KR20080037176A - Apparatus for depositing thin film on a wafer - Google Patents

Abstract

An apparatus for depositing a thin film is provided to prevent a reaction chamber from being polluted due to reaction gases by preventing the reaction gases from being attached to an outer wall of the reaction chamber. An apparatus for depositing a thin film comprises a reaction chamber(140), a wafer block(110), and a ring-shaped baffle(150). The reaction chamber is provided with an inner space. The wafer block is provided at the inner space of the reaction chamber. A wafer is positioned on the wafer block. The baffle engages with the reaction chamber and is arranged to enclose the wafer block. The baffle includes a gas inlet, a gat outlet, and a gas channel. Gas is introduced to the gas inlet. The gas outlet injects the gas introduced to the gas inlet toward an edge portion of the wafer. The gas channel is formed inside the baffle, and connects the gas inlet and the gas outlet to each other.

Description

Thin film deposition apparatus {Apparatus for depositing thin film on a wafer}

1 is a diagram illustrating an example in which a thin film is normally formed at an edge portion of a wafer.

2 is a view showing an example in which a thin film is abnormally formed at an edge portion of a wafer.

Figure 3 is a side cross-sectional view of a thin film deposition apparatus according to an embodiment of the present invention.

4 is a partially enlarged view of a partial cross section around the baffle of the thin film deposition apparatus shown in FIG.

5 is an enlarged view of a portion "A" shown in FIG. 4;

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

100: thin film deposition apparatus 110: wafer block

120: cover 130: shower head

140: reaction chamber 144: exhaust passage

145: exhaust port 150: baffle

153: inner side of the baffle 154: gas inlet

155: gas outlet 156: gas channel

156a: diffusion space portion 156b: first supply passage

156c: injection passage 161: second supply passage

171: sealing member 190: cone baffle

w: wafer

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thin film deposition apparatus, and more particularly, to a thin film deposition apparatus that can be controlled such that a thin film is not formed at an edge portion of a wafer in a process of depositing a thin film on a wafer.

A thin film deposition apparatus is a device for depositing a desired thin film on a wafer using chemical reactions of various reaction gases in a semiconductor manufacturing process. Generally, a reaction chamber having an internal space in which chemical reactions of reaction gases occur, and a reaction chamber It is installed in the inner space and includes a wafer block on which the wafer is mounted on the upper surface. The wafer block not only supports the seated wafer, but also heats the wafer to a predetermined temperature necessary for depositing a thin film.

The thin film deposited on the wafer using the thin film deposition apparatus has various compositions which form a thin film according to the use, and one of them is a tungsten film which is a metal film. The tungsten film is attracting much attention today as an excellent material for forming a conductive film due to its low specific resistance. However, since tungsten is not easily attached to the surface of the wafer made of silicon, it is not possible to deposit a tungsten film directly on the wafer, but first deposit a medium film on which the tungsten can be easily attached onto the wafer, and then tungsten on the medium film. It is common to deposit a film.

1 is a diagram illustrating an example in which a thin film is normally formed at an edge of a wafer, and FIG. 2 is a diagram illustrating an example in which an abnormally thin film is formed at an edge of a wafer.

Referring to FIG. 1, in order to deposit the tungsten film 3 on the wafer w, first, an intermediate film 1 (2) is formed to facilitate the deposition of the tungsten film 3 on the wafer w. have. For example, a titanium (Ti) film 1 is formed directly on the wafer w, and a titanium nitride (TiN) film 2 is formed on the titanium film 1. Tungsten is easily attached to the titanium nitride (TiN) 2 and its bonding force is also strong so that tungsten does not fall off from the wafer w during the subsequent semiconductor manufacturing process. However, as shown in FIG. 2, in the process of depositing a thin film on the wafer w, the tungsten may be directly attached on the edge of the silicon wafer w to which the titanium nitride film 2 is not attached. do.

As such, tungsten, which is not deposited on the titanium nitride 2 and directly attached to the silicon wafer w, is weakly bonded to silicon, and thus easily detached from the wafer during the subsequent semiconductor manufacturing process. There is a problem in that particles are generated as a source of damage to a circuit pattern on a semiconductor chip.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and it is possible to obtain as many useful dies as possible from a single wafer by fundamentally blocking the source of particles by preventing unwanted thin films from being formed at the edge of the wafer. It is an object of the present invention to provide a thin film deposition apparatus having an improved structure.

In the thin film deposition apparatus of the present invention to achieve the above object, in the thin film deposition apparatus including a reaction chamber provided with an inner space, and a wafer block is installed in the inner space of the reaction chamber and the wafer is seated on the upper surface, An annular baffle coupled to the reaction chamber to surround the wafer block, wherein the baffle includes a gas inlet through which gas supplied from the outside is introduced, and a gas introduced into the gas inlet. And a gas outlet sprayed toward the edge of the wafer, and a gas channel formed inside the baffle and connecting the gas inlet and the gas outlet.

In the thin film deposition apparatus according to the present invention, preferably, the baffle is formed such that the surface on which the gas outlet is formed is not higher than the upper surface of the wafer block.

In the thin film deposition apparatus according to the present invention, Preferably, the gas outlet is formed on the inner peripheral surface of the baffle.

In the thin film deposition apparatus according to the present invention, preferably, the baffles are arranged at a predetermined distance from the wafer block over the entire circumference of the inner circumferential surface thereof.

In the thin film deposition apparatus according to the present invention, preferably, the gas channel is formed such that the gas injected through the gas outlet is injected 10 degrees to 15 degrees upwards.

In the thin film deposition apparatus according to the present invention, preferably, the gas channel is formed of an annular diffusion space portion for uniformly injecting gas through the gas outlet, connecting the diffusion space portion and the gas inlet. And a supply passage connecting the supply passage and the diffusion space to the gas outlet.

In the thin film deposition apparatus according to the present invention, preferably, the baffle is composed of a single body.

In the thin film deposition apparatus according to the present invention, preferably, the thin film deposition apparatus further includes a second supply passage connected to the gas inlet and formed through the reaction chamber.

In the thin film deposition apparatus according to the present invention, Preferably, the second supply passage and the gas inlet are sealed and connected by a sealing member.

In the thin film deposition apparatus according to the present invention, preferably, the sealing member is a rubber ring or a metal ring.

Hereinafter, preferred embodiments of the thin film deposition apparatus according to the present invention will be described in detail with reference to the accompanying drawings.

3 is a side cross-sectional view of a thin film deposition apparatus according to an embodiment of the present invention, FIG. 4 is a partially enlarged view of a partial cross-section around the baffle of the thin film deposition apparatus shown in FIG. 3, and FIG. Partial enlarged view of A ″ section.

3 to 5, the thin film deposition apparatus 100 according to the present embodiment is for depositing a thin film on the wafer w, the reaction chamber 140, the wafer block 110, and a cover. The part 120, the shower head 130, and the baffle 150 are provided.

The reaction chamber 140 has a wafer inlet 141 which is a passage through which the wafer w to be transported in and out is formed on a sidewall thereof, and an inner space for accommodating the wafer block 110 to be described later is formed therein. It is prepared. Since the wafer entrance and exit 141 is closed by the shielding means except when the wafer w enters and exits, the reaction chamber 140 forms a closed space independent of the outside. The wafer block 110 is installed in the inner space of the reaction chamber 140 and the wafer w is mounted on the upper surface 111 of the wafer block 110. The wafer block 110 is provided with a heater (not shown) therein for heating the wafer w to a predetermined temperature required for depositing a thin film.

The cover part 120 is coupled to an upper side of the reaction chamber 140 so as to cover the reaction chamber 140 to form an inner space of the reaction chamber 140 together with the reaction chamber 140. The cover 120 and the reaction chamber 140 are well sealed by a sealing member (not shown) to prevent the reaction gases from leaking. The shower head 130 refers to a member that is coupled to a lower surface of the cover part 120 and sprays a reaction gas and an inert gas supplied from the outside in the direction of the wafer w.

Since the above-mentioned members are well-known each, further detailed description of each of them will be omitted.

The thin film deposition apparatus 100 of the present invention is characterized in that it further includes a baffle 150 in which a flow path for injecting gas to the edge of the wafer w is formed therein. The baffle 150 is disposed to surround the wafer block 110 between the reaction chamber 140 and the wafer block 110, and is manufactured in an annular annular shape along the shape of the wafer w. .

The inner circumferential surface 153 of the baffle faces the outer circumferential surface 112 of the wafer block and is spaced apart from the wafer block 110 over the entire circumference of the inner circumferential surface 153, and the outer circumferential surface 157 of the baffle is It is coupled to the inner circumferential surface 143 of the reaction chamber 140 and fixed.

The inner circumferential surface 153 of the baffle is formed not to be higher than the upper surface 111 of the wafer block. That is, the inner circumferential surface 153 of the baffle located close to the outer circumferential surface 112 of the wafer block is at the same height as the height of the upper surface 111 of the wafer block or lower than the height of the upper surface 111 of the wafer block. Formed. Thus, after the wafer w is seated on the wafer block 110, the thin film is deposited thereon while the edge side surface wl is not surrounded by the inner circumferential surface 153 of the baffle. do.

As a means for transporting and injecting gas through the baffle 150, the baffle 150 includes a gas inlet 154, a gas outlet 155, and a gas channel 156.

The gas inlet 154 refers to an inlet through which gas supplied from the outside flows into the baffle 150. The gas flowing through the gas inlet 154 is a gas that does not react with the reaction gas injected from the showerhead 130 onto the wafer w, and an inert gas such as argon (Ar) gas is used. do. In the present embodiment, the gas inlet 154 is formed on the lower surface of the baffle 150.

The gas outlet 155 refers to an outlet through which an inert gas introduced through the gas inlet 154 is injected toward an edge of the wafer w. The gas outlet 155 surrounds the entire circumference of the wafer w, and is formed in the form of a plurality of holes that are densely arranged to inject the inert gas without falling out toward the edge of the wafer w. In the present embodiment, the gas outlet 155 is formed on the inner circumferential surface 153 directly below the vertex 159 where the inner circumferential surface 153 of the baffle and the upper surface 158 of the baffle meet.

The gas channel 156 includes a diffusion space portion 156a, a first supply passage 156b, and an injection passage 156c.

The diffusion space portion 156a is for uniformly injecting inert gas injected from the gas outlet 155 and is an annular space portion provided in the baffle 150. The inert gas supplied from the outside is accumulated in the diffusion space portion 156a, and due to the sufficient flow rate of the inert gas accumulated in the diffusion space portion 156a, a uniform flow velocity through the cross section of the gas outlet 155 and It is possible to inject an inert gas having a flow rate.

The first supply passage 156b connects the diffusion space 156a and the gas inlet 154, and the inert gas supplied through the gas inlet 154 is inside the diffusion space 156a. It serves as a conveying passage to be transported to. The first supply passage 156b is formed inside the baffle 150 and extends downward from the diffusion space 156a to penetrate the bottom surface of the baffle 150. The first supply passage 156b may be configured as a single hole, but the inert gas may be uniformly provided in the entire internal space of the diffusion space 156a while the inert gas is supplied to the diffusion space 156a. In order to be distributed, it is preferable that a plurality of holes are formed around the lower surface of the baffle 150.

The injection passage 156c connects the diffusion space 156a and the gas outlet 155, and serves as a transfer passage through which the inert gas in the diffusion space 156a is transferred to the gas outlet 155. Do it. The injection passage 156c is formed in the baffle 150 and extends from the diffusion space 156a toward the inner circumferential surface 153 of the baffle and passes through the inner circumferential surface 153 of the baffle. consist of.

At the portion where the injection passage 156c and the gas outlet 155 meet, the injection passage 156c is formed to face upwards of about 10 degrees to 15 degrees with respect to a horizontal plane. Therefore, even if the gas outlet 155 is formed on the inner circumferential surface 153 of the baffle formed not to be higher than the upper surface 111 of the wafer block, the inert gas injected through the gas outlet 155 is the wafer (w). It can be sprayed more efficiently toward the edge of the.

The baffle 150 is arranged to be spaced apart from the wafer block 110 over the entire circumference of the inner circumferential surface 153 by a predetermined distance, so that the baffle 150 and the wafer block 110 have an annular pressure passage ( 180) is formed. Inert gas is injected from the lower side of the wafer block 110 to the upper direction through the pressure passage 180.

The conical baffle 190 is detachably provided from the reaction chamber 140 below the baffle 150. The baffle 150 may be supported by the reaction chamber 140 and the conical baffle 190 and installed inside the reaction chamber 140. The conical baffle 190 is formed in a conical shape in which the opening area of the upper part is larger than the opening area of the lower part, and the opening area thereof becomes smaller toward the lower side. The conical baffle 190 is detachably mounted to the reaction chamber 140. When the inner surface 191 is contaminated by particles, only the conical baffle 190 is separated from the reaction chamber 140 and cleaned. As a result, the cleaning of the reaction chamber 140 may be more easily and easily performed.

Between the conical baffle 190 and the reaction chamber 140, an exhaust passage 144 is formed which is a passage for discharging the remaining reaction gas and by-products to the outside without reacting in the reaction chamber 140, have. Unreacted gases remaining in the reaction chamber 140 without being reacted after being injected onto the wafer through the shower head 130 are formed through a plurality of exhaust holes (not shown) passing through the upper and lower surfaces of the baffle 150. ) Flows into the exhaust passage 144 and is discharged to the outside through the exhaust port 145 formed under the side wall of the reaction chamber 140.

On the other hand, the thin film deposition apparatus 100 of the present embodiment, the second supply passage 161 for supplying the inert gas to the gas inlet 154 side of the baffle 150 is formed on the outer wall of the reaction chamber 140 have. The second supply passage 161 is formed to penetrate the outer wall of the reaction chamber 140 so that inert gas supplied from the outside is provided through the gas inlet 154 formed on the bottom surface of the baffle 150. 150 can be introduced into the interior.

The second supply passage 161 and the gas inlet 154 are hermetically connected by a sealing member 171 to prevent leakage of the inert gas to be transported. In this embodiment, the second supply passage 161 and the gas inlet 154 are connected to a rubber ring or a metal ring. Is sealed by.

Hereinafter, referring to FIGS. 3 to 5, an operation principle of injecting inert gas into the edge portion of the wafer w through the baffle 150 of the thin film deposition apparatus 100 of the present embodiment configured as described above will be schematically described. Let's explain.

An inert gas such as argon (Ar) gas is supplied from the outside of the thin film deposition apparatus 100 through the second supply passage 161. The inert gas is accumulated in the diffusion space 156a via the gas inlet 154 and the first supply passage 156b formed in the baffle 150. When a predetermined amount or more of inert gas is accumulated in the diffusion space 156a, the inert gas is injected toward the edge of the wafer w through the injection passage 156c and the gas outlet 155 due to a pressure difference with the outside. The inert gas injected through the gas outlet 155 blocks the thin film from being deposited on the upper surface of the edge of the wafer w.

As described above, the inert gas is injected through the gas outlet 155 of the baffle and at the same time, the same inert gas as the inert gas is provided through the pressure passage 180 formed between the wafer block 110 and the baffle 150. Argon (Ar) gas is injected. The inert gas is injected from the lower side to the upper side of the wafer block 110 to block the reaction gases from penetrating into the internal space 142 between the wafer block 110 and the reaction chamber 140 during the thin film deposition process. In addition, reaction gases may be prevented from being attached to the inner surface 191 of the cone baffle.

When the thin film deposition apparatus 100 according to the present exemplary embodiment configured as described above is used, thin film deposition is performed while inert gas is injected toward the edge of the wafer w using the gas channel 156 formed inside the baffle 150. Since the process can be performed, it is possible to prevent the formation of unwanted thin films at the unwanted sites. Therefore, in the subsequent semiconductor manufacturing process, there is an effect of fundamentally blocking the generation of a thin film that can be separated from the wafer and become a particle source of the semiconductor.

In addition, the inert gas is injected through the gas outlet 155 of the baffle, and the inert gas is injected to the upper side of the wafer block 110 through the pressure passage 180, so that the reaction gases are pressurized during the thin film deposition process. It may be prevented from entering the space 142 between the wafer block 110 and the reaction chamber 140 through the passage 180 to be attached to the inner surface 191 of the cone baffle. Due to contamination by the reaction gases, the reaction chamber 140 needs to be periodically cleaned, and the cleaning cycle can be extended.

In the embodiment of the present invention, the baffle is composed of a single body, it is also possible to manufacture a structure in which the two bodies of the upper baffle and the lower baffle are combined.

In the exemplary embodiment of the present invention, the gas outlet is formed on the inner circumferential surface 153 directly below the vertex 159 where the inner circumferential surface 153 of the baffle and the upper surface 158 of the baffle meet, as shown in FIG. 5. In addition, the inner peripheral surface 153 of the baffle and the upper surface 158 of the baffle may be formed so as to face the edge portion of the wafer immediately above the vertex 159.

In the embodiment of the present invention, although both the inert gas injected through the gas channel and the inert gas injected through the pressure passage have been described by using argon (Ar) gas as an example, it is possible to use other types of inert gas. .

Although preferred embodiments and modifications have been described above, the thin film deposition apparatus according to the present invention is not limited to the examples described above, and various modifications and combinations thereof may be made within the scope not departing from the technical spirit of the present invention. Thin film deposition apparatus of the type can be embodied.

Using the thin film deposition apparatus of the present invention, it is possible to prevent the generation of unwanted thin films at the edge of the wafer to fundamentally remove particles that may occur in subsequent semiconductor manufacturing processes. Thus, there is an effect of obtaining as many useful dies as possible from one wafer.

In addition, the thin film deposition apparatus of the present invention can prevent the reaction gases from adhering to the outer wall of the reaction chamber, thereby preventing the reaction chamber from being contaminated by the reaction gases.

Claims (10)

In the thin film deposition apparatus comprising a reaction chamber provided with an inner space, and a wafer block is installed in the inner space of the reaction chamber and the wafer is seated on the upper surface, An annular baffle, coupled to the reaction chamber and disposed to surround the wafer block, The baffle, A gas inlet into which the gas supplied from the outside flows, a gas outlet through which the gas introduced into the gas inlet is injected toward an edge of the wafer, and a gas formed inside the baffle and connecting the gas inlet to the gas outlet Thin film deposition apparatus comprising a channel. The method of claim 1, The baffle, Thin film deposition apparatus, characterized in that the surface on which the gas outlet is formed is not formed higher than the upper surface of the wafer block. The method of claim 2, The gas outlet, the thin film deposition apparatus, characterized in that formed on the inner peripheral surface of the baffle. The method of claim 1, The baffle is a thin film deposition apparatus, characterized in that spaced apart from the wafer block a predetermined distance over the entire circumference of the inner circumferential surface. The method of claim 1, The gas channel is a thin film deposition apparatus, characterized in that the gas injected through the gas outlet is formed to be injected 10 degrees to 15 degrees upwards. The method of claim 1, The gas channel, An annular diffusion space portion for uniformly injecting gas through the gas outlet, a first supply passage connecting the diffusion space portion and the gas inlet, and an injection passage connecting the diffusion space portion and the gas outlet Thin film deposition apparatus comprising a. The method of claim 6, The baffle is a thin film deposition apparatus, characterized in that consisting of a single body. The method of claim 1, And a second supply passage connected to the gas inlet and formed through the reaction chamber. The method of claim 8, And the second supply passage and the gas inlet are sealed and connected by a sealing member. The method of claim 9, The sealing member is a thin film deposition apparatus, characterized in that the rubber ring or metal ring.

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