source gas S and the exposure time of the substrate 10. According to the present invention, the reaction cell 120 surrounds the substrate 10 so that the deposition process is performed only inside the reaction cell 120, thereby substantially minimizing the volume of the reaction space in which the deposition process is performed. . Therefore, the volume reduction of the reaction space due to the reaction cell 120 increases the partial pressure of the source gas S inside the reaction cell 120, thereby improving the adsorption rate of the source gas S. In addition, there is an effect of improving the deposition rate by causing a deposition reaction for a quick time.

On the other hand, according to the present invention, changing the height of the reaction cell 120 changes the actual volume of the reaction space. In addition, the volume change of the reaction cell 120 changes the partial pressure of the source gases S1 and S2 in the reaction cell 120, and the flow rate and flow of the source gases S1 and S2. You can change the shape. In addition, the partial pressures and flow patterns of the source gases S1 and S2 correspond to process conditions that substantially affect the thin film deposition process. In addition, the distance between the showerhead 110 and the susceptor 130 is also a process condition in the thin film deposition process. Accordingly, the process conditions may be variously changed by simply changing the height of the reaction cell 120, and the thin film deposition process may be performed under various process conditions.

In addition, the reaction cell 120 may reduce the volume of the reaction space, thereby reducing the amount of source gas (S) consumed in the deposition process. In addition, the time required for supply and exchange of the source gas (S) can be saved, thereby reducing the overall process time and improving the yield.

In addition, since the deposition reaction is performed only in the inner space surrounded by the reaction cell 120, the source gas S is prevented from being adsorbed on the inner wall of the process chamber 101. Therefore, by having the reaction cell 120, source gases S remaining on the wall of the process chamber 101 are mixed with each other to prevent reaction by-products from occurring and to minimize an area where such contamination may occur. Can be. In addition, contamination in the deposition process may prevent impurities in the thin film from being contained or uniformity, thereby preventing the quality of the thin film from being degraded.

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

2 is a cross-sectional view for describing another embodiment of the exhaust unit of FIG. 1;

3 is a cross-sectional view illustrating the operation of a reaction cell according to an embodiment of the present invention.

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

10: substrate 100: atomic layer deposition apparatus

101: process chamber 110: shower head

115: source gas supply unit 120: reaction cell

121: body 123: height adjustment member

125: elastic member 130: susceptor

135: driving part 150, 250: exhaust part

151: exhaust chamber 152, 252: exhaust hole

155, 255: exhaust line 251: exhaust pump

S: source gas

Claims (7)

A process chamber in which a plurality of substrates are accommodated and a deposition process is performed; A shower head provided above the substrate in the process chamber to inject a source gas to the substrate; A susceptor provided in a lower portion of the shower head in the process chamber to support the substrate and to be moved up and down with respect to the shower head; Coupled to either of the showerhead or the susceptor and in contact with the other in accordance with the lifting movement of the susceptor to selectively seal a space containing the substrate between the susceptor and the showerhead, Reaction cell having an elastic member so that the height is elastically adjustable according to the lifting movement of the; And An exhaust unit provided inside the reaction cell to discharge exhaust gas inside the reaction cell; Atomic layer deposition apparatus comprising a. delete The method of claim 1, The reaction cell, A body forming an appearance; A height adjusting member that is retractably received from the body and is inserted into the body and is elastically supported by the elastic member by a lifting movement of the susceptor; And An elastic member provided inside the body to apply an elastic force to the height adjusting member from the rear of the height adjusting member; An atomic layer deposition apparatus comprising a. The method of claim 3, The body is coupled to any one of the shower head or the susceptor, the height adjustment member is an atomic layer deposition apparatus, characterized in that provided by the lifting movement of the susceptor to adjust the withdrawal length of the height adjustment member . delete delete The method of claim 1, At least one of the first exhaust portion provided in the shower head to discharge the exhaust gas to the upper substrate and the second exhaust portion formed around the substrate in the susceptor to discharge the exhaust gas to the lower substrate An atomic layer deposition apparatus, characterized in that the exhaust portion is provided.

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