KR20070042668A - Apparatus for forming a layer using a plasma - Google Patents

Abstract

In an apparatus for forming a film on a substrate using plasma, a shower head for uniformly providing a reaction gas and a high frequency electrode for forming a reaction gas into plasma are disposed above the process chamber. The shower head is connected to the reaction gas supply part through the first and second gas supply pipes and the reaction gas supply pipe, and an insulating member made of ceramic material is disposed between the first and second gas supply pipes to provide electrical insulation. A cleaning gas supply unit for cleaning the inside of the process chamber is connected to a side portion of the second gas supply pipe through a cleaning gas supply pipe, and the reaction gas supply pipe extends toward the insulating member through an upper end of the second gas supply pipe. An end portion of the reaction gas supply pipe is disposed closer to the shower head than a portion to which the cleaning gas supply pipe is connected. Therefore, the phenomenon in which the reaction gas flows back into the cleaning gas supply pipe during the process can be suppressed.

Description

Film forming apparatus using plasma {Apparatus for forming a layer using a plasma}

1 is a schematic configuration diagram illustrating a conventional plasma film forming apparatus.

2 is a schematic diagram illustrating a plasma film forming apparatus according to an embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10 semiconductor substrate 200 plasma film forming apparatus

202 reaction chamber 204 chuck

206: heater 208: vacuum system

210: shower head 212: high frequency electrode

214: power supply 216: buffer space

218: reaction gas supply unit 220: first gas supply pipe

222: second gas supply pipe 224: insulating member

226 reaction gas supply pipe 228 cleaning gas supply unit

230: cleaning gas supply pipe 232: first temperature control unit

234: second gas supply pipe

The present invention relates to a film forming apparatus using plasma. More particularly, the present invention relates to an apparatus for forming a film on a semiconductor substrate such as a silicon wafer using a reaction gas in a plasma state.

In general, a semiconductor device may be manufactured by repeatedly performing a series of unit processes on a semiconductor substrate such as a silicon wafer. Specifically, the semiconductor device may be manufactured by forming various films such as an insulating film, a dielectric film, and a conductive film on the semiconductor substrate, and patterning the films to form electrical circuit patterns.

The unit processes may include a deposition process for forming a film on the semiconductor substrate, a photolithography process for forming a mask pattern and patterning the film, a planarization process for planarizing the film, and a process for cleaning the film or patterns. Cleaning processes, inspection processes for inspecting defects of the film or patterns, and the like.

The deposition process includes physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), and the like. It may be classified into thermal chemical vapor deposition, plasma enhanced chemical vapor deposition, photochemical vapor deposition and the like, and may be classified into atmospheric pressure chemical vapor deposition and low pressure chemical vapor deposition according to the process pressure.

Chemical vapor deposition using the plasma improves the reactivity by forming the reaction gas in a plasma state, and is mainly used when a low temperature process is required. 1 is a schematic configuration diagram illustrating a conventional plasma film forming apparatus.

Referring to FIG. 1, the conventional plasma film forming apparatus 100 includes a reaction chamber 102, a chuck 104, a shower head 106, a high frequency electrode 108, a reaction gas supply unit 110, and a cleaning gas supply unit ( 112, vacuum system 114, and the like.

Specifically, the chuck 104 for supporting the semiconductor substrate 10 is provided in the reaction chamber 102, and the heater for heating the temperature of the semiconductor substrate 10 to the reaction temperature in the chuck 104. 116 is built in. In addition, the internal pressure of the reaction chamber 102 may be regulated by the vacuum system 114, which is a reaction byproduct or unreacted reaction that occurs during the reaction with pressure control inside the reaction chamber 102. It serves to discharge the gas from the reaction chamber (102).

The shower head 106 and the high frequency electrode 108 are disposed above the reaction chamber 102, and the reaction gas supply unit 110 and the cleaning gas supply unit 112 are provided through the high frequency electrode 108. 106).

A gas supply pipe 118 for supplying a reaction gas and a cleaning gas is connected to the high frequency electrode 108, and a reaction gas supply unit 110 is connected to an upper end of the gas supply pipe 118, and the gas supply pipe 118 is provided. Cleaning gas supply 112 is connected to the side portion of the.

On the other hand, the high frequency electrode 108 is connected to a power supply device 120 for applying a radio frequency (RF) power to excite the reaction gas supplied into the reaction chamber 102 to the plasma state.

Although not shown in detail, an insulating member (not shown) may be interposed between the high frequency electrode 108 and the gas supplies 110 and 112 to provide electrical insulation. However, in the related art, since the insulating member is made of fluororesin, its lifespan is very short.

On the other hand, as shown, since the reaction gas supply unit 110 is connected to the upper end of the gas supply pipe 118 through the reaction gas supply pipe 122, the reaction gas may flow back to the cleaning gas supply 112 during the process. have. At this time, the reaction gas is maintained at a constant temperature by the temperature control unit 124 installed in the reaction gas supply pipe 122, the cleaning gas supply unit 112 does not have such a temperature control function. Therefore, the reaction gas flowed back to the cleaning gas supply unit 112 may be condensed inside the cleaning gas supply pipe 126, thereby causing particle contamination.

An object of the present invention for solving the above problems is to provide a plasma film forming apparatus that can provide a stable electrical insulation between the gas supply and the high frequency electrode.

Another object of the present invention is to provide a plasma film forming apparatus capable of suppressing backflow of a reaction gas in a gas supply pipe.

A film forming apparatus using a plasma according to an aspect of the present invention for achieving the above object, the reaction chamber for receiving the substrate to form a film on the substrate, and disposed above the reaction chamber to the substrate A shower head providing a reactive gas for forming a film, a high frequency electrode disposed on the shower head, the high frequency electrode for forming the reaction gas in a plasma state, and connected to the shower head through the high frequency electrode, It may include a reaction gas supply for providing a shower head, and an insulating member made of a ceramic material to electrically insulate between the high frequency electrode and the reaction gas supply.

According to an embodiment of the present invention, a first gas supply pipe and a second gas supply pipe which are in communication with the shower head and connected in series with the insulating member interposed therebetween may be disposed on the high frequency electrode, and the insulating member may be in the form of a tube. It can have

An upper end of the second gas supply pipe is closed, and the reactive gas supply part includes a reaction gas supply pipe extending toward the insulating member through an upper end of the second gas supply pipe.

In addition, the cleaning gas supply unit for supplying a cleaning gas for cleaning the inside of the process chamber is connected to the side portion of the second gas supply pipe. The cleaning gas supply unit includes a cleaning gas supply pipe connected to a side of the second gas supply pipe and a cleaning gas supply pipe to surround the cleaning gas supply pipe to maintain a constant temperature of the cleaning gas flowing through the cleaning gas supply pipe. can do.

According to the embodiment of the present invention as described above, since an insulating member made of a ceramic material is disposed between the reaction gas supply unit and the high frequency electrode, stable electrical insulation may be provided. In addition, since the reaction gas supply pipe extends adjacent to the insulating member, the backflow of the reaction gas into the cleaning gas supply pipe can be suppressed.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the following embodiments and may be implemented in other forms. The embodiments introduced herein are provided to make the disclosure more complete and to fully convey the spirit and features of the invention to those skilled in the art. In the drawings, the thickness of each device or film (layer) and regions has been exaggerated for clarity of the invention, and each device may have a variety of additional devices not described herein. If (layer) is mentioned as being located on another film (layer) or substrate, it may be formed directly on another film (layer) or substrate, or an additional film (layer) may be interposed therebetween.

2 is a schematic diagram illustrating a plasma film forming apparatus according to an embodiment of the present invention.

Referring to FIG. 2, the plasma film forming apparatus 200 according to an embodiment of the present invention may be used to form a film using a reaction gas excited in a plasma state on a semiconductor substrate 10 such as a silicon wafer. The device 200 includes a reaction chamber 202 that houses a semiconductor substrate 10 and provides a closed reaction space.

The reaction chamber 202 is provided with a chuck 204 for supporting the semiconductor substrate 10, and a heater 206 is embedded in the chuck 204 to heat the semiconductor substrate 10 to a process temperature. Can be. For example, an electric resistance heating wire may be used as the heater 206. In addition, various types of heaters may be applied.

In addition, although not shown, a bias power for controlling the behavior of the plasma may be applied to the chuck 204, and an adsorption mechanism for fixing the semiconductor substrate 10 by using electrostatic force or vacuum pressure may be installed. have.

In addition, a vacuum system 208 is connected to the reaction chamber 202 to control the pressure inside the reaction chamber 202 and to remove reaction by-products and unreacted gases generated during the film forming process. . The vacuum system may include an isolation valve, a vacuum pump, and the like. In addition, although the reference numeral is not given, a gate door for entering and exiting the semiconductor substrate 10 is provided on one wall of the reaction chamber 202.

An upper portion of the reaction chamber 202 is disposed facing the semiconductor substrate 10 supported on the chuck 204, and a shower head 210 is disposed to uniformly provide the reaction gas onto the semiconductor substrate 10. On the shower head 210, a high frequency electrode 212 is applied to apply RF power for exciting the provided reactive gas in a plasma state. The high frequency electrode 212 is connected to a power supply 214 for generating RF power.

A buffer space 216 is temporarily provided between the shower head 210 and the high frequency electrode 212, and the buffer space 216 is a reaction gas supply part 218 through the high frequency electrode 212. Connected with In detail, a gas inlet through which a reaction gas flows is formed at a central portion of the high frequency electrode 212, and gas supply pipes 220 and 222 communicating with the gas inlet are disposed on the high frequency electrode 212.

As shown, the first gas supply pipe 220 and the second gas supply pipe 222 communicating with the buffer space 216 of the shower head 210 and connected in series are disposed on the high frequency electrode 212. An insulating member 224 is provided between the first gas supply pipe 220 and the second gas supply pipe 222 to provide electrical insulation between the high frequency electrode 212 and the reactive gas supply part 218. The insulating member 224 has a tubular shape and is used as a passage of the reaction gas together with the gas supply pipes 220 and 222. The insulating member 224 may be made of a ceramic material. In addition, the insulating member 224 may be made of aluminum nitride (AlN).

The upper end of the second gas supply pipe 222 is closed, and the reaction gas supply part 218 extends toward the insulating member 224 through the upper end of the second gas supply pipe 222. It may be in communication with the shower head 210 through. Specifically, an end portion of the reaction gas supply pipe 226 may extend to a portion of the second gas supply pipe 222 adjacent to the insulating member 224.

On the other hand, a cleaning gas supply unit 228 that provides a cleaning gas for cleaning the inside of the reaction chamber 202 is connected to the side portion of the second gas supply pipe 222. Specifically, the cleaning gas supply unit 228 may be in communication with the shower head 210 through the cleaning gas supply pipe 230 connected to the side portion of the second gas supply pipe 222. At this time, since the end portion of the reaction gas supply pipe 226 is disposed closer to the shower head 210 than the cleaning gas supply pipe 230, a phenomenon in which the reaction gas flows back to the cleaning gas supply pipe 230 during the process is greatly increased. It can be suppressed. Therefore, particle contamination by the backflow of reaction gas can be suppressed.

As shown, the end of the reaction gas supply pipe 226 is simply located lower than the end of the cleaning gas supply pipe 230, but the length of the reaction gas supply pipe 226, the length of the second gas supply pipe 222 and the cleaning The position where the gas supply pipe 230 is connected may be adjusted to an optimal position by those skilled in the art, and the shapes thereof may also be variously changed. That is, within the technical scope of the present invention in which the end portion of the reaction gas supply pipe 226 is disposed closer to the shower head 210 than the connection portion of the cleaning gas supply pipe 230, to prevent the backflow of the reaction gas. It may be changed in various ways.

The reaction gas may include a material to be formed on the semiconductor substrate 10. For example, a gaseous TEOS gas may be provided to form a TEOS (Tetra Ethyl Ortho Silicate) oxide film on the semiconductor substrate 10. In this case, the reaction gas supply unit 218 may include a bubbler system or a liquid delivery system to vaporize the liquid TEOS to the gaseous TEOS. On the other hand, a fluorine compound gas may be used as the cleaning gas.

As shown, although the reaction gas supply unit 218 and the cleaning gas supply unit 228 are very schematically represented, the configuration of the gas supply units 218 and 228 is well known to those skilled in the art. Omit.

A first temperature control unit 232 is disposed around the reaction gas supply pipe 226 to maintain a constant temperature of the reaction gas, and the cleaning gas supply pipe 232 is disposed around the cleaning gas supply pipe 230. The second temperature controller 234 is disposed to maintain the internal temperature substantially the same as the temperature of the reaction gas. For example, the temperature of the reaction gas may be maintained at about 80 ℃ to 200 ℃. The heating jacket 234 may be used as the first and second temperature controllers 232. Therefore, even when a small amount of reaction gas is introduced into the cleaning gas supply pipe 230, condensation of the introduced reaction gas does not occur, and particle contamination by condensation of the reaction gas may be sufficiently suppressed.

According to the embodiment of the present invention as described above, by forming the insulating member disposed between the reaction gas supply unit for providing the reaction gas and the high frequency electrode made of a ceramic material or aluminum nitride can greatly extend the life of the insulating member, accordingly Stable electrical isolation can be ensured.

In addition, the end of the reaction gas supply pipe is located closer to the shower head than the end of the cleaning gas supply pipe so that the reaction gas backflow into the cleaning gas supply pipe can be suppressed, and the temperature inside the cleaning gas supply pipe is substantially equal to the temperature of the reaction gas. By keeping the same, it is possible to greatly suppress particle contamination caused by reaction gas condensation.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art will be variously modified and changed within the scope of the invention without departing from the spirit and scope of the invention described in the claims below I can understand that you can.

Claims (5)

A reaction chamber containing the substrate to form a film on the substrate; A shower head disposed above the reaction chamber to provide a reaction gas for forming the film into the substrate; A high frequency electrode disposed on the shower head and configured to form the reaction gas into a plasma state; A reaction gas supply unit connected to the shower head through the high frequency electrode and configured to provide the reaction gas to the shower head; And And an insulating member made of a ceramic material to electrically insulate the high frequency electrode from the reactive gas supply unit. The first gas supply pipe and the second gas supply pipe which are in communication with the shower head and connected in series with the insulation member are disposed on the high frequency electrode, and the insulation member has a tubular shape. A film forming apparatus using plasma. 3. The plasma of claim 2, wherein an upper end of the second gas supply pipe is closed, and the reactive gas supply part includes a reactive gas supply pipe extending toward the insulating member through an upper end of the second gas supply pipe. Film forming apparatus using the. The film forming apparatus of claim 2, further comprising a cleaning gas supply unit connected to a side of the second gas supply pipe and configured to clean the inside of the reaction chamber. The cleaning gas supply unit of claim 4, wherein the cleaning gas supply unit is provided to surround the cleaning gas supply pipe connected to the side of the second gas supply pipe and the cleaning gas supply pipe to maintain a constant temperature of the cleaning gas flowing through the cleaning gas supply pipe. Film forming apparatus using a plasma, characterized in that it comprises a temperature control unit for.

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