JP5195227B2 - Film forming apparatus and method of using the same - Google Patents

Description

  The present invention relates to a film forming apparatus for forming a thin film made of a silicon-containing film such as a silicon oxynitride film (SiON) on a semiconductor wafer or the like and a method of using the same.

  Generally, in order to manufacture a semiconductor integrated circuit, various processes such as a film formation process, an etching process, an oxidation process, a diffusion process, a modification process, and a natural oxide film removal process are performed on a semiconductor wafer made of a silicon substrate or the like. Is done. For example, when these processes are performed by a so-called batch-type heat treatment apparatus disclosed in Patent Document 1 or the like, first, from a cassette that can accommodate a plurality of, for example, about 25 semiconductor wafers, Is transferred to a vertical wafer boat and supported in multiple stages. This wafer boat can place about 30 to 150 wafers, for example, depending on the wafer size. After the wafer boat is loaded (loaded) into the evacuable processing container from below, the inside of the processing container is kept airtight. Then, a predetermined heat treatment is performed while controlling various process conditions such as the flow rate of process gas, process pressure, and process temperature.

Here, as an example of an insulating film used for a gate insulating film or the like as one of the factors for improving the characteristics of the semiconductor integrated circuit, conventionally, as the gate insulating film, a silicon oxide film (SiO ₂ ) or a silicon nitride film ( SiN) has been used (for example, Patent Documents 2 to 5), but leakage current characteristics are good even if it is thin due to further demands for higher integration, higher miniaturization, faster switching characteristics, and lower operating voltage For this reason, recently, it has been proposed to use a silicon oxynitride film (SiON) instead of the thin film.

  In order to form the silicon oxynitride film, for example, a silicon oxide film is formed by a CVD (Chemical Vapor Deposition) method using TEOS, and the silicon oxide film is nitrided to obtain a silicon oxynitride film. Also disclosed is a method (ALD method: Atomic Layered Deposition) in which two types of gas necessary for the gas flow are alternately and repeatedly flowed (for example, Patent Document 6).

Japanese Patent Laid-Open No. 11-172439 JP 2004-281853 A JP 2002-334869 A Japanese Patent Laid-Open No. 2002-367992 JP 2005-093677 A JP 2007-0119145 A

  By the way, in the film forming process as described above, the process temperature in the processing container is about 600 ° C., for example, depending on the type of gas used, whereas the exhaust port of the processing container is about 150 ° C. It is quite low. Under such temperature conditions, when a source gas containing silicon and chlorine, for example, hexachlorodisilane (hereinafter also referred to as “HCD”) is used as the source gas as described above, the temperature is increased as described above. In some cases, a flammable chlorosilane polymer was deposited as a reaction by-product on the wall surface near the exhaust port, which is a rapidly decreasing portion.

When reaction by-products accumulate in the vicinity of the exhaust port in this way, the chlorosilane polymer is flammable and the ignition temperature is about 300 ° C. Therefore, after the film formation process, the SiN film on the wafer surface is oxidized. When O ₂ gas is flowed as an oxidizing gas to form the SiON film, there is a problem that the high temperature O ₂ gas and the chlorosilane polymer adhering to the exhaust port react violently and burn.

When such combustion occurs, a sealing member such as an O-ring used for the exhaust system piping becomes higher than the heat resistance temperature, and the sealing performance deteriorates, or from stainless steel which is a piping material exposed to high temperature. The contained components are scattered to cause metal contamination of the semiconductor wafer, and further, SiO _{2 and the} like, which are by-products generated by combustion, flow backward as particles and adhere to the semiconductor wafer in the processing vessel. It was causing the problem.

  The present invention has been devised to pay attention to the above problems and to effectively solve them. An object of the present invention is to provide a film forming apparatus capable of preventing a reaction by-product attached in the vicinity of an exhaust port from burning, and a method of using the same.

  The invention according to claim 1 is a film formation process for forming a thin film made of a silicon-containing film using a silicon-containing gas as a source gas for an object to be processed, and an oxidation process for oxidizing the object to be processed using an oxidizing gas. A processing container having a length capable of accommodating a plurality of objects to be processed, source gas supply means for supplying a source gas into the processing container, and the processing container A reaction gas supply means for supplying a reaction gas that reacts with the raw material gas, an oxidizing gas supply means for supplying an oxidizing gas into the processing container, a first exhaust port provided in the processing container, A second exhaust port provided at a position different from the first exhaust port, a first exhaust system connected to the first exhaust port and used during the film formation process, and the second exhaust port Second connected and used during the oxidation process An exhaust system, a film forming apparatus characterized by comprising, an inert gas introducing means for introducing inert gas into the first exhaust port during the oxidation process.

  In this way, a film forming process for forming a thin film made of a silicon-containing film using a silicon-containing gas as a raw material gas and an oxidation process for oxidizing the object to be processed using an oxidizing gas are performed. In the film forming apparatus capable of performing the above process, the first exhaust port used during the film formation process and the second exhaust port used during the oxidation process are provided separately, and the first exhaust port portion is not provided during the oxidation process. Since the reaction by-product is not exposed to the oxidizing gas by covering with the atmosphere of the active gas, the combustible reaction by-product adhering to the vicinity of the first exhaust port during the film forming process is prevented from burning. It becomes possible. As a result, it becomes possible to prevent deterioration of the sealing performance of the exhaust system, metal contamination of the object to be processed, and generation of particles.

According to a second aspect of the present invention, in the first aspect of the invention, the second exhaust port is positioned away from the first exhaust port in a direction opposite to a flow direction of the source gas during the film forming process. It is characterized by being.
According to a third aspect of the present invention, in the first or second aspect of the present invention, the oxygen concentration detection means for detecting the oxygen concentration in the vicinity of the first exhaust port during the oxidation treatment and the oxygen concentration detection means are predetermined. And an avoidance operation command unit for performing an avoidance operation when an oxygen concentration equal to or higher than the concentration is detected.

  According to a fourth aspect of the present invention, there is provided a temperature detector that detects a temperature in the vicinity of the first exhaust port during the oxidation process according to any one of the first to third aspects, and the temperature detector has a predetermined temperature. And an avoidance operation command unit for performing an avoidance operation when the above temperature is detected.

  According to a fifth aspect of the present invention, the processing container according to any one of the first to fourth aspects includes a cylindrical inner cylinder and a cylindrical outer cylinder arranged in a concentric manner outside the inner cylinder. The first exhaust port is provided so as to face a space between the inner cylinder and the outer cylinder, and the second exhaust port is provided so as to face a space below the inner cylinder. It is characterized by.

According to a sixth aspect of the present invention, in the fifth aspect of the present invention, the inner cylinder is formed with a ceiling portion at the upper end, and the inner cylinder and the outer cylinder are formed along the height direction on the side wall of the inner cylinder. A gas circulation port communicating with the space between is formed.
According to a seventh aspect of the present invention, in the sixth aspect of the present invention, the source gas supply means and the reactive gas supply means have a plurality of gas injection holes formed along the length direction thereof, It has the gas nozzle arrange | positioned along the height direction, respectively.
The invention according to claim 8 is the invention according to claim 6, wherein the source gas supply means and the reaction gas supply means are respectively provided with gas nozzles whose gas injection holes are positioned at the upper end or the lower end in the inner cylinder. It is characterized by having.

According to a ninth aspect of the present invention, in the seventh or eighth aspect of the invention, the oxidizing gas supply means has a gas nozzle having a gas injection hole positioned at an upper end portion in the inner cylinder. .
According to a tenth aspect of the present invention, in the seventh or eighth aspect of the present invention, the oxidizing gas supply means has a plurality of gas injection holes formed along a length direction thereof, and is formed in the height direction in the inner cylinder. It has the gas nozzle arrange | positioned along, It is characterized by the above-mentioned.
An eleventh aspect of the invention is characterized in that the second exhaust port according to any one of the sixth to ninth aspects is provided in a lower side wall of the processing container.
According to a twelfth aspect of the present invention, in the fifth aspect of the invention, the inner cylinder is open at an upper end.

According to a thirteenth aspect of the present invention, in the twelfth aspect of the present invention, the source gas supply means and the reactive gas supply means each have a gas nozzle having a gas injection hole positioned in a space below the inner cylinder. It is characterized by that.
A fourteenth aspect of the invention is characterized in that, in the thirteenth aspect of the invention, the oxidizing gas supply means has a gas nozzle having a gas injection hole positioned at an upper end portion in the inner cylinder.
According to a fifteenth aspect of the invention, in the thirteenth aspect of the invention, the oxidizing gas supply means has a plurality of gas injection holes formed along the length direction thereof, and the height direction in the inner cylinder. It has the gas nozzle arrange | positioned, It is characterized by the above-mentioned.
A sixteenth aspect of the invention is characterized in that the second exhaust port according to any one of the twelfth to fourteenth aspects is provided in a lower side wall of the processing container.

The invention of claim 17 is characterized in that the processing container according to any one of claims 1 to 4 has one cylindrical body with a ceiling.
The invention according to claim 18 is the invention according to claim 17, wherein the first exhaust port is provided in a ceiling portion of the processing container, and the second exhaust port is provided in a lower side wall of the processing container. It is characterized by.
According to a nineteenth aspect of the present invention, in the eighteenth aspect, the raw material gas supply means and the reaction gas supply means each have a gas nozzle having a gas injection hole positioned at a lower end portion in the processing container. It is characterized by that.
According to a twentieth aspect of the present invention, in the invention of the eighteenth aspect, the source gas supply means and the reaction gas supply means have a plurality of gas injection holes formed along a length direction of the raw material gas supply means and the reaction gas supply means. It has the gas nozzle arrange | positioned along the height direction, respectively.

A twenty-first aspect of the invention is characterized in that, in the nineteenth or twentieth aspect, the oxidizing gas supply means has a gas nozzle having a gas injection hole positioned at an upper end portion in the cylindrical body.
The invention of claim 22 is the invention of claim 19 or 20, wherein the oxidizing gas supply means has a plurality of gas injection holes formed along a length direction thereof and extends in the height direction of the cylinder. It has the gas nozzle arrange | positioned.
According to a twenty-third aspect of the present invention, the first exhaust port is provided in a lower side wall of the processing container according to the seventeenth aspect, and the second exhaust port is provided in a ceiling portion of the processing container. It is characterized by that.
According to a twenty-fourth aspect of the present invention, in the invention of the twenty-third aspect, the source gas supply means and the reactive gas supply means have a plurality of gas injection holes formed along a length direction thereof, It has the gas nozzle arrange | positioned along the length direction, It is characterized by the above-mentioned.
According to a twenty-fifth aspect of the present invention, in the twenty-third aspect, the source gas supply means and the reactive gas supply means each have a gas nozzle having a gas injection hole positioned at an upper end portion in the cylindrical body. It is characterized by.

According to a twenty-sixth aspect of the present invention, in the invention according to any one of the twenty-third to twenty-fifth aspects, the oxidizing gas supply means has a gas nozzle having a gas injection port positioned at a lower end portion of the cylindrical body. It is characterized by being.
A twenty-seventh aspect of the present invention is the invention according to any one of the twenty-third to twenty-fifth aspects, wherein the oxidizing gas supply means has a plurality of gas injection holes formed along a length direction thereof and the cylindrical body. And a gas nozzle arranged along the height direction.
The invention of claim 28 is the invention according to any one of claims 1 to 26, wherein the first exhaust system and the second exhaust system have at least an exhaust pump shared with each other. It is characterized by that.
The invention of claim 29 is the invention according to any one of claims 1 to 28, wherein each of the first exhaust system and the second exhaust system has an exhaust pump individually. Features.
The invention of claim 30 is the invention according to any one of claims 1 to 28, wherein the silicon-containing gas is a gas containing silicon and chlorine.

The invention of claim 31 is the invention of claim 30, wherein the gas containing silicon and chlorine is dichlorosilane (DCS), trichlorosilane, hexachlorodisilane (HCD), hexamethyldisilazane (HMDS), tetrachlorosilane. It is one or more gases selected from the group consisting of (TCS).
The invention of claim 32 is the invention according to any one of claims 1 to 31, wherein the oxidizing gas is O ₂ , O ₃ , NO, N ₂ O, NO ₂ , H ₂ O, H ₂ O. _{2. It} consists of 1 or more gas selected from the group which consists of radical oxygen, It is characterized by the above-mentioned.

The invention of claim 33 is the invention according to any one of claims 1 to 32, wherein the inert gas comprises one or more gases selected from the group consisting of N ₂ gas and rare gas. Features.

A thirty-fourth aspect of the present invention is the method of using a film forming apparatus according to any one of the first to thirty-third aspects, wherein a thin film made of a silicon-containing film is formed on the object to be processed using a source gas and a reactive gas. A method of using a film forming apparatus is characterized in that a film forming process for forming a film to be formed and an oxidation process for performing an oxidation process on an object to be processed by using an oxidizing gas are performed.
A thirty-fifth aspect of the invention is characterized in that, in the thirty-fourth aspect, the film forming step and the oxidizing step are continuously performed on the same object.

According to the film forming apparatus and the method of using the same according to the present invention, the following excellent operational effects can be exhibited.
A film forming process for forming a thin film made of a silicon-containing film using a silicon-containing gas as a raw material gas on the object to be processed and an oxidation process for oxidizing the object to be processed using an oxidizing gas can be performed. In the film apparatus, the first exhaust port used during the film formation process and the second exhaust port used during the oxidation process are separately provided, and the first exhaust port portion is provided with an inert gas atmosphere during the oxidation process. Since the reaction by-product is not exposed to the oxidizing gas by covering with, it is possible to prevent the combustible reaction by-product adhering to the vicinity of the first exhaust port during the film forming process from burning. Become. As a result, it is possible to prevent deterioration of the sealing performance of the exhaust system, metal contamination of the object to be processed, and generation of particles.

Hereinafter, an embodiment of a film forming apparatus and a method of using the same according to the present invention will be described in detail with reference to the accompanying drawings.
<First Embodiment>
First, a first embodiment of the film forming apparatus of the present invention will be described. 1 is a longitudinal sectional view showing a first embodiment of a film forming apparatus according to the present invention, FIG. 2 is a sectional view showing a processing container, and FIG. 3 is a plan view showing a gas flow port provided in an inner cylinder of the processing container. It is. Here, hexachlorodisilane (HCD), which is a silicon-containing gas, is used as a source gas, ammonia gas (NH ₃ ), which is a nitriding gas, is used as a reactive gas, oxygen (O ₂ ) gas is used as an oxidizing gas, and purge gas is used. using N ₂ gas, using N ₂ gas as the inert gas to prevent combustion of the reaction by-products, and, initially by forming a silicon nitride film (SiN) as the silicon-containing film, by oxidizing this A case where a silicon oxynitride film (SiON) is finally formed will be described as an example.

  As shown in the figure, the film forming apparatus 2 has a processing container 4 having a length capable of accommodating a plurality of objects to be processed therein. This processing container 4 has an inner cylinder 4A formed into a cylindrical shape with a ceiling, and an inner cylindrical outer cylinder 4B arranged concentrically outside the inner cylinder 4A. Both the cylinder 4A and the outer cylinder 4B are made of quartz. Both the inner cylinder 4A and the outer cylinder 4B have a flat ceiling, and the inner cylinder 4A and the outer cylinder 4B are both open at the lower ends.

  Further, a manifold 6 formed in a cylindrical shape from, for example, stainless steel is connected to a lower end opening of the outer cylinder 4B via a seal member 8 such as an O-ring. There is also an apparatus in which a stainless-steel manifold 6 is not provided, and the whole is constituted by a cylindrical quartz processing vessel. Further, a support piece 9 is formed in a ring shape on the upper part of the inner wall of the manifold 6, and the lower end portion of the inner cylinder 4 </ b> A is supported on the support piece 9 to constitute the entire processing container 4. ing.

  The lower end of the manifold 6 is open, and a quartz wafer boat 10 as a holding means on which a plurality of semiconductor wafers W as processing objects are placed in multiple stages is inserted / removed in a vertically movable manner. It is made freely. In this embodiment, the wafer boat 10 can support, for example, about 50 to 100 wafers W having a diameter of 300 mm in multiple stages at a substantially equal pitch.

  The wafer boat 10 is placed on a table 14 via a quartz heat insulating cylinder 12, and this table 14 passes through a lid 16 made of, for example, stainless steel that opens and closes the lower end opening of the manifold 6. It is supported on the rotating shaft 18. For example, a magnetic fluid seal 20 is interposed in the penetrating portion of the rotating shaft 18, and the rotating shaft 18 is rotatably supported while hermetically sealing. Further, a seal member 22 made of, for example, an O-ring or the like is interposed between the peripheral portion of the lid portion 16 and the lower end portion of the manifold 6 to maintain the sealing performance in the processing container 4.

  The rotating shaft 18 is attached to the tip of an arm 24A supported by an elevating mechanism 24 such as a boat elevator, for example, and the wafer boat 10 and the lid 16 are moved up and down integrally and inserted into the processing container 4. It can be removed. Note that the table 14 may be fixedly provided on the lid portion 16 side and the wafer W may be processed without rotating the wafer boat 10.

Each manifold 6 is provided with each gas supply means for supplying each gas into the processing container 4. Specifically, in the manifold 6, a raw material gas supply unit 26 that supplies, for example, an HCD gas that is a silicon-containing gas as a raw material gas, and a reactive gas supply unit that supplies, for example, an NH ₃ gas that is a nitriding gas, as a reactive gas. 28, purge gas supply means 30 for supplying, for example, N ₂ gas as purge gas, and oxidizing gas supply means 32 for supplying, for example, O ₂ gas as oxidizing gas.

  Specifically, the source gas supply means 26 has a gas nozzle 34 made of a quartz tube that penetrates the side wall of the manifold 6 inward and is bent upward and extends to the upper end. A plurality (a large number) of gas injection holes 34A are formed in the gas nozzle 34 at predetermined intervals along the length direction thereof, and the HCD gas is substantially uniformly distributed in the horizontal direction from the gas injection holes 34A. Can be injected. This type of gas nozzle is referred to as a distributed gas nozzle.

Similarly, the reaction gas supply means 28 has a gas nozzle 36 made of a quartz tube that penetrates the side wall of the manifold 6 inward and is bent upward and extends to the upper end. In the gas nozzle 36, a plurality of (many) gas injection holes 36A are formed at predetermined intervals along the length direction thereof, and NH ₃ is formed substantially uniformly from the gas injection holes 36A in the horizontal direction. Gas can be injected. Similarly, the purge gas supply means 30 has a gas nozzle 38 made of a quartz tube that penetrates the side wall of the manifold 6 inward and is bent upward and extends to the upper end. A plurality (a large number) of gas injection holes 38A are formed at predetermined intervals along the length direction of the gas nozzle 38. The gas nozzles 38 are substantially uniformly purged from the gas injection holes 38A in the horizontal direction. N ₂ gas can be injected.

Similarly, the oxidizing gas supply means 32 has a gas nozzle 40 made of a quartz tube that penetrates the side wall of the manifold 6 inward and is bent upward and extends to the upper end. Unlike the gas nozzles 34, 36, and 38, the gas nozzle 40 is formed with a gas injection hole 40A only at the upper end, and the O ₂ gas is directed from the gas injection hole 40A toward the upper end in the inner cylinder 4A. Can be injected. A gas nozzle of a type in which gas is injected and supplied in a concentrated manner is called a straight gas nozzle.

Gas passages 42, 44, 46, 48 are connected to the gas nozzles 34, 36, 38, 40, respectively. The gas passages 42 to 48 are respectively provided with on-off valves 42A, 44A, 46A, 48A and flow controllers 42B, 44B, 46B, 48B such as a mass flow controller, for HCD gas and NH ₃ gas. , N ₂ gas and O ₂ gas can be supplied while controlling the flow rate. In FIG. 1, the four gas nozzles 34, 36, 38, and 40 are arranged in the horizontal direction in order to facilitate understanding of the invention, but in actuality, as shown in FIG. It is arranged in an arc shape in a concentrated manner.

  On the other hand, the side wall of the inner cylinder 4A is scraped off, for example, on the side opposite to the installation position of the gas nozzles 34, 36, 38, 40 with the center of the processing vessel 4 as point symmetry. The gas circulation port 50 formed by the above is provided, and the inside of the inner cylinder 4A is communicated with the space 52 between the inner cylinder 4A and the outer cylinder 4B. Here, as shown in FIG. 3, a plurality of the gas circulation ports 50 are formed along the height direction of the inner cylinder 4 </ b> A. Thus, the conductance is set to be large so that the lateral flow velocity in the inner cylinder 4A is made uniform. The shape of the gas distribution port 50 is not particularly limited.

  The processing container 4 is provided with a first exhaust port 54 for film formation processing in order to exhaust the internal atmosphere. Specifically, the first exhaust port 54 is provided on the side wall of the lower end portion of the outer cylinder 4B so as to face the space 52, and the gas that has passed through the gas vent 50 is supplied to the first exhaust port 54. The air is discharged through the exhaust port 54. The first exhaust port 54 is connected to a first exhaust system 56 used during the film forming process. Specifically, the first exhaust system 56 has a first exhaust passage 58 connected to the first exhaust port 54.

  The first exhaust passage 58 includes a first on-off valve 60, a first pressure adjusting valve 62 for adjusting the pressure in the processing container 4, and a first exhaust pump from the upstream side toward the downstream side. 64 is sequentially provided so that the atmosphere in the processing container 4 can be exhausted while controlling the pressure. As the first exhaust pump 64, a vacuum pump may be used when the process pressure is low, and an exhaust pump having a capacity corresponding to the process pressure to be implemented is used.

Then, an inert gas introduction means 66 for introducing an inert gas into the first exhaust port 54 or in the vicinity thereof at the time of oxidation treatment is provided. The inert gas introducing means 66 has a gas passage 68 connected to the side wall portion of the first exhaust port 54. The gas passage 68 has a flow controller such as an on-off valve 70 and a mass flow controller. 72 is sequentially provided so that an inert gas, for example, N ₂ gas in this case, can be introduced into the first exhaust port 54 while controlling the flow rate when necessary, that is, during the oxidation process.

In this case, the connection position of the upstream end of the gas passage 68 is not limited to the side wall of the first exhaust port 54, but is connected to the first exhaust passage 58 in the portion upstream of the first on-off valve 60. In any case, as long as the vicinity of the inside of the first exhaust port 54 can be covered with O ₂ gas during the oxidation process, the connection may be made anywhere.

  An oxygen concentration detection means 74 for detecting the oxygen concentration in the vicinity of the first exhaust port 54 is provided at or near the first exhaust port 54 during the oxidation process. Specifically, the oxygen concentration detection means 74 has a bypass passage 76 that communicates the first exhaust port 54 with the first exhaust passage 58 on the downstream side of the first on-off valve 60. In the middle of the bypass passage 76, an on-off valve 78 and an oxygen concentration detector 80 are sequentially provided from the upstream side to the downstream side to detect the oxygen concentration in the atmosphere flowing through the bypass passage 76. The oxygen concentration in the vicinity of the first exhaust port 54 can be recognized.

  In this case, the pipe diameter of the bypass passage 76 is designed to be very small and the conductance is very small, and only a small amount of gas flows through the bypass passage 76. Further, a temperature detector 82 for detecting the temperature in the vicinity of the first exhaust port 54 at the time of oxidation treatment is provided at or near the first exhaust port 54. As the temperature detector 82, for example, a thermocouple can be used. The detected value of the oxygen concentration detector 80 and the detected value of the temperature detector 82 are input to an avoidance operation command unit 84 made of, for example, a computer, and various danger avoidances are made as necessary. A command to take action is output.

  In addition, a second exhaust port 88 for oxidation treatment, which is a feature of the present invention, is provided at a position different from the first exhaust port 54. The second exhaust port 88 is located away from the first exhaust port 54 in the direction opposite to the flow direction of the source gas during the film forming process. Specifically, the second exhaust port 88 is provided on the side wall of the manifold 6 here. The second exhaust port 88 is connected to a second exhaust system 90 used during the oxidation process.

  Specifically, the second exhaust system 90 has a second exhaust passage 92 connected to the second exhaust port 88. A second opening / closing valve 94 is interposed in the middle of the second exhaust passage 92, and the downstream side of the second exhaust passage 92 is connected to the first opening / closing valve 60 and the first exhaust valve 92. The first pressure adjusting valve 62 and the first exhaust pump 64 are used in common.

  Thereby, the oxygen atmosphere in the processing container 4 can be discharged through the second exhaust port 88 during the oxidation process. The first pressure regulating valve 62 and the first exhaust pump 64 are not shared, and the second pressure regulating valve and the second exhaust pump are separately provided in the second exhaust passage 92, respectively. May be. A cylindrical heating means 86 having a heater 86A is provided to heat the processing container 4 and the wafer W inside the processing container 4 so as to surround the outer periphery of the processing container 4.

  The overall operation of the film forming apparatus 2 configured as described above, for example, process pressure, process temperature, supply of each gas, supply stop, switching of each gas, control of gas flow rate, control of opening / closing of each on-off valve, etc. For example, it is performed by the device control unit 96 made of a computer or the like. The apparatus control unit 96 includes a storage medium 98 in which a program for performing the above control is stored. As the storage medium 98, for example, a flexible disk, a CD (Compact Disc), a CD-ROM, a hard disk, a flash memory, a DVD, or the like can be used.

  Next, a film forming method (so-called ALD film forming process and oxidation process) of the present invention performed using the film forming apparatus 2 configured as described above will be described with reference to FIGS. 4 is a flowchart showing each step of the method of the present invention, FIG. 5 is a timing chart showing a supply mode of each gas in the method of the present invention, FIG. 6 is a diagram showing a gas flow in the processing container in the film forming step, FIG. FIG. 3 is a diagram showing a gas flow in a processing container in an oxidation process.

The method of the present invention includes a film forming process for forming a thin film made of a silicon-containing film on a target object using a source gas and a reactive gas, and an oxidizing gas for the target object. An oxidation process for performing an oxidation treatment is performed. Specifically, here, as shown in FIG. 4, a raw material gas (HCD) and a reactive gas (NH ₃ ) are supplied into the processing container 4 to contain silicon on the surface of the object to be processed, for example, the semiconductor wafer W. A film forming step S1 for forming a thin film (SiN) made of a film and an oxidation step S2 for forming a SiON film by oxidizing SiN using an oxidizing gas (O ₂ ) on the object to be processed.

  First, a wafer boat 10 on which a large number of normal temperature wafers, for example, 50 to 100 wafers 300 mm in size are placed, is loaded into a processing container 4 that has been previously set at a predetermined temperature by being raised from below. The inside of the processing vessel 4 is sealed by closing the lower end opening of the manifold 6 with the lid 16.

Then, the inside of the processing container 4 is evacuated and maintained at a predetermined process pressure, and the power supplied to the heating means 86 is increased to raise the wafer temperature and maintain the process temperature. First, a film forming step (S1 in FIG. 4) is performed. In this film forming process, the HCD gas is supplied from the source gas supply means 26, NH ₃ gas is supplied from the reaction gas supply means 28, and N ₂ gas is supplied from the purge gas supply means 30 as a purge gas.

In this case, the HCD gas flows through the gas nozzle 34 while the flow rate is controlled, and is discharged toward the wafer W in the horizontal direction from the gas injection holes 34A provided therein. Further, the NH ₃ gas flows in the gas nozzle 36 while the flow rate is controlled, and is discharged toward the wafer W in the horizontal direction from each gas injection hole 36A provided therein. Further, the N ₂ gas flows through the gas nozzle 38 while the flow rate is controlled, and is discharged toward the wafer W in the horizontal direction from each gas injection hole 38A provided therein.

  And after each said gas passes each gas circulation port 50 located in a horizontal direction, it flows down in the space 52 between the inner cylinder 4A and the outer cylinder 4B, flows into the 1st exhaust port 54, and It flows in the first exhaust passage 58 of the first exhaust system 56 in the drive state, and is discharged out of the system through the first on-off valve 60, the first pressure regulating valve 62, and the first exhaust pump 64 sequentially. Going to be. In this film forming process, the second on-off valve 94 provided in the second exhaust passage 92 of the second exhaust system 90 is maintained in a closed state, and gas is prevented from flowing here. .

Specifically, as shown in FIG. 5, first, adsorption processing is performed for a predetermined time T1 by supplying HCD gas into the processing container 4 (see FIG. 5A). In this adsorption process, for example, HCD gas molecules are adsorbed on the surface of the wafer W made of a silicon substrate. Next, the supply of the HCD gas is stopped, and a purge gas process for exhausting the residual gas in the processing container 4 by flowing N ₂ gas as a purge gas into the processing container 4 is performed for a predetermined time T2 (see FIG. 5C). ). Next, by supplying NH ₃ gas into the processing container 4, nitriding is performed as a reaction process for a predetermined time T3 (see FIG. 5B).

Next, the supply of NH ₃ gas is stopped, and the purge process for exhausting the residual gas in the processing container 4 by flowing N ₂ gas again as the purge gas into the processing container 4 is performed for a predetermined time T4 (FIG. 4 ( C)). Then, each of the above processes is repeated a predetermined number of times. That is, in FIG. 5, one cycle is from the HCD gas adsorption process to the next adsorption process, and this is repeated a predetermined number of times. Here, the times T1, T2, T3, and T4 are about 30 sec, 30 sec, 30 sec, and 30 sec, respectively.

The thickness of the SiN film formed in one cycle is approximately 1 mm, although it depends on the process temperature, process pressure, gas flow rate, and the like. The process conditions at this time are a process temperature within a range of 300 to 700 ° C., preferably within a range of 400 to 700 ° C., a process pressure within a range of 10 to 3000 Pa, and preferably within a range of 100 to 1500 Pa. . The flow rate of HCD gas is in the range of 10 to 1000 sccm, preferably in the range of 100 to 500 sccm, the flow rate of NH ₃ gas is in the range of 100 to 10,000 sccm, preferably in the range of 500 to 5000 sccm, and the flow rate of N ₂ gas is It is in the range of 100 to 30,000 sccm, preferably in the range of 500 to 10,000 sccm.

The flow of each gas when performing the film forming process as described above is shown in FIG. 6, and HCD, NH ₃ and N ₂ which are intermittently flowed in the horizontal direction are horizontally moved between the wafers W. After passing through each gas circulation port 50 as shown by the arrow 100, it flows down in the space 52 between the inner cylinder 4A and the outer cylinder 4B and flows into the first exhaust port 54, and the first The exhaust system 56 flows through the first exhaust passage 58 and is discharged out of the system.

  Here, the exhaust gas contains a chlorosilane polymer, which is a reaction byproduct generated by the film formation reaction, and the exhaust gas is at a temperature lower than the temperature in the processing vessel 4, for example, about 150 ° C. When the first exhaust port 54 is reached, it is rapidly cooled, and the chlorosilane polymer, which is a reaction byproduct, adheres to the inner wall of the first exhaust port 54 and the inner wall portion in the vicinity thereof. A deposit 102 is generated.

The chlorosilane polymer in the deposit 102 is a combustible material that is ignited at about 300 ° C. in the presence of oxygen. When the next oxidation process is performed in this state, the deposit 102 is exhausted at a high temperature. Oxygen flows and the deposit 102 burns, causing various inconveniences. Therefore, in the method of the present invention, as described below, oxygen is prevented from flowing into the deposit 102 and this portion is covered with an inert gas (N ₂ ).

That is, when the film formation step S1 is completed as described above, the process proceeds to the oxidation step S2. In this oxidation step, as shown in FIGS. 7, 5 (D) and 5 (E), the supply of HCD gas, NH ₃ gas, and N ₂ gas (purge gas) is stopped and the oxidizing gas supply is performed. O ₂ gas is allowed to flow as an oxidizing gas from the means 32, and N ₂ gas which is an inert gas is introduced from the inert gas introduction means 66 toward the first exhaust port 54. In this oxidation step, the first on-off valve 60 of the first exhaust system 56 is closed, and the second on-off valve 94 of the second exhaust system 90 is opened instead. Since the shared first exhaust pump 64 continues to be driven, the atmosphere in the processing container 4 is exhausted through the second exhaust port 88 instead of the first exhaust port 54. .

The O ₂ gas flows through the gas nozzle 40 and is discharged toward the wafer W in the horizontal direction from the gas injection hole 40A provided at the upper end portion of the gas nozzle 40. As a result, this O ₂ gas reacts with the SiN film formed on the surface of each wafer W and oxidizes it to form a SiON film (silicon oxynitride film).

Then, the O ₂ gas that has passed between the wafers W flows downward through the inner cylinder 4 </ b> A as indicated by an arrow 104 and flows toward the second exhaust port 88. Therefore, since this O ₂ gas does not reach the first exhaust port 54, the combustible deposit 102 adhering to the O ₂ gas does not come into contact with oxygen and prevents this from burning. be able to.

Further, the N ₂ gas supplied from the inert gas supply means 66 is introduced into the first exhaust port 54 from the gas passage 68. The introduced N ₂ gas flows toward the inside of the processing container 4 as shown by an arrow 106, passes through each gas flow port 50 of the inner cylinder 4A, flows into the inner cylinder 4A, and further below It flows toward the second exhaust port 88. Therefore, the N ₂ gas is in a state of covering the surface of the combustible deposit 102 that has adhered to the first exhaust port 54 so that the deposit 102 is in contact with the O ₂ gas. Can be reliably prevented. As described above, the deposit 102 can be prevented from burning, so that the seal member of the piping system can be prevented from being deteriorated by heat, and metal contamination can be generated from the stainless steel constituting the piping. Can be prevented.

Then, the O ₂ gas or N ₂ gas that has reached the second exhaust port 88 flows through the second exhaust passage 92 and then reaches the first exhaust passage 58, and further the first pressure adjustment. The gas is discharged out of the system through the valve 62 and the first exhaust pump 64.

The process conditions at this time are a process temperature of, for example, about 800 ° C. and a process pressure of, for example, about 760 Torr (normal pressure). The flow rate of O ₂ gas is about 10,000 sccm, the flow rate of N ₂ gas (inert gas) is about 15000 sccm, and the process time is about 300 to 400 minutes.

  Further, in this oxidation step, the on-off valve 78 of the oxygen concentration measuring means 74 is opened, and the atmosphere of the first exhaust port 54 is slightly passed through the bypass passage 76 having a small conductance, so that the oxygen in this atmosphere The concentration is detected by the oxygen concentration detector 80, and the detection result is sent to the avoidance operation command unit 84. In general, the chlorosilane polymer may ignite when it comes into contact with a gas having an oxygen concentration of 2% or more. Therefore, when the oxygen concentration reaches a predetermined limit, for example, 2%, the avoidance operation command unit 84 A command signal for performing a danger avoiding operation is output to the device control unit 96.

  Further, the temperature of the first exhaust port 54 is detected by the temperature detector 82, and the detection result is input to the avoidance operation command unit 84. As described above, since the ignition temperature of the chlorosilane polymer is about 300 ° C., for example, if a temperature lower than 300 ° C., for example, 250 ° C. is detected, the avoidance operation command unit 84 controls the device control. A command signal for performing a danger avoiding operation is output to the unit 96.

Examples of the danger avoidance operation performed at this time include, for example, stopping the supply of oxygen, increasing the supply amount of N ₂ gas (inert gas), increasing the exhaust amount of the first exhaust pump 64, Alternatively, various aspects such as stopping the processing itself can be performed singly or in combination. The ALD method described here is merely an example at the end, and any gas supply mode may be adopted.

As described above, according to the present invention, a film-forming process for forming a thin film made of a silicon-containing film (silicon nitride film) using a silicon-containing gas, for example, an HCD gas, as a source gas for a semiconductor wafer that is an object to be processed, In a film forming apparatus capable of performing an oxidation process for oxidizing an object to be processed using an oxidizing gas, for example, O ₂ gas, a first exhaust port 54 used during the film forming process and a first exhaust port used during the oxidizing process. In addition, during the oxidation process, a portion of the first exhaust port 54 is covered with an atmosphere of an inert gas such as N ₂ gas to oxidize a reaction by-product such as a chlorosilane polymer. gas, for example, since as not exposed to O ₂ gas, can be flammable reaction by-products adhering to the vicinity of the first exhaust port 54 is prevented from burning in the film forming process and That. As a result, it is possible to prevent deterioration of the sealing performance of the first exhaust system 56, metal contamination of the object to be processed, and generation of particles.
Here, although distributed gas nozzles are used as the gas nozzle 34 of the raw material gas supply means 26 and the gas nozzle 36 of the reaction gas supply means 28, respectively, instead of this, a tip like a gas nozzle 40 of the oxidizing gas supply means 32 is used. You may make it use what is called a straight type gas nozzle which has a gas injection hole only in a part, respectively. In this case, the raw material gas and the reaction gas may be supplied to the lower part (lower end part) in the inner cylinder 4A, or may be supplied to the upper part (upper end part) in the inner cylinder 4A.
Further, here, as the gas nozzle 40 of the oxidizing gas supply means 32, a straight type gas nozzle is used as described above, but instead, a gas is supplied from the lateral direction of each wafer W using a distributed type gas nozzle. You may make it supply.

Second Embodiment
Next, a second embodiment of the film forming apparatus of the present invention will be described. FIG. 8 is a schematic cross-sectional view showing the main part of the second embodiment of the film forming apparatus of the present invention. The same components as those shown in FIGS. 1 to 3 are denoted by the same reference numerals and the description thereof is omitted, and only the main parts of the components are described here, and some components The description of parts is omitted.

  In the second embodiment, the upper end of the inner cylinder 4A is opened, and the ceiling of the outer cylinder 4B is formed in a dome shape. The gas nozzle 34 of the source gas supply means 26, the gas nozzle 36 of the reaction gas supply means 28, and the gas nozzle 38 of the purge gas supply means 30 are all short straight tube gas nozzles instead of dispersion nozzles, and each gas nozzle 34, 36, 38 is used. The gas injection holes 34 </ b> A, 36 </ b> A, 38 </ b> A are positioned in a space below the inner cylinder 4 </ b> A so as to supply each gas to the lower part in the processing container 4.

  Further, the gas nozzle 40 of the oxidizing gas supply means 32 is formed in an L shape similarly to the case of the first embodiment, and the gas injection hole 40A is positioned at the upper end portion of the inner cylinder 4A, so that the processing container 4 An oxidizing gas is supplied to the upper part of the inside.

In this case, during the film forming process, HCD gas, NH ₃ gas, and N ₂ gas (purge gas) are respectively supplied to the lower side of the processing container 4, and each gas is indicated by an arrow 108 in the inner cylinder 4 A. Then, it turns back at the ceiling and flows down in the space 52 between the inner cylinder 4A and the outer cylinder 4B and as shown by the arrow 110, and finally the first exhaust from the first exhaust port 54. It is discharged out of the system through the system 56.

On the other hand, during the oxidation process, the O ₂ gas supplied from the gas injection hole 40A located at the ceiling in the processing container 4 flows down in the inner cylinder 4A as indicated by an arrow 112, and the _second gas It is discharged out of the system through the exhaust port 88. At this time, the N ₂ gas (inert gas) introduced from the inert gas introduction means 66 into the first exhaust port 54 is moved through the first exhaust port 54 in the processing container 4 as indicated by an arrow 114. Backwardly flows upward to rise in the space 52 between the inner cylinder 4A and the outer cylinder 4B, and then turns back at the top to flow down in the inner cylinder 4A with the O ₂ gas as indicated by an arrow 112. Finally, it is discharged out of the system through the second exhaust port 88. Also in this case, the same effect as the first embodiment can be exhibited.
In this case, a straight type gas nozzle is used as the gas nozzle 40 of the oxidizing gas supply means 32, but instead, a gas is supplied from the lateral direction of each wafer W using a distributed type gas nozzle. Also good.

<Third Embodiment>
Next, a third embodiment of the film forming apparatus of the present invention will be described. FIG. 9 is a schematic cross-sectional view showing the main part of a third embodiment of the film forming apparatus of the present invention. The same components as those shown in FIGS. 1 to 3 and FIG. 8 are given the same reference numerals and their description is omitted, and only the main parts of the components are shown here. The description of the component parts is omitted.

  In the previous first and second embodiments, a processing container having a double-pipe structure having an inner cylinder 4A and an outer cylinder 4B was used as the processing container 4, but here, the processing container 4 is a ceiling 1 A single tube structure using two cylindrical bodies 120 is used. A cylindrical manifold may be joined to the lower end of the cylindrical body 120 to form the entire processing container.

  Then, a first exhaust port 54 is formed in the lower side wall of the processing container 4 made of the cylindrical body 120, and a first exhaust system 56, an inert gas introducing means 66, and the like are connected to the first exhaust port 54. ing. On the other hand, here, a second exhaust port 88 is formed at the upper end of the cylindrical body 120, that is, the top, and the second exhaust system 90 is connected to the second exhaust port 88.

  Further, as the gas nozzles 34, 36, 38 of the source gas supply means 26, the reaction gas supply means 28, and the purge gas supply means 30, a dispersed gas nozzle having the same shape as the gas nozzle used in the first embodiment shown in FIG. Each gas can be uniformly supplied from the lateral direction to each wafer W in the processing container 4.

On the other hand, as the gas nozzle 40 of the oxidizing gas supply means 32, an oxidizing gas can be supplied to the lower part in the cylinder 120 using a straight tubular gas nozzle. Also in this case, HCD gas, NH ₃ gas or the like at the time of the film forming process is exhausted from the lower first exhaust port 54, and O ₂ gas which is an oxidizing gas at the time of the oxidizing process is exhausted from the upper second exhaust port. In this case, the same effects as those of the first and second embodiments can be exhibited.
Here, as the gas nozzle 34 of the raw material gas supply means 26 and the gas nozzle 36 of the reaction gas supply means 28, distributed gas nozzles are used, but instead, straight gas nozzles may be used. . In this case, the source gas and the reaction gas are supplied to the upper part (upper end part) in the processing container 4 (cylinder 120).
Further, here, as the gas nozzle 40 of the oxidizing gas supply means 32, a straight type gas nozzle is used as described above, but instead, a gas is supplied from the lateral direction of each wafer W using a distributed type gas nozzle. You may make it supply.

<Fourth embodiment>
Next, a fourth embodiment of the film forming apparatus of the present invention will be described. FIG. 10 is a schematic cross-sectional view showing the main part of the fourth embodiment of the film forming apparatus of the present invention. The same components as those shown in FIGS. 1 to 3, 8 and 9 are given the same reference numerals and the description thereof is omitted, and only the main parts of the components are described here. Some of the components are omitted from the description.

  Here, the processing container 4 has a single-pipe structure using one cylindrical body 120 having a ceiling as in the third embodiment shown in FIG. A cylindrical manifold may be joined to the lower end of the cylindrical body 120 to form the entire processing container.

  Contrary to the case of the third embodiment, the first exhaust port 54 is formed in the upper end portion of the processing container 4 made of the cylindrical body 120, that is, the ceiling portion, and the first exhaust port 54 has the first exhaust port 54. The exhaust system 56 and the inert gas introducing means 66 are connected. On the other hand, here, the second exhaust port 88 is formed in the lower end side wall of the cylindrical body 120, and the second exhaust system 90 is connected to the second exhaust port 88.

  Further, as the gas nozzles 34, 36, 38 of the source gas supply means 26, the reaction gas supply means 28, and the purge gas supply means, a straight pipe type gas nozzle having the same shape as the gas nozzle used in the second embodiment shown in FIG. Each gas can be supplied to the lower part in the processing container 4.

On the other hand, the gas nozzle 40 of the oxidizing gas supply means 32 is an L-shaped gas nozzle 40 as in the first embodiment shown in FIG. 1 and the second embodiment shown in FIG. The gas injection hole 40 </ b> A is formed at the upper end thereof, and the oxidizing gas can be supplied to the upper part in the cylindrical body 120. In this case, HCD gas, NH ₃ gas or the like during the film forming process is exhausted from the upper first exhaust port 54, and O ₂ gas which is an oxidizing gas during the oxidizing process is exhausted from the lower second exhaust port 88. In this case, the same effects as those of the first, second, and third embodiments can be exhibited.
Here, the supply positions of the raw material gas, the reactive gas and the oxidizing gas in the processing vessel 4 are different between the lower part and the upper part in the container, but the gas nozzle 34 of the raw material gas supply means 26 and the reactive gas supply means 28 As the gas nozzle 36 and the gas nozzle 40 of the oxidizing gas supply means 32, straight gas nozzles are used, but instead, gas is supplied from the lateral direction of each wafer W by using distributed gas nozzles. Also good.

<Fifth Embodiment>
Next, a fifth embodiment of the film forming apparatus of the present invention will be described. FIG. 11 is a schematic cross-sectional view showing the main part of a fifth embodiment of the film forming apparatus of the present invention, FIG. 11 (A) shows a vertical cross-sectional view, and FIG. 11 (B) shows a cross-sectional view. The same components as those shown in FIGS. 1 to 3 and FIGS. 8 to 10 are denoted by the same reference numerals, and the description thereof is omitted. Here, only the main parts of the components are described. Some of the components are omitted from the description.

In each of the previous embodiments, plasma was not used during the film formation process. However, the present invention is not limited to this, and NH ₃ gas that is a nitriding gas may be activated using plasma during film formation. In the fifth embodiment, in order to use plasma, a processing vessel having a double-pipe structure having an inner cylinder 4A and an outer cylinder 4B is used as the processing vessel 4 as in the first embodiment shown in FIG. A plasma box 124 is formed on one side of the processing container 4 so as to protrude radially outward of the processing container 4 and open into the inner cylinder 4A. The plasma box 124 is partitioned by a box partition wall 126 made of, for example, quartz, and is provided along the height direction of the processing container 4.

  A pair of plasma electrodes 128 are provided outside the box partition wall 126 along the height direction, and a high frequency power source 132 of 13.56 MHz, for example, is connected to the plasma electrodes 128 via a matching circuit 130. Yes.

In the plasma box 124, a distributed gas nozzle 36 of the reactive gas supply means 28 is located. Thus, when NH ₃ gas is supplied from the gas nozzle 36, high frequency power is applied to the plasma electrode 128 to generate plasma, thereby activating the NH ₃ gas and promoting nitriding treatment. And the 1st exhaust port 54 and the 2nd exhaust port 88 are each provided in the position similar to the case of 1st Embodiment shown in FIG. Also in this case, the same effect as the first embodiment can be exhibited.

<Evaluation of supply amount of inert gas (N ₂ gas) during oxidation treatment>
Here, if turbulent flow is generated in the first exhaust system when N ₂ gas is flowed during the oxidation treatment, oxygen is involved and it is not preferable, so the conditions for maintaining the laminar flow state were examined by simulation. In the embodiment of the present invention, N ₂ gas is allowed to flow as an inert gas from the inert gas introduction means 66 to the first exhaust port 54 during the oxidation process, and the atmosphere in the processing container 4 is exhausted from the second exhaust port 88. Since the state of the flow of N ₂ gas at the time was confirmed by simulation, the evaluation result will be described.

FIG. 12 is a graph showing the relationship between the amount of N ₂ gas and the number of lay nozzles when an inert gas (N ₂ gas) is flowed into the processing container from the first exhaust port.
Here, the number of ray nozzles Re is given by the following equation.
Re = ρ · U · L / μ
ρ: Density of N ₂ gas U: Typical velocity of N ₂ gas L: Typical length of an object in a flow μ: Viscosity coefficient of gas, specifically, N ₂ gas is 41 [μPa · s].

Here, the inner diameter of the first exhaust port 54 was examined for 2.5 cm, 5 cm, 7.5 cm, and 10 cm, respectively. When the N ₂ gas is introduced into the first exhaust passage 58, the inner diameter becomes the inner diameter of the first exhaust passage 58. Here, the flow rate of the N ₂ gas is not particularly limited, but the number of lay nozzles is 4000 or less in order to maintain the laminar flow state of the N ₂ gas without generating turbulent flow in the first exhaust port 54. Preferably, 2000 or less is desirable.

As shown in FIG. 12, the number of lay nozzles increases linearly as the flow rate of N ₂ gas increases at each diameter, and the inclination angle of the straight line increases as the diameter of the first exhaust port increases. It gradually gets smaller. In this case, since the capacity in the processing container is about 100 liters, for example, the diameter of the first exhaust port is too small when the diameter is about 2.5 cm or 5 cm. Then, considering the case where the diameter of the first exhaust port is 7.5 cm and 10 cm, in order to maintain a laminar flow state without generating turbulent flow at the first exhaust port, the case of 7.5 cm The flow rate of N ₂ gas should be 55 slm or less, preferably 23 slm or less, and in the case of 10 cm, the flow rate of N ₂ gas should be 64 slm or less, preferably 32 slm or less. I understand that.

Incidentally, the above-described embodiments, N ₂ gas was used as an inert gas purge or inert gas supply means 66 of the purge gas supply means 30 is not limited to this, as the purge gas or an inert gas N ₂ One or more gases selected from the group consisting of a gas and a rare gas such as Ar, He, Ne, and Xe may be used.

Here, O ₂ gas is used as the oxidizing gas used for the oxidizing gas supply means 32, but the present invention is not limited to this, and examples of the oxidizing gas include O ₂ , O ₃ , NO, N ₂ O, NO ₂ , H One or more gases selected from the group consisting of ₂ O, H ₂ O ₂ and radical oxygen may be used.
Furthermore, although HCD gas is used here as a silicon-containing gas containing silicon and chlorine, which is a raw material gas, the silicon-containing gas containing silicon and chlorine is not limited to this, and dichlorosilane (DCS) is used. ), Trichlorosilane, hexachlorodisilane (HCD), hexamethyldisilazane (HMDS), or tetrachlorosilane (TCS).

In this case, the film forming process and the oxidation process are continuously performed on the same semiconductor wafer W. However, in some cases, these processes are not performed continuously but separately on different wafers. In this case, the present invention can be applied. In any case, when the oxidation treatment is performed when the combustible deposit 102 is attached to the first exhaust port 54, an inert gas (N ₂ gas) is always allowed to flow from the inert gas introduction means 66. This prevents the deposit 102 from burning.

  Although the semiconductor wafer is described as an example of the object to be processed here, the semiconductor wafer includes a silicon substrate and a compound semiconductor substrate such as GaAs, SiC, GaN, and the like, and is not limited to these substrates. The present invention can also be applied to glass substrates, ceramic substrates, and the like used in display devices.

It is a longitudinal section lineblock diagram showing a 1st embodiment of a film deposition system concerning the present invention. It is sectional drawing which shows a processing container. It is a top view which shows the gas distribution port provided in the inner cylinder of a processing container. It is a flowchart which shows each process of this invention method. It is a timing chart which shows the supply aspect of each gas in this invention method. It is a figure which shows the flow of the gas in the processing container in the film-forming process. It is a figure which shows the flow of the gas in the processing container in an oxidation process. It is a cross-sectional schematic diagram which shows the principal part of 2nd Embodiment of the film-forming apparatus of this invention. It is a cross-sectional schematic diagram which shows the principal part of 3rd Embodiment of the film-forming apparatus of this invention. It is a cross-sectional schematic diagram which shows the principal part of 4th Embodiment of the film-forming apparatus of this invention. It is a cross-sectional schematic diagram which shows the principal part of 5th Embodiment of the film-forming apparatus of this invention. It is a graph showing the relationship between the N ₂ gas amount and the Reynolds number at which the processing vessel inert gas (N ₂ gas) flowed from the first outlet.

Explanation of symbols

2 Film forming apparatus 4 Processing container 4A Inner cylinder 4B Outer cylinder 10 Wafer boat (holding means)
26 Source gas supply means 28 Reactive gas supply means 30 Purge gas supply means 32 Oxidizing gas supply means 34, 36, 38, 40 Gas nozzle 54 First exhaust port 56 First exhaust system 58 First exhaust passage 64 First exhaust Pump 66 Inert gas introduction means 74 Oxygen concentration detection means 80 Oxygen concentration detector 82 Concentration detector 86 Heating means 88 Second exhaust port 90 Second exhaust system 120 Cylindrical body W Semiconductor wafer (object to be processed)

Claims (36)

A film forming process for forming a thin film made of a silicon-containing film using a silicon-containing gas as a raw material gas on the object to be processed and an oxidation process for oxidizing the object to be processed using an oxidizing gas can be performed. In the membrane device,
A processing container having a length capable of accommodating a plurality of the objects to be processed;
Source gas supply means for supplying source gas into the processing vessel;
Reactive gas supply means for supplying a reactive gas that reacts with the source gas into the processing vessel;
An oxidizing gas supply means for supplying an oxidizing gas into the processing vessel;
A first exhaust port provided in the processing container;
A second exhaust port provided at a position different from the first exhaust port;
A first exhaust system connected to the first exhaust port and used during the film formation process;
A second exhaust system connected to the second exhaust port and used during the oxidation process;
An inert gas introduction means for introducing an inert gas into the first exhaust port during the oxidation treatment;
A film forming apparatus comprising: The said 2nd exhaust port is located away from the said 1st exhaust port in the direction opposite to the flow direction of the said source gas at the time of the said film-forming process. Membrane device. Oxygen concentration detecting means for detecting the oxygen concentration in the vicinity of the first exhaust port during the oxidation treatment;
An avoidance operation command unit for performing an avoidance operation when the oxygen concentration detection means detects an oxygen concentration equal to or higher than a predetermined concentration;
The film forming apparatus according to claim 1, further comprising: A temperature detector for detecting a temperature in the vicinity of the first exhaust port during the oxidation treatment;
An avoidance operation command unit for performing an avoidance operation when the temperature detector detects a temperature equal to or higher than a predetermined temperature; and
The film forming apparatus according to claim 1, further comprising: The processing container has a cylindrical inner cylinder and a cylindrical outer cylinder arranged in a concentric manner outside the inner cylinder,
The first exhaust port is provided so as to face a space between the inner cylinder and the outer cylinder,
The film forming apparatus according to claim 1, wherein the second exhaust port is provided so as to face a space below the inner cylinder. The inner cylinder is formed with a ceiling at the upper end, and a gas flow port is formed on the side wall of the inner cylinder along the height direction thereof so as to communicate with the space between the inner cylinder and the outer cylinder. The film forming apparatus according to claim 5, wherein: The raw material gas supply means and the reactive gas supply means each have a gas nozzle in which a plurality of gas injection holes are formed along the length direction and are arranged along the height direction in the inner cylinder. The film forming apparatus according to claim 6, wherein: The said raw material gas supply means and the said reactive gas supply means each have the gas nozzle which located the gas-injection hole in the upper end part in the said inner cylinder, or a lower end part, respectively. Deposition device. 9. The film forming apparatus according to claim 7, wherein the oxidizing gas supply means has a gas nozzle having a gas injection hole positioned at an upper end portion in the inner cylinder. The oxidizing gas supply means has a gas nozzle in which a plurality of gas injection holes are formed along the length direction and is disposed along the height direction in the inner cylinder. The film forming apparatus according to claim 7 or 8. The film forming apparatus according to claim 6, wherein the second exhaust port is provided in a lower side wall of the processing container. The film forming apparatus according to claim 5, wherein an upper end of the inner cylinder is open. 13. The film forming apparatus according to claim 12, wherein each of the source gas supply unit and the reaction gas supply unit includes a gas nozzle having a gas injection hole positioned in a space below the inner cylinder. 14. The film forming apparatus according to claim 13, wherein the oxidizing gas supply means has a gas nozzle having a gas injection hole positioned at an upper end portion in the inner cylinder. The oxidizing gas supply means has a gas nozzle in which a plurality of gas injection holes are formed along the length direction and is disposed along the height direction in the inner cylinder. The film forming apparatus according to claim 13. 15. The film forming apparatus according to claim 12, wherein the second exhaust port is provided on a lower side wall of the processing container. 5. The film forming apparatus according to claim 1, wherein the processing container has one cylindrical body with a ceiling. The film forming apparatus according to claim 17, wherein the first exhaust port is provided in a ceiling portion of the processing container, and the second exhaust port is provided in a lower side wall of the processing container. 19. The film forming apparatus according to claim 18, wherein each of the source gas supply unit and the reaction gas supply unit includes a gas nozzle having a gas injection hole positioned at a lower end portion in the processing container. The raw material gas supply means and the reactive gas supply means each have a gas nozzle in which a plurality of gas injection holes are formed along the length direction and are arranged along the height direction in the processing container. The film forming apparatus according to claim 18, wherein: 21. The film forming apparatus according to claim 19, wherein the oxidizing gas supply means has a gas nozzle having a gas injection hole positioned at an upper end portion in the cylindrical body. The oxidizing gas supply means includes a gas nozzle having a plurality of gas injection holes formed along a length direction thereof and disposed along the height direction in the cylindrical body. Item 20. The film forming apparatus according to Item 20 or 21. The film forming apparatus according to claim 17, wherein the first exhaust port is provided in a lower side wall of the processing container, and the second exhaust port is provided in a ceiling portion of the processing container. . The source gas supply means and the reactive gas supply means each have a gas nozzle in which a plurality of gas injection holes are formed along the length direction and are arranged along the height direction in the cylinder. 24. The film forming apparatus according to claim 23. 24. The film forming apparatus according to claim 23, wherein each of the source gas supply unit and the reaction gas supply unit has a gas nozzle having a gas injection hole positioned at an upper end portion of the cylindrical body. The film forming apparatus according to any one of claims 23 to 25, wherein the oxidizing gas supply unit includes a gas nozzle having a gas injection port positioned at a lower end portion in the cylindrical body. The oxidizing gas supply means includes a gas nozzle having a plurality of gas injection holes formed along a length direction thereof and disposed along the height direction in the cylindrical body. Item 26. The film forming apparatus according to any one of Items 23 to 25. 27. The film forming apparatus according to claim 1, wherein the first exhaust system and the second exhaust system have at least an exhaust pump shared with each other. 29. The film forming apparatus according to claim 1, wherein each of the first exhaust system and the second exhaust system has an exhaust pump individually. The film forming apparatus according to any one of claims 1 to 28, wherein the silicon-containing gas is a gas containing silicon and chlorine. The gas containing silicon and chlorine is at least one gas selected from the group consisting of dichlorosilane (DCS), trichlorosilane, hexachlorodisilane (HCD), and tetrachlorosilane (TCS). 30. The film forming apparatus according to 30. The oxidizing gas is composed of one or more gases selected from the group consisting of O ₂ , O ₃ , NO, N ₂ O, NO ₂ , H ₂ O, H ₂ O ₂ , and radical oxygen. Item 32. The film forming apparatus according to any one of Items 1 to 31. The film forming apparatus according to any one of claims 1 to 32, wherein the inert gas includes one or more gases selected from the group consisting of N ₂ gas and rare gas. In the usage method of the film-forming apparatus as described in any one of Claims 1 thru | or 33,
A film forming step for performing a film forming process for forming a thin film made of a silicon-containing film on the object to be processed using a source gas and a reactive gas;
A method of using a film forming apparatus, characterized in that an oxidation process is performed on an object to be processed using an oxidizing gas. 35. The method of using a film forming apparatus according to claim 34, wherein the film forming step and the oxidizing step are continuously performed on the same object. 35. When performing processing on an object to be processed using the film forming apparatus according to any one of claims 1 to 33, the method for using the film forming apparatus according to claim 34 or 35 is performed. A storage medium for storing a computer-readable program for controlling the membrane device.

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