JP2005347697A - Thermal treatment apparatus and thermal treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermal treatment apparatus that efficiently and stably carries out thermal treatment on a substrate, and also to provide its thermal treatment method. <P>SOLUTION: The thermal treatment apparatus has: a dual-structure heating furnace having a heater 1 and a furnace orifice part 16 and comprised of an external reaction tube 2 and an internal reaction tube 3; a wafer holding jig 9 that holds a wafer 10; a furnace palate 8 and a lift 6 that transport the wafer holding jig 9 so as to transport in and out the wafer 10 from the internal reaction tube 3; an inert gas heating mechanism 31 that is provided near the furnace orifice part 16 of the internal reaction tube 3; and an inert gas heater 32 that heats and supplies the inert gas to the inert gas heating mechanism 31. The inert gas heating mechanism 31 has an injection aperture that injects a heated inert gas to the wafer 10 entered into the internal reaction tube 3 from a peripheral direction approximately orthogonal to the wafer 10's entry direction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat treatment apparatus and a heat treatment method.

  Among various heat treatment apparatuses, for example, in a heat treatment apparatus that involves heat treatment such as a batch CVD apparatus or a diffusion apparatus, generally, a high temperature (400) in which a wafer held in a wafer holding jig is replaced with an inert gas. Insert into a reaction tube at a temperature of from 0 ° C to 900 ° C. Then, a reactive gas necessary for wafer processing is introduced, and device processing is performed by heat treatment (hereinafter referred to as heat treatment as appropriate) including reactions such as low-pressure chemical vapor deposition, impurity diffusion, and oxidation.

  At this time, Patent Document 1 discloses a technique for preventing moisture adhering to a semiconductor wafer or boat from entering the furnace. FIG. 7 is a cross-sectional view schematically showing a configuration of a preheating means of a conventional semiconductor manufacturing heating furnace.

  Specifically, in this heating furnace for manufacturing a semiconductor, a nitrogen gas nozzle 211 is disposed in the vicinity of the furnace port 203c so that the gas jet port 211a faces the semiconductor wafer 201 and the boat 202. Then, an exhaust duct 207 is provided on the opposite side of the nitrogen gas nozzle 211 to discharge the nitrogen gas. Further, when the nitrogen gas is blown out from the gas replacement nozzle 211, the nitrogen gas is heated to 100 ° C. to 200 ° C. by the gas heating device 212.

  For this reason, the moisture adhering to the semiconductor wafer 201 and the boat 202 is warmed and evaporated. Therefore, this document describes that moisture adhering to the semiconductor wafer 201 and the boat 202 can be prevented from entering the heating furnace 203 and the semiconductor wafer 201 can be prevented from being oxidized in the furnace. .

  Further, Patent Document 2 discloses a method for suppressing the formation of an unnecessary natural oxide film. FIG. 6 is a schematic vertical sectional view showing the vertical diffusion / CVD apparatus described in Patent Document 2. As shown in FIG.

  This vertical diffusion / CVD apparatus has a manifold 118 for injecting an inert gas into a boat 109 that is a wafer holding jig and a wafer holding jig below the furnace opening 116 of the internal reaction tube 103, and the manifold 118. And an intake manifold 119 that is an exhaust portion that intakes the inert gas and has an inert gas curtain unit. For this reason, this document describes that the atmosphere (oxygen or moisture) can be replaced with an inert gas before the wafer 110 or the boat 109 is inserted into the internal reaction tube 103.

  Specifically, in the batch-type CVD apparatus or diffusion apparatus described in Patent Document 2, there is a furnace port portion 116 into which the wafer 110 and the boat 109 are inserted below the external reaction tube 102. An inert gas curtain unit 117 is provided below the furnace opening 116. The curtain unit 117 is provided with an inert gas manifold 118 having a required height and an inert gas intake manifold 119 having a height equal to the height of the ejection manifold 118 facing each other. The ejection manifold 118 has a number of inert gas ejection nozzles 120 and is connected to an inert gas source such as nitrogen gas. The intake manifold 119 has a number of inert gas intake holes 121 and is connected to an exhaust blower.

  The inert gas ejected from the inert gas ejection nozzle 120 of the ejection manifold 118 is sucked from the inert gas intake hole 121 of the intake manifold 119, thereby forming an inert gas curtain that circulates in one horizontal direction. . The ejection manifold 118 and the intake manifold 119 may be connected in a ring shape to surround the lower portion of the furnace port portion 116. Alternatively, the flat ejection manifold 118 and the intake manifold 119 may be connected by side plates to surround the furnace port portion 116 in a rectangular shape.

Then, an inert gas is supplied to the internal reaction tube 103, and the inside of the internal reaction tube 103 is set to an inert gas atmosphere. In the process in which the boat 109 passes through the inert gas curtain, the atmosphere (oxygen, moisture) existing between the boat 109 and the wafer 110 is pushed out by the one-way flow of the inert gas. Is done.
JP-A-6-151342 JP 2002-359202 A

  However, in the techniques described in Patent Document 1 and Patent Document 2, the temperature of the wafer during the insertion operation is lower than the set temperature of the heat treatment in the reaction tube. The heat treatment is started after the temperature inside the reaction tube is stabilized at the set temperature. For this reason, even if the wafer insertion operation is completed, it takes time to stabilize the wafer temperature at the heat treatment set temperature. For this reason, the temperature stabilization time of the wafer becomes longer, and there is room for improvement in terms of the processing capability of the heat treatment apparatus. Further, since the inert gas is blown from one direction, it is difficult to uniformly heat the wafer.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a heat treatment apparatus capable of heat-treating a substrate efficiently and stably.

  According to the present invention, a heating furnace having a heater and an opening, a substrate holding part for holding the substrate, a transport means for transporting the substrate holding part so as to put the substrate in and out of the heating furnace, and an opening of the heating furnace An inert gas releasing means provided in the vicinity of the unit, and an inert gas heating means for heating the inert gas and supplying the inert gas to the inert gas releasing means. The inert gas releasing means is provided in the heating furnace. Provided is a heat treatment apparatus having a discharge port for discharging a heated inert gas from an outer peripheral direction substantially orthogonal to a substrate introduction direction with respect to a substrate to be introduced.

  According to this configuration, since the substrate held in the substrate holder can be preheated uniformly with the inert gas heated to a high temperature before being introduced into the heating furnace, the substrate after the substrate introduction operation is completed. Temperature stabilization time can be shortened. Therefore, the substrate can be efficiently and stably heat treated.

  According to the present invention, the heating furnace including the heater and the opening, the substrate holding unit that holds the substrate, and the substrate holding unit move with the substrate holding unit on the side opposite to the substrate introduction direction. An inert gas discharge means, an inert gas heating means for heating the inert gas and supplying it to the inert gas discharge means, and a substrate holding part and an inert gas so as to put the substrate in and out of the heating furnace. Transporting means for transporting the active gas discharge means, and the inert gas discharge means discharges the heated inert gas from the opposite side of the substrate introduction direction with respect to the substrate introduced into the heating furnace. There is provided a heat treatment apparatus having a discharge port.

  According to this configuration, the substrate held by the substrate holder can be preheated uniformly with the inert gas heated to a high temperature before being introduced into the heating furnace. In addition, since the substrate on the opposite side to the introduction direction, which is to be introduced in the vicinity of the furnace opening, can be preliminarily heated, the temperature stabilization time of the substrate after the substrate introduction operation is completed can be shortened. Therefore, the substrate can be efficiently and stably heat treated.

  Further, according to the present invention, there is provided a method for heat treating a substrate using a heating furnace, the step of preheating the substrate when the substrate is introduced into the heating furnace, and the step of preheating the substrate in the heating furnace. The step of preheating, including the step of heat treatment, was heated from the outer peripheral direction substantially orthogonal to the substrate introduction direction with respect to the substrate introduced into the heating furnace and the step of heating the inert gas And a step of releasing an inert gas.

  According to this method, since the substrate held in the substrate holding part is preheated uniformly with the inert gas heated to a high temperature before being introduced into the heating furnace, the substrate after the substrate introduction operation is completed. Temperature stabilization time can be shortened. Therefore, the substrate can be efficiently heat-treated.

  Further, according to the present invention, there is provided a method for heat treating a substrate using a heating furnace, the step of preheating the substrate when the substrate is introduced into the heating furnace, and the step of preheating the substrate in the heating furnace. The step of pre-heating includes the step of heating, and the step of heating the inert gas and the inert gas heated from the opposite side of the substrate introduction direction with respect to the substrate introduced into the heating furnace And a step of releasing the heat treatment method.

  According to this method, the substrate held by the substrate holder can be preheated uniformly with the inert gas heated to a high temperature before being introduced into the heating furnace. In addition, since the substrate on the opposite side to the introduction direction, which is to be introduced in the vicinity of the furnace opening, can be preliminarily heated, the temperature stabilization time of the substrate after the substrate introduction operation is completed can be shortened. Therefore, the substrate can be efficiently and stably heat treated.

  In the present invention, the heat treatment apparatus is not particularly limited, and generally means an apparatus that performs a process involving heat treatment on a substrate or the like. For example, a batch type CVD apparatus or a diffusion apparatus is included. Moreover, the heating furnace provided in this heat treatment apparatus may be a vertical type or a horizontal type.

  That is, the heat treatment apparatus according to the present invention includes a batch type CVD apparatus for forming various films on a wafer by low pressure chemical vapor deposition in a semiconductor device manufacturing process. Alternatively, a batch type diffusion apparatus that performs impurity diffusion, oxidation, and heat treatment on the wafer is included. Among these, the heat processing apparatus which has the structure which inserts especially the wafer hold | maintained at the jig | tool for wafer holding in the reaction tube of a heating furnace is contained.

  According to the present invention, since the inert gas discharge means having a specific configuration is provided, a heat treatment apparatus excellent in the heat treatment efficiency of the substrate is provided.

  In the heat treatment apparatus according to the present invention, the inert gas discharge means includes an inert gas container provided in a ring shape immediately below the opening of the heating furnace, and the discharge port is provided inside the inert gas container. It can be set as the structure arrange | positioned at substantially equal intervals.

  According to this configuration, from the outer circumferential direction substantially orthogonal to the substrate introduction direction with respect to the substrate introduced into the heating furnace from the discharge ports arranged at substantially equal intervals inside the ring-shaped inert gas container. The heated inert gas can be released. For this reason, since the substrate held by the substrate holding part can be preheated without unevenness, a heat treatment apparatus having excellent heat treatment efficiency of the substrate can be obtained. In addition, since the entrainment of atmospheric gas into the heating furnace is reduced, the formation of an oxide film on the substrate in the heating furnace can be suppressed.

  Here, the number of discharge ports inside the inert gas container may be, for example, three or more, and particularly preferably four or more. The greater the number of outlets, the more uniformly the substrate can be heated.

  In the heat treatment apparatus according to the present invention, a plurality of inert gas releasing means can be provided along the substrate introduction direction.

  According to this configuration, since the temperature of the substrate and the substrate holding part can be sufficiently raised before the substrate is introduced into the heating furnace, the temperature stabilization time of the furnace port part of the heating furnace can be shortened more efficiently. it can.

  In the heat treatment apparatus according to the present invention, the plurality of inert gas discharge means may be configured to discharge inert gases at different temperatures.

  According to this configuration, since the substrate and the substrate holding part can be heated so that the temperature gradually increases as they move in the direction of the heating furnace, it is possible to suppress a sudden temperature change from being applied to the substrate and to reduce the quality of the substrate. Can be suppressed.

  Further, in the heat treatment apparatus according to the present invention, the inert gas discharge means can be configured to discharge the heated inert gas along the introduction direction of the substrate introduced into the heating furnace.

  According to this configuration, since the substrate held by the wafer holding unit can be preheated uniformly, a heat treatment apparatus having excellent heat treatment efficiency of the substrate can be obtained.

  Further, in the heat treatment apparatus according to the present invention, the inert gas discharge means includes an inert gas container provided in a shape that can be inserted into the opening of the heating furnace, and the discharge port has an outer periphery of the inert gas container and It can be set as the structure arrange | positioned at the upper part.

  According to this configuration, from the discharge port at the top of the inert gas container that can be inserted into the opening of the heating furnace, the substrate heated in the substrate introduction direction with respect to the substrate introduced into the heating furnace. An inert gas can be released. For this reason, since the substrate held by the wafer holder can be preheated without unevenness, a heat treatment apparatus having excellent heat treatment efficiency of the substrate can be obtained.

  In addition, the heated inert gas can be discharged into the space between the inert gas container and the inner wall of the heating furnace from the discharge port on the outer periphery of the inert gas container that can be inserted into the opening of the heating furnace. For this reason, since the entrainment of the atmospheric gas into the heating furnace is reduced, the formation of an oxide film on the substrate in the heating furnace can be suppressed.

  Moreover, the heat processing apparatus which concerns on this invention WHEREIN: A board | substrate holding | maintenance part can be set as the structure which hold | maintains two or more substrates in parallel along the introduction direction of a board | substrate.

  According to this configuration, the substrate held on the wafer holder can be preheated uniformly by the above-described inert gas releasing means, and a large number of substrates can be heat-treated at a time, so that the heat treatment efficiency of the substrate is excellent. A heat treatment apparatus is obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

<Embodiment 1>
FIG. 1 is a cross-sectional view schematically showing a configuration of preheating means of the heat treatment apparatus according to the first embodiment.
The heat treatment apparatus according to the present embodiment includes a double-structured heating furnace having a heater 1 and a furnace port portion 16 (opening portion) and composed of an external reaction tube 2 and an internal reaction tube 3.

  The heat treatment apparatus also includes a wafer holding jig 9 (substrate holding unit) that holds the wafer 10 (substrate). The heat treatment apparatus includes a transfer means configured of a furnace lid 8 and a lift elevator 6 for transferring the wafer holding jig 9 so that the wafer 10 is taken in and out of the internal reaction tube 3.

  The heat treatment apparatus further includes an inert gas heating mechanism 31 (inert gas discharge means) provided in the vicinity of the furnace port 16 of the internal reaction tube 3. In addition, the heat treatment apparatus includes an inert gas heater 32 (inert gas heating unit) that heats the inert gas and supplies the inert gas to the inert gas heating mechanism unit 31. The inert gas heating mechanism unit 31 includes: In addition, the wafer 10 introduced into the internal reaction tube 3 has a discharge port for discharging the heated inert gas from the outer peripheral direction substantially orthogonal to the introduction direction of the wafer 10.

Since the heat treatment apparatus according to the present embodiment has such an inert gas heating mechanism 31, the wafer 10 of the batch type CVD apparatus or the diffusion apparatus, the wafer holding jig 9, and the like are inserted into the internal reaction tube 3. Previously, it can be preheated with an inert gas heated to a high temperature. Therefore, the temperature of the wafer 10, the wafer holding jig 9 and the like can be raised while suppressing unnecessary natural oxide films formed on the wafer 10. As a result, after the operation of introducing the wafer 10 and the wafer holding jig 9 into the internal reaction tube 3 is completed, the time required for the temperature rise of the wafer 10 and the wafer holding jig 9 can be shortened.
Hereinafter, the configuration of the heat treatment apparatus of Embodiment 1 will be described in more detail.

  In this heat treatment apparatus, an outer reaction tube 2 into which a wafer holding jig 9 is inserted, and a ring-shaped inner reaction tube 3 are installed concentrically on the inner side, and the temperature of the inner reaction tube 3 is arranged on the outer periphery of the outer reaction tube 2. A heater 1 for controlling the temperature to a high temperature is provided. Further, in this heat treatment apparatus, a pipe for introducing an inert gas 4 between the outer reaction tube 2 and the inner reaction tube 3 and a reaction gas 5 for performing device processing such as heat treatment on the inner reaction tube 3 are provided. The pipe to be introduced is connected. This heat treatment apparatus has a wafer holding jig 9 that holds the unprocessed wafer 10 below the external reaction tube 2, and a furnace opening lid 8 that supports the wafer holding jig 9 below the wafer holding jig 9. The furnace port lid 8 is connected to a lift elevator 6 that rises when the wafer holding jig 9 is inserted into the external reaction tube 2.

  This heat treatment apparatus has a ring-shaped inert gas container 33 having an inner diameter larger than that of the furnace mouth cover 8 immediately below the outer reaction tube 2, and the inert gas is jetted into the inner surface of the inert gas container 33 both vertically and horizontally. There are a number of holes to do this. This heat treatment apparatus has an inert gas heater 32 for heating the inert gas to a high temperature (400 ° C. to 900 ° C.) on the outer periphery of the inert gas container 33.

The inert gas source and the inert gas container 33 not shown in FIG. 1 are connected by a gas pipe 34a and a gas pipe 34b. The heat treatment apparatus has a structure having a shutoff valve 35 that shuts off the flow of the inert gas between the gas pipe 34a and the gas pipe 34b.
Hereinafter, a method for inserting the wafer 10 into the heating furnace using the heat treatment apparatus having the above configuration will be described.

  The heat treatment method of the wafer 10 (substrate) using the internal reaction tube 3 (heating furnace) according to the present embodiment includes a step of preheating the wafer 10 when the wafer 10 is introduced into the internal reaction tube 3, and an internal reaction. And heat-treating the preheated wafer 10 in the tube 3.

  The preliminary heating step includes the step of heating the inert gas and the step of heating the wafer 10 introduced into the internal reaction tube 3 from the outer peripheral direction substantially orthogonal to the introduction direction of the wafer 10. Releasing an active gas.

  In FIG. 1, the wafer 10 before the device processing such as heat treatment is held by the wafer holding jig 9 and is waiting under the external reaction tube 2. Except during device processing such as heat treatment, the internal reaction tube 3 is always replaced with the inert gas 4 and is in a low oxygen state.

  FIG. 2 is a plan view and a cross-sectional view schematically showing a high-temperature inert gas purge mechanism of the heat treatment apparatus according to the first embodiment. In FIG. 2, the shutoff valve 35 provided between the inert gas container 33 and the inert gas source is in a closed state, but is opened only when the elevator elevator 6 is in the ascending operation. The inert gas container 33 is heated by an inert gas heater 32 provided on the outer periphery thereof (for example, the temperature is 400 ° C. to 900 ° C.). The inert gas heater 32 is adjusted to a preset temperature by a heater temperature controller not shown in FIG. That is, the temperature of the inert gas in the inert gas container 33 is not limited to the range of 400 ° C. to 900 ° C., and can be appropriately adjusted depending on the type and mode of heat treatment.

  In FIG. 1 and FIG. 2, when the lifting elevator 6 starts the raising operation, the wafer holding jig 9 supported by the furnace port lid 8 starts to move upward. At this time, the shutoff valve 35 provided between the inert gas container 33 and the inert gas source is opened, and the inert gas is introduced into the inert gas container 33 from the gas pipe 34b via the gas pipe 34a. Is done. Since the inert gas container 33 is heated to a preset temperature, the temperature of the introduced inert gas is also heated to a high temperature. After that, the inert gas heated to a high temperature is ejected from the plurality of holes formed in the inner surface of the inert gas container 33 evenly in the vertical and horizontal directions toward the center of the inert gas container 33.

  When the raising / lowering elevator 6 continues to rise, the wafer 10 held by the wafer holding jig 9 passes through the inert gas layer heated to the high temperature and is inserted into the external reaction tube 2. When the wafer 10 and the wafer holding jig 9 are completely inserted into the external reaction tube 2, the lifting operation of the lift elevator 6 is stopped. At that time, the shutoff valve 35 provided between the inert gas container 33 and the inert gas source is closed, and the supply of the inert gas heated to a high temperature is stopped. Thereafter, after the temperature of the internal reaction tube 3 is stabilized at the set temperature, the reaction gas 5 is supplied, and device processing such as heat treatment is started.

As described above, during the lifting operation of the elevator elevator 6, the shutoff valve 35 is opened, and the inert gas flows into the inert gas container 33 heated to a high temperature and is heated to a high temperature. The inert gas heated to a high temperature flows out evenly toward the center of the inert gas container 33 from a plurality of holes formed in the inner surface of the inert gas container 33 in the vertical and horizontal directions. When passing through the inert gas layer heated to a high temperature, the wafer 10 and the wafer holding jig 9 are heated to a high temperature while being replaced with the inert gas.
Hereinafter, the operational effects of the above configuration of the present embodiment will be described.

  In the heat treatment apparatus according to the present embodiment, the wafer 10 and the wafer holding jig 9 are preheated by the heated inert gas layer before being inserted into the external reaction tube 2 and then inserted into the external reaction tube 2. Therefore, heat exchange between the inert gas in the internal reaction tube 3 and the wafer 10 being inserted or the wafer holding jig 9 is suppressed. Thereby, after the insertion of the wafer 10 and the wafer holding jig 9 is completed, the temperature fluctuation of the furnace port portion 16 is suppressed. As a result, after the wafer 10 rises to the device processing position of the external reaction tube 2, the time for the temperature of the furnace port portion 16 to stabilize at the set temperature is shortened, and the heat treatment apparatus (for example, a batch type CVD apparatus or a diffusion apparatus) is processed. Time can be shortened and processing capacity is improved.

  On the other hand, in the prior art described in Patent Document 2, as shown in FIG. 6, a furnace port lid 108 below the furnace port part 116 opens to the internal reaction tube 103 and is held by a boat 109 which is a wafer holding jig. The processed wafer 110 is inserted. At this time, the temperature of the furnace port portion 116 is lowered because heat exchange is performed between the wafer 110 and the boat 109 at room temperature (20 ° C. to 25 ° C.). Due to the configuration of the apparatus, the insertion direction of the wafer 110 is always unidirectional, so the temperature of the furnace opening 116 during the insertion operation is lower than the set temperature, and it takes time to stabilize to the set temperature even when the insertion operation is completed. It takes.

  Device processing such as heat treatment is started after the temperature inside the internal reaction tube 103 is stabilized at a set temperature, but the temperature stabilization time of the furnace port portion 116 becomes long, which causes a reduction in processing capability. In addition, the thermal history of the wafer 110 that has already been inserted into the internal reaction tube 103 becomes longer, and a useless natural oxide film is formed, thereby causing deterioration in film formation quality or device characteristics. It is also a factor inviting.

  That is, in the prior art described in Patent Document 2, the wafer 110 and the boat 109 at room temperature (20 ° C. to 25 ° C.) are inserted into the furnace port portion 116 of the internal reaction tube 103. Then, heat exchange is performed between the inert gas kept at a high temperature (400 ° C. to 900 ° C.) inside the internal reaction tube 103 and the wafer 110 or the boat 109, and the temperature is lowered.

  In the vertical diffusion CVD apparatus described in Patent Document 2, the heater 101 installed on the outer periphery of the external reaction tube 102 tries to control the furnace port 116 of the internal reaction tube 103 to a set temperature. Since the direction is one direction, heat exchange with the normal temperature wafer 110 is always performed, and the temperature of the furnace opening 116 is not stabilized at the set temperature during the insertion operation. Device processing such as heat treatment is started after the temperature inside the internal reaction tube 103 is stabilized at a set temperature, but the temperature stabilization time of the furnace port portion 116 becomes long, which causes a reduction in processing capability.

  Therefore, the prior art described in Patent Document 2 is less effective in shortening the temperature stabilization time of the furnace port portion 116 after the insertion operation is completed, and is less effective in suppressing a reduction in processing capacity.

  Further, in the heating furnace for semiconductor manufacturing according to the prior art described in Patent Document 1, as shown in FIG. 7, moisture adhering to the wafer 201 and the boat 202 is not allowed to enter the heating furnace 203, so A nitrogen gas nozzle 211 that blows an inert gas heated in a range of 100 ° C. to 200 ° C. supplied from the gas heating device 212 to the wafer 201 and the boat 202, and an exhaust duct 207 that exhausts the inert gas to a position opposed to the nitrogen gas nozzle 211. Provided. Thus, since the warm air of 100 ° C. to 200 ° C. is blown in one direction, moisture between the wafers 201 can be removed.

  In this structure, there is a certain effect in removing moisture from the wafer 201 and the boat 202, but since the inert gas curtain structure blows the inert gas from one direction, the atmosphere is easily involved. Therefore, when the temperature of the inert gas is raised to the heat treatment temperature (400 ° C. to 900 ° C.) in the heating furnace 203 by the gas heating device 212, a natural oxide film is likely to be generated on the wafer 201.

  Further, in this structure, since the inert gas at 100 ° C. to 200 ° C. is blown from one direction to the wafer 201 and the boat 202, the temperature distribution of the wafer 201 and the boat 202 becomes uneven, and the subsequent rise The stability of the temperature process and heat treatment process may be reduced.

  On the other hand, in the heat treatment apparatus of this embodiment, as shown in FIG. 1, the inert gas heating mechanism section is inserted before the wafer 10 mounted on the wafer holding jig 9 is inserted into the internal reaction tube 3. 31 is preheated with an inert gas heated to a high temperature in the range of 400 ° C to 900 ° C.

  For this reason, the air (oxygen, moisture) around the wafer 10 being inserted is preheated while being replaced with a high-temperature inert gas. The inert gas heating mechanism 31 is provided with three or more inert gas outlets on the circumference at substantially equal intervals. For this reason, since the inert gas is blown out from the entire outer periphery of the wafer 10 and the wafer holding jig 9, the wafer 10 and the wafer holding jig 9 can be heated evenly in a state close to a 100% inert gas atmosphere. . That is, the entire wafer 10 can be heated at once. And the temperature of the wafer 10 and the boat 9 can be raised to the temperature (400 degreeC-900 degreeC) close | similar to the internal reaction tube 3 of a heating furnace before insertion. Therefore, according to the present embodiment, the entire wafer 10 can be preheated stably with high heat treatment efficiency.

  Therefore, when heating is performed in a state where the oxygen concentration is high, the wafer 10 before processing and the wafer holding jig 9 can be preheated while suppressing a natural oxide film formed on the wafer 10. As a result, the temperature stabilization time of the furnace port portion 16 after the insertion operation is completed can be shortened. Further, since the wafer 10 and the wafer holding jig 9 can be heated evenly, the subsequent temperature raising process and heat treatment process are stabilized.

<Embodiment 2>
FIG. 3 is a cross-sectional view schematically showing the configuration of the preheating means of the heat treatment apparatus according to the second embodiment. FIG. 4 is an enlarged cross-sectional view schematically showing a high-temperature inert gas purge mechanism of the heat treatment apparatus according to the second embodiment. The configuration of the heat treatment apparatus according to the second embodiment is basically the same as that of the heat treatment apparatus according to the first embodiment.

  The heat treatment apparatus according to the present embodiment includes a double-structured heating furnace including an external reaction tube 2 and an internal reaction tube 3 that includes a heater 1 and a furnace port 16 (opening). The heat treatment apparatus also includes a wafer holding jig 9 (substrate holding unit) that holds the wafer 10 (substrate).

  Further, this heat treatment apparatus includes an inert gas discharge means provided so as to move together with the wafer holding jig 9 on the opposite side of the introduction direction of the wafer 10 with respect to the wafer holding jig 9. The inert gas discharge means has a discharge port for discharging heated inert gas from the opposite side of the introduction direction of the wafer 10 with respect to the wafer 10 introduced into the internal reaction tube 3.

  In addition, this heat treatment apparatus heats an inert gas and supplies the inert gas to the inert gas discharge means, and includes an inert gas heater 53, an inert gas container 52, and a heater controller 54. Means. The heat treatment apparatus transports the wafer holding jig 9 and the inert gas discharge means so that the wafer 10 is taken in and out of the internal reaction tube 3. Is provided.

Since the heat treatment apparatus according to the present embodiment has such an inert gas discharge means, before inserting the wafer 10 of the batch type CVD apparatus or the diffusion apparatus, the wafer holding jig 9 and the like into the internal reaction tube 3. It can be preheated with an inert gas heated to a high temperature. Therefore, the temperature of the wafer 10, the wafer holding jig 9 and the like can be raised while suppressing unnecessary natural oxide films formed on the wafer 10. As a result, after the operation of introducing the wafer 10 and the wafer holding jig 9 into the internal reaction tube 3 is completed, the time required for the temperature rise of the wafer 10 and the wafer holding jig 9 can be shortened.
Hereinafter, the configuration of the heat treatment apparatus according to the second embodiment will be described in more detail.

  This heat treatment apparatus has an external reaction tube 2 into which a wafer holding jig 9 is inserted. A ring-shaped internal reaction tube 3 is installed concentrically on the inside thereof, and an internal reaction tube 3 is arranged on the outer periphery of the external reaction tube 2. A heater 1 is provided to control the temperature of the heater to a high temperature. The heat treatment apparatus includes a heat retaining jig 41, a heat insulating material 42, and a pedestal 43 below the wafer holding jig 9, and these are installed on the furnace port lid 8. The furnace mouth cover 8 is connected to the lift elevator 6. The elevator lifting / lowering means includes a motor 21 that moves the elevator 6 up and down and an encoder 22 that detects the elevator position.

  This heat treatment apparatus has a structure in which a gas pipe 55a is connected to the center of the furnace port lid 8 and is connected to an inert gas container 52 through the gas pipe 55b. This heat treatment apparatus has a shutoff valve 51 between the gas pipe 55a and the gas pipe 55b. In this heat treatment apparatus, an inert gas heater 53 is installed on the outer periphery of the inert gas container 52.

The heat treatment apparatus also includes a shut-off valve opening / closing controller 23 that opens and closes the shut-off valve 51 after receiving a position signal of the lift elevator 6 from the encoder 22. This heat treatment apparatus has a gas flow path at the center of the furnace port lid 8 as an inert gas discharge means, and a gas flow path is also provided inside the pedestal 43. A plurality of holes are formed in the side surface and the upper surface of the heat retaining jig 41 as an inert gas discharge port.
Hereinafter, a method for inserting the wafer 10 into the heating furnace using the heat treatment apparatus having the above configuration will be described.

  The heat treatment method of the wafer 10 (substrate) using the internal reaction tube 3 (heating furnace) according to the present embodiment includes a step of preheating the wafer 10 when the wafer 10 is introduced into the internal reaction tube 3, and an internal reaction. And heat-treating the preheated wafer 10 in the tube 3.

  The preliminary heating step includes heating the inert gas from the side opposite to the introduction direction of the wafer 10 with respect to the step of heating the inert gas and the wafer 10 introduced into the internal reaction tube 3. Releasing.

  In the step of preheating the wafer 10, an inert gas is supplied to the inert gas container 52 from an inert gas source not shown in the drawing. While the lift elevator 6 is waiting under the external reaction tube 2, the shutoff valve 51 is closed and heated to a high temperature (400 ° C. to 900 ° C.) by the inert gas heater 53.

  When the elevator 6 starts the ascending operation, the wafer 10 held by the wafer holding jig 9 performs the insertion operation into the external reaction tube 2, and when the heat retaining jig 41 is inserted into the furnace port 16, the encoder 22 transmits the position signal of the elevator 6 to the cutoff valve opening / closing controller 23, and the cutoff valve opening / closing controller 23 opens the cutoff valve 51.

  The inert gas heated to a high temperature in the inert gas container 52 is introduced from the gas pipe 55b through the gas pipe 55a into the central portion of the furnace port lid 8. The inert gas is dispersed by the pedestal 43, introduced into the heat retaining jig 41, and ejected from a plurality of holes opened on the side surface and the upper surface of the heat retaining jig 41.

  When all the wafer holding jigs 9 holding the wafer 10 are inserted into the external reaction tube 2 and the lifting operation of the lift elevator 6 is completed, the shutoff valve opening / closing controller 23 sends a position signal of the lift elevator 6 from the encoder 22. Then, the shutoff valve 51 is closed.

  Hereinafter, the operational effects of the above configuration of the present embodiment will be described. The operational effects of the heat treatment apparatus according to the second embodiment are basically the same as the operational effects of the heat treatment apparatus according to the first embodiment.

  In the present embodiment, the wafer 10 held by the wafer holding jig 9 completes the insertion operation by the configuration and operation described above, and the heat holding jig 41 reaches the furnace port 16 of the external reaction tube 2. From this point, the inert gas heated to a high temperature is jetted from the heat retaining jig 41 to the side surface and the upper surface via the central portion of the furnace lid 8.

  For this reason, while keeping unnecessary natural oxide films from being formed on the wafer 10, the warming jig 41, the thermal insulation material 42, and the wafer 10 held under the wafer holding jig 9 are reserved. Can be heated. As a result, it is possible to shorten the time during which the temperature of the furnace port portion 16 after the insertion operation is completed is stabilized at the set temperature.

  In addition, as a function and effect peculiar to the heat treatment apparatus of the second embodiment, an inert gas heated to a high temperature is ejected from the heat retaining jig 41 to the side surface and the upper surface, and the wafer 10 held by the wafer holding jig 9 is retained. The heat retaining jig 41 and the heat retaining material 42 can be preheated. For this reason, preheating can be performed without newly installing an inert gas purge mechanism below the external reaction tube 2, thereby realizing cost saving and space saving.

  Further, the inert gas heated to a high temperature and ejected from the heat retaining jig 41 to the side surface and the upper surface reaches the entire wafer 10 held by the wafer holding jig 9 and is not uneven in the horizontal direction of the wafer. The entire wafer 10 is heated. That is, the entire wafer 10 can be heated at once. Further, with respect to the introduction direction of the wafer, since the wafer 10 that takes time to heat in the vicinity of the furnace opening can be preferentially heated, the temperature of the furnace opening 16 after the insertion operation is completed is stabilized at the set temperature. Time can be shortened.

<Embodiment 3>
FIG. 5 is a cross-sectional view schematically showing the configuration of the preheating means of the heat treatment apparatus according to the third embodiment. The configuration of the heat treatment apparatus according to the third embodiment is the same as that of the first embodiment, but differs in that a plurality of inert gas heating mechanisms are arranged.

  Specifically, the heat treatment apparatus according to this embodiment includes a triple inert gas heating mechanism 31 in the vicinity of the furnace port 16 of the heating furnace having the external reaction tube 2 and the internal reaction tube 3. The configuration of the inert gas heating mechanism 31 is the same as that of the inert gas heating mechanism 31 described in the first embodiment.

  However, the inert gas heating mechanism 31 is not limited to three stations, and may be two stations, or four or more stations. Further, by providing a space formed in the center in parallel with each other so that the wafer 10 and the wafer holding jig 9 can pass, efficient preheating can be performed.

  Further, the temperature of the inert gas released by the inert gas heating mechanism 31 is configured to gradually increase from the bottom to the top. For this reason, the timing for starting the preheating of the wafer 10 with the inert gas is performed not only immediately before the insertion of the wafer 10 into the internal reaction tube 3 but also during the transport a little before compared to the case of the first embodiment. be able to.

  Since this heat treatment apparatus has such a configuration, in addition to the same functions and effects as those of the first embodiment, the following specific functions and effects are exhibited. That is, when the wafer 10 is introduced into the heating furnace, the wafer 10 can be gradually heated. For this reason, the production | generation of the natural oxide film on the wafer 10 can further be suppressed. In addition, since the temperature of the wafer 10 and the wafer holding jig 9 can be sufficiently increased until just before the furnace port 16 of the internal reaction tube 3, the temperature stabilization time of the furnace port 16 is further shortened. it can.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

  For example, in the above embodiment, the heating furnace has a vertical structure, but may have a horizontal structure. Further, although the heating furnace has a double structure consisting of the internal reaction tube 3 and the external reaction tube 2, a single structure may be used. Moreover, although nitrogen gas was used as an inert gas, you may use other inert gas, such as Ar gas.

3 is a cross-sectional view schematically showing a configuration of a preheating unit of the heat treatment apparatus according to Embodiment 1. FIG. 2 is a plan view and a cross-sectional view schematically showing a high-temperature inert gas purge mechanism of the heat treatment apparatus according to Embodiment 1. FIG. It is sectional drawing which showed typically the structure of the preheating means of the heat processing apparatus which concerns on Embodiment 2. FIG. 6 is an enlarged cross-sectional view schematically showing a high-temperature inert gas purge mechanism of a heat treatment apparatus according to Embodiment 2. FIG. It is sectional drawing which showed typically the structure of the preheating means of the heat processing apparatus which concerns on Embodiment 3. FIG. It is sectional drawing which showed typically the structure of the preheating means of the conventional vertical diffusion and CVD apparatus. It is sectional drawing which showed typically the structure of the preheating means of the conventional heating furnace for semiconductor manufacture.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heater 2 External reaction tube 3 Internal reaction tube 4 Inert gas 5 Reaction gas 6 Elevator 8 Furnace cover 9 Wafer holding jig 10 Wafer 11 Exhaust line 16 Furnace part 21 Motor 22 Encoder 23 Shut-off valve opening / closing controller 31 Not Active gas heating mechanism 32 Inert gas heater 33 Inactive gas container 34a Gas pipe 34b Gas pipe 35 Shut-off valve 41 Warming jig 42 Heat-insulating material 43 Base 51 Shut-off valve 52 Inert gas container 53 Inert gas heater 54 Heater controller 55a Gas piping 55b Gas piping

Claims (10)

A heating furnace comprising a heater and an opening;
A substrate holder for holding the substrate;
Transport means for transporting the substrate holder so as to put the substrate in and out of the heating furnace;
An inert gas discharge means provided in the vicinity of the opening of the heating furnace;
An inert gas heating means for heating the inert gas and supplying the inert gas to the inert gas discharge means;
With
The inert gas discharge means includes
A heat treatment apparatus, comprising: a discharge port that discharges the heated inert gas from an outer peripheral direction substantially orthogonal to a substrate introduction direction with respect to the substrate introduced into the heating furnace. The heat treatment apparatus according to claim 1,
The inert gas discharge means includes
An inert gas container provided in a ring shape just below the opening of the heating furnace,
The outlet is
A heat treatment apparatus, wherein the heat treatment apparatus is disposed at substantially equal intervals inside the inert gas container. The heat treatment apparatus according to claim 1 or 2,
The inert gas discharge means includes
A plurality of heat treatment apparatuses are provided along the substrate introduction direction. In the heat treatment apparatus according to claim 3,
The plurality of inert gas discharge means include
A heat treatment apparatus configured to release inert gases at different temperatures. A heating furnace comprising a heater and an opening;
A substrate holder for holding the substrate;
An inert gas discharge means provided so as to move with the substrate holding portion on the side opposite to the substrate introduction direction with respect to the substrate holding portion;
An inert gas heating means for heating the inert gas and supplying the inert gas to the inert gas discharge means;
Transport means for transporting the substrate holder and the inert gas discharge means so as to put the substrate in and out of the heating furnace;
With
The inert gas discharge means includes
A heat treatment apparatus comprising a discharge port for discharging a heated inert gas from the opposite side of the substrate introduction direction with respect to the substrate introduced into the heating furnace. The heat treatment apparatus according to claim 5,
The said inert gas discharge | release means discharge | releases the heated inert gas along the introduction direction of the said board | substrate introduced in a heating furnace, The heat processing apparatus characterized by the above-mentioned. The heat treatment apparatus according to claim 5 or 6,
The inert gas discharge means includes
An inert gas container provided in a shape that can be inserted into the opening of the heating furnace,
The outlet is
A heat treatment apparatus, which is disposed on an outer periphery and an upper part of the inert gas container. The heat treatment apparatus according to any one of claims 1 to 7,
The substrate holder is
A heat treatment apparatus, wherein a plurality of the substrates are held in parallel along the substrate introduction direction. A method of heat treatment of a substrate using a heating furnace,
A step of preheating the substrate when the substrate is introduced into the heating furnace;
Heat treating the preheated substrate in the heating furnace;
Including
The preheating step includes
Heating the inert gas;
Discharging the heated inert gas from the outer peripheral direction substantially orthogonal to the substrate introduction direction with respect to the substrate introduced into the heating furnace;
A heat treatment method comprising: A method of heat treatment of a substrate using a heating furnace,
A step of preheating the substrate when the substrate is introduced into the heating furnace;
Heat treating the preheated substrate in the heating furnace;
Including
The preheating step includes
Heating the inert gas;
Discharging the heated inert gas from the opposite side of the substrate introduction direction with respect to the substrate introduced into the heating furnace;
A heat treatment method comprising:

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