JP6447338B2 - Vertical heat treatment equipment - Google Patents

Description

  The present invention relates to a vertical heat treatment apparatus that holds a substrate in a shelf shape on a substrate holder, heats the substrate by a heating unit surrounding a processing container, and supplies a processing gas to the substrate to form a film.

  In general, in order to manufacture a semiconductor product, a film processing such as ALD (Atomic Layer Deposition) or CVD (Chemical Vapor Deposition) is performed on a semiconductor wafer (hereinafter referred to as a wafer). This film formation process may be performed by a batch type vertical heat treatment apparatus that processes a plurality of wafers at once. In that case, for example, the wafer is transferred to a vertical wafer boat and held in multiple stages in a shelf shape, and then the wafer boat is loaded (loaded) from below into a processing container in which a vacuum atmosphere is formed. Then, the entrance of the wafer boat is closed with a lid. Thereafter, a film is formed by supplying a processing gas into the processing container while heating the processing container.

  In the processing container described above, a heat insulating member is disposed between the lid and the mounting area of the wafer boat in order to prevent the temperature of the carry-in entrance and the surrounding area from rising. In some cases, the heat insulating member includes a plurality of heat shield plates stacked on each other and a support column that supports each plate. Patent Document 1 discloses a heat insulating member having such a configuration. For example, after a plurality of boat loading / unloading and film formation processes are repeatedly performed, a wafer boat on which no wafer is mounted is loaded into the processing container, the loading port is closed, and the processing container is heated. A cleaning gas is supplied and a cleaning process is performed. By this cleaning process, the film formed on the surface of the wafer boat, the inner wall surface of the processing container, and the surface of the heat insulating member is etched and removed.

  By the way, since the gap between the heat shield plates adjacent to each other is relatively small, it is difficult to supply the process gas for the film formation process to the gap, but the film is also formed in this gap by repeatedly performing the film formation process. Therefore, the cleaning process is required to be performed so that the film formed in the gap can also be removed. However, it is difficult to supply the cleaning gas to the gap as well as the processing gas. On the other hand, the end portion of the heat shield plate and the side surface of the column that faces the outside of the heat insulating member are more easily exposed to the cleaning gas than the gap. That is, due to the shape of the heat insulating member, there are a portion that is relatively difficult to be exposed to the cleaning gas and a portion that is relatively easily exposed.

Further, when a single film such as a SiN (silicon nitride) film is formed by the above vertical heat treatment apparatus, the cleaning process can be performed under such a condition that the film can be selectively etched and removed. . That is, the cleaning process can be performed so that the influence on the heat insulating member is suppressed. However, the vertical heat treatment apparatus may form a plurality of types of films such as a laminated film of a SiN film and a SiO ₂ (silicon oxide) film. When the cleaning process conditions are set so that the various films can be removed even between the heat shield plates of the heat insulating member where the cleaning gas is difficult to enter as described above, there are places where the heat insulating member is easily exposed to the cleaning gas. There is a risk of etching relatively large. When etching occurs in such a manner, there is a possibility that a problem occurs in durability of the heat insulating member from a long-term viewpoint.

  If the conditions for the cleaning process are set so that such etching of the heat insulating member does not occur, the film may remain after the cleaning process in the gap between the adjacent heat shield plates. When the film thickness accumulated by repeating the film formation process is increased, cracks are generated in the film, and fragments of the film may be scattered and become particles and adhere to the wafer.

  The apparatus disclosed in Patent Document 1 does not consider the problem of forming a film on such a heat insulating member. Patent Document 2 describes that purge gas is supplied from a heat insulating member, but the heat insulating member does not have a structure in which the heat shield plates as described above are stacked, and the adjacent ones described above. There is no focus on the problem of film formation between the heat shield plates.

JP-A-7-176490 JP-A-7-122512

  The present invention has been made under such circumstances, and its purpose is to hold a substrate in a shelf shape on a substrate holder, heat the substrate by a heating unit surrounding the processing container, and supply a processing gas to the substrate. In the vertical heat treatment apparatus for forming a film, the film is prevented from being formed on the heat insulating member provided below the substrate holder.

The vertical heat treatment apparatus of the present invention holds a substrate in a shelf shape on a substrate holder, carries it in from a lower entrance of a vertical processing container, heats the substrate by a heating unit surrounding the processing container, and In a vertical heat treatment apparatus for forming a film by supplying a processing gas to a substrate,
A lid that is mounted thereon and is movable up and down to close the carry-in port;
A heat insulating member composed of a cylindrical column provided on the lid on the lower side of the substrate holder, and a plurality of heat shield plates arranged in a shelf along the column;
A purge gas supply port formed in a pipe wall of the support column for supplying a purge gas between the heat shield plates adjacent to each other when the processing gas is supplied;
A rotating unit for rotating the substrate holder;
Equipped with a,
The rotating part is
A table provided on the lid and for placing the column;
A shaft member extending from the table to the outside of the processing container through the lid,
A drive mechanism that is provided outside the processing vessel and rotates the shaft member;
With
The table and the shaft member are provided with a flow path for introducing purge gas from the outside of the processing container to the purge gas supply port .
Another vertical heat treatment apparatus of the present invention holds a substrate in a shelf shape on a substrate holder, carries it in from a lower entrance of a vertical processing container, and heats the substrate by a heating unit surrounding the processing container. And a vertical heat treatment apparatus for forming a film by supplying a processing gas to the substrate,
A lid that is mounted thereon and is movable up and down to close the carry-in port;
A heat insulating member composed of a cylindrical column provided on the lid on the lower side of the substrate holder, and a plurality of heat shield plates arranged in a shelf along the column;
A purge gas supply port formed in a pipe wall of the support column for supplying a purge gas between the heat shield plates adjacent to each other when the processing gas is supplied;
A cleaning gas supply unit for supplying a cleaning gas for cleaning the inside of the processing container into the processing container when supply of the processing gas to the substrate is stopped;
Supplying the purge gas from the purge gas supply port at a first flow rate in parallel with the supply of the processing gas to the substrate; and the purge gas supply port in parallel with the supply of the cleaning gas from the cleaning gas supply unit. Supplying the purge gas at a second flow rate smaller than the first flow rate, and a control unit that outputs a control signal so as to be performed,
It is provided with.

  According to the present invention, the support constituting the heat insulating member is formed in a cylindrical shape, and when the process gas is supplied from the purge gas supply port formed on the tube wall of the support, the purge gas is supplied between the heat shield plates adjacent to each other vertically. Is done. With such a configuration, it is possible to remove the processing gas flowing between the heat shield plate and the heat shield plate and suppress film formation on the heat insulating member.

It is a vertical side view of the vertical heat processing apparatus which concerns on the 1st Embodiment of this invention. It is a vertical side view of the cover body, turntable, and heat insulation member provided in the vertical heat treatment apparatus. It is a perspective view of the said heat insulation member. It is explanatory drawing which shows the flow of the gas inside the processing container provided in the said vertical heat processing apparatus. It is explanatory drawing which shows the flow of the gas in the said heat insulation member. It is a vertical side view of the vertical heat processing apparatus which concerns on the 2nd Embodiment of this invention. It is a vertical side view of the heat insulation member provided in the said vertical heat processing apparatus. It is explanatory drawing of a structure of a heat insulation member. It is a cross-sectional top view which shows the other structural example of the support | pillar which comprises a heat insulation member.

(First embodiment)
A vertical heat treatment apparatus 1 according to a first embodiment of the present invention will be described with reference to FIG. 1 which is a vertical side view. The vertical heat treatment apparatus 1 is a film forming apparatus that forms a laminated film made of SiN and SiO _{2 on a} wafer W by CVD. In the figure, reference numeral 11 denotes a processing container formed of, for example, quartz in a vertical cylindrical shape, and the upper side in the processing container 11 is sealed with a ceiling plate 12. Further, a manifold 13 formed, for example, in a cylindrical shape is connected to the lower end side of the processing container 11. The lower end of the manifold 13 is opened as a substrate loading / unloading port 14 and is configured to be airtightly closed by a lid body 2 made of, for example, quartz. The lid 2 is configured to be movable up and down by a boat elevator 15 so that the substrate loading / unloading port 14 can be opened and closed. In the figure, reference numeral 20 denotes an O-ring interposed between the lid body 2 and the manifold 13.

  A circular turntable 21 in plan view is provided on the lid 2, and a heat insulating member 7 described later is provided on the turntable 21. On the heat insulating member 7, a wafer boat 3 as a substrate holder is mounted. The wafer boat 3 is provided with, for example, three columns 31 (only two are shown in FIG. 1), and supports the outer edge portion of the wafer W, which is a circular substrate, to provide a plurality of, for example, 125 wafers. W can be held in a shelf shape in the vertical direction.

  When the lid 2 is moved up and down by the boat elevator 15, the wafer boat 3 is loaded (loaded) into the processing container 11, and the processing position where the substrate loading / unloading port 14 of the processing container 11 is blocked by the lid 2. And an unloading position on the lower side of the processing container 11 are configured to be movable up and down. The unloading position is a position where the wafer W is transferred to the wafer boat 3 by a transfer mechanism (not shown).

  An exhaust port 16 that is vertically elongated is formed on the side wall of the processing container 11 in order to evacuate the atmosphere in the processing container 11. An exhaust cover member 17 having a U-shaped cross section made of quartz, for example, is attached to the exhaust port 16 so as to cover it. The exhaust cover member 17 extends, for example, vertically along the side wall of the processing container 11 and is configured to cover the upper side of the processing container 11. For example, a gas outlet 18 is provided on the ceiling side of the exhaust cover member 17. Is formed. The gas outlet 18 is connected to an exhaust mechanism 19 configured by a vacuum pump and an adjusting unit for adjusting the exhaust flow rate. In the figure, reference numeral 10 denotes a heater that forms a heating unit, which is provided so as to surround the outer periphery of the processing container 11 and heats the inside of the processing container 11.

  One end (downstream end) of a gas supply path 41 is inserted into the side wall of the manifold 13, and a gas nozzle 42 made of, for example, a quartz tube is connected to one end of the gas supply path 41. A gas nozzle 42 as a processing gas supply unit extends along the side wall of the processing container 11 and is provided to face the exhaust port 16. In the figure, reference numeral 43 denotes a gas supply port, and a large number of openings are provided along the length direction of the gas nozzle 42 so that gas can be supplied from the side to each wafer W held on the wafer boat 3.

The other end side (upstream side) of the gas supply path 41 is branched into, for example, four to form branch paths 44A to 44D, and the upstream end of the branch paths 44A to 44D is a nitrogen (N ₂ ) gas supply source 45A, An ammonia (NH ₃ ) gas supply source 45B, a dichlorosilane (DCS: SiH ₂ Cl ₂ ) gas supply source 45C, and a nitrogen dioxide (NO ₂ ) gas supply source 45D are connected to each other. NH ₃ gas, DCS gas, and NO ₂ gas are process gases for forming a film, and N ₂ gas is a purge gas for purging each part. Mass flow controllers MFC1 to MFC4 are respectively provided upstream of the branch paths 44A to 44D, and valves V1 to V4 are respectively provided downstream of the branch paths 44A to 44D.

Further, one end (downstream end) of a gas supply path 46 that is a cleaning gas supply unit is inserted in the side wall of the manifold 13, and the upstream end of the gas supply path 46 is branched into, for example, two branches 47 </ b> A, 47B is formed, and the upstream ends of the branch paths 47A and 47B are connected to a fluorine (F ₂ ) gas supply source 48A and a hydrogen fluoride (HF) gas supply source 48B, respectively. A mixed gas of HF gas and F ₂ gas is used as the cleaning gas described in the background art section. Mass flow controllers MFC5 and MFC6 are provided upstream of the branch paths 47A and 47B, respectively, and valves V5 and V6 are provided downstream of the branch paths 47A and 47B, respectively.

  The lid 2 and the turntable 21 will be described in more detail with reference to FIG. 2 which is a longitudinal side view. A through-hole penetrating the lid 2 vertically is formed at the center of the lid 2, and the upper end portion of the rotary cylinder 51 that forms a shaft member is vertically inserted into the through-hole from the lower side. The turntable 21 is connected to the center of the back surface. The lower end of the rotating cylinder 51 is folded outward to form a ring-shaped recess 53 in a plan view. A plate 54 is attached to the lower surface of the lid 2. The plate 54 includes a through hole, and the rotating cylinder 51 is provided through the through hole of the plate 54.

  Further, the peripheral edge portion of the through hole of the plate 54 is extended downward so as to enter the concave portion 53 to form a fixed cylinder 55. A bearing 56 is provided in the gap between the outer surface of the fixed cylinder 55 and the side surface of the recess 53, and a seal member 57 is provided below the bearing 56 to seal the gap. A cup body 58 having an upper opening is provided below the plate 54 so as to surround the fixed cylinder 55 and the rotary cylinder 51, and the upper end of the cup body 58 is connected to the peripheral edge of the plate 54.

One end of a vertical gas supply pipe 61 enters the lower end of the rotating cylinder 51 from below, the other end of the gas supply pipe 61 penetrates the cup body 58, and the valves V7 and MFC7 are connected in this order. And is connected between the N ₂ gas supply source 45A and the MFC 1 in the branch path 44A (see FIG. 1). A bearing 62 is provided in the gap between the outer surface of the gas supply pipe 61 and the inner surface of the rotating cylinder 51. Further, a seal member 63 for sealing the gap is provided below the bearing 62. The rotary cylinder 51 is supported by the bearing 62 and the bearing 56 so as to be rotatable with respect to the lid body 2. Further, the sealing members 57 and 63 are made of, for example, a magnetic fluid so as not to prevent the rotation of the rotary cylinder 51.

  Further, assuming that the clearance between the inner peripheral surface of the through hole of the lid body 2 and the inner peripheral surface of the fixed cylinder 55 and the outer peripheral surface of the rotary cylinder 51 is 60, on the upper side of the concave portion 53 of the fixed cylinder 55, One end of the gas supply pipe 64 is connected so as to open into the gap 60. The other end of the gas supply pipe 64 passes through the cup body 58, and is connected between the N2 gas supply source 45A and the MFC1 in the branch passage 41A through the valve V8 and the MFC8 in this order (see FIG. 1). . With such a configuration, N 2 gas is supplied from the gas supply pipe 64 to the gap 60, and the N 2 gas flows from the gap 60 into the processing container 11. By forming the flow of N 2 gas in this way, it is possible to prevent the deposition of each processing gas for film formation into the gap 60 to form a film. Each valve V adjusts gas supply, and each flow rate adjustment unit MF adjusts gas supply amount.

  Outside the cup body 58, a motor 65, which is a drive mechanism, is provided fixed to the lid body 2. The motor 65 and the rotating cylinder 51 are connected by a belt 66 through an opening 59 provided in the cup body 58, and the rotating cylinder 51 rotates around the axis by the rotation of the motor 65. As a result, the turntable 21 connected to the rotating cylinder 51 rotates in the circumferential direction, and the wafer boat 3 on the heat insulating member 7 also rotates. As the wafer boat 3 rotates in this manner, the wafer W rotates in the circumferential direction.

  A heat insulating member 7 made of, for example, quartz is provided on the turntable 21. The heat insulating member 7 is located below the bottom plate of the wafer boat 3 indicated as 32 in FIG. 1, and the atmosphere above the bottom plate 32 of the wafer boat 3 in the processing container 11 and the atmosphere of the substrate loading / unloading port 14. Insulate. The heat insulating member 7 will be described with reference to FIG. 3 which is a perspective view. The heat insulating member 7 includes six vertical columns 71 and six horizontal heat shield plates 72. Each column 71 is disposed along the circumferential direction of the turntable 21, and the lower end portion thereof is inserted into a recess 24 provided on the upper surface of the turntable 21. The heat shield plates 72 are formed in a circular shape and are provided so as to overlap each other with an interval in the vertical direction. That is, the heat shield plates 72 are arranged in a shelf shape along the support columns 71.

  The support column 71 supports the peripheral edge portion of each heat shield plate 72, and is supported by penetrating the support column 71, for example. A cylindrical support leg 33 is provided on the lower surface of the bottom plate 32 of the wafer boat 3 at a position corresponding to the column 71, and a convex portion formed on the upper end surface of the column 71 and the lower end surface of the support leg 33. The wafer boat 3 is supported on the heat insulating member 7 by the engagement with the concave portion formed in. In addition, in FIG. 3, the display of the convex part of said support | pillar 71 is abbreviate | omitted. The distance H1 between the heat shield plates 72 adjacent to each other in the vertical direction shown in FIG. 2 is, for example, 7 mm to 25 mm, and in this example, 12 mm.

Inside each column 71, a flow path 73 of N ₂ gas is formed along the length direction of the column 71. Accordingly, the support column 71 has a cylindrical shape and is configured as an N ₂ gas supply pipe. A gas supply port 74 communicating with the flow path 73 is opened on the side wall (tube wall) of the support 71 so as to be directed toward the center of the heat shield plate 72 between the heat shield plates 72 adjacent in the vertical direction. . The turntable 21 has an upstream end opened in the cylinder of the rotary cylinder 51, a downstream end opened in the bottom surface of the recess 24, and an N ₂ gas flow path communicating with the flow path 73 of the column 71. 67 is formed, and the N ₂ gas supplied from the gas supply pipe 61 into the rotary cylinder 51 is discharged from the gas supply port 74 through the flow paths 67 and 73.

  The vertical heat treatment apparatus 1 includes a control unit 100 configured by, for example, a computer (see FIG. 1). The control unit 100 moves the lid 2 up and down by the boat elevator 15, the temperature of the heater 10, the gas supply amount by the flow rate adjustment unit MFC, the gas supply / disconnection by opening and closing the valve V, the exhaust amount by the exhaust mechanism 19, and the motor 65. Is configured to control the rotation of the turntable 21. More specifically, the control unit 100 includes a program for executing a series of processing steps to be described later performed in the processing container 11, reads out the instructions of the program, and controls each unit of the vertical heat treatment apparatus 1. Output a signal. The program is stored in the control unit 100 while being stored in a storage medium such as a hard disk, a flexible disk, a compact disk, a magnetic optical disk (MO), or a memory card.

  Subsequently, a film forming process performed in the vertical heat treatment apparatus 1 will be described. First, a large number of wafers W are placed on the wafer boat 3 in a shelf shape, loaded (loaded) into the processing container 11 from below, the substrate loading / unloading port 14 is closed with the lid 2, and the processing container 11 is sealed. To do. The inside of the processing container 11 is evacuated by the exhaust mechanism 19 so that a vacuum atmosphere of a predetermined pressure is obtained, and the inside of the processing container 11 is heated to a predetermined temperature by the heater 10.

Then, the turntable 21 is rotated by the motor 65, and supply of DCS gas and NH ₃ gas as a film forming process gas from the gas nozzle 42 is started, and N ₂ from the gap 60 and the gas supply port 74 of the column 71 is started. Gas supply is started. In FIG. 4, the flow of each gas in the processing container 11 at this time is schematically indicated by solid arrows. As the turntable 21 rotates, DCS gas and NH ₃ gas are supplied to the surface of the rotating wafer W as indicated by the dotted arrows in the figure, and these gases react with each other due to the heat of the wafer W, thereby forming SiN. The SiN is generated and deposited on the wafer W. That is, a SiN film is formed on the wafer W surface by CVD.

FIG. 5 shows between the heat shielding plates 72 and 72 adjacent to each other, and the processing gas is indicated by a dotted arrow, and the N ₂ gas (purge gas) discharged from the column 71 is indicated by a solid arrow. The processing gas that has flowed into the region (indicated as 75 in the figure) inside the region where the support 71 is disposed between the heat shield plates 72 and 72 is purged toward the center of the heat shield plate 72 by the N ₂ gas. The As a result, it is possible to prevent each gas from reacting with each other on the side surface of the support 71 facing the inner region 75 and the surface of the heat shield plate 72 facing the inner region 75 to form a SiN film. The purged process gas flows from the space where the conductance between the adjacent heat shield plates 72 is large into the process chamber outside the heat shield plate 72, and then flows to the exhaust port 16 to be removed from the process vessel 11. .

When DCS gas and NH ₃ gas are discharged for a predetermined time, discharge of these gases is stopped. Also, the discharge of N ₂ gas from the gap 60 and the gas supply port 74 of the support 71 is stopped. Thereafter, N ₂ gas is discharged from the gas nozzle 42 and the processing gas remaining in the processing container 11 is purged. When N ₂ gas is discharged from the gas nozzle 42 for a predetermined time, the discharge of the N ₂ gas is stopped. Then, supply of DCS gas and NO ₂ gas, which are processing gases, is started from the gas nozzle 42, and supply of N ₂ gas is resumed from the gap 60 and the gas supply port 74 of the support 71.

DCS gas and NO ₂ gas are supplied to the rotating wafer W surface, and a SiO ₂ film is formed by CVD. When the SiO ₂ film is formed, the processing gas that has flowed into the inner region 75 of the above-described heat insulating member 7 is purged from the inner region 75 by the N ₂ gas, as in the case of forming the SiN film. Exhausted from. Therefore, it is possible to prevent the SiO ₂ film from being formed on the side surface of the support 71 and the surface of the heat shield plate 72 toward the inner region 75.

When the DCS gas and the NO2 gas are discharged for a predetermined time, the discharge of these gases is stopped. Also, the discharge of N ₂ gas from the gap 60 and the gas supply port 74 of the support 71 is stopped. Then, when the degree of vacuum in the processing container 11 decreases and the output of the heater 10 decreases and the rotation of the turntable 21 stops, the lid body 2 is lowered and the wafer boat 3 is unloaded from the processing container 11, The film forming process ends. This film forming process is an example, and a SiN film may be formed on the upper side of the SiO 2 film, or the SiO 2 film and the SiN film may be alternately and repeatedly formed. Even in the case where the film is formed as described above, the purge gas is supplied from the support column 71 when each processing gas is supplied as described above, and the film formation on the heat insulating member 7 is suppressed.

  Next, the cleaning process in the processing container 11 will be described. After the above film forming process is repeated, for example, a predetermined number of times, the wafer boat 3 is loaded into the processing container 11 in the same manner as during the film forming process without the wafer W mounted, and the substrate loading / unloading port is opened by the lid 2. 14 is closed, and the inside of the processing container 11 is evacuated with a predetermined exhaust amount to form a vacuum atmosphere. Moreover, while the inside of the processing container 11 is heated by the heater 10, the turntable 21 rotates.

Thereafter, F ₂ gas and HF gas are supplied to the gas supply path 46, mixed, and discharged into the processing container 11 as a cleaning gas. Further, simultaneously with the start of the discharge of the cleaning gas, the discharge of the N 2 gas from the gap 60 and the gas supply port 74 of the support 71 is started in the same manner as the film forming process. This discharge of N ₂ gas is performed to prevent the cleaning gas from flowing into the gap 60 and the column 71 and etching the lid 2 and column 71.

The cleaning gas discharged into the processing container 11 reaches each part in the processing container 11 to remove the SiO ₂ film and the SiN film. By the way, in the heat insulating member 7, since the gas supply port 74 is formed toward the inner region 75 as described above, each part that does not face the inner region 75, specifically, the shielding is formed during the film forming process. The SiN film and the SiO2 film are formed on the side surface of the hot plate 72 opposite to the side of the support plate 71 facing the inner region 75. However, each part that does not face the inner region 75 is not in a more complicated position than each part that faces the inner region 75, so that it easily comes into contact with the cleaning gas. Therefore, the SiN film and the SiO 2 film of each part not facing the inner region 75 are removed by this cleaning process.

Further, even if film formation is slightly performed on each portion of the support 71 and the heat shield plate 72 facing the inner region 75 in the above-described film formation process, the cleaning gas is supplied to the inner region 75 during the cleaning process. The amount of N ₂ gas discharged from the support 71 during the cleaning process is controlled so that the film is removed. Specifically, the flow rate of N ₂ gas supplied from the gas supply source 45A to each column 71 during the cleaning process is smaller than the flow rate of N ₂ gas supplied from the gas supply source 45A to each column 71 during the film forming process. Controlled.

When the cleaning gas is supplied for a predetermined time, the supply of the cleaning gas is stopped, and the supply of N ₂ gas from the gap 60 and the supply of N ₂ gas from the gas supply port 74 of the support 71 are also stopped. Then, when the pressure in the processing container 11 increases and the output of the heater 10 decreases and the rotation of the turntable 21 stops, the lid 2 descends and the wafer boat 3 is unloaded from the processing container 11 to form a film. The process ends.

  According to the vertical heat treatment apparatus 1, the purge gas is supplied between the heat shield plates 72 and 72 from the support 71 constituting the heat insulating member 7 in parallel with the supply of the processing gas during the film forming process. Thus, film formation between the heat shield plates 72 and 72 can be suppressed. Accordingly, in order to remove the film between the heat shield plates 72, 72, it is not necessary to perform a cleaning process under such a condition that the etching amount of each part not facing the inner region 75 is increased. 7 can be extended in service life. Further, since the remaining film after the cleaning process is suppressed in each part facing the inner region 75, it is possible to suppress the generation of particles from the remaining film and the adhesion to the wafer W.

  Further, according to the vertical heat treatment apparatus 1, the wafer boat 3 is moved in a state where the purge gas is discharged from the support column 71 as described above by the rotating unit including the motor 65, the rotating cylinder 51, and the turntable 21. Can be rotated. By rotating the wafer boat 3, the processing gas can be supplied to the surface of the wafer with high uniformity, so that the uniformity of the film thickness of each film in the plane of the wafer W can be increased.

(Second Embodiment)
Next, the vertical heat treatment apparatus 8 according to the second embodiment will be described focusing on the differences from the vertical heat treatment apparatus 1 with reference to the vertical sectional side view of FIG. The vertical heat treatment apparatus 8 includes a lid 81 instead of the lid 2. The lid 81, which is a thick plate, includes a base 82 connected to the boat elevator 15 and a main body 83 made of, for example, quartz. The base 82 and the main body 83 are formed in a plate shape. A main body 83 is embedded in a recess 84 formed in the upper part of the base 82, and the base 82 and the main body 83 are fitted to each other.

  This will be described with reference to the longitudinal side view of FIG. The O-ring 20 and each support 71 of the heat insulating member 7 are provided on the main body 83. Further, in this second embodiment, the heat shield plate 72 of the heat insulating member 7 is configured as a circular ring plate having an open central portion, and the central portion of the heat shield plate 72 is formed on the main body portion 83. A vertical support shaft 22 is provided so as to penetrate. In FIG. 6, reference numeral 23 denotes a stage that holds the wafer boat 3, and is constituted by the upper end of the support shaft 22. In the main body 83, six through holes 85 (only three are shown in FIG. 7) are perforated in the thickness direction of the main body 83, and are arranged at positions that overlap with the columns 71. The peripheral edge of the through-hole 85 rises on the upper surface and the lower surface of the main body portion 83 to form ring-shaped convex portions 86 and 87, respectively. The outer peripheral side surface of the convex portion 86 is fitted to the side peripheral surface forming the flow path 73 of the column 71.

Moreover, the bottom surface of the concave portion 84 of the base portion 82 is provided with holes at positions corresponding to the convex portions 87, and the outer peripheral side surfaces of the convex portions 87 and the side peripheral surfaces of the holes are fitted to each other. These holes of the recess 84 constitute the downstream end of the N 2 gas flow path 89, the upstream sides of the flow path 89 merge with each other, and the upstream end of the merged flow path 89 is on the side surface of the base 82. It is open. The upstream end of the flow path 89 is connected between the N ₂ gas supply source 45A and the MFC 1 in the branch path 44A via the gas supply path 91 as shown in FIG. Valves V9 and MFC9 are interposed in this order toward the upstream side. For convenience, the MFC 9 is shown in FIG. 7 so as to be close to the lid 81, but is actually installed at a position not affected by the heat from the heater 10 or the lid 2.

With the above configuration, the N 2 gas is supplied from the N 2 gas supply source 45A to the flow path 73 of the support 71 through the flow path 89 and the through hole 85, and the N ₂ gas is discharged from the gas supply port 74. it can. In this vertical heat treatment apparatus 8, since the turntable 21 and the motor 65 are not provided, the vertical heat treatment apparatus except that the heat insulating member 7 and the wafer boat 3 are not rotated during the film forming process and the cleaning process. The film forming process and the cleaning process are performed in substantially the same manner as in FIG. Therefore, during the film forming process and the cleaning process, the N 2 gas is discharged from the support column 71 as in the vertical heat treatment apparatus 1.

  By the way, the heat insulating member 7 of the vertical heat treatment apparatus 8 is divided into two along the diameter of the heat shield plate 72 as shown in FIG. The support 71 is configured to be detachable from the main body 83 of the lid 81. With such a configuration, the heat insulating member 7 can be easily replaced and maintained. The main body 83 is also configured to be detachable from the base 82 and can be easily replaced and maintained. The heat insulating member 7 of the vertical heat treatment apparatus 1 is also divided as shown in FIG. 8, for example, and is configured to be detachable from the turntable 21. In order to be detachable from the turntable 21, the side peripheral surface of the recess 24 into which the support 71 described in FIG. 2 is inserted and the outer periphery of the support 71 may be fitted to each other. 7 may be provided on the turntable 21. As shown in FIG. In addition, about the number of the heat shield plates 72 and the number of the support | pillars 71, it is not restricted to the above-mentioned example.

In each embodiment, the direction of gas supply from the support column 71 is not limited to the above example. In the example shown in FIG. 9, three gas supply ports 74 are formed at intervals in the circumferential direction of the column 71, and N ₂ gas can be supplied toward a wider range toward the inner region 75. By supplying N ₂ gas in a wide range in this way, a gas barrier is formed, and it becomes difficult for the processing gas to flow into the inner region 75, and formation of a film in the inner region 75 and generation of particles from the film Can be prevented more reliably.

  In the above example, a vertical heat treatment apparatus that performs CVD has been described. However, the present invention is not limited to such an apparatus for film formation, and may be applied to an apparatus for film formation by ALD. In addition, the film formed on the wafer W by the vertical heat treatment apparatus is not limited to being composed of SiN and SiO 2, and is not limited to a stacked film in which different types of films are stacked. This film may be used.

W Wafer 1 Vertical heat treatment apparatus 11 Processing vessel 19 Exhaust mechanism 2, 81 Cover 3 Wafer boat 42 Gas nozzle 65 Motor 7 Heat insulation member 71 Support column 72 Heat shield plate 74 Gas supply port

Claims (5)

A substrate is held on a substrate holder in a shelf shape, carried in from a carry-in port at the lower end of a vertical processing container, heated by a heating unit surrounding the processing container, and supplied with a processing gas to the substrate. In a vertical heat treatment apparatus that forms a film,
A lid that is mounted thereon and is movable up and down to close the carry-in port;
A heat insulating member composed of a cylindrical column provided on the lid on the lower side of the substrate holder, and a plurality of heat shield plates arranged in a shelf along the column;
A purge gas supply port formed in a pipe wall of the support column for supplying a purge gas between the heat shield plates adjacent to each other when the processing gas is supplied;
A rotating unit for rotating the substrate holder;
With
The rotating part is
A table provided on the lid and for placing the column;
A shaft member extending from the table to the outside of the processing container through the lid,
A drive mechanism that is provided outside the processing vessel and rotates the shaft member;
With
A vertical heat treatment apparatus, wherein the table and the shaft member are provided with a flow path for introducing purge gas into the purge gas supply port from the outside of the processing vessel . Vertical heat treatment apparatus according to claim 1, wherein a purge gas supply unit for supplying a purge gas is provided in a gap between the lid and the shaft member. 3. The heat treatment apparatus according to claim 1, wherein the rotating unit rotates the substrate holder during the supply of the purge gas and the processing gas. A substrate is held on a substrate holder in a shelf shape, carried in from a carry-in port at the lower end of a vertical processing container, heated by a heating unit surrounding the processing container, and supplied with a processing gas to the substrate. In a vertical heat treatment apparatus that forms a film,
A lid that is mounted thereon and is movable up and down to close the carry-in port;
A heat insulating member composed of a cylindrical column provided on the lid on the lower side of the substrate holder, and a plurality of heat shield plates arranged in a shelf along the column;
A purge gas supply port formed in a pipe wall of the support column for supplying a purge gas between the heat shield plates adjacent to each other when the processing gas is supplied;
A cleaning gas supply unit for supplying a cleaning gas for cleaning the inside of the processing container into the processing container when the supply of the processing gas to the substrate is stopped;
Supplying the purge gas from the purge gas supply port at a first flow rate in parallel with the supply of the processing gas to the substrate; and the purge gas supply port in parallel with the supply of the cleaning gas from the cleaning gas supply unit. Supplying the purge gas at a second flow rate smaller than the first flow rate, and a control unit that outputs a control signal so as to be performed,
A vertical heat treatment apparatus comprising: The strut has a plurality provided to support the periphery of the heat shield plate, claims 1, characterized in that each of said purge gas discharge port is opened toward the center of the heat shield plate 4 The vertical heat treatment apparatus according to any one of the above.

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