JP2007227804A - Manufacturing method of semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of smoothly generating plasma by effectively discharging water produced in an activation process of a gas so as not to leave the water in an apparatus for remote plasma excitation. <P>SOLUTION: The method includes the steps of: supplying a raw material gas to a substrate; supplying a gas-containing oxygen atoms and a gas-containing hydrogen atoms to a plasma unit in a plasma generating state so as to activate the gas, and supplying the activated gases to the substrate; and maintaining a state of the plasma unit for generating the plasma while the supply of the gas-containing oxygen atoms and the gas-containing hydrogen atoms to the plasma unit is stopped. The method forms a film on the substrate by repeating the steps above for a plurality of number of times. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a semiconductor device manufacturing method for manufacturing a semiconductor device by forming a thin film on a substrate such as a silicon wafer or a glass substrate, and performing impurity diffusion, annealing, and the like.

  Of the substrate processing, which is one process of the semiconductor manufacturing process, there is a film forming process for generating a thin film on the substrate.

  Thin film deposition methods used in semiconductor manufacturing include physical vapor deposition (PVD) such as sputtering and chemical vapor deposition (CVD) utilizing chemical reaction.

  In general, CVD is sensitively dependent on temperature, and may have characteristics such as step coverage and initial film formation characteristics that have different film formation speeds.

  CVD is suitable for mass production from the viewpoint of improving productivity such as not having to open the reaction chamber to the atmosphere for exchanging raw materials (targets) in addition to improving film characteristics such as superior step coverage compared to PVD. Yes.

  As a material for CVD (MOCVD) using an organic material for a hafnium silicate film, for example, Hf [OC (CH3) 3] 4 (tetraxista-salibutroxy-hafnium, hereinafter abbreviated as Hf-OtBu), Hf [OC ( CH3) 2 CH2 OCH3] 4 (tetrakis (1-methoxy-2-methyl-2-propoxy) hafnium, hereinafter abbreviated as Hf-MMP), Si [OC (CH3) 2 CH2 OCH3] 4 (tetrakis (1-methoxy) Various chemical substances such as 2-methyl-2-propoxy) silane (hereinafter abbreviated as Si-MMP), Si (OC2 H5) 4 (abbreviated as TEOS) are used in combination. Many of such materials are liquid or solid at normal temperature and pressure. For this reason, most raw materials are heated to increase vapor pressure and converted to gas.

International Publication No. 2005/071723 Pamphlet

  As an oxidant for advancing or promoting the reaction of organic raw materials, oxygen, water (gas), ozone, etc. excited by oxygen / remote plasma are used, but when a mixed gas of oxygen and hydrogen is excited by remote plasma, Oxygen (O) radicals, water oxygen (OH) radicals are generated, and water (H2 O) is also generated.

  The present inventor has a phenomenon in which the generation of plasma is hindered, for example, when the water generated in the remote plasma excitation device or piping remains in the remote plasma excitation device, the probability of failure to ignite plasma becomes very high. I found.

  In view of such circumstances, the present invention provides a method for smoothly discharging the water generated in the gas activation process so that it does not remain in the remote plasma excitation device and smoothing the generation of plasma.

  The present invention includes a step of supplying a source gas to a substrate, and supplying a gas containing oxygen atoms and a gas containing hydrogen atoms to a plasma unit in a plasma-generated state to activate the activated gas. Supplying to the substrate, and maintaining the state in which plasma is generated in the plasma unit in a state where supply of the gas containing oxygen atoms and the gas containing hydrogen atoms to the plasma unit is stopped. And a method of manufacturing a semiconductor device in which a film is formed on a substrate by repeating these steps a plurality of times.

  According to the present invention, the source gas is supplied to the substrate, and the plasma unit in a state where the plasma is generated is supplied by supplying the gas containing oxygen atoms and the gas containing hydrogen atoms to be activated and activated. A step of supplying a gas to the substrate, and a step of maintaining a state in which plasma is generated in the plasma unit in a state where supply of a gas containing oxygen atoms and a gas containing hydrogen atoms to the plasma unit is stopped. And by repeating these steps a plurality of times, a film is formed on the substrate, so that water generated when activated by supplying a gas containing oxygen atoms and a gas containing hydrogen atoms to the plasma unit is It is discharged without remaining in the plasma unit, and exhibits an excellent effect that generation of plasma is not hindered by water remaining.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  First, with reference to FIGS. 1 and 2, a substrate processing apparatus in which a method for manufacturing a semiconductor device according to the present invention is implemented will be described.

  The substrate processing apparatus described below is a single wafer type that processes substrates one by one. In the substrate processing apparatus, a substrate transport container for transporting a substrate such as a wafer is a FOUP (front opening unified pod). Hereinafter referred to as a pod).

  In the following description, front, rear, left and right are based on FIG. That is, with respect to the paper shown in FIG. 1, the front is below the paper, the back is above the paper, and the left and right are the left and right of the paper.

  As shown in FIGS. 1 and 2, the substrate processing apparatus includes a first transfer chamber 1 configured in an airtight structure capable of withstanding a pressure (negative pressure) less than atmospheric pressure such as a vacuum state. The casing 2 of the first transfer chamber 1 is formed in a box shape in which the plan view is hexagonal and the upper and lower ends are closed. The first transfer chamber 1 is provided with a first wafer transfer device 4 for transferring the wafer 3 under a negative pressure. The first wafer transfer device 4 is configured to be moved up and down by an elevator 5 while maintaining the airtightness of the first transfer chamber 1.

  Among the side walls surrounding the first transfer chamber 1, a first auxiliary chamber 6 for carrying in and a second auxiliary chamber 7 for carrying out are respectively connected to gate walls 8 and 9 through two side walls located on the front side. They are connected in series, and each has an airtight structure that can withstand negative pressure. Further, the first preliminary chamber 6 is provided with a substrate placing table 11 for carrying in, and the second spare chamber 7 is provided with a substrate placing table 12 for carrying out.

  A second transfer chamber 13 used under a substantially atmospheric pressure is connected to the front sides of the first preliminary chamber 6 and the second preliminary chamber 7 via gate valves 14 and 15. A second wafer transfer device 16 for transferring the wafer 3 is installed in the second transfer chamber 13. The second wafer transfer device 16 is configured to be moved up and down by an elevator 17 installed in the second transfer chamber 13 and to be reciprocated in the left-right direction by a linear actuator 18. .

  An alignment device 19 for aligning the posture of the wafer 3 by a notch or an orientation flat of the wafer 3 is installed at the left end portion of the second transfer chamber 13. A clean unit 21 for supplying clean air is installed in the upper part of the second transfer chamber 13.

  A wafer loading / unloading port 23 for loading / unloading the wafer 3 into / from the second transfer chamber 13 and a pod opener 24 are installed on the front side of the housing 22 of the second transfer chamber 13. An IO stage 25 is installed on the opposite side of the pod opener 24 with respect to the wafer loading / unloading port 23, that is, on the outside of the housing 22. The pod opener 24 can open and close the lid 27 of the pod 26 and can open and close the wafer loading / unloading port 23. By opening and closing the lid 27 of the pod 26 mounted on the IO stage 25, the pod opener 24 The wafer 3 can be taken in and out of the pod 26. The pod 26 is supplied to and discharged from the IO stage 25 by an in-process transfer device (RGV) (not shown).

  A first processing furnace 28 for performing a desired process on the wafer 3 and a second processing furnace 29 are provided via gate valves 31 and 32 on two side walls located on the rear side (back side) of the housing 2. Each one is connected. The first processing furnace 28 and the second processing furnace 29 are both configured by a cold wall type processing furnace. Further, a first cooling unit 33 and a second cooling unit 34 are connected to the remaining two opposite side walls of the housing 2 in an airtight manner, and the first cooling unit 33 and the second cooling unit 34 are connected to each other. Each of the cooling units 34 is configured to cool the processed wafer 3.

  Hereinafter, processing steps using the substrate processing apparatus having the above-described configuration will be described.

  An unprocessed wafer 3 is transferred by the in-process transfer apparatus to a substrate processing apparatus for performing a process step in a state where a predetermined number, for example, 25 sheets are accommodated in the pod 26. The pod 26 that has been transported is placed on the IO stage 25. The lid 27 of the pod 26 is removed by the pod opener 24, and the wafer inlet / outlet of the pod 26 is opened.

  When the pod 26 is opened by the pod opener 24, the second wafer transfer device 16 picks up the wafer 3 from the pod 26 and carries it into the first preliminary chamber 6, and the wafer 3 is placed on the substrate. Transfer to the table 11. During the transfer operation, the gate valve 8 is closed, and the negative pressure in the first transfer chamber 1 is maintained. When a predetermined number of wafers 3 stored in the pod 26 are transferred to the substrate table 11, the gate valve 14 is closed, and the inside of the first preliminary chamber 6 is negatively charged by an exhaust device (not shown). Exhausted to pressure.

  When the pressure in the first preliminary chamber 6 reaches a preset pressure value, the gate valve 8 is opened, and the first preliminary chamber 6 and the first transfer chamber 1 are communicated. Subsequently, the first wafer transfer machine 4 picks up the wafer 3 from the substrate table 11 and carries it into the first transfer chamber 1. After the gate valve 8 is closed, the gate valve 31 is opened, and the first transfer chamber 1 and the first processing furnace 28 are communicated with each other. Subsequently, the first wafer transfer device 4 carries the wafer 3 from the first transfer chamber 1 into the first processing furnace 28 and transfers it to a support in the first processing furnace 28. After the gate valve 31 is closed, a processing gas is supplied into the first processing furnace 28 and a desired process is performed on the wafer 3.

  When the processing on the wafer 3 is completed in the first processing furnace 28, the gate valve 31 is opened, and the processed wafer 3 is unloaded to the first transfer chamber 1 by the first wafer transfer device 4. After unloading, the gate valve 31 is closed.

  The first wafer transfer device 4 transports the wafer 3 unloaded from the first processing furnace 28 to the first cooling unit 33, and the processed wafer 3 is cooled.

  When the processed wafer 3 is transported to the first cooling unit 33, the first wafer transfer device 4 operates the wafer 3 prepared in advance in the substrate table 11 of the first preliminary chamber 6 in the same manner as described above. Then, the wafer 3 is transferred to the first processing furnace 28, and a desired process is performed on the wafer 3 in the first processing furnace 28.

  When a preset cooling time elapses in the first cooling unit 33, the cooled wafer 3 is unloaded from the first cooling unit 33 to the first transfer chamber 1 by the first wafer transfer device 4. The

  After the cooled wafer 3 is unloaded from the first cooling unit 33 to the first transfer chamber 1, the gate valve 9 is opened. The first wafer transfer device 4 transports the wafer 3 unloaded from the first cooling unit 33 to the second preliminary chamber 7 and transfers it to the substrate table 12. It is closed by the gate valve 9.

  By repeating the above operation, a predetermined number of, for example, 25 wafers 3 carried into the first preliminary chamber 6 are sequentially processed.

  The processing for all the wafers 3 carried into the first preliminary chamber 6 is completed, all the processed wafers 3 are stored in the second preliminary chamber 7, and the second preliminary chamber 7 is stored in the gate valve 9. When closed by the above, the inside of the second preliminary chamber 7 is returned to the substantially atmospheric pressure by the inert gas. When the inside of the second preliminary chamber 7 is returned to substantially atmospheric pressure, the gate valve 15 is opened, and the lid 27 of the empty pod 26 placed on the IO stage 25 is opened by the pod opener 24. . Subsequently, the second wafer transfer device 16 picks up the wafer 3 from the substrate mounting table 12, carries it out to the second transfer chamber 13, and stores it in the pod 26 through the wafer carry-in / out port 23. When the storage of the 25 processed wafers 3 into the pod 26 is completed, the lid 27 of the pod 26 is closed by the pod opener 24. The pod 26 is transferred from the IO stage 25 to the next process by the in-process transfer device.

  The above operation has been described by taking the case where the first processing furnace 28 and the first cooling unit 33 are used as an example, but also when the second processing furnace 29 and the second cooling unit 34 are used. Similar operations are performed. In the above-described substrate processing apparatus, the first preliminary chamber 6 is used for carrying in and the second preliminary chamber 7 is used for carrying out. However, the second preliminary chamber 7 is used for carrying in, and the first preliminary chamber 6 is carried out. It may be used.

  In addition, the first processing furnace 28 and the second processing furnace 29 may perform the same processing, or may perform different processing. When the first processing furnace 28 and the second processing furnace 29 perform different processing, for example, after the processing on the wafer 3 is performed in the first processing furnace 28, another processing is performed in the second processing furnace 29. Processing may be performed. In addition, when a process is performed on the wafer 3 in the first processing furnace 28 and then another process is performed in the second processing furnace 29, the first processing unit 28 passes through the first cooling unit 33 or the second cooling unit 34. You may do it.

  Next, an example of a processing furnace used in the substrate processing apparatus will be described.

  FIG. 3 shows a processing furnace of a single wafer processing apparatus in which a remote plasma unit is incorporated. The first processing furnace 28 and the second processing furnace 29 have the same configuration, and the first processing furnace 28 (hereinafter referred to as the processing furnace 28) will be described below.

  As shown in FIG. 3, a support base 43 that supports a substrate to be processed is provided in a processing chamber 42 formed by the processing container 41. A susceptor 44 as a support plate for supporting the substrate is provided on the upper portion of the support base 43. A heater 45 as a heating mechanism (heating means) is provided inside the support base 43, and the wafer 3 placed on the susceptor 44 is heated by the heater 45. The heater 45 is controlled by a temperature controller 46 as a temperature control unit (temperature control means) so that the substrate temperature becomes a predetermined temperature. The substrate placed on the susceptor 44 is, for example, a semiconductor wafer or a glass substrate.

  A rotation mechanism (rotation means) 47 is provided outside the processing chamber 42, and the support base 43 is rotated by the rotation mechanism 47 to rotate the wafer 3 on the susceptor 44. Further, an elevating mechanism (elevating means) 48 is provided outside the processing chamber 42, and the support base 43 can be moved up and down by the elevating mechanism 48.

  A shower head 51 having a plurality of holes 49 as gas ejection holes is provided at the upper portion of the processing chamber 42 so as to face the susceptor 44. The shower head 51 is divided into two chambers, that is, a source gas supply unit 52 and an activation gas supply unit 53, and a source gas and an activation gas to be described later are supplied from the divided gas supply units 52 and 53, respectively. These can be sprayed separately on the wafer 3 in the form of a shower. The source gas supply unit 52 and the activation gas supply unit 53 constitute separate supply ports for supplying the source gas and the activation gas to the wafer 3, respectively. The source gas and the activation gas are not mixed in the shower head 51.

  A first raw material supply source 54 that supplies a first raw material that is a liquid raw material is provided outside the processing chamber 42, and a liquid raw material supply pipe 55 is connected to the first raw material supply source 54. The liquid raw material supply pipe 55 is connected to a vaporizer 57 that vaporizes the first raw material via a liquid flow rate controller 56 as a flow rate control device (flow rate control means) that controls the liquid supply flow rate of the first raw material. .

  As the first raw material, for example, an organometallic material that is liquid at room temperature, that is, an organometallic liquid raw material is used.

  When the hafnium silicate film is formed, the first source gas is a gas obtained by vaporizing a liquid source containing Hf and a liquid source containing Si. Examples of the first source gas include Hf-OtBu and Hf. -Various chemical substances such as MMP, Si-MMP and TEOS are used in combination. Here, a mixed raw material in which Hf-MMP and Si-MMP are mixed in a liquid state is used as the first raw material.

  A source gas supply pipe 58 is connected to the vaporizer 57, and the source gas supply pipe 58 is connected to the source gas supply unit 52 of the shower head 51 through a valve 59.

  An inert gas supply source 61 that supplies an inert gas as a non-reactive gas is provided outside the processing chamber 42, and an inert gas supply pipe 62 is connected to the inert gas supply source 61. Yes. The inert gas supply pipe 62 is connected to the source gas supply pipe 58 via a gas flow rate controller 63 and a valve 64 as a flow rate control device (flow rate control means) for controlling the supply flow rate of the inert gas. As the inert gas, for example, Ar, He, N2 or the like is used.

  The source gas supply pipe 58 is connected to the source gas supply section 52 of the shower head 51, the first source gas vaporized by the vaporizer 57, that is, the source gas, and the inert gas from the inert gas supply pipe 62. To supply. The gas from the source gas supply pipe 58 and the inert gas supply pipe 62 can be controlled by opening and closing the valves 59 and 64.

  Outside the processing chamber 42, a remote plasma unit 65 is provided as an activation mechanism (activation means) for activating gas with plasma. A gas supply pipe 66 is provided on the upstream side of the remote plasma unit 65. The gas supply pipe 66 includes a second raw material supply source 67 for supplying a second raw material, a plasma ignition gas supply source 68 for supplying a gas for generating plasma, and a cleaning gas supply source 69 for supplying a cleaning gas. These are connected via supply pipes 71, 72, 73, respectively, so that each gas is supplied to the remote plasma unit 65. The supply pipes 71, 72, 73 are provided with gas flow rate controllers 74, 75, 76 for controlling the supply flow rates of the respective gases, and valves 77, 78, 79, respectively. Each gas supply can be controlled by opening and closing the valves 77, 78, and 79.

  As the second raw material, a gas containing oxygen atoms (O) and a gas containing hydrogen atoms (H) are used. For example, argon (Ar) gas is used as the plasma ignition gas. As the cleaning gas, for example, a gas containing fluorine atoms (F) or a gas containing chlorine atoms (Cl) is used.

  Here, the gas containing oxygen atoms (O) is at least one gas selected from the group consisting of O2, N2 O and NO, and the gas containing hydrogen atoms (H) consists of H2 and NH3. At least one gas selected from the group. Here, O2 is used as a gas containing oxygen atoms, and H2 is used as a gas containing hydrogen atoms.

  An activated gas supply pipe 81 is provided on the downstream side of the remote plasma unit 65. The activated gas supply pipe 81 is connected to the activated gas supply unit 53 via a valve 82, and the activated gas is supplied to the activated gas supply unit 53 by the remote plasma unit 65, that is, an activated gas. To supply. The supply of the activated gas can be controlled by opening and closing the valve 82 provided in the activated gas supply pipe 81.

  An exhaust port 83 is provided in the lower side wall of the processing container 41, and an exhaust pipe 84 is communicated with the exhaust port 83. The exhaust pipe 84 has a vacuum pump 85 as an exhaust device (exhaust means), an abatement device. (Not shown) is connected. The exhaust pipe 84 is provided with a pressure controller 86 as a pressure control unit (pressure control means) for controlling the pressure in the processing chamber 42 and a raw material recovery trap 87 for recovering the raw material. The exhaust port 83, the exhaust pipe 84, the vacuum pump 85, and the like constitute an exhaust system. The raw material recovery trap 87 can be omitted if recovery of the raw material is not required. For example, when it is difficult to liquefy and solidify the raw material and its reaction by-products, conversely, it is possible to treat all by the detoxifying device without liquefying and solidifying by the route to the detoxifying device.

  A plate 88 as a current plate for adjusting the flow of gas supplied from the shower head 51 is provided on the support base 43 in the processing chamber 42. The plate 88 has an annular shape and is provided around the substrate. The gas supplied from the shower head 51 to the wafer 3 flows radially outward of the wafer 3, passes over the plate 88, and passes between the plate 88 and the side wall (inner wall) of the processing vessel 41. The air is exhausted from the exhaust port 83. In addition, when there is a portion where it is not desired to form a film on the wafer 3 such as the outer peripheral portion of the substrate, the inner diameter of the plate 88 may be made smaller than the outer diameter of the wafer 3 to cover the outer peripheral portion of the wafer 3. . In this case, in order to enable substrate transfer, the plate 88 may be fixed at a substrate processing position in the processing chamber 42, or a mechanism for moving the plate 88 up and down may be provided.

  The source gas supply pipe 58 and the activation gas supply pipe 81 are provided with a source gas bypass pipe 89 and an activation gas bypass pipe 91 connected to the source recovery trap 87 provided in the exhaust pipe 84, respectively. . The source gas bypass pipe 89 and the activated gas bypass pipe 91 are provided with valves 92 and 93, respectively.

  A substrate loading / unloading port 95 that is opened and closed by a gate valve 94 as a gate valve is provided on the side wall facing the exhaust port 83, and the wafer 3 can be loaded into and unloaded from the processing chamber 42 through the substrate loading / unloading port 95. It is configured like this.

  The valves 59, 64, 77, 78, 79, 82, 92, 93, the flow controllers 56, 63, 74, 75, 76, the temperature controller 46, the pressure controller 86, the vaporizer 57, the remote plasma unit 65, the operation of each part of the substrate processing apparatus such as the rotation mechanism 47 and the lifting mechanism 48 is controlled by a main controller 96 as a main control unit (main control means).

  Next, a method of depositing a thin film on a substrate as one step of a semiconductor device manufacturing process using the processing furnace having the configuration as shown in FIG. 3 will be described. In this embodiment mode, an organic metal liquid raw material that is liquid at room temperature is used, and a CVD (Chemical Vapor Deposition) method, particularly a MOCVD (Metal Organic Chemical Vapor Deposition) method, or an ALD (Atomic Layer Deposition) method is used. A case where a thin film such as a metal film or a metal oxide film is formed will be described.

  In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the main controller 96.

  When the gate valve 94 is opened and the substrate loading / unloading port 95 is opened while the support base 43 is lowered to the substrate transfer position, the wafer 3 is transferred by the first wafer transfer device 4 (see FIG. 1). Are loaded into the processing chamber 42 (substrate loading step). After the wafer 3 is loaded into the processing chamber 42 and placed on a push-up pin (not shown), the gate valve 94 is closed. The support base 43 rises from the substrate transfer position to the substrate processing position above it. In the meantime, the wafer 3 is mounted on the susceptor 44 from above the push-up pins (substrate mounting step).

  When the support table 43 reaches the substrate processing position, the wafer 3 is rotated by the rotation mechanism 47. Further, electric power is supplied to the heater 45, and the wafer 3 is uniformly heated so as to reach a predetermined processing temperature (substrate heating step). At the same time, the inside of the processing chamber 42 is evacuated by the vacuum pump 85 and controlled so as to have a predetermined processing pressure (pressure adjusting step). Note that the valve 64 provided in the inert gas supply pipe 62 is always open when the substrate is transported, when the temperature of the substrate is increased, or when the pressure is adjusted, and the processing is performed from the inert gas supply source 61. An inert gas always flows into the chamber 42. Thereby, adhesion of particles or metal contaminants to the wafer 3 can be prevented.

  When the temperature of the wafer 3 and the pressure in the processing chamber 42 reach a predetermined processing temperature and a predetermined processing pressure, respectively, and stabilize, the source gas is supplied into the processing chamber 42. That is, the organometallic liquid raw material as the first raw material supplied from the first raw material supply source 54 is flow-controlled by the liquid flow controller 56 and supplied to the vaporizer 57 for vaporization. The valve 92 is closed and the valve 59 is opened, and the vaporized first raw material, that is, the raw material gas passes through the raw material gas supply pipe 58 and passes through the raw material gas supply unit 52 of the shower head 51 to the wafer. 3 is supplied. Also at this time, the valve 64 is kept open, and an inert gas is always flowed into the processing chamber 42. The raw material gas and the inert gas are mixed in the raw material supply pipe 58, guided to the raw material gas supply unit 52, and supplied in a shower form onto the wafer 3 on the susceptor 44 (raw material gas supply step). The source gas is easily stirred by being diluted with an inert gas.

  After supplying the source gas for a predetermined time, the valve 59 is closed and the supply of the source gas to the wafer 3 is stopped. Also at this time, since the valve 64 remains open, the supply of the inert gas into the processing chamber 42 is maintained. Thereby, the inside of the processing chamber 42 is purged with the inert gas, and the residual gas in the processing chamber 42 is removed (purge process).

  At this time, it is preferable not to stop the supply of the raw material gas from the vaporizer 57 by opening the valve 92 and exhausting the raw material gas from the bypass pipe 89. Since it takes time to vaporize the liquid raw material and to stably supply the vaporized raw material gas, it is allowed to bypass the processing chamber 42 without stopping the supply of the raw material gas from the vaporizer 57. In other words, in the next source gas supply process, the source gas can be immediately supplied to the wafer 3 by simply switching the flow.

  After purging the processing chamber 42 for a predetermined time, an activation gas is supplied into the processing chamber 42. That is, the valve 78 is opened, and Ar gas as plasma ignition gas supplied from the plasma ignition gas supply source 68 passes through the supply pipe 72 and is controlled in flow rate by the gas flow rate controller 75. Supplied to the remote plasma unit 65, Ar plasma is generated. After the Ar plasma is generated, the valve 77 is opened, the second raw material supplied from the second raw material supply source 67 passes through the supply pipe 71, the flow rate is controlled by the gas flow rate controller 74, and the Ar plasma is The generated remote plasma unit 65 is supplied and the second raw material is activated by the plasma. Thereby, reactive species such as O radical (oxygen active species) and OH radical (hydroxyl active species) are generated.

  The valve 93 is closed and the valve 82 is opened. A gas obtained by activating the second raw material from the remote plasma unit 65 by plasma, that is, an activated gas passes through an activated gas supply pipe 81 and passes through the activated gas. It is supplied as a shower onto the wafer 3 via the supply unit 53 (activated gas supply step). At this time, the valve 64 is kept open, and an inert gas is always supplied into the processing chamber 42. The activated gas containing O radicals and OH radicals has a role as an oxidizing agent, and oxidizes using O radicals and OH radicals generated by activating O2 and H2 by the remote plasma unit 65. The treatment is also referred to as remote plasma oxidation treatment (RPO: Remote Plasma Oxidation).

  After supplying the activation gas for a predetermined time, the valve 82 is closed and the supply of the activation gas to the wafer 3 is stopped. Also at this time, since the valve 64 remains open, the supply of the inert gas into the processing chamber 42 is maintained. Thereby, the inside of the processing chamber 42 is purged with the inert gas, and the residual gas in the processing chamber 42 is removed (purge process).

  At this time, it is preferable not to stop the supply of the activated gas from the remote plasma unit 65 by opening the valve 93 and exhausting the activated gas from the bypass pipe 91. Since it takes time until the activation gas is stably supplied, if the process chamber 42 is allowed to flow without stopping the supply of the activation gas from the remote plasma unit 65, the next activation In the activated gas supply process, the activated gas can be immediately supplied to the wafer 3 by simply switching the flow.

  After purging the processing chamber 42 for a predetermined time, the valve 92 is closed and the valve 59 is opened again, and the vaporized first raw material, that is, the raw material gas, together with the inert gas, is added to the shower head 51. The material gas is supplied onto the wafer 3 via the material gas supply unit 52, and a material gas supply process is performed.

  The raw material gas supply process, the purge process, the activation gas supply process, and the purge process as described above are performed as one cycle, and a thin film having a predetermined film thickness is formed on the wafer 3 by performing cycle processing that repeats this cycle a plurality of times. It can be formed (thin film forming step).

  After completion of the thin film formation process on the wafer 3, the rotation of the wafer 3 by the rotating mechanism 47 is stopped, and the processed wafer 3 is carried out of the processing chamber 42 in the reverse procedure of the substrate carrying-in process (substrate carrying-out process). ).

  When the thin film forming step is performed by the CVD method, the processing temperature is controlled to be a temperature range in which the source gas is self-decomposed. In this case, in the raw material gas supply step, the raw material gas is thermally decomposed to form a thin film of about several atomic layers or less (about 10 mm or less) on the wafer 3. During this time, since the wafer 3 is kept at a predetermined temperature while rotating, a uniform film can be formed over the substrate surface. In the activated gas supply process, impurities such as carbon atoms (C) and hydrogen atoms (H) are removed from the thin film of about several atomic layers or less (about 10 mm or less) formed on the wafer 3 by the activated gas. Is done. During this time, since the wafer 3 is kept at a predetermined temperature while rotating, impurities can be quickly and uniformly removed from the thin film.

  Further, when the thin film forming process is performed by the ALD method, the processing temperature is controlled to be a temperature range in which the raw material gas is not self-decomposed. In this case, in the source gas supply step, the source gas is adsorbed on the wafer 3 without being thermally decomposed. During this time, since the wafer 3 is maintained at a predetermined temperature while rotating, the raw material can be uniformly adsorbed over the substrate surface. In the activation gas supply step, the raw material adsorbed on the wafer 3 reacts with the activation gas, whereby a thin film of about several atomic layers or less (about 10 mm or less) is formed on the wafer 3. During this time, since the wafer 3 is kept at a predetermined temperature while rotating, a uniform film can be formed over the substrate surface. At this time, impurities such as carbon atoms (C) and hydrogen atoms (H) mixed in the thin film can be desorbed by radical components contained in the activation gas.

  In the above processing furnace, the remote plasma in the case where a gas containing oxygen atoms (O) and a gas containing hydrogen atoms (H) are used as the second source gas and argon (Ar) gas is used as the plasma ignition gas. The supply of the second source gas (oxidant) and the generation state of the plasma in the unit 65 will be described with reference to FIGS.

  FIG. 4 shows a case where plasma is continuously generated by supplying an oxidizer in a pulsed manner and continuously supplying an argon gas.

  When an oxidant containing oxygen atoms and hydrogen atoms is supplied to the remote plasma unit 65 with the plasma generated, oxygen (O) radicals and hydroxyl (OH) radicals are generated and water (H2 O) is also generated. When the supply of the oxidizing agent is stopped, it may remain in the remote plasma unit 65 and the activated gas supply pipe 81.

  In the embodiment shown in FIG. 4, since plasma is continuously generated, the generated water is adsorbed on the inner wall of the remote plasma unit 65, the activated gas supply pipe 81, and the like. And is discharged without remaining in the remote plasma unit 65, the activated gas supply pipe 81, or the like.

  In the embodiment shown in FIG. 5, plasma is generated in a pulse manner. When the plasma is generated in a pulsed manner, the plasma generation is continued for a predetermined time Q after the oxidant is supplied. By continuing the generation of the plasma, the heating by the plasma is maintained, and the adsorption of the generated water to the inner wall of the remote plasma unit 65, the inner wall of the activated gas supply pipe 81, etc. is hindered by the active particles by the plasma, It is discharged without remaining in the remote plasma unit 65, the activated gas supply pipe 81 or the like.

  Since the value of the predetermined time Q varies depending on the configuration of the substrate processing apparatus, the value at which water does not remain is obtained in advance by experimentation or actual operation.

  In the present invention, following the oxidant supply step of supplying the oxidant in a pulsed manner, a step of maintaining the generation of plasma (moisture removal step, Q in FIGS. 4 and 5) is provided, so that the remote Water is prevented from remaining in the piping such as the plasma unit 65 and the activated gas supply pipe 81.

  Since moisture does not remain in the remote plasma unit 65, the activated gas supply pipe 81, and the like, the generation of plasma can be ensured, and the probability of the generation failure can be significantly reduced.

  In order to prevent moisture from remaining, it is also effective to heat the piping or to raise the temperature of the supply gas to the remote plasma unit 65 with a heat exchanger or the like. Further, by changing the supply position of the gas containing oxygen and the gas containing hydrogen, for example, the gas containing oxygen is supplied from the upstream of the remote plasma unit 65, and the gas containing hydrogen is supplied from the remote plasma unit 65. The generation of water may be suppressed so that oxygen and hydrogen are separately excited. In consideration of excitation efficiency, it is preferable to supply the remote plasma unit 65 with a mixed gas of oxygen and hydrogen for excitation.

  In the case where the CVD process is performed using the remote plasma unit 65, the present invention can be widely applied not only to the formation of hafnium silicate but also to the case where a gas containing oxygen and a gas containing hydrogen are used as the oxidizing agent.

  According to the present invention, when a CVD process is performed using a gas containing oxygen and a gas containing hydrogen, film formation can be performed stably.

  In the processing furnace of the present embodiment, the processing conditions for processing the substrate by the CVD method are, for example, when a HfSiO film is formed, a processing temperature of 350 to 500 ° C., a processing pressure of 50 to 300 Pa, Examples include a mixed solution of 1 raw material Hf-MMP and Si-MMP, supply flow rate 0.05 g / min to 0.4 g / min, total flow rate of second raw material H2 + O2 and supply flow rate H2 + O2, 10 to 500 sccm.

  In addition, as a processing condition for processing a substrate by the ALD method in the processing furnace of the present embodiment, for example, when a HfSiO film is formed, a processing temperature of 200 to 350 ° C., a processing pressure of 50 to 300 Pa, Examples include a mixed solution of 1 raw material Hf-MMP and Si-MMP, supply flow rate 0.05 g / min to 0.4 g / min, total flow rate of second raw material H2 + O2 and supply flow rate H2 + O2, 10 to 500 sccm.

(Appendix)
The present invention includes the following embodiments.

  (Supplementary note 1) Supplying a raw material gas to the substrate, supplying a gas containing oxygen atoms and a gas containing hydrogen atoms to a plasma unit in a plasma-generated state, and activating the activated gas Supplying to the substrate, and maintaining the state in which plasma is generated in the plasma unit in a state where supply of the gas containing oxygen atoms and the gas containing hydrogen atoms to the plasma unit is stopped. And forming a film on the substrate by repeating these steps a plurality of times.

  (Appendix 2) In the step of maintaining the state in which the plasma is generated in the plasma unit, the removal of moisture generated when the gas containing oxygen atoms and the gas containing hydrogen atoms are activated in the plasma unit. The manufacturing method of the semiconductor device of the additional note 1 performed.

  (Supplementary Note 3) In the step of maintaining the state where the plasma is generated in the plasma unit, the gas containing oxygen atoms and the gas containing hydrogen atoms are activated in the plasma unit by the plasma of the inert gas. The method for manufacturing a semiconductor device according to appendix 1, wherein moisture generated during the removal is removed.

  (Supplementary Note 4) The gas containing oxygen atoms is at least one gas selected from the group consisting of O2, N2 O and NO, and the gas containing hydrogen atoms is selected from the group consisting of H2 and NH3. The method of manufacturing a semiconductor device according to appendix 1, wherein the semiconductor device is at least one gas.

  (Additional remark 5) The said source gas is the gas which vaporized the liquid raw material containing Hf, and the liquid raw material containing Si, The film | membrane to form is a manufacturing method of the semiconductor device of Additional remark 1 which is a hafnium silicate film | membrane.

(Supplementary Note 6) The liquid raw material containing Hf is Hf [OC (CH3) 3] 4 (Hf-OtBu), Hf [OC (CH3) 2 CH2 OCH3] 4 (Hf-MMP), and a liquid containing Si The method of manufacturing a semiconductor device according to appendix 5, wherein the raw material is Si [OC (CH3) 2 CH2 OCH3] 4 (Si-MMP), Si (OC2 H5) 4 (TEOS).

  (Additional remark 7) It has the process of removing each gas supplied with respect to a board | substrate after each process of the process of supplying source gas with respect to a board | substrate, and the process of supplying the activated gas with respect to a board | substrate, The method of manufacturing a semiconductor device according to appendix 1, wherein the step of maintaining the state in which the plasma is generated in the plasma unit is performed in parallel with the step of removing each gas supplied to the substrate.

  (Appendix 8) A processing chamber for processing a substrate, a source gas supply pipe for supplying a source gas into the processing chamber, a plasma unit for activating the gas with plasma, a gas containing oxygen atoms in the plasma unit, hydrogen atoms A supply pipe for supplying an inert gas, an activated gas supply pipe for supplying a gas activated by plasma into the processing chamber, an exhaust pipe for exhausting the processing chamber, and oxygen to the plasma unit A substrate processing apparatus comprising: a controller that maintains a state in which plasma is generated in the plasma unit in a state where supply of a gas containing atoms and a gas containing hydrogen atoms is stopped.

1 is a plan sectional view of a substrate processing apparatus in which the present invention is implemented. It is a sectional side view of this substrate processing apparatus. It is the schematic which shows the processing furnace of this substrate processing apparatus. It is a graph which shows the 1st processing mode concerning an embodiment of the invention. It is a graph which shows the 2nd processing mode concerning an embodiment of the invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Wafer 4 1st wafer transfer machine 28 1st processing furnace 29 2nd processing furnace 41 Processing container 43 Support stand 51 Shower head 54 1st raw material supply source 56 Liquid flow controller 57 Vaporizer 61 Inert gas supply source 63 Gas flow rate Controller 65 Remote plasma unit 67 Second raw material supply source 68 Plasma ignition gas supply source 69 Cleaning gas supply source 74 Gas flow controller 75 Gas flow controller 76 Gas flow controller 85 Vacuum pump 86 Pressure controller 87 Raw material recovery trap

Claims (1)

  A step of supplying a source gas to the substrate, and a plasma unit in a state where plasma is generated are activated by supplying a gas containing oxygen atoms and a gas containing hydrogen atoms, and the activated gas is supplied to the substrate. And a step of maintaining a state in which plasma is generated in the plasma unit in a state where supply of a gas containing oxygen atoms and a gas containing hydrogen atoms to the plasma unit is stopped. A method of manufacturing a semiconductor device, wherein a film is formed on a substrate by repeating the step of a plurality of times.

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