JP2010283153A - Method for manufacturing semiconductor device, heat treatment apparatus, and member for heat treatment - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a semiconductor device which extends the life of a peeling phenomenon by suppressing the growth of an oxide film of a member in a region for processing a substrate and improve productivity by extending the frequency of maintenance, and provide a heat treatment apparatus and a member for heat treatment. <P>SOLUTION: A method for manufacturing a semiconductor device includes: a process of supplying a nitrogen-containing gas into a reaction vessel having silicon or silicon carbide at least at a part of a surface to nitride at least a part of the surface; a process of conveying the substrate into the reaction vessel; and a process of heat-treating the substrate in the reaction vessel having the nitrided surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a semiconductor device manufacturing method, a heat treatment apparatus, and a heat treatment member used for heat treatment of, for example, a semiconductor wafer and a glass substrate.

  An SOI (Silicon On Insulator) wafer is attracting attention as a semiconductor substrate that enables high performance of semiconductor devices. This is because by adopting an SOI structure and embedding an oxide film under the single crystal silicon thin film, parasitic capacitance can be reduced, operation speed can be improved, and power consumption can be suppressed. The buried oxide film is required to have a thickness of several μm or more, and a batch type high temperature oxidation apparatus capable of oxidizing a large number of wafers at a high temperature for a long time is used.

  Quartz material is used for the conventional reaction chamber component, but the quartz material is deformed by heat treatment for a long time at a high temperature, and it is necessary to frequently replace the in-furnace component. Further, the buried oxide film used in the optical device, sensor, and power device is required to be thicker. In this case, the lifetime of the quartz member is further shortened. In order to prevent the deformation of the quartz material, there is also a furnace provided with a reaction chamber in which the quartz member is replaced with SiC (silicon carbide) or Si (silicon) material. However, when SiC or Si material is used, an oxide film grows on the surface of the SiC or Si material simultaneously with the formation of the buried oxide film on the wafer. When the oxide film is formed thick on the SiC or Si material, the oxide film is peeled off due to a difference in thermal expansion between the oxide film and the SiC or Si material, which causes generation of particles. The generation of particles may include contamination of the oxide film during the formation of the buried oxide film, which may adversely affect the film thickness uniformity. In other words, when a thick oxide film is formed with an in-furnace structure using SiC or Si material, it is necessary to periodically remove the oxide film of the in-furnace component.

  For example, a vertical heat treatment apparatus used to oxidize or anneal a substrate such as a silicon wafer, and the operating temperature in the processing furnace is about 1000 ° C. or more, and a SiC (silicon carbide) boat is used. The technology used is one in which the operating temperature in the processing furnace exceeds 1200 ° C., and a technology using a SiC reaction tube and a SiC gas introduction nozzle is known. These techniques are known in which a SiC film is coated in advance on the surface of a SiC member such as a SiC boat, a SiC reaction tube, and a SiC gas introduction nozzle. (For example, refer to Patent Document 1).

JP 9-235163 A

However, when the surface of the SiC or Si member is exposed (including the SiC (CVD) coated state and the oxide film deposited state), the base material is immediately oxidized and modified to SiO ₂ . Resulting in. Since the SiO ₂ film is scraped by the subsequent wet etching process, the thickness of the SiC or Si member is steadily reduced. As a result, the replacement frequency of SiC and Si members such as the reaction vessel is increased. Further, since the SiC member contains a metal component such as Fe (iron) or Al (aluminum) in the base material, when the SiC-CVD film on the surface is peeled off, the metal component diffuses into the reaction vessel, and the substrate Contaminated with metal components. Further, when a nitride film is coated on a SiC or Si member, the nitride film is easily peeled off at a high temperature of 1,200 ° C. or higher.

  It is an object of the present invention to manufacture a semiconductor device capable of suppressing the peeling phenomenon by suppressing oxide film growth of a member in a region where a substrate is processed, extending the life of the member, extending the maintenance frequency, and improving productivity. It is providing the method, the heat processing apparatus, and the member for heat processing.

  According to one aspect of the present invention, a step of supplying a nitrogen-containing gas into a reaction vessel having silicon or silicon carbide on at least a part of the surface and nitriding at least a part of the surface; There is provided a method for manufacturing a semiconductor device, which includes a step of carrying a substrate and a step of heat-treating the substrate in the reaction vessel having the nitrided surface.

  According to the present invention, a semiconductor device capable of suppressing the oxide film growth of a member in a region where a substrate is processed, suppressing a peeling phenomenon, extending the life of the member, extending the maintenance frequency, and improving the productivity. A manufacturing method, a heat treatment apparatus, and a member for heat treatment can be provided.

It is a perspective view which shows the whole heat processing apparatus which concerns on embodiment of this invention. It is sectional drawing which shows the reaction furnace used for the heat processing apparatus which concerns on embodiment of this invention. An example of the process sequence used for the heat processing apparatus which concerns on embodiment of this invention is shown. It is sectional drawing which shows the surface vicinity of the reaction container used for the heat processing apparatus which concerns on embodiment of this invention. (A) concerning the 2nd Embodiment of this invention shows a processing sequence, (b) is sectional drawing which shows the surface vicinity of the reaction container formed using the processing sequence of (a). (A) which concerns on the 4th Embodiment of this invention shows a processing sequence, (b) is sectional drawing which shows the surface vicinity of the reaction container formed using the processing sequence of (a). (A) which concerns on the 5th Embodiment of this invention shows a processing sequence, (b) is sectional drawing which shows the surface vicinity of the reaction container formed using the processing sequence of (a). It is sectional drawing of the SiC member coated with the SiC-CVD film | membrane, and shows the change of the member when the surface is exposed to oxygen atmosphere. It is a figure which shows the relationship with the oxide film thickness formed in the SiC member for every oxidation process on Si substrate. It is a figure which shows the relationship between the oxide film thickness on a SiC member, and the foreign material generation amount. It shows the relationship between the temperature difference the _Si 3 _{N 4} film thickness and the furnace when the surface of the SiC member is coated with _{the Si} 3 _{N 4} film.

Next, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an example of a heat treatment apparatus 10 according to an embodiment of the present invention. This heat treatment apparatus 10 is a batch type vertical heat treatment apparatus and has a casing 12 in which a main part is arranged. A pod stage 14 is connected to the front side of the housing 12, and the pod 16 is conveyed to the pod stage 14. For example, 25 substrates (wafers) 54 (see FIG. 2) are stored in the pod 16 and set on the pod stage 14 with a lid (not shown) closed.

A pod transfer device 18 is disposed on the front side in the housing 12 and at a position facing the pod stage 14. Further, a pod shelf 20, a pod opener 22, and a substrate number detector 24 are arranged in the vicinity of the pod transfer device 18. The pod shelf 20 is disposed above the pod opener 22, and the substrate number detector 24 is disposed adjacent to the pod opener 22. The pod carrying device 18 carries the pod 16 among the pod stage 14, the pod shelf 20, and the pod opener 22. The pod opener 22 opens the lid of the pod 16, and the number of substrates 54 in the pod 16 with the lid opened is detected by the substrate number detector 24.

  Further, a substrate transfer machine 26, a notch aligner 28, and a support tool (boat) 30 are disposed in the housing 12. The substrate transfer machine 26 has an arm (tweezer) 32 that can take out, for example, five substrates 54. By moving this arm 32, a pod placed at the position of the pod opener 22, a notch aligner 28, and The substrate 54 is transferred between the supports 30. The notch aligner 28 detects notches or orientation flats formed on the substrate 54 and aligns the notches or orientation flats of the substrate 54 at a certain position.

  Further, a reaction furnace 40 is disposed at the upper part on the back side in the housing 12. In the reaction furnace 40, the support 30 loaded with a plurality of substrates 54 is inserted by an elevator 48a (see FIG. 2) as a transport unit and subjected to heat treatment.

  An example of the reaction furnace 40 is shown in FIG. The reaction furnace 40 has a reaction tube 42 made of silicon carbide (SiC). The reaction tube 42 has a cylindrical shape in which the upper end is closed and the lower end is opened, and the opened lower end is formed in a flange shape. A quartz adapter 44 is disposed below the reaction tube 42 so as to support the reaction tube 42. The adapter 44 has a cylindrical shape with an open upper end and a lower end, and the open upper end and the lower end are formed in a flange shape. The lower surface of the lower end flange of the reaction tube 42 is in contact with the upper surface of the upper end flange of the adapter 44. A reaction vessel 43 is formed by the reaction tube 42 and the adapter 44. In addition, a heater 46 that is a heating unit that heats the inside of the reaction vessel is disposed around the reaction tube 42 excluding the adapter 44 in the reaction vessel 43.

  The lower part of the reaction vessel 43 formed by the reaction tube 42 and the adapter 44 is opened to insert the support 30, and this open part (furnace port part) is an adapter with the furnace port seal cap 48 sandwiching the O-ring. It is made to seal by contacting the lower surface of the lower end flange of 44. The furnace port seal cap 48 supports the support tool 30 via a support tool receiver 53 as a support tool receiving member, and is provided so as to be movable up and down together with the support tool 30. Between the furnace port seal cap 48 and the support 30, there is a first heat insulating member 52 made of quartz and a second heat insulating member 50 made of SiC disposed on the upper portion of the first heat insulating member 52. Is provided. The support 30 is made of SiC, supports a large number of, for example, 25 to 100 substrates 54 in a substantially horizontal state with a plurality of gaps, and is loaded into the reaction tube 42.

  In order to enable processing at a high temperature of 1200 ° C. or higher, the reaction tube 42 is made of SiC. When this SiC reaction tube 42 is extended to the furnace port portion, and this furnace port portion is sealed with a furnace port seal cap via an O-ring, the seal portion is sealed by the heat transmitted through the SiC reaction tube. The O-ring that is a sealing material may be melted. If the seal part of the reaction tube 42 made of SiC is cooled so as not to melt the O-ring, the reaction tube 42 made of SiC is damaged due to a difference in thermal expansion due to a temperature difference. In view of this, the heating region by the heater 46 of the reaction vessel 43 is configured by the SiC reaction tube 42, and the portion outside the heating region by the heater 46 is configured by the quartz adapter 44, whereby the SiC reaction tube 42 is formed. It is possible to soften the transfer of heat from the furnace and seal the furnace port without melting the O-ring and damaging the reaction tube 42. Further, if the seal between the SiC reaction tube 42 and the quartz adapter 44 is improved in both surface accuracy, a temperature difference occurs because the SiC reaction tube 42 is disposed in the heating region of the heater 46. Without thermal expansion. Therefore, the flange portion at the lower end of the reaction tube 42 made of SiC can be kept flat, and no gap is formed between the adapter 44 and the sealing property can be obtained simply by placing the reaction tube 42 made of SiC on the adapter 44 made of quartz. Can be secured.

The adapter 44 is provided with a gas supply port 56 and a gas exhaust port 59 integrally with the adapter 44. Gas introduction pipes 80, 81, 82, 83 are connected to the gas supply port 56, and an exhaust pipe 62 is connected to the gas exhaust port 59, respectively. An oxygen-containing gas supply unit 80a, a valve 80b, and a mass flow controller 80c as a flow rate controller are connected to the gas introduction pipe 80 in order from the upstream side. An inert gas supply unit 81a, a valve 81b, and a mass flow controller 81c as a flow rate controller are connected to the gas introduction pipe 81 in order from the upstream side. A chlorine-containing gas supply unit 82a, a valve 82b, and a mass flow controller 82c as a flow rate controller are connected to the gas introduction pipe 82 in order from the upstream side. A nitrogen-containing gas supply unit 83a, a valve 83b, and a mass flow controller 83c as a flow rate controller are connected to the gas introduction pipe 83 in order from the upstream side. The oxidizing gas supply system is mainly configured by the gas introduction pipe 80, the oxygen-containing gas supply unit 80a, the valve 80b, and the mass flow controller 80c. Further, an inert gas supply system is mainly configured by the gas introduction pipe 81, the inert gas supply unit 81a, the valve 81b, and the mass flow controller 81c. In addition, a chlorine-based gas supply system is mainly configured by the gas introduction pipe 82, the chlorine-containing gas supply unit 82a, the valve 82b, and the mass flow controller 82c. Further, a nitriding gas supply system is mainly configured by the gas introduction pipe 83, the nitrogen-containing gas supply unit 83a, the valve 83b, and the mass flow controller 83c. For example, O ₂ (oxygen), O ₃ (ozone), H ₂ O (water vapor), or the like is used as the oxygen-containing gas supplied from the oxygen-containing gas supply unit 80a. Further, as the inert gas supplied from the inert gas supply unit 81a, for example, Ar (argon), _{N 2} (nitrogen) or the like is used. Moreover, as chlorine containing gas supplied from the chlorine containing gas supply unit 82a used as the cleaning gas in the furnace, HCl (hydrogen chloride), Cl ₂ (chlorine), SiH ₂ Cl ₂ (dichlorosilane) _, DCE (dichloroethylene), etc. Is used. Further, N ₂ (nitrogen), NO (nitrogen monoxide), N ₂ O (dinitrogen monoxide), NH ₃ (ammonia), or the like is used as the nitrogen-containing gas supplied from the nitrogen-containing gas supply unit 83a.

  The inner wall of the adapter 44 is on the inner side (projects) from the inner wall of the reaction tube 42, and the side wall (thick part) of the adapter 44 communicates with the gas supply port 56, and the gas introduction path 64 extends in the vertical direction. The nozzle mounting hole is provided in the upper part so as to open upward. The nozzle mounting hole is opened on the upper surface of the adapter 44 on the upper end flange side inside the reaction tube 42 and communicates with the gas supply port 56 and the gas introduction path 64. A SiC nozzle 66 is inserted and fixed in the nozzle mounting hole. That is, the nozzle 66 is connected to the upper surface of the portion of the adapter 44 that protrudes inward from the inner wall of the reaction tube 42 in the reaction tube 42, and the nozzle 66 is supported by the upper surface of the adapter 44. With this configuration, the nozzle connection portion is not easily deformed by heat and is not easily damaged. Further, there is an advantage that the assembly and disassembly of the nozzle 66 and the adapter 44 are facilitated. The processing gas introduced into the gas supply port 56 from the gas introduction pipes 80, 81, 82, 83 is supplied into the reaction tube 42 through a gas introduction path 64 and a nozzle 66 provided on the side wall of the adapter 44. . The nozzle 66 is configured to extend along the inner wall of the reaction tube 42 above the upper end of the substrate arrangement region, that is, above the upper end of the support 30.

Next, the operation of the heat treatment apparatus 10 configured as described above will be described.
In the following description, the operation of each part constituting the substrate processing apparatus is controlled by the controller 70.

  First, when the pod 16 containing a plurality of substrates 54 is set on the pod stage 14, the pod 16 is transferred from the pod stage 14 to the pod shelf 20 by the pod transfer device 18 and stocked on the pod shelf 20. Next, the pod 16 stocked on the pod shelf 20 is transported and set to the pod opener 22 by the pod transport device 18, the lid of the pod 16 is opened by the pod opener 22, and the pod 16 is detected by the substrate number detector 24. The number of substrates 54 accommodated in is detected.

  Next, the substrate transfer machine 26 takes out the substrate 54 from the pod 16 at the position of the pod opener 22 and transfers it to the notch aligner 28. In the notch aligner 28, the notch is detected while rotating the substrate 54, and the notches of the plurality of substrates 54 are aligned at the same position based on the detected information. Next, the substrate transfer machine 26 takes out the substrate 54 from the notch aligner 28 and transfers it to the support 30.

In this way, when one batch of the substrates 54 is transferred to the support 30, for example, the support having a plurality of substrates 54 loaded in the reaction furnace 40 (reaction vessel 43) set to a temperature of about 600 ° C. 30 is charged, and the inside of the reaction furnace 40 is sealed with a furnace port seal cap 48. Next, the furnace temperature is raised to the heat treatment temperature, the valve 80 b is opened, and the oxygen-containing gas is introduced into the reaction vessel 43. The oxygen-containing gas is supplied from the oxygen-containing gas supply unit 80a through the valve 80b and the mass flow controller 80c, from the gas introduction pipe 80 to the gas supply port 56, the gas introduction path 64 provided in the side wall of the adapter 44, and the nozzle 66. A processing gas is introduced into the reaction tube 42 (oxidation process). Instead of this, the gas 80 may be opened by opening the valve 80b and the valve 81b and introducing an inert gas into the reaction vessel 43 in addition to the oxygen-containing gas. The processing gas includes nitrogen (N ₂ ), argon (Ar), hydrogen (H ₂ ), oxygen (O ₂ ), water vapor (H ₂ O), ozone (O ₃ ), and the like. Note that the flow rate of the processing gas is controlled to be a preset flow rate by the mass flow controllers 80c and 81c. When the substrate 54 is heat-treated, the substrate 54 is heated to a temperature of, for example, about 1200 ° C. or higher.

  When the heat treatment of the substrate 54 is completed, for example, the temperature in the furnace is lowered to a temperature of about 600 ° C., and then the support tool 30 supporting the substrate 54 after the heat treatment is unloaded from the reaction furnace 40 and supported by the support tool 30. The support 30 is kept in a predetermined position until all the substrates 54 are cooled.

  Next, when the substrate 54 of the support tool 30 that has been put on standby is cooled to a predetermined temperature, the substrate transfer machine 26 takes out the substrate 54 from the support tool 30 and puts it into the empty pod 16 set on the pod opener 22. Transport and store. Next, the pod conveying device 18 conveys the pod 16 containing the substrate 54 to the pod shelf 20 or the pod stage 14 to complete a series of processing (batch processing). In addition, after performing the above-described series of processes a predetermined number of times (predetermined time), or cleaning the inside of the reaction container 43 at a desired timing (cleaning process). Specifically, the cleaning process is performed as follows.

For example, the support 30 that is not loaded with the substrate 54 is inserted into the reaction furnace 40 (reaction vessel 43) set to a temperature of about 600 ° C., and the reaction vessel 43 is sealed with the furnace port seal cap 48. Next, the valve 82b is opened, and the chlorine-containing gas is supplied from the chlorine-containing gas supply unit 82a to the valve 82b, through the mass flow controller 82c, from the gas inlet pipe 82 to the gas supply port 56, the gas introduction path 64, and the nozzle 66. Introduce in. The chlorine-containing gas introduced into the reaction vessel 43 is exhausted through the gas exhaust port 59 and the exhaust pipe 62, thereby being attached to or floating in the reaction vessel 43, such as heavy metals such as iron (Fe), copper (Cu ) Etc. Here, for example, HCl (hydrogen chloride), Cl ₂ (chlorine), DCE (dichloroethylene), or the like is used as the chlorine-containing gas.

In a region where the substrate 54 in the reaction furnace 40 of the heat treatment apparatus 10 is heat treated, a member 72 (for example, the reaction tube 42, the support tool 30, the support tool receiver 53, and the second heat insulating member 50) that is a heat treatment member made of SiC. In addition, an oxide film is formed on the surface of the member 72 at the same time as an oxide film is formed by processing the substrate. When the oxide film is formed thick on the surface of the member 72, the oxide film is peeled off due to a difference in thermal expansion between the oxide film and the member 72, which causes generation of particles.
In this embodiment, before starting the substrate processing in the reaction furnace 40 in order to suppress the oxide film growth of the member 72 in the region where the substrate is processed, suppress the occurrence of the peeling phenomenon, and extend the life of the member 72. The member 72 is previously nitrided.

In FIG. 3, before starting the substrate processing in the reaction furnace 40, for example, after setting up the substrate processing apparatus, the substrate is not processed in the reaction furnace 40, or the reaction furnace 40 such as the reaction vessel 43 is configured. A sequence for nitriding the member 72 that is a heat treatment member made of SiC in advance after the member 72 is wet-cleaned is shown.
For example, an empty support tool (boat) 30 on which no substrate is loaded is inserted into the reaction furnace 40 (reaction vessel 43) set to a temperature of about 600 ° C., and the reaction vessel 43 is sealed with a furnace port seal cap 48. To do. Next, a nitrogen-containing gas is introduced into the reaction vessel 43. Specifically, the valve 83 b is opened and a nitrogen-containing gas is introduced into the reaction vessel 43. The nitrogen-containing gas passes through the nitrogen-containing gas supply unit 83a, the valve 83b, and the mass flow controller 83c, and from the gas introduction pipe 83 to the gas supply port 56, the gas introduction path 64 provided in the side wall of the adapter 44, and the nozzle 66. A nitrogen-containing gas is introduced into the reaction vessel 43. Then, the furnace temperature is raised to, for example, about 1350 ° C. with the nitrogen-containing gas filled in the reaction vessel 43. The nitrogen-containing gas is continuously supplied for about a predetermined time of about 1350 ° C., the furnace temperature is lowered to, for example, about 600 ° C., and the nitrogen-containing gas introduced into the reaction vessel 43 is supplied to the gas exhaust port 59, The gas is exhausted through the exhaust pipe 62. Here, for example, N ₂ (nitrogen), N ₂ O (dinitrogen monoxide), NO (nitrogen monoxide), NH ₃ (ammonia), or the like is used as the nitrogen-containing gas. Thereafter, an inert gas is introduced from the gas introduction pipe 81 into the reaction vessel 43 through the gas supply port 56, the gas introduction path 64, and the nozzle 66. The inert gas introduced into the reaction vessel 43 is exhausted through the gas exhaust port 59 and the exhaust pipe 62 to discharge nitrogen-containing gas from the reaction vessel 43, and the gas filled in the reaction vessel 43 is discharged. Replace with inert gas (gas purge). Here, for example, Ar (argon), N ₂ (nitrogen), or the like is used as the inert gas. Thereafter, an empty support (boat) 30 is pulled out from the reactor 40. When N ₂ (nitrogen) is used as the nitrogen-containing gas, it is not necessary to introduce an inert gas into the reaction vessel 43 and replace the gas in the reaction vessel 43.

FIG. 4 shows a cross section near the surface of the reaction vessel 43 formed by using the sequence of FIG. 3 described above.
According to the above-described operation, the surface of the SiC member 90 as the member 72 in which the SiC base material 90a in the reaction vessel 43 is coated with the SiC-CVD film (also simply referred to as the SiC film) 90b is nitrided to form SiCN or SiCON ( 90c), or a mixture of these.

  In the present embodiment, a gas introduction pipe 83 is connected to the gas supply port 56, and a nitrogen-containing gas is supplied into the reaction tube 42 via the gas introduction path 64 and the nozzle 66, as with other processing gases. However, the nitrogen-containing gas may be supplied into the reaction tube 42 through a nozzle different from the nozzle 66 by being connected to an introduction tube different from the gas introduction tubes 80, 81, 82. .

Next, as a second embodiment of the present invention, an example will be described in which the substrate is processed in the reaction vessel 43 and the member 72, which is a heat treatment member made of SiC, is nitrided.
FIG. 5A shows a processing sequence according to the second embodiment of the present invention, and FIG. 5B shows a cross section near the surface of the reaction vessel 43 formed by (a).
As shown in FIG. 5A, for example, after inserting the boat 30 on which the substrate 54 is placed in the reaction furnace 40 (reaction vessel 43) set to a temperature of about 600 ° C., the oxygen-containing gas is introduced. The temperature is raised to about 1350 ° C. Specifically, the valve 80 b is opened and an oxygen-containing gas is introduced into the reaction vessel 43. The oxygen-containing gas is supplied from the oxygen-containing gas supply unit 80a through the valve 80b and the mass flow controller 80c, and from the gas introduction pipe 80 to the reaction vessel 43 through the gas supply port 56, the gas introduction path 64 and the nozzle 66. be introduced. The oxygen-containing gas introduced into the reaction vessel 43 is exhausted through the gas exhaust port 59 and the exhaust pipe 62. Thereby, an oxide film grows on the substrate 54 and the surface of the heat treatment member 72 in the reaction vessel 43. Thereafter, after a predetermined time has passed in a state maintained at about 1350 ° C., the inside of the reaction vessel 43 is purged with gas by introducing the above-described inert gas into the reaction vessel 43. Thereafter, the nitrogen-containing gas described above is introduced into the reaction vessel 43 for a predetermined time while being maintained at about 1350 ° C. As a result, at least the surface of the heat treatment member 72 made of SiC in the reaction vessel 43 is nitrided. Thereafter, the temperature in the reaction vessel 43 is lowered to about 600 ° C. Then, the inside of the reaction vessel 43 is purged with gas by introducing the above-described inert gas into the reaction vessel 43 while keeping the inside of the reaction vessel 43 at about 600 ° C. Here, O ₂ (oxygen), H ₂ O (water vapor), O ₃ (ozone), or the like is used as the oxygen-containing gas. As the inert gas, Ar (argon), _{N 2} (nitrogen) or the like is used. As the nitrogen-containing gas, N ₂ (nitrogen), N ₂ O (dinitrogen monoxide), NO (nitrogen monoxide), NH ₃ (ammonia), or the like is used. Then, the boat 30 on which the processed substrate 54 is placed is pulled out from the reaction furnace 40.
As a result, as shown in FIG. 5B, a part of the surface of the SiC member 90 in which the SiC base material 90a of the reaction vessel 43 is coated with the SiC-CVD film 90b is modified, and the other part is deposited by SiO. _Two films 92 are formed. The interface on the side of the SiO ₂ film 92 in the SiC member 90 (SiC-CVD film 90b) is nitrided and modified to SiCN and SiCON (silicon carbonitride) 90c.

Next, as a third embodiment of the present invention, after processing the substrate in the reaction vessel 43 (heat treatment step) a predetermined number of times or for a predetermined time, further oxide film growth of the member 72 in the region where the substrate is processed The member 72 is nitrided so as to suppress the occurrence of the peeling phenomenon and extend the life of the member 72.
The sequence for nitriding the member 72 after performing the substrate processing (heat treatment step) in the reaction vessel 43 a predetermined number of times or for a predetermined time, that is, after the oxide film has grown on the member 72 is shown in FIG. It is the same.
As a result, as shown in FIG. 5B according to the second embodiment, the interface of the SiC-CVD film 90b on the SiO ₂ film 92 side in which the surface of the SiC-CVD film 90b in the SiC member 90 is modified. Is nitrided and modified to SiCN, SiCON (silicon carbonitride) 90c.

  In addition, instead of all or part of these SiC members 72 (for example, the reaction tube 42, the support member 30, the support member receiver 53, the second heat insulating member 50, the nozzle 66, etc.), Si heat treatment members are used. It may be used.

As a fourth embodiment of the present invention, a heat treatment member made of Si is used in advance before starting substrate processing in the reaction furnace 40 by using a heat treatment member made of Si instead of a member made of SiC. An example for nitriding is described. The first embodiment is generally the same as the first embodiment except that a Si heat treatment member is used instead of the SiC member.
FIG. 6A shows a processing sequence according to the fourth embodiment of the present invention, and FIG. 6B shows a cross section near the surface of the reaction vessel 43 formed by (a).
In the fourth embodiment, a Si member is used for the reaction vessel 43, and as shown in FIG. 6A, the reaction vessel 43 is emptied in a reaction furnace 40 (reaction vessel 43) set at a temperature of about 600 ° C., for example. The boat 30 is inserted, and the temperature is raised to about 1350 ° C. in a state where the reaction vessel 43 is filled with the nitrogen-containing gas. Thereafter, the temperature is maintained at about 1350 ° C. for a predetermined time, and the temperature in the reaction vessel 43 is lowered to about 600 ° C. Thereby, the Si heat treatment member 72 in the reaction vessel 43 is nitrided. Thereafter, the inert gas described above is introduced into the reaction vessel 43 to purge the inside of the furnace. Then, the empty boat 30 is pulled out from the reaction furnace 40.
As a result, as shown in FIG. 6B, the surface of the Si member 94 of the reaction vessel 43 is nitrided and modified to SiON (silicon oxynitride) 94c.

Next, as a fifth embodiment of the present invention, an example in which a substrate is processed and a member 72 that is a Si heat treatment member is nitrided will be described. The second embodiment is generally the same as the second embodiment except that a Si heat treatment member is used instead of the SiC heat treatment member.
FIG. 7A shows a processing sequence according to the fifth embodiment of the present invention, and FIG. 7B shows a cross section near the surface of the reaction vessel 43 formed by FIG.
In the fifth embodiment, Si members are used for the processing vessel 43 and the like, and as shown in FIG. 7A, the substrate is placed in the reaction furnace 40 (reaction vessel 43) set at a temperature of about 600 ° C., for example. The boat 30 on which 54 is placed is inserted, and the temperature is raised to about 1350 ° C. and maintained in a state where the reaction vessel 43 is filled with the above-mentioned oxygen-containing gas. Thereafter, the inert gas described above is introduced and purged with the inside of the reaction vessel 43 maintained at about 1350 ° C. or higher, and then a nitrogen-containing gas is introduced into the reaction vessel 43 while maintaining the temperature at about 1350 ° C. or higher. The temperature is lowered to about 600 ° C. Thereafter, the inert gas described above is introduced into the reaction vessel 43 while maintaining the temperature at about 600 ° C., and a gas purge is performed. Then, the boat 30 on which the processed substrate 54 is placed is pulled out from the reaction furnace 40.
As a result, as shown in FIG. 7B, a part of the surface of the Si member 94 of the reaction vessel 43 is modified and the other part is deposited to form an SiO ₂ film 92. The interface of the Si member 94 is It is nitrided and modified to SiON (silicon oxynitride) 94c.

Next, as a sixth embodiment of the present invention, after processing the substrate (heat treatment step) in the reaction vessel 43, which is a Si member, a predetermined number of times or for a predetermined time, The member 72 is nitrided in order to suppress further oxide film growth of the member 72 that is a heat treatment member, suppress the occurrence of the peeling phenomenon, and extend the life of the member 72.
FIG. 6 shows a sequence for nitriding the member 72 after the substrate processing (heat treatment step) is performed a predetermined number of times or for a predetermined time in the reaction vessel 43, that is, after the oxide film is grown on the member 72, as shown in FIG. It is the same.
As a result, as shown in FIG. 7B according to the fifth embodiment, a part of the surface of the Si member 94 is modified, and the other part is deposited to form a SiO ₂ film 92. The interface of the member 94 is nitrided and modified to SiON (silicon oxynitride) 94c.

It should be noted that the SiC and Si members are preferably nitrided by setting the temperature in the reaction vessel to 1350 ° C. as a suitable condition. Can be nitrided without thermal degradation. Therefore, while the temperature inside the reaction vessel is maintained at 1350 ° C., a nitrogen-containing gas may be supplied into the reaction vessel to nitride a member made of SiC or Si. If the nitrogen-containing gas is started to be supplied into the reaction vessel in the process of raising the temperature, for example, the process of raising the temperature from 600 ° C., the nitriding time is shortened and the throughput can be improved.
Further, the SiC member and the Si member may be nitrided at a temperature in the reaction vessel of 1000 ° C. or higher and 1800 ° C. or lower.

Comparative Example FIG. 8 is a cross-sectional view of an SiC member 90a coated with an SiC-CVD film 90b, and is an example showing changes in the member when the surface is exposed to an oxygen atmosphere. FIG. 9 shows the thickness of the oxide film formed on the inner wall of the reaction vessel 43 as the SiC heat treatment member 72 for each oxidation treatment (one batch) on the Si substrate 54 supported by the support 30. It is a table | surface of an example which shows these relationships. FIG. 8A shows an SiC member 90a coated with an SiC-CVD film 90b, and the film thickness of the SiC-CVD film 90b is, for example, 50 to 100 μm. By performing an oxidation process of 2 microns (μm) / batch on the Si substrate 54, as shown in FIGS. 8B and 9, the surface of the SiC member 90a coated with the SiC-CVD film 90b is formed. A SiO ₂ film 92 of about 1.4 μm is formed. If the Si substrate 54 is oxidized at 2 microns (μm) / batch without performing maintenance such as wet cleaning, 2.0 μm (μm) of SiO ₂ is formed on the inner wall of the reaction vessel 43. A film is accumulated and formed. Further, by repeating the oxidation process of 2 microns (μm) on the Si substrate 54 and performing seven batches of the oxidation process, as shown in FIGS. 8C and 9, the accumulated SiO ₂ film 92 is formed. The film thickness exceeds 4 μm. Here, FIG. 10 shows the relationship between the oxide film thickness on the SiC material and the amount of foreign matter generated. The horizontal axis represents the film thickness of the oxide film on the SiC member, and the vertical axis represents the number of foreign substances attached to one wafer (substrate) 54 supported by the support 30. ■ mark is a foreign object with a size greater than 0.10 micron (μm) and less than or equal to 0.20 micron (μm), ● mark is a size greater than 0.20 micron (μm) and less than or equal to 1.00 micron (μm) Foreign matters and ◯ marks are shown as foreign matters having a size larger than 1.00 microns (μm). As can be seen from FIG. 10, the number of foreign matters is increased from the oxide film thickness on the SiC material of about 4 to 5 μm, and the film thickness at which the oxide film peeling phenomenon occurs is estimated to be about 4 μm. That is, as shown in FIG. 9, it is understood that maintenance is required in 7 batches. Maintenance, that is, the heat treatment member 72 is removed from the reaction furnace 40, and wet cleaning with hydrofluoric acid (HF) or the like is performed to remove the oxide film (SiO ₂ film 92) as shown in FIG. The SiC-CVD film 90b oxidized by the modification is also removed. The film thickness of the removed SiC-CVD film 90b is about half the thickness of the SiO ₂ film 92, which is −2 microns (μm). That is, in a state where the surfaces of the SiC and Si members are exposed, the SiC and Si members are immediately oxidized and modified into the SiO ₂ film 92. Since the SiO ₂ film 92 is scraped by the subsequent wet etching process, the thicknesses of the SiC and Si members are steadily reduced. As a result, the replacement frequency of SiC and Si members such as the reaction vessel is increased. In general, the purity of the SiC member is inferior to that of the SiC-CVD film, and contains a large amount of metal components such as Fe and Al. Therefore, in the case of a SiC member on which a SiC-CVD film is formed, when the SiC-CVD film is removed and the SiC member is exposed on the surface, the metal component diffuses into the reaction vessel and the substrate is contaminated with the metal component. Therefore, it becomes necessary to replace it, and the replacement frequency becomes even higher.
Next, FIG. 11 shows the relationship between the Si ₃ N ₄ film thickness and the temperature difference in the furnace when the surface of the SiC member 90a is coated with a Si ₃ N ₄ film that is a nitride film. As shown in FIG. 11, when a wafer is inserted into a reaction chamber maintained at a temperature of about 600 ° C., which is a normal process, and then heated to, for example, 1200 ° C., which is a heat treatment temperature, the temperature difference ΔT becomes 600 ° C. Therefore, it is expected that film peeling occurs when the Si ₃ N ₄ film thickness is 0.8 μm or more. Therefore, it is considered that the coating of the Si ₃ N ₄ film causes a foreign matter to be generated.

As described above, in a state where the SiC or Si member is exposed (including a state where the SiC-CVD coating or an oxide film is deposited), the member is oxidized and modified to SiO _2. . Further, when the nitride film is coated on the SiC or Si member, the nitride film is peeled off at a high temperature of 1,200 ° C. or higher, whereas according to the present embodiment, the surface of the SiC or Si member or SiC, Oxidation of SiC and Si members can be delayed by nitriding the interface of Si members (including SiC-CVD coated and oxide film deposited states), suppressing the occurrence of peeling phenomenon Thus, the life of the heat treatment member can be extended, the maintenance frequency can be increased, and the productivity can be improved.

  In the above-described embodiment, the form of nitriding the surface of the SiC or Si member or the interface of the SiC or Si member with the reaction vessel 43 has been described. However, the present invention is not limited to this, and the inside of the reaction furnace 40 of the heat treatment apparatus 10 The same effect as described above can be obtained in the heat treatment member (for example, the reaction tube 42, the support tool 30, the support tool receiver 53, the second heat insulating member 50, the nozzle 66, etc.) in the region where the substrate 54 is heat treated. It is done.

The present invention is characterized by the matters described in the claims, but further includes the following matters.
(1) supplying a nitrogen-containing gas into a reaction vessel having silicon or silicon carbide on at least a part of the surface to nitride at least a part of the surface; and carrying the substrate into the reaction vessel; And a step of forming an oxide film on the substrate in the reaction vessel having the nitrided surface.
(2) The nitrogen-containing gas is any one of nitrogen (N ₂ ), dinitrogen monoxide (N ₂ O), nitric oxide (NO), and ammonia (NH ₃ ) gas. (1) A method for manufacturing a semiconductor device according to (1).
(3) In the nitriding step, at least a part of the surface of the member is modified to silicon carbonitride (SiCN, SiCON) or silicon oxynitride (SiON). .
(4) The method for manufacturing a semiconductor device according to (1), wherein the oxygen-containing gas is one of oxygen (O ₂ ), ozone (O ₃ ) gas, and water vapor (H ₂ O).
(5) The method for manufacturing a semiconductor device according to claim 1, wherein, in the heat treatment step, the substrate is heated at 1200 ° C. or higher.
(6) The method for manufacturing a semiconductor device according to (1), wherein, in the oxide film forming step, the substrate is heated at 1200 ° C. or higher.
(7) The oxide film forming step is performed one or more times, and a step of nitriding the surface of the member by supplying a nitrogen-containing gas into the reaction vessel with the substrate taken out from the reaction vessel is performed. A method for manufacturing a semiconductor device according to claim 1.
(8) The semiconductor according to (1), further comprising a step of carrying out the substrate from the reaction vessel and cleaning the inside of the reaction vessel by supplying a chlorine-containing gas into the reaction vessel after the oxide film forming step. Device manufacturing method.
(9) The method for manufacturing a semiconductor device according to (8), wherein the chlorine-containing gas is one of hydrogen chloride (HCl), chlorine (Cl ₂ ), and dichlorosilane (DCE).
(10) A heat treatment apparatus comprising a reaction vessel in which a silicon carbide film is formed on a silicon or silicon carbide member, or a silicon or silicon carbide member surface, and the substrate is processed inside, wherein the reaction vessel includes: A heat treatment apparatus in which at least a part of a member surface is modified to silicon carbonitride (SiCN, SiCON) or silicon oxynitride (SiON).
(11) An oxygen-containing gas supply unit that supplies an oxygen-containing gas into the reaction vessel is further provided, and the controller supplies the nitrogen-containing gas into the reaction vessel while heating the reaction vessel. After nitriding the surface of the member, the substrate is inserted into the reaction vessel by the transfer unit, and the nitrided member or a part of the member in which a silicon carbide film is formed on the nitrided surface is formed. The heat treatment apparatus according to claim 1, wherein an oxide film is formed on the substrate in the exposed reaction vessel.
(12) A heat treatment member having at least a part made of silicon or silicon carbide, wherein at least a part of the inner surface is modified to silicon carbonitride (SiCN, SiCON) or silicon oxynitride (SiON) Heat treatment member.
(13) A step of forming a silicon carbide film on a member made of silicon or silicon carbide, and at least a part of the surface of the member is modified to silicon carbonitride (SiCN, SiCON) or silicon oxynitride (SiON). And a method for producing a member for heat treatment.
(14) A step of forming a silicon carbide film on at least an inner surface of a reaction vessel made of silicon or silicon carbide, and at least part of the inner surface of the reaction vessel is made of silicon carbonitride (SiCN, SiCON) or silicon oxynitride And a step of modifying to (SiON).
(15) A method for manufacturing a member for heat treatment, comprising a step of modifying at least a part of a surface of a member made of silicon or silicon carbide into silicon carbonitride (SiCN, SiCON) or silicon oxynitride (SiON).
(16) A method for producing a reaction vessel comprising: modifying at least part of a surface of a member made of silicon or silicon carbide into silicon carbonitride (SiCN, SiCON) or silicon oxynitride (SiON).

DESCRIPTION OF SYMBOLS 10 Heat processing apparatus 30 Support tool 40 Reaction furnace 42 Reaction tube 43 Reaction vessel 60 Gas introduction tube 90 SiC member 90a SiC base material 90b SiC-CVD film | membrane 90c SiCN, SiCON
92 SiO ₂ film 94 Si member 94c SiON

Claims (3)

Supplying a nitrogen-containing gas into a reaction vessel having silicon or silicon carbide on at least a part of the surface and nitriding at least a part of the surface;
Carrying the substrate into the reaction vessel;
Heat treating the substrate in the reaction vessel having the nitrided surface;
A method for manufacturing a semiconductor device comprising: A reaction vessel having silicon or silicon carbide at least in part of the surface and heat-treating the substrate therein;
A heating unit for heating the inside of the reaction vessel;
A nitrogen-containing gas supply unit for supplying a nitrogen-containing gas into the reaction vessel;
A transport unit for inserting and ejecting the substrate into and out of the reaction container;
A controller that controls the heating unit, the nitrogen-containing gas supply unit, and the transport unit;
The control unit supplies the nitrogen-containing gas into the reaction vessel while nitriding at least a part of the surface while heating the inside of the reaction vessel, and then inserts the substrate into the reaction vessel by the transfer unit And a heat treatment apparatus for controlling the substrate to be heat-treated in the reaction vessel having the nitrided surface. A heat treatment member having a member made of silicon or silicon carbide at least partially, wherein at least a part of the surface is modified to silicon carbonitride or silicon oxynitride.

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