JP5924336B2 - Nozzle for supplying source gas for chemical vapor deposition - Google Patents

Description

  The present invention relates to a chemical vapor deposition process in which vapor deposition is performed on a metal strip, in particular, in a treatment furnace in a chemical vapor deposition process in which a steel film is subjected to vapor deposition with a silicon coating or TiN, TiC, or SiN. The present invention relates to a nozzle for supplying a source gas for chemical vapor deposition suitable as a nozzle used when spraying a source gas on the steel plate.

In recent years, it has been studied to apply silicon deposition by continuously attaching Si to a metal strip such as a steel plate by chemical vapor deposition (CVD) or to coat a ceramic material such as TiN, TiC, or SiN. In order to apply a chemical vapor deposition method to continuously perform a silicidation treatment or form a ceramic film on a metal strip, the metal strip in the processing furnace where the chemical vapor deposition treatment is performed is applied with a raw material gas for the siliconization treatment. It is important to uniformly blow a certain silicon gas (a gas containing SiCl ₄ ) or a gas serving as a raw material of the ceramic coating so that the raw material gas concentration in the vicinity of the surface of the metal strip is uniform, particularly in the width direction of the metal strip. . This source gas is usually supplied toward the metal strip through the nozzle, and it is important that the source gas is sprayed from the nozzle evenly in the width direction of the metal strip.

  For example, Patent Document 1 describes a gas supply nozzle for adjusting the atmosphere in a furnace applied to a chemical vapor deposition furnace or the like of a continuous siliconization processing facility in which a steel sheet is subjected to a siliconization process to obtain a high silicon steel sheet, and has a nozzle structure. A concentric double cylinder composed of an outer cylinder and an inner cylinder inserted into the outer cylinder, wherein a heater device is provided in the inner cylinder, and a blow-out hole for blowing gas into the furnace is formed in the outer cylinder. It is disclosed. In Patent Document 1, the gas supply nozzle is configured as described above, and the gas blown into the furnace from the gas blowing holes provided in the outer cylinder by heating the raw material gas through the inner cylinder and heating and raising the temperature. It is described that there is almost no temperature difference from the atmosphere, natural convection is prevented from flowing in the furnace atmosphere, and the gas flow is stabilized. Patent Document 1 describes that a horizontally long slit hole is provided in the middle portion of the outer cylinder so as to face the steel plate as a blowout port.

In Patent Document 2, a plurality of slit nozzles are arranged at intervals in the furnace length direction in a siliconizing furnace, and a processing gas is blown onto a steel plate passing through the slit nozzle, whereby Si steel is applied to the steel plate from its surface. In a method of continuously producing high silicon steel sheets by performing a siliconizing treatment for infiltrating silicon and then performing a heat treatment for diffusing Si in the thickness direction in a diffusion soaking furnace, each slit nozzle is provided in the siliconizing furnace. The slit nozzle is supplied with a processing gas from one end thereof, and a ratio a ₁ / a ₂ between the opening area a ₁ of the slit and the nozzle pipe radial direction cross-sectional area a ₂ inside the slit is a predetermined range. It is disclosed that the Si concentration distribution in the plate width direction is made uniform by optimizing the gas blowing angle from the slit nozzle. Further, as a slit nozzle, a nozzle having a single tube structure or a double tube structure including an outer tube having a slit and an inner tube to which a processing gas is supplied from one end side and the other end side is opened inside the outer tube is disclosed. ing.

  However, in these technologies, the flow state of the material gas blown by the shape of the nozzle and the size of the slit provided in the nozzle, for example, the gas flow velocity distribution changes, and a uniform flow velocity distribution in the width direction of the metal strip such as a steel plate is obtained. It was difficult to secure.

  In particular, in a slit nozzle having a double tube structure as disclosed in Patent Document 2, when the gas supplied from the tip of the inner tube into the outer tube exits from the slit of the nozzle, the tip of the inner tube, that is, the gas nozzle It is pointed out in Patent Document 3 that the closer to the inlet, the higher the flow velocity, and the gas exiting the slit has a flow in the tube axis direction, resulting in a non-uniform flow.

  The invention described in Patent Document 3 relates to a source gas supply nozzle for chemical vapor deposition used in a chemical vapor deposition process in which a ceramic film such as TiN is vapor-deposited on a metal strip. In Patent Document 3, for a chemical vapor deposition source gas supply nozzle having a slit-like discharge port, the source gas is introduced into the nozzle from a position sufficiently away from the source gas discharge port to discharge the nozzle in the nozzle. It is disclosed that a flow having a vector of a component perpendicular to the outlet direction (component in the tube axis direction) is suppressed and a uniform flow velocity distribution is obtained in the longitudinal direction of the discharge port. In Patent Document 3, a nozzle that blows a raw material gas toward a metal strip introduced into a processing furnace that performs chemical vapor deposition, the raw material is disposed on one busbar of a tubular body having an axial length that extends over the entire width of the metal strip. A nozzle for supplying a raw material gas for chemical vapor deposition has been proposed, characterized in that a gas discharge port is formed in a slit shape, and a raw material gas introduction port is provided on the back side spaced radially from the discharge port. In particular, since a flow having a vector in the tube axis direction is likely to occur, it is disclosed that the ratio of the opening area S1 of the discharge port and the area S2 of the cross section perpendicular to the tube axis is preferably 0.35 or less. Has been.

  As a chemical vapor deposition apparatus for vapor-depositing a ceramic coating such as TiN on a metal strip, Patent Document 4 includes a vertical processing furnace for conveying the metal strip in the vertical direction, and the inside of the processing furnace. , Providing a nozzle that pairs the metal strip and supplies process gas toward the surface of the metal strip.

Japanese Patent Laid-Open No. 7-278819 JP-A-8-176793 JP 2005-256084 A Japanese Patent Laying-Open No. 2005-256075

In particular, in the case of a siliconization process performed when manufacturing a high-silicon steel sheet, the distribution of the gas when spraying a silicon-containing gas that is a raw material gas for chemical vapor deposition, that is, a gas containing SiCl ₄ , is as follows. Greatly affects physical and electromagnetic properties. In addition, if the Si concentration distribution in the width direction of the steel sheet after the siliconization treatment becomes non-uniform, the lattice constant difference due to the Si amount difference may cause a steel plate shape defect or uneven magnetic characteristics due to the Si amount difference. Therefore, it has been desired to obtain a uniform gas distribution particularly in the width direction. In the siliconization treatment, as described above, a nozzle having a double tube structure is used, and the siliconization treatment is performed by blowing the raw material gas blown into the inner tube to the steel plate from the slit provided in the axial direction of the outer tube. It has been broken. For this reason, there has been a demand for a nozzle having such a double-pipe structure that can supply a uniform raw material gas in the width direction.

  On the other hand, in the technique described in Patent Document 3, as described above, for a nozzle having a double tube structure in which the inner tube is inserted inside the outer tube, the discharge of the raw material gas formed in the slit shape at the tip of the inner tube is performed. Introducing a source gas introduction port that opens on the back side that is radially separated from the outlet, and an opening area S1 of the discharge port and a cross-sectional area perpendicular to the tube axis, that is, in a double tube structure, It is disclosed that the ratio S1 / S2 with the area S2 of the cross section orthogonal to the axis is as small as 0.35 or less. However, when the width of the steel plate to be subjected to the siliconization process is increased, it is necessary to increase the width of the discharge port, and the area S1 of the discharge port is increased. It was necessary to increase the diameter of the tube, and it was difficult to arrange the steel plate in a siliconizing furnace.

  Therefore, the present invention is a nozzle used for supplying a raw material gas in a chemical vapor deposition method, and has a double-pipe structure applicable to a steel plate siliconizing process, and the blowing of the raw material gas is performed in the width direction of the metal strip. An object is to provide a nozzle for supplying a raw material gas that can be made uniform.

  The gist configuration of the present invention is shown below.

  [1] An outer tube that is disposed in a processing furnace that performs chemical vapor deposition on a metal strip, has a closed end that is provided with a slit in the axial length direction and has a closed end, a source gas is supplied from one end side, and the other end side is It has a double pipe structure with an inner pipe having an open end opened inside the outer pipe, and the source gas supplied from one end side of the inner pipe is blown out from the open end of the inner pipe toward the closed end of the outer pipe. A chemical vapor deposition nozzle for performing chemical vapor deposition processing by blowing into a metal strip through a slit provided in the outer pipe, and outside the slit provided in the outer pipe in the pipe axis direction. For supplying raw material gas for chemical vapor deposition processing, characterized in that a shielding plate for adjusting the flow of raw material gas is provided between the inner tube and the outer tube between the tube closed end side and the inner tube open end. nozzle.

  [2] In the above [1], the shielding plate is provided so that an opening area in a gap between the inner tube and the outer tube is increased on the back side of the slit in a cross section in the tube radial direction. A nozzle for supplying a raw material gas for the chemical vapor deposition described.

  [3] The nozzle for supplying a source gas for chemical vapor deposition according to [1] or [2], wherein the shielding plate is disposed at an open end portion of the inner tube.

  [4] The material gas supply for chemical vapor deposition according to [2] or [3], wherein an opening on the back side of the slit by the shielding plate has an angle of 290 ° or less in the tube diameter direction. Nozzle.

  [5] For supplying the raw material gas for the chemical vapor deposition process according to any one of [1] to [4], wherein the metal strip is a steel plate, and the chemical vapor deposition process is a siliconization process. nozzle.

  According to the raw material gas supply nozzle of the chemical vapor deposition process of the present invention, since the raw material gas can be sprayed uniformly regardless of the nozzle diameter, the metal strip such as the siliconization process of the steel plate or the deposition process of the ceramic coating The chemical vapor deposition process is extremely effective especially for forming a uniform film and for carrying out solid deposition and diffusion of various substances by chemical vapor deposition.

It is a schematic diagram in the vertical processing furnace in a chemical vapor deposition apparatus. It is a figure which shows the nozzle vicinity in the vertical processing furnace of a chemical vapor deposition apparatus. It is a schematic diagram of the external appearance of the raw material gas supply nozzle which has a double pipe structure. It is a schematic diagram which shows the internal structure of the nozzle for raw material gas supply which has a double pipe structure. It is a schematic diagram near the edge part of the nozzle for source gas supply of this invention. It is a schematic diagram of the shielding member which has the shielding board of the nozzle for raw material gas supply of this invention. It is a schematic diagram of the shielding member which has the shielding board of the nozzle for raw material gas supply of this invention. It is a schematic diagram explaining the attachment state of the shielding board of the source gas supply nozzle of this invention. It is a schematic diagram of the pipe diameter direction cross section of the part which provided the shielding board of the nozzle for raw material gas supply of this invention. It is a schematic diagram of the pipe diameter direction cross section of the part which provided the shielding board of the nozzle for raw material gas supply of this invention. It is a figure which shows the position which calculated | required the flow-velocity distribution of FIG. It is a figure which shows the flow-velocity distribution of a pipe-axis direction at the time of blowing out gas by a nozzle. It is a schematic diagram of the pipe diameter direction cross section of the part which provided the shielding board of the nozzle which is a comparative example. It is the result (constant velocity diagram) which computed the flow of the gas in the horizontal cross section containing a pipe axis at the time of using the nozzle of this invention. It is the result (constant velocity diagram) which computed the flow of the gas in a cross section perpendicular | vertical to a pipe axis at the time of using the nozzle of this invention. It is the result (constant velocity diagram) which computed the flow of the gas in the horizontal cross section containing the pipe axis at the time of using the nozzle of a comparative example. It is the result (constant velocity diagram) which computed the flow of the gas in a cross section perpendicular | vertical to a pipe axis at the time of using the nozzle of a comparative example. It is a schematic diagram of the edge part vicinity of the nozzle for raw material gas supply of this invention which has a baffle plate. 2 is a schematic diagram of a raw material gas supply nozzle of the present invention used in Example 1. FIG. It is a schematic diagram of the pipe diameter direction cross section of the part which provided the shielding board of the nozzle for raw material gas supply of this invention used for Example 1. FIG.

  First, for chemical vapor deposition processing in a vertical processing furnace which is an example of a chemical vapor deposition (hereinafter also referred to as CVD) apparatus to which the nozzle of the present invention is applied, a case where a metal strip is a steel plate using FIGS. An example will be described.

  As shown in FIGS. 1 and 2, in a vertical processing furnace, a steel plate 1 that is a metal strip passes through in the vertical direction, and nozzles 2 are arranged at corresponding positions with the steel plate 1 interposed therebetween. The nozzle 2 is a source gas supply nozzle. As shown in FIGS. 1 and 2, the raw material gas 4 is sprayed onto the steel plate 1 from the gas discharge port 2 s of the nozzle 2 while heating the steel plate 1 and the nozzle 2 with the heater 3. The in-furnace gas 5 is used as a non-reactive inert gas, the raw material gas 4 and the steel plate 1 are reacted, and various elements such as silicon (Si) are concentrated in a desired range in the steel plate. Alternatively, the in-furnace gas 5 is used as a reactive gas, and a chemical reaction is caused between the raw material gas 4 and the gas 5 supplied into the furnace to form the coating 6 on the surface of the steel plate 1.

  In the nozzle 2 used in such a CVD apparatus, the raw material gas 4 supplied therefrom must be a uniform jet. For example, when a TiN film is formed by a vapor deposition reaction, the jet velocity of the raw material gas 4 from the nozzle 2 needs to be 0.5 m / s or more, and preferably 1.5 m / s or more. At that time, the temperatures of the steel plate 1, the raw material gas 4 and the furnace gas 5 need to be 600 ° C. or higher, preferably 1000 ° C. or higher. Under these conditions, the film 6 is formed only on the surface of the steel sheet by a chemical reaction. For example, when silicon is concentrated in the steel plate 1, the temperature of the steel plate 1, the raw material gas 4, and the furnace gas 5 is desirably 800 ° C. or higher at the same jet velocity.

  What is important here is the uniformity of the raw material gas 4 blown out from the nozzle 2 and the blowout speed (injection speed). The structure of the nozzle 2 is important for this. Therefore, a nozzle with a double-pipe structure used for siliconization treatment was examined.

  3 and 4 schematically show the basic shape (appearance) and internal structure of the nozzle 2 having a double-pipe structure. For example, in the siliconization process, the nozzle 2 is a source gas supply nozzle for supplying a siliconization gas. The nozzle 2 has a double tube structure in which an inner tube 21 is inserted into the outer tube 20, and one end side 21a of the inner tube 21 serves as a gas blowing port through which a raw material gas is supplied to the inner tube. The other end side has an open end 21b opened inside the outer tube. The outer tube 20 is provided with a slit 2s, which is a discharge port for the source gas, in the axial direction, the open end 21b side of the inner tube is closed, and has a closed end 20b.

  3 and 4, when the source gas 4 is blown from the gas inlet 21a, the source gas 4 flows through the inner pipe to the open end 21b of the inner pipe, and the outer pipe is closed at the open end 21b of the inner pipe. It blows out toward the end 20b. The raw material gas 4 is folded at the closed end 20b of the outer tube, flows in the space between the inner tube 21 and the outer tube 20, and is a steel plate that is a metal strip from a slit 2s that is a gas discharge port provided in the outer tube 20. Is blown out.

  Here, in the case of a simple double tube structure as shown in FIGS. 3 and 4, the raw material gas 4 supplied from the open end 21 b of the inner tube into the outer tube 20 is a gas outlet of the nozzle. When blown out from the slit 2s toward the steel plate, the closer to the open end 21b of the inner tube 21, the higher the flow velocity, and the flow velocity distribution in the tube axis direction, resulting in a non-uniform flow. A uniform flow cannot be obtained when spraying on

  A schematic view of the vicinity of the closed end 20b side of the outer tube inside the nozzle of the present invention is shown in FIG. The basic structure of the nozzle of the present invention except that a shielding plate described later is provided has a double tube structure similar to that shown in FIGS. In the nozzle 2 of the present invention, the outer tube before being blown out from the slit 2s is blown out at the open end 21b of the inner tube toward the closed end 20b of the outer tube and turned back at the closed end 20b of the outer tube. A shielding plate 110 is provided between the end 2sb on the outer tube closing end side of the slit 2s provided in the outer tube in the tube axis direction and the inner tube open end 21b. By providing and adjusting the flow of the source gas, the source gas can be uniformly sprayed onto the steel plate. Note that the shielding plate 110 is preferably disposed at the open end of the inner tube. This is because by providing the shielding plate 110 at the above-described position, it is possible to prevent the raw material gas 4 from directly entering the slit 2s through which the gas is ejected and causing a non-uniform flow.

  The shielding plate 110 can be provided inside the nozzle 2 by a shielding member 100 having a shielding part 111 and an attachment part 120 to the inner tube as shown in FIG. In the configuration shown in FIG. 5, the shielding portion 111 is the shielding plate 110. Further, the shielding member 100 can be configured as shown in FIG. 7 so as to have a holding shielding portion 112 in order to reinforce the fixation of the shielding member 100 to the inner tube. By providing the holding shielding portion 112 and fixing the shielding member 100 to the inner tube, the position of the shielding plate 110 when it is provided between the inner tube and the outer tube can be stabilized. In FIG. 7, the shielding plate 110 includes a holding shielding part 112 and a shielding part 111.

Further, the shielding member 100 may be fixed by being attached to the inner tube by threading or installing the key after the inner tube is installed. As an example, FIG. 8 shows a schematic diagram of a state in which the shielding member 100 is attached to the inner tube 21 by threading and keys. In FIG. 8, the screwing member 121 is provided with a threaded part 121a, and the inner tube 21 is provided with a threaded part 121b capable of being screwed corresponding to the threaded part 121a. In addition, a key groove 122 a is provided as a detent in the attachment portion 120 of the shielding member 100 to the inner tube, and a key 122 b is provided at a corresponding position of the inner tube 21. In FIG. 8, after installing the inner pipe 21, the key groove 122 a provided in the attaching portion 120 of the shielding member 100 to the inner pipe is inserted into the key 122 b provided in the inner pipe 21, and the shielding member 100 is inserted into the inner pipe 21. Then, the shielding member 100 is fixed to the inner tube 21 by screwing the screwing member 121. The holding member such as the shielding member 100 and the screwing member 121 may be made of a machinable ceramic such as carbon or Si ₃ N ₄ , for example. In addition, since the processing method and accuracy are very good, it is possible to process ordinary ceramics without problems.

  FIG. 9 is a cross-sectional view in the tube diameter direction of a portion having the shielding member 100 shown in FIG. 6 and provided with the shielding plate 110 in the nozzle 2 of the example of the present invention. Here, the shielding plate 110 is provided on the outer tube so that the slit equivalent position 2sx is at the center. The slit equivalent position 2sx is a position where the slit 2s exists on the outer tube when it is assumed that the slit 2s is extended to the outer tube position where the shielding plate 110 is provided. The shielding plate 110 exists to prevent the raw material gas 4 emitted from the inner tube open end 21b from reaching the slit 2s directly in order to make the velocity distribution ejected from the slit 2s uniform. Therefore, the shielding plate 110 is configured to open at a position on the back surface that is symmetrical to the slit 2 s in the gap between the inner tube 21 and the outer tube 20. At this time, when the opening by the shielding plate 110 is small, the flow rate of the raw material gas 4 is increased. Therefore, the raw material gas 4 squirts after the raw material gas 4 wraps around the slit 2 s while maintaining the axial velocity, and the raw material gas 4 Has a velocity component in the axial direction, thereby promoting non-uniform flow velocity distribution. Therefore, the shielding plate 110 is configured so that the opening area in the gap between the inner tube 21 and the outer tube 20 becomes larger on the back side of the slit in the cross section in the tube radial direction, that is, in FIG. It is preferable to set the angle A in the tube diameter direction to 180 ° or more in order to alleviate that the raw material gas 4 ejected from the slit 2s has a velocity component in the axial direction and to prevent unevenness in the flow velocity distribution. However, if the opening of the shielding plate 110 becomes too large, the source gas 4 is directly ejected from the slit 2s close to the inner tube opening 21b, which is the same as the conventional non-uniform flow velocity distribution. Accordingly, it is preferable that the opening of the shielding plate 110 has an appropriate angle. Accordingly, the angle A in the tube radial direction of the opening is preferably set to 290 ° or less in order to prevent the raw material gas 4 from being directly ejected from the slit 2s close to the inner tube opening 21b. When the angle A of the opening is 290 °, the angle B in the tube diameter direction of the shielding plate 110 is 70 °.

  FIG. 10 is a cross-sectional view in the tube diameter direction of a portion where the shielding plate 110 in the nozzle 2 of the present invention example using the shielding member 100 shown in FIG. 7 having the shielding portion 111 and the holding shielding portion 112 is provided. Show. As described above, the shielding plate 110 includes the shielding part 111 and the shielding part 112 for holding. In this case, the opening area in the gap between the inner tube 21 and the outer tube 20 is determined from the area of the gap between the inner tube 21 and the outer tube 20 by the area of the shielding plate 110, that is, the shielding portion 111 and the holding portion. This is the area of the portion excluding the area shielded by the shielding section 112 for use. It is preferable that the area of this portion is increased on the back side of the slit. That is, in the tube diameter cross section, the area of the portion shielded by the shielding plate 110 on the slit side (SL side) is preferably made larger than the area of the portion shielded on the back side (SB side) of the slit.

  As shown in FIG. 10, when the holding shielding portion 112 is provided, the area of the opening, that is, the angle of the opening in the tube diameter direction is slightly reduced by the shielding by the holding shielding portion 112. It will be. In that case, what is important is the shielding on the SL side. This is a problem that the raw material gas 4 reaches the slit 2s close to the opening directly as described above. In order to prevent this, the angle B in the tube radial direction of the shielding part 111 provided on the SL side is desirable. Is 70 ° or more. There is no problem as long as the shielding portion 112 for attaching the holding portion is not affected and can hold the necessary strength. In that case, as shown in FIG. 10, the shield part for holding attachment is provided on the SB side, and the angles C1 and C2 in the tube diameter direction of the shield part 112 for attaching the holder part may be 20 ° or less, respectively. Is 10 ° or less. In FIG. 10, the angle in the tube diameter direction of the opening is a value obtained by removing B, C1, and C2 from 360 °.

  FIG. 12 shows the result of calculation at the flow velocity measurement position shown in FIG. 11 regarding the distribution of the flow velocity v in the tube axis direction of the flow of the raw material gas from the slit when the nozzle of the present invention example shown in FIG. 10 is used (invention). Example) is shown in relation to the distance L from the nozzle center. The distance shown in FIGS. 11 and 12 is a value normalized by the nozzle inner diameter D. In addition, FIG. 12 also shows, as a comparison, a result (comparative example) of calculating a flow velocity distribution when a nozzle provided with the shielding plate 210 shown in FIG. 13 is used. Here, the shielding plate 210 shown in FIG. 13 is an example in which evenly distributed holes h are arranged as openings in the gap between the inner tube 21 and the outer tube 20 that are source gas passages. As shown in FIG. 12, when the nozzle 2 of the present invention is used, it can be seen that the flow velocity distribution is uniform in the tube axis direction, that is, in the plate width direction of the metal strip, as compared with the comparative example.

  FIG. 14 is a constant velocity diagram which is a result of calculating the gas flow in the horizontal section including the tube axis when the nozzle of the present invention shown in FIG. 10 is used, and FIG. 15 is a cross-sectional view perpendicular to the tube axis. An isometric diagram which is the result of calculating the gas flow is shown. 16 is a constant velocity diagram that is a result of calculating the gas flow in the horizontal section including the tube axis when the nozzle of the comparative example shown in FIG. 13 is used. FIG. An isometric diagram which is a result of calculating a gas flow in a cross section is shown. Since FIGS. 15 and 17 are symmetrical in the Y direction, only the + side 1/2 in the Y direction is shown in the vertical cross section.

  As shown in FIG. 14, when the nozzle of the example of the present invention is used, it is understood that the horizontal flow velocity distribution of the gas flow blown out from the slit which is the gas discharge port provided in the outer tube is almost uniform. Further, as shown in FIG. 15, even when viewed in a cross section perpendicular to the tube axis, no significant disturbance is observed in the gas flow. On the other hand, as shown in FIG. 16, when the nozzle of the comparative example is used, the horizontal flow velocity distribution of the gas flow blown out from the slit, which is the gas discharge port provided in the outer tube, is biased, and as shown in FIG. Thus, it can be seen that there is also a bias when viewed in a cross section perpendicular to the tube axis.

  As described above, by using the raw material gas supply nozzle of the present invention, the flow from the slit which is the gas discharge port can be made uniform. In addition, since it has a structure in which a shielding plate is provided in the nozzle, it can be applied regardless of the nozzle diameter and length, and can be applied as a source gas supply nozzle in a chemical vapor deposition process in which a siliconization process or a ceramic coating is provided. Can do.

  Further, in addition to the above-described shielding plate, a rectifying plate 300 is provided between the open end 21b of the inner tube and the shielding plate 110 in the nozzle of the present invention, so that the SL side is shifted to the SB side. It is possible to control the flow of the air and to make it more uniform, and to increase the stability when holding the inner pipe. By providing such a current plate 300, the uniformity can be further improved.

  Using the CVD apparatus shown in FIGS. 1 and 2, a silicon steel plate was used as the metal strip, and a silicon immersion treatment (silicon concentration) was performed as a chemical vapor deposition treatment in order to reduce iron loss. The conditions are shown in Table 1. The flow rate of the raw material gas was adjusted so that the amount of silicon in the steel sheet was 6.5% by mass. The silicon steel plate used had a plate thickness of 100 μm, a plate width of 600 mm, a Si concentration of 3.1% by mass, and a Young's modulus of 210 GPa (normal temperature).

  The nozzle 2 of the present invention shown in FIGS. 19 and 20 was used as a nozzle for blowing the source gas onto the silicon steel plate. FIG. 19 is a schematic view of a nozzle provided with a shielding member 100, and FIG. 20 is a cross-sectional view in the tube diameter direction of a portion provided with a shielding plate 110 in the nozzle 2 of the present invention used in the above-described siliconization treatment. ing. In addition, the shielding board 110 consists of the shielding part 111 and the shielding part 112 for holding | maintenance in FIG. As shown in FIG. 20, the nozzle used here has a shielding plate 110 made up of a shielding part 111 and a holding shielding part 112, the angle A1 in the tube radial direction of the opening is 76 °, and A2 is 38 °. A3 is 38 °, A4 is 55 °, and A5 is 55 °. The opening on the back surface of the slit is 152 ° (A1 + A2 + A3) in the tube diameter direction, and the opening area in the gap between the inner tube and the outer tube Was made larger on the back side of the slit.

  A sample having a length of 500 mm was collected from the steel sheet obtained by the above-described siliconization treatment, and the distribution of waviness and warpage in the width direction and the length direction was investigated as the shape of the steel sheet. For comparison, swells and warp distributions were similarly obtained for silicon steel sheets obtained by performing siliconizing treatment under the same conditions using a nozzle having the shielding plate 210 shown in FIG. The results are shown in Table 2.

  From the results of Table 2, by using the nozzle of the present invention, it is possible to obtain a flat and well-shaped silicon steel sheet with less waviness and warpage, that is, by performing a siliconizing treatment by blowing gas evenly from the nozzle. You can see that On the other hand, when the siliconizing treatment was performed using the comparative nozzle, the swell and warpage increased. For this reason, when using it by slitting, it causes the meandering and it has become difficult to take up multiple strips. From this result, it has become clear that it is important to obtain a uniform jet from the nozzle in order to achieve stable production.

  As a nozzle for spraying the raw material gas onto the silicon steel plate, the siliconization treatment was performed under the same conditions as in Example 1 using the nozzle having the same structure as in Example 1 and having the rectifying plate 300 shown in FIG. . In addition, the same shielding plate 110 as the nozzle of Example 1 was used for the shielding plate. The results are shown in Table 3 for the obtained steel plate. In particular, the silicon concentration distribution in the width direction of the steel plate was obtained, and the distance (length) from the end of the steel plate at the portion where the silicon concentration became usable in terms of electromagnetic characteristics was also investigated. For comparison, the silicon concentration distribution in the width direction of the steel plate is similarly applied to the silicon steel plate obtained by performing the siliconizing treatment under the same conditions using the nozzle having the shielding plate 210 shown in FIG. Asked.

  The width end of the steel sheet that does not have characteristics that can be used in terms of electromagnetic characteristics needs to be cut off when making a product. From the results in Table 3, it can be seen that when the nozzle of the present invention is used, the amount of cutting off at the end of the steel sheet can be greatly reduced, and the productivity can be improved.

  The present invention is not limited to a siliconizing process in which Si is immersed in a steel sheet or the formation of a ceramic coating such as TiN, but also to a chemical vapor deposition process for a metal strip such as a steel sheet, an aluminum plate, a copper plate, etc. It can be applied, and can be applied to the semiconductor field.

1 Steel plate 2 Nozzle 2s Gas outlet (slit)
2 sb End on the outer tube closed end side of the slit 3 Heater 4 Source gas 5 Furnace gas 6 Coating 20 Outer tube 20 b Outer tube closed end 21 Inner tube 21 a Inner tube gas inlet 21 b Open end of inner tube 100 Shielding member 110 Shielding plate 111 Shielding portion 112 Shielding portion for holding 120 Mounting portion 121 Screw fixing member 121a Threaded portion 121b Threaded portion 122a Keyway 122b Key 210 Shielding plate 300 Current plate

Claims (5)

  An outer tube that is disposed in a processing furnace that performs chemical vapor deposition on a metal strip, has a closed end that is provided with a slit in the axial length direction and has a closed end, a source gas is supplied from one end side, and the other end side is the inside of the outer tube A double pipe structure having an inner pipe having an open end opened at the outside, and the source gas supplied from one end side of the inner pipe is blown out from the open end of the inner pipe toward the closed end of the outer pipe. A nozzle for chemical vapor deposition, which is supplied into the tube and blows out to a metal strip through a slit provided in the outer tube to perform chemical vapor deposition, and the outer tube closed end of the slit provided in the outer tube in the tube axis direction A source gas supply nozzle for chemical vapor deposition, wherein a shielding plate for adjusting the flow of source gas is provided between an inner tube and an outer tube between a side end and an inner tube open end.   2. The chemical vapor deposition according to claim 1, wherein the shielding plate is provided so that an opening area in a gap between the inner pipe and the outer pipe is increased on a back side of the slit in a cross section in the radial direction of the pipe. Nozzle for supplying raw material gas for processing.   The said gas-shielding plate is arrange | positioned in the open end part of an inner pipe | tube, The nozzle for the raw material gas supply of the chemical vapor deposition process of Claim 1 or Claim 2 characterized by the above-mentioned.   The raw gas supply nozzle for chemical vapor deposition according to claim 2 or 3, wherein an opening on the back side of the slit by the shielding plate has an angle of 290 ° or less in the tube diameter direction.   5. The raw material gas supply nozzle for chemical vapor deposition according to claim 1, wherein the metal strip is a steel plate, and the chemical vapor deposition is a siliconization process.

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