KR20120066851A - Thin layer deposition method - Google Patents

Abstract

PURPOSE: A method for depositing a thin film is provided to form a uniform thin film by supplying gas to a space between substrates. CONSTITUTION: A processing chamber(10) includes a gas supply inlet in a fixed position of a sidewall. A substrate(S) of multiple columns is parallelly loaded inside the processing chamber in an inline form. A gas supply device(20) includes a tank and a valve storing a reaction gas and a purge gas. A gas spread and supply groove(30) is formed on one sidewall of the processing chamber. An exhaust device(40) exhausts the processing chamber.

Description

Thin Film Deposition Method {THIN LAYER DEPOSITION METHOD}

The present invention relates to a thin film deposition method, and more particularly, after a predetermined reaction gas is injected into a process chamber having a laminar flow of gas, a heterogeneous purge gas is directly injected to the process chamber. The present invention relates to a thin film deposition method having a short process tack time because an atomic layer deposition process is performed on a plurality of substrates while the virtually divided space moves in the chamber space while the internal space is virtually divided by the gases.

In general, a semiconductor device or a flat panel display device is subjected to various manufacturing processes, and among these, a process of depositing a predetermined thin film on a wafer or a glass (hereinafter, referred to as a substrate) is essential. The thin film deposition process is mainly used for sputtering, chemical vapor deposition (CVD), atomic layer deposition (ALD) and the like.

First, the sputtering method injects an inert gas such as argon into the process chamber while a high voltage is applied to the target, for example, to generate argon ions in a plasma state. At this time, argon ions are sputtered on the surface of the target, and atoms of the target are separated from the surface of the target and deposited on the substrate.

Such a sputtering method can form a high purity thin film having excellent adhesion with a substrate, but in the case of depositing a highly integrated thin film having a process difference by the sputtering method, it is very difficult to secure uniformity over the entire thin film. There is a limit to the application of.

Next, chemical vapor deposition is the most widely used deposition technique, and is a method of depositing a thin film having a required thickness on a substrate using a reaction gas and a decomposition gas. For example, chemical vapor deposition first deposits a variety of gases into a reaction chamber and deposits a thin film of the required thickness on a substrate by chemically reacting gases induced by high energy such as heat, light or plasma.

In addition, the chemical vapor deposition method increases the deposition rate by controlling the reaction conditions through the ratio and amount of plasma or gases applied by the reaction energy.

However, in chemical vapor deposition, the reactions are fast, and thus, it is very difficult to control the thermodynamic stability of atoms.

Finally, Atomic Layer Deposition (ALD) is a method of atomic layer deposition by injecting two or more reactants one by one into a reaction chamber to form a thin film. It is a method of vapor deposition in units. That is, after the first reaction gas is supplied by a pulsing method and chemically deposited on the lower layer inside the chamber, the remaining first reaction gas which is physically bound is removed by a purge method. Subsequently, a desired thin film is deposited on the substrate while the second reaction gas is chemically combined with the first reaction gas (first reactant) through pulsing and purging. Al ₂ O ₃ , Ta ₂ O ₃ , TiO ₂ and Si ₃ N ₄ are typical thin films formed by the atomic layer deposition method.

The atomic layer deposition can form a thin film having excellent step coverage even at a low temperature of less than 600 ℃, a new use that is expected to use a lot in the process of manufacturing next-generation semiconductor devices, displays, solar cells, etc. Process technology. In the above-described atomic layer deposition process, the time at which each reaction gas is pulsed and purged is called a cycle.

A general batch atomic layer deposition apparatus 100 will be described with reference to FIG. 1.

As shown, in the atomic layer deposition apparatus 100, a cassette is loaded into the process chamber 110. A plurality of substrates S are stacked in the cassette. The cassette is loaded or unloaded using the cassette moving unit 120.

Gas supply means 130 for supplying the first and second reaction gas and purge gas to the process chamber 110, injection means 131 for uniformly injecting the gas into the process chamber, and the process Exhaust means 140 for exhausting the chamber 110 is also provided.

The operating state of the conventional atomic layer deposition apparatus constructed as described above will be described.

First, the gate valve is opened and the cassette is brought into the process chamber.

Next, while exhausting the process chamber using the exhaust means, atomic layer deposition is performed on the substrate by alternately supplying a purge gas and a reaction gas.

More specifically, first, the process chamber is exhausted, the first reaction gas is supplied, the exhaust gas is again exhausted, the purge gas is supplied, the second reaction gas is supplied again, and the purge gas is supplied again.

Figure 2 shows the amount of each gas supplied to the process chamber over time (X axis represents time, Y axis represents the gas flow rate).

That is, t1 to t2 supply the first reaction gas, t2 to t3 exhaust the process chamber, t3 to t4 supply the purge gas, t4 to t5 exhaust again, and t5 to t6 the second reaction gas. T6 to t7 are exhausted, and t7 to t8 are purge gases. Of course, after stopping supply of the first and second reaction gases, a method of immediately supplying an excessive amount of purge gas without exhausting the process chamber is also used. This process is repeated to form a predetermined thin film on the substrate.

However, in the conventional atomic layer deposition method, after supplying each gas into the entire process chamber, exhausting the entire space in the process chamber or purging completely using purge gas, and then supplying and purging other process gases in the same manner. Because of this method, the process tack time is very long.

The present invention has been made to solve the above problems, an object of the present invention after the injection of a predetermined reaction gas into the process chamber of the structure in which the gas laminar flow (laminar flow), the heterogeneous purge gas immediately In the state where the space inside the process chamber is virtually divided by the gases by spraying, the virtual partition space moves inside the process chamber, and an atomic layer deposition process is performed on a plurality of substrates so that the process tack time is short and the throughput is excellent. In providing a method.

In order to solve the above technical problem, the thin film deposition method according to the present invention includes 1) a cassette in which a plurality of substrates are stacked in a process chamber, and a gap between the substrate and the substrate and a gap between the cassette and the process chamber are less than or equal to the laminar flow interval. Loading to exhaust and evacuating the interior of the process chamber; 2) injecting a first reaction gas so that the first reaction gas space occupied by the first reaction gas in the space in the process chamber sequentially moves from one space of the process chamber to the other space; 3) A first purge gas space is formed at the same time as the first reaction gas is blocked and a purge gas is connected to the first reaction gas space, and the first purge gas space is moved in the same direction as the first reaction gas space. Spraying to; 4) At the same time as the blocking of the purge gas and the second reaction gas, a second reaction gas space is formed in succession with the first purge gas space, the second reaction gas space in the same direction as the first purge gas space Spraying to move; And 5) blocking the second reaction gas and simultaneously connecting the purge gas to the second reaction gas space, wherein the second reaction gas space is formed, and the second reaction gas space is connected to the first purge gas space. Spraying to move in the same direction; wherein the exhaust operation of sucking and discharging the gas inside the process chamber to the outside in a direction opposite to the direction in which the gas is supplied in the process chamber is performed in steps 1) to 5). It is characterized by being made without interruption over.

In the present invention, it is preferable that a plurality of cycles are repeatedly performed by setting 1 cycle that steps 2) to 5) are sequentially performed.

And in the present invention, the laminar flow interval is preferably 0.2 ~ 10 mm.

In addition, in the present invention, it is preferable that the substrates are stacked to be spaced apart from each other below a layer flow interval so that a space between the columns forms a layer flow of the gases.

In addition, it is preferable that a plurality of the cassettes are stacked side by side in an inline form so that side surfaces thereof coincide with a substrate loaded in an adjacent cassette.

According to the present invention, after a predetermined reaction gas is injected into the process chamber with a process chamber and a case in a structure in which a laminar flow of each gas supplied into the process chamber is formed, heterogeneous purge gases are provided. Sprays directly to the plurality of substrates loaded in the process chamber while the virtual partition space by the gases moves as if scanning the inside of the process chamber while the space inside the process chamber is virtually divided by the gases. Since the atomic layer deposition process is performed sequentially, the process tack time is short.

That is, in the present invention, the pumping time or purging process for complete exhaust of each reaction gas to the entire process chamber is not performed, and atomic layer deposition is continuously performed without process interruption while the process gas and purge gas flow sequentially into one chamber. The process is going on.

In addition, by arranging a plurality of substrates in an in-line form, the gas is supplied to the space between the substrates, so that uniform thin film formation is possible.

1 shows a conventional atomic layer deposition apparatus.
FIG. 2 is a graph showing a gas injection amount over time in the process chamber shown in FIG. 1.
3 and 4 show a thin film deposition method according to the present invention.
FIG. 5 shows a use state of deposition using the apparatus shown in FIG. 3.

Hereinafter, with reference to the accompanying drawings will be described the configuration and operation of the embodiment according to the present invention.

3 and 4, the thin film deposition method 1 according to the present invention includes a process chamber 10 in which a gas supply port is formed at a predetermined position of a side wall, a gas supply means 20, and an exhaust means 50. It includes.

In the process chamber 10, a plurality of cassettes C loaded with substrates S in a standing state (a state inclined at a predetermined angle vertically or vertically) may be loaded in an inline form to process a plurality of substrates at the same time. .

That is, a plurality of rows of substrates are stacked side by side in an inline form inside the process chamber. In addition, the substrates are stacked in a plurality of rows so that a space between the columns forms a flow path of the gases.

Specifically, in the present embodiment, in the state in which the cassette C is loaded in the process chamber 10, the gap between the cassette C and the chamber wall and between the substrates S loaded on the cassette C are shown. The interval of is loaded so that it is below the laminar flow interval.

Herein, the laminar flow refers to a 'flow of gas that flows in a direction with little gas being injected into the space between the narrow gaps and not freely diffused, and there is little disturbance in a certain direction'.

In addition, the laminar flow interval refers to the `` gap between two plates in which gas moves in the laminar flow form, '' and in this embodiment, the laminar flow interval is preferably 0.2 to 10 mm. If the laminar flow interval is less than 0.2 mm, not only is it difficult to process and manufacture, but also difficult to control the supply of gas. If the laminar flow interval exceeds 10 mm, the laminar flow of gas is broken and the gas is freely diffused. There is this.

In the present embodiment, as well as the distance between each substrate S loaded on the cassette C, the gap between the cassette C and the chamber walls, and the tip of the cassette C or the substrate S, which will be described later. The gap between the gas straight supply grooves 33 is also manufactured and loaded to have the laminar flow gap.

Next, the gas supply means 20 includes a tank for storing a first reaction gas, a second reaction gas, a purge gas, and the like, and a valve for selectively injecting the gases according to a process sequence.

In particular, the one side wall 11 of the process chamber 10 is further formed with a gas diffusion supply groove 30 for delivering the gas injected through the gas supply port 16 to the front end of the side wall along the side wall.

The gas diffusion supply groove 30 is formed by stepping the groove 31 on the outer wall of the one side wall 11 of the process chamber and sealing the upper portion of the groove 31 with a cover 32. Of course, even if the cover 32 is closed, it is not in close contact with the bottom surface of the groove 31 to form a space in which gas can flow.

The gas diffusion supply groove 30 may be formed on any sidewall such as the left and right walls 12 and 11 and the upper and lower walls 13 and 14 of the process chamber 10.

The gas diffusion supply groove 30 is formed to have a larger cross-sectional area from the gas supply port 16 formed in the side wall toward the tip portion of the side wall 11. This is to allow the gas to diffuse sufficiently evenly before flowing into the front surface of the process chamber 10, that is, the gas straight supply groove 33, through the gas diffusion supply groove 30. The gas supplied by the gas supply port 16 maintains the laminar flow even while passing through the gas diffusion supply groove 30. Therefore, the gap between the gas diffusion supply groove 30 and the cover 32 is also formed to maintain the laminar flow gap.

Next, the gas straight supply groove 33 may be engraved in a rectangular shape at a predetermined depth on the side wall of the front end of the process chamber, and as shown in FIG. 5, the gas straight supply groove 33 is formed. The depth is formed so that the space | interval with the front-end | tip part of the board | substrate S may maintain the layered flow space | interval. Therefore, the gas diffused sufficiently in the width corresponding to the entire sidewall of the front end side of the process chamber through the gas diffusion supply groove 31 is simultaneously supplied to the entire gas straight supply groove 33, thereby providing the gas straight supply groove ( 33) the laminar flow is maintained.

The exhaust means 50 exhausts the process chamber 10, and may include a vacuum pump and the like.

Hereinafter, an operating state of the deposition apparatus described above with reference to FIG. 5 will be described.

First, when the gas is supplied to the gas supply port 16 formed on one side wall of the process chamber 10 by using the gas supply means, the gas is along the gas diffusion supply groove 30 in front of the process chamber (a front end of the side wall). ), Which is uniformly diffused by the shape of the gas diffusion supply groove 30 during the movement.

Next, the gas sufficiently diffused through the gas diffusion supply groove 30 moves in a layered manner in the direction of the opposite side wall along the gas straight supply groove 33 of the side wall formed on the front surface of the process chamber 10.

Next, the gas that reaches the front of the substrate, that is, the gas straight supply groove 33, moves in a layered flow through the space between the rows of the substrate to form a thin film on the substrate.

Therefore, the space between the rows is a flow path that maintains the laminar flow interval so that the gas moves in the laminar flow form in the process chamber. In addition, the plurality of cassettes C1 to C4 are closely stacked in an inline form, and the substrates S1 to S4 stacked on the neighboring cassettes are also closely stacked to uniformly stack the plurality of cassettes while maintaining a gas flow layer. Let it flow.

In this embodiment, after the supply of the first process gas is stopped, immediately after the first process gas, without proceeding to pump or purge the first process gas to remove all the first process gas present in the process chamber. Since the purge gas is supplied into the process chamber, the first process gas and the purge gas coexist in a virtually divided space in the vacuum chamber in one vacuum chamber.

In the present exemplary embodiment, the first process gas space refers to a virtual space filled by the first process gas among the spaces in the process chamber, and the first purging gas space is continuously filled by the purging gas in the first process gas space. The virtual space refers to the virtual space, and the second process gas space refers to the virtual space filled by the second process gas, and the second purging gas space is the virtual space filled to the purging gas subsequent to the second process gas space. To say. In the present exemplary embodiment, the first process gas space, the first purging gas space, the second process gas space, and the second purging gas space do not stay at a predetermined position, but move simultaneously in a constant direction at a constant speed.

Specifically, the process of forming the gas space is as follows. First, when the first process gas is supplied into the process chamber, a virtual first process gas space filled with the first process gas is formed in the vacuum chamber, and the first process gas space is formed in a predetermined direction in the process chamber. Will move sequentially.

When the first process gas supply is stopped and the purge gas is supplied, a first purge gas space is formed in the vacuum chamber in succession to the first process gas space, and the first process gas space is pushed in the moving direction to provide the first process gas. Move along the gas space. At this time, the interface between the first process gas space and the first purging gas space is not completely separated, but there is a section where the first process gas and the purging gas are mixed to some extent, and the first process gas space is gradually moved toward the center of the first process gas space. The density | concentration of a process gas is high, and the density | purification gas concentration becomes high toward the center of a 1st purging gas space.

Meanwhile, in the present embodiment, as described above, in order to completely purge the first process gas, the purging gas forming the first purging gas space is injected in an excessive amount compared to the first process gas, and thus the movement of the first purging gas space is performed. By this, the first process gas is completely moved in the opposite direction of the gas straight supply groove 33.

The second process gas is subsequently supplied to the first purge gas space to form a second process gas space. In addition, the second process gas space is subsequently supplied with an excessive amount of purging gas again to form a second purging gas space, and the second process gas is completely removed by the movement of the second purging gas space.

In this embodiment, the first process gas space, the first purging gas space, the second process gas space, and the second purging gas space sequentially perform the atomic layer deposition process while moving inside the process chamber. Therefore, in the present embodiment, the process gas supply and purging is continuously performed as if the substrate is scanned in one process chamber as compared with the conventional method in which the process gas supply and purging processes are intermittently performed for the entire process chamber. The process time is significantly shortened and the trough is greatly improved.

If necessary, the above-described process may be repeatedly performed in a plurality of cycles. Of course, the exhaust operation is always performed while supplying each gas.

1: thin film deposition method 10: process chamber
11: gas inlet 20: gas supply means
30: vent hole 31: home
32: cover 40: exhaust means

Claims (5)

1) loading a cassette having a plurality of substrates loaded in the process chamber such that the gap between the substrate and the substrate and the gap between the cassette and the process chamber is a laminar flow gap, and evacuating the inside of the process chamber;
2) injecting the first reaction gas so that the first reaction gas space occupied by the first reaction gas in the process chamber moves sequentially from one space of the process chamber to the other space;
3) A first purge gas space is formed at the same time as the first reaction gas is blocked and the purge gas is connected to the first reaction gas space, and the first purge gas space is in the same direction as the first reaction gas space. Spraying to move;
4) At the same time as the blocking of the purge gas and the second reaction gas, a second reaction gas space is formed in succession with the first purge gas space, the second reaction gas space in the same direction as the first purge gas space Spraying to move; And
5) the second purge gas is blocked and the purge gas is connected to the second reaction gas space and the second purge gas space is formed, and the second purge gas space is the same as the second reaction gas space. And spraying to move in a direction;
Thin film deposition method characterized in that the exhaust operation to inhale and discharge the gas inside the process chamber to the outside in the direction opposite to the direction in which the gas is supplied in the process chamber through the steps 1) to 5) without interruption.
The method of claim 1,
Thin film deposition method, characterized in that a plurality of cycles are repeatedly performed with 1 cycle that the steps 2) to 5) are sequentially performed.
The method of claim 1,
The layer flow interval is a thin film deposition method, characterized in that 0.2 ~ 10 mm.
The method of claim 3,
And stacking the substrates so as to be spaced apart from each other by a laminar flow interval to form a laminar flow of the gases in the space between the rows.
The method of claim 4, wherein
And a plurality of the cassettes are stacked side by side in an inline form so as to connect the layer flow gaps formed between the substrates stacked in the adjacent cassettes.

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