Raw material supply method, silicon single crystal manufacturing method, raw material supply control device and silicon single crystal manufacturing system

Abstract

To provide a raw material supply method capable of easily and appropriately determining the supply completion of a silicon raw material.SOLUTION: A raw material supply method for supplying a silicon raw material to a silicon melt using a raw material supply device including a cylindrical charge pipe and an opening / closing member for opening and closing the lower end opening of the charge pipe, comprises: a supply start step of supplying the silicon raw material to the silicon melt by installing the raw material supply device charged with the silicon raw material on one end side of a wire to descend the opening / closing member to the charge pipe so as to open the lower end opening; and a supply completion step of determining that the supply of the silicon raw material is completed on the basis of the weight of the material supply device installed on the one end side of the wire detected by a weight detection part.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a raw material supply method, a silicon single crystal manufacturing method, a raw material supply control device, and a silicon single crystal manufacturing system. [Background technology]

[0002] Before growing a silicon single crystal, there is a step of melting a silicon raw material in a crucible to produce a silicon melt. From the viewpoint of cost reduction, it is effective to increase the length of the silicon single crystal to be grown by increasing the amount of silicon raw material charged in the crucible as much as possible. However, the amount of silicon raw material that can be loaded into the crucible at one time is limited by the size of the crucible, etc. Therefore, after all of the silicon raw material loaded in the crucible is melted to generate a silicon melt, it is necessary to supply new silicon raw material to the silicon melt. As a method for supplying new silicon raw material to such a silicon melt, a method using a raw material supply device having a quartz charge tube and an opening / closing member for opening and closing the lower end opening of the charge tube is known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-244236 Summary of the Invention [Problem to be solved by the invention]

[0004] However, Patent Document 1 does not disclose a method for determining the end of the supply of silicon raw material. One possible method for determining the end of the supply of silicon raw material is for an operator to visually inspect the raw material supply device, but this increases the burden of monitoring work and may result in variations in the operator's sensory evaluation. Furthermore, as the number of times the charge tube is used increases, the quartz surface may become cloudy, making it difficult to visually check the condition inside the charge tube.

[0005] An object of the present invention is to provide a raw material supply method, a silicon single crystal manufacturing method, a raw material supply control device, and a silicon single crystal manufacturing system that can easily and appropriately determine when the supply of silicon raw material has ended. [Means for solving the problem]

[0006] The raw material supply method of the present invention is a raw material supply method for supplying silicon raw material to a silicon melt in a crucible placed in a chamber using a raw material supply device having a cylindrical charge tube and an opening / closing member that opens and closes a lower end opening of the charge tube, and includes a supply start step of supplying the silicon raw material to the silicon melt by attaching the raw material supply device loaded with the silicon raw material to one end of a wire and lowering the opening / closing member relative to the charge tube to open the lower end opening, and a supply end step of determining that the supply of the silicon raw material has ended based on the weight of the raw material supply device attached to the one end of the wire detected by a weight detection unit.

[0007] In the raw material supply method of the present invention, it is preferable that the charge tube comprises a cylindrical portion having the lower end opening, a closing portion closing the upper end of the cylindrical portion, and a protruding portion protruding from the outer peripheral surface of the cylindrical portion or the closing portion, the open / close member comprises a shaft that is inserted into the closing portion and has an upper end attached to the one end of the wire, and a bottom cover that is fixed to the lower end of the shaft and opens and closes the lower end opening, the chamber is provided with a charge tube stopper that abuts against the lower end of the protruding portion to restrict descent of the charge tube, and the supply starting step comprises lowering the open / close member relative to the charge tube to open the lower end opening after the protruding portion abuts against the charge tube stopper, thereby supplying the silicon raw material.

[0008] In the raw material supply method of the present invention, it is preferable that the shaft is provided with a bottom cover stopper that abuts against the upper end of the blocking portion to restrict the descent of the bottom cover relative to the charge tube, and the supply start process supplies the silicon raw material by lowering the opening / closing member until the bottom cover stopper abuts against the blocking portion after the protrusion abuts against the charge tube stopper, and the supply end process raises the opening / closing member until the bottom cover stopper moves away from the blocking portion and the protrusion moves away from the charge tube stopper, and when the weight detection result by the weight detection unit matches a specified weight, it is determined that the supply of the silicon raw material has been completed, and the specified weight is the weight of the raw material supply device only.

[0009] In the raw material supply method of the present invention, it is preferable that the supply termination step determines that the supply of the silicon raw material has been terminated when the weight detection result of the weight detection unit matches a specified weight when the opening / closing member is not raised, and the specified weight is the weight of the opening / closing member only.

[0010] In the raw material supply method of the present invention, if the weight detection result in the supply termination step does not match the specified weight, it is preferable to perform an opening / closing member lifting / lowering step in which the opening / closing member is raised and lowered, and then perform the supply termination step.

[0011] In the raw material supply method of the present invention, it is preferable that if the weight detection result does not match the specified weight even after the supply completion step and the open / close member lifting and lowering step have been performed a set number of times, an abnormality is reported.

[0012] In the raw material supply method of the present invention, it is preferable that a drum is fixed to the other end of the wire, which rotates by driving a motor to wind up or wind down the wire, the weight detection unit is a load cell that detects the weight of the raw material supply device attached to the one end of the wire by detecting the load acting on the motor, and the supply start process and the supply end process control the motor to move the raw material supply device.

[0013] The silicon single crystal manufacturing method of the present invention includes a raw material supply step of supplying the silicon raw material to the silicon melt by the raw material supply method described above, and a growth step of growing a silicon single crystal by the CZ method using the silicon melt.

[0014] The raw material supply control device of the present invention is a raw material supply control device that uses a raw material supply device that is located in a chamber and has a cylindrical charge tube and an opening / closing member that opens and closes a lower end opening of the charge tube, to supply silicon raw material to a silicon melt in a crucible located in the chamber, and is equipped with a supply start control unit that supplies the silicon raw material to the silicon melt by lowering the opening / closing member relative to the charge tube, the raw material supply device being loaded with the silicon raw material and attached to one end of a wire, so as to open the lower end opening, and a supply end control unit that determines that the supply of the silicon raw material has ended based on the weight of the raw material supply device attached to the one end of the wire detected by a weight detection unit.

[0015] In the raw material supply control device of the present invention, it is preferable that the charge tube comprises a cylindrical portion having the lower end opening, a closing portion closing the upper end of the cylindrical portion, and a protruding portion protruding from the outer peripheral surface of the cylindrical portion or the closing portion, the open / close member comprises a shaft that is inserted into the closing portion and has an upper end attached to the one end side of the wire, and a bottom cover that is fixed to the lower end of the shaft and opens and closes the lower end opening, the chamber is provided with a charge tube stopper that abuts against the lower end of the protruding portion to restrict descent of the charge tube, and the supply start control unit supplies the silicon raw material by lowering the open / close member relative to the charge tube so as to open the lower end opening after the protruding portion abuts against the charge tube stopper.

[0016] In the raw material supply control device of the present invention, it is preferable that the shaft is provided with a bottom cover stopper that abuts against the upper end of the blocking portion to restrict the descent of the bottom cover relative to the charge tube, the supply start control unit supplies the silicon raw material by lowering the opening / closing member until the bottom cover stopper abuts against the blocking portion after the protrusion abuts against the charge tube stopper, the supply end control unit raises the shaft until the bottom cover stopper moves away from the blocking portion and the protrusion moves away from the charge tube stopper, and when the weight detection result by the weight detection unit matches a specified weight, determines that the supply of the silicon raw material has ended, and the specified weight is the weight of the raw material supply device only.

[0017] In the raw material supply control device of the present invention, it is preferable that the supply termination control unit determines that the supply of the silicon raw material has ended when the weight detection result of the weight detection unit matches a specified weight when the opening / closing member is not raised, and the specified weight is the weight of the opening / closing member only.

[0018] In the raw material supply control device of the present invention, when it is determined that the weight detection result does not match the specified weight, it is preferable that the supply termination control unit performs an opening / closing member lifting and lowering process to raise and lower the opening / closing member, and then determines whether the supply of the silicon raw material has been terminated based on the weight detection result.

[0019] In the raw material supply control device of the present invention, it is preferable that the supply termination control unit reports an abnormality if the weight detection result does not match the specified weight even after performing the process of determining whether the supply of the silicon raw material has ended and the process of raising and lowering the opening and closing member a set number of times.

[0020] In the raw material supply control device of the present invention, it is preferable that a drum is fixed to the other end of the wire, which rotates by driving a motor to wind up or wind down the wire, the weight detection unit is a load cell that detects the weight of the raw material supply device attached to the one end of the wire by detecting the load acting on the motor, and the supply start control unit and the supply end control unit control the motor to move the raw material supply device.

[0021] The silicon single crystal manufacturing system of the present invention includes the above-mentioned raw material supply control device, the raw material supply device, the wire to one end of which the raw material supply device or a seed crystal is attached, the weight detection unit, and a growth control unit that grows a silicon single crystal by the CZ method by immersing the seed crystal attached to the one end of the wire in the silicon melt and then pulling it up.

[0022] The silicon single crystal manufacturing system of the present invention includes the above-mentioned raw material supply control device, the raw material supply device, the wire to which the raw material supply device or the seed crystal is attached at one end, the drum, and a pulling unit having the motor, the load cell, and a growth control device that grows a silicon single crystal by the CZ method by immersing the seed crystal attached at the one end of the wire in the silicon melt and then pulling it up. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a schematic diagram of a silicon single crystal production system according to first and second embodiments, showing a state during silicon single crystal growth. [Figure 2] 1 is a schematic diagram of a silicon single crystal production system according to the first and second embodiments, showing a state during supply of silicon raw material. [Figure 3] 1A and 1B are longitudinal cross-sectional views of a raw material supply device according to a first embodiment, in which (A) shows a state in which the bottom opening of a charge tube is closed, and (B) shows a state in which the bottom opening is open. [Figure 4] 1 is a flowchart of a silicon single crystal manufacturing method according to the first and second embodiments. [Figure 5] 4 is a flowchart of a raw material supplying step according to the first embodiment. [Figure 6] 4 is a graph showing the relationship between time and the weight detected by a load cell in the raw material supplying step according to the first embodiment. [Figure 7] FIG. 3 is an explanatory diagram of a raw material supplying step according to the first embodiment. [Figure 8] 4 is a flowchart of a raw material supplying step according to the first and second embodiments. [Figure 9] 10A and 10B are longitudinal cross-sectional views of a raw material supply device according to a second embodiment, in which (A) shows a state in which the bottom opening of the charge tube is closed, and (B) shows a state in which the bottom opening is open. [Figure 10] 10 is a flowchart of a raw material supplying step according to a second embodiment. [Figure 11] 10 is a graph showing the relationship between time and the weight detected by a load cell in a raw material supplying step according to the second embodiment. [Figure 12] FIG. 10 is an explanatory diagram of a raw material supplying step according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0024] [First embodiment] <Configuration of silicon single crystal production system> First, the configuration of a silicon single crystal production system according to a first embodiment of the present invention will be described. The silicon single crystal production system 1 shown in FIGS. 1 and 2 includes a silicon single crystal production apparatus 2. The silicon single crystal manufacturing apparatus 2 uses the Czochralski (CZ) method to manufacture a silicon single crystal (ingot) SM doped with a volatile dopant. Examples of the volatile dopant include arsenic, red phosphorus, and antimony. The silicon single crystal manufacturing apparatus 2 includes a chamber 21, a crucible 22, a heater 23, a heat-retaining tube 24, a shield 25, and a pulling unit 26.

[0025] The chamber 21 includes a main chamber 211 in which the silicon single crystal SM is pulled, and a pull chamber 212 connected to the top of the main chamber 211 and accommodating the pulled silicon single crystal SM. The main chamber 211 accommodates a crucible 22 , a heater 23 , a heat-retaining tube 24 and a shield 25 . A gate valve 213 is provided at the bottom of the pull chamber 212 to isolate the upper end of the main chamber 211 from the lower end of the pull chamber 212 . A first gas supply unit 214 is provided at the top of the pull chamber 212 to supply an inert gas Gf, such as argon (Ar) gas, into the pull chamber 212. A first gas exhaust unit 215 is provided at the bottom of the pull chamber 212 to exhaust the inert gas Gf from the pull chamber 212. A second gas supply unit 216 is provided at the top of the main chamber 211 to introduce the inert gas Gf into the chamber 21. A second gas exhaust unit 217 is provided at the bottom of the main chamber 211 to exhaust an internal gas Gn, such as Ar gas, containing evaporated products such as SiO generated in the main chamber 211, to the outside of the silicon single crystal production apparatus 2. A charge pipe stopper 212A that restricts the descent of the raw material supply device 3, which will be described later, is provided in the pull chamber 212 above the gate valve 213. The charge pipe stopper 212A is provided so as to protrude like a brim toward the center of the pull chamber 212 from the entire outer periphery of the inner wall surface of the pull chamber 212 or from multiple locations. The charge pipe stopper 212A may also be provided in the main chamber 211.

[0026] Crucible 22 is composed of an outer graphite crucible and an inner quartz crucible. Crucible 22 is placed in main chamber 211 and stores silicon melt M to which a volatile dopant has been added. Crucible 22 is fixed to the upper end of support shaft 221, which is rotatable and can be raised and lowered. The heater 23 is formed in a cylindrical shape and is disposed so as to surround the crucible 22. The heater 23 generates heat to melt the silicon raw material R in the crucible 22. The heat-retaining cylinder 24 is formed in a cylindrical shape and is disposed so as to surround the heater 23 . The shield 25 is made of a carbon material and has a substantially cylindrical shape. The shield 25 is disposed so as to surround the silicon single crystal SM being pulled up from the silicon melt M, and blocks radiant heat from the heater 23 to the silicon single crystal SM.

[0027] The pulling unit 26 is provided above the pull chamber 212 and includes a wire 261, a drum 262, a motor 263, and a load cell 264 as a weight measuring unit. One end of the wire 261 is attached to the seed crystal SC shown in FIG. 1 or the raw material supply device 3 shown in FIG. The other end of the wire 261 is fixed to the drum 262. The drum 262 is rotated by the drive of a motor 263, and winds up and down the wire 261 while maintaining the wire 261 positioned coaxially with the support shaft 221 above the crucible 22. The load cell 264 detects the load acting on the motor 263 , thereby detecting the weight of the silicon single crystal SM or the raw material supply device 3 attached to one end of the wire 261 .

[0028] The silicon single crystal production system 1 further includes a raw material supply device 3. The raw material supply device 3 supplies solid silicon raw material R to the silicon melt M stored in the crucible 22. The raw material supply device 3 includes a charge pipe 31 and an opening / closing member 32 shown in Figures 3(A) and 3(B). Note that in each figure, the silicon raw material R is illustrated as a sphere for convenience, but in reality it is not a perfect sphere, but is a lumpy raw material formed by crushing polycrystalline silicon raw material rods.

[0029] The charge tube 31 is made of quartz and comprises a cylindrical tube portion 33 and a metallic charge tube cover body 34 formed in a disk shape with a diameter larger than the outer diameter of the tube portion 33. Charging pipe cover 34 is fixed to the upper end of cylindrical portion 33. The portion of charging pipe cover 34 that closes the upper end opening of cylindrical portion 33 constitutes closing portion 341. The portion of charging pipe cover 34 that protrudes outward from cylindrical portion 33 constitutes protruding portion 342. Note that protruding portion 342 may be provided on the outer circumferential surface of cylindrical portion 33.

[0030] The opening / closing member 32 includes a shaft 35, a bottom lid 36, a guide tube 37, a guide tube lid body 38, and a bottom lid stopper 39. The shaft 35, the guide tube lid body 38, and the bottom lid stopper 39 are made of metal. The bottom lid 36 and the guide tube 37 are made of quartz. The shaft 35 is inserted through the closed portion 341 of the charge pipe 31 , and its upper end is attached to one end of the wire 261 . The bottom lid 36 is fixed to the lower end of the shaft 35. The bottom lid 36 is formed in a conical shape with a bottom diameter equal to the inner diameter of the cylindrical portion 33, and is configured so that it can close the lower end opening 331 of the cylindrical portion 33 as shown in Fig. 2(A) or open the lower end opening 331 as shown in Fig. 2(B). The bottom lid 36 may also be formed in a conical shape with a bottom diameter equal to or greater than the inner diameter of the cylindrical portion 33. To prevent direct contact between the silicon raw material R and the shaft 35, the guide tube 37 is formed in a cylindrical shape that covers the shaft 35 inside the cylindrical portion 33, and its lower end is fixed to the bottom cover . Guide tube cover body 38 closes the upper end of guide tube 37, and shaft 35 is inserted therethrough. Guide tube cover body 38 restricts the descent of charge tube 31 relative to opening / closing member 32 by abutting against the underside of closing portion 341 when bottom cover 36 closes lower end opening 331. The bottom cover stopper 39 is fixed to the upper end side of the shaft 35, and restricts the descent of the opening / closing member 32 relative to the charge pipe 31 by abutting against the upper surface of the closing portion 341, as shown in FIG. 2(B).

[0031] The silicon single crystal production system 1 further includes a control device 4 shown in FIGS. The control device 4 is connected to the load cell 264. The weight measurement value detected by the load cell 264 is transferred to the control device 4 and recorded. The control device 4 is configured to be able to control a first gas supply control unit 271 that supplies an inert gas Gf from a first gas supply unit 214 into the pulling chamber 212, a first gas exhaust control unit 272 that exhausts the inert gas Gf from the pulling chamber 212 through a first gas exhaust unit 215, a second gas supply control unit 273 that supplies an inert gas Gf from a second gas supply unit 216 into the chamber 21, a second gas exhaust control unit 274 that exhausts the internal gas Gn from the chamber 21 through a second gas exhaust unit 217, a gate valve driving unit 275 that drives the gate valve 213, a crucible driving unit 276 that rotates the crucible 22, the heater 23, and the motor 263. The control device 4 includes an input unit 41, a display unit 42, a memory unit 43, and a control unit 44.

[0032] The input unit 41 is configured by, for example, a touch panel or physical buttons, and outputs a signal corresponding to an input operation to the control unit 44. The display unit 42 displays various information based on the control of the control unit 44. The storage unit 43 stores various pieces of information relating to the supply of the silicon raw material R and the growth of the silicon single crystal SM so that the control unit 44 can read them.

[0033] The control unit 44 includes a CPU, and realizes various functions by the CPU executing programs stored in the storage unit 43. The control unit 44 includes a supply start control unit 45, a supply end control unit 46, and a growth control unit 47. The supply start control unit 45 and the supply end control unit 46 constitute the raw material supply control device 5, and control the supply of the silicon raw material R to the silicon melt M.

[0034] The supply start control unit 45 lowers the raw material supply device 3 loaded with the silicon raw material R to a supply position above the silicon melt M, and then supplies the silicon raw material R to the silicon melt M. At this time, the supply start control unit 45 lowers the opening / closing member 32 until the protruding portion 342 abuts against the charge tube stopper 212A and the bottom cover stopper 39 abuts against the closing portion 341, thereby positioning the bottom cover 36 below the lower end position of the cylindrical portion 33 and opening the lower end opening 331.

[0035] The supply termination control unit 46 determines that the supply of the silicon raw material R to the silicon melt M has been completed based on the weight detected by the load cell 264. At this time, the supply termination control unit 46 raises the open / close member 32 until the bottom cover stopper 39 is separated from the closing portion 341 and the protruding portion 342 is separated from the charge pipe stopper 212A, and determines that the supply has been completed when the weight detected by the load cell 264 matches the specified weight. The specified weight in the first embodiment is the weight of only the raw material supply device 3.

[0036] The growth control unit 47 grows a silicon single crystal SM by immersing the seed crystal SC in the silicon melt M and then pulling it up. The growth control unit 47 acquires the weight detection result of the silicon single crystal SM being grown from the load cell 264, and adjusts the manufacturing conditions so that a silicon single crystal SM having a desired shape can be manufactured.

[0037] <Silicon single crystal manufacturing method> Next, a method for producing a silicon single crystal will be described. 4, the growth control unit 47 of the control device 4 heats the crucible 22 that contains the silicon raw material R but does not contain the silicon melt M to generate the silicon melt M (step S1: initial melt generation step). In the initial melt generation step of step S1, the gate valve 213 is open, and the chamber 21 is maintained in a reduced pressure state by supplying the inert gas Gf only from the first gas supply unit 214 and exhausting the internal gas Gn only from the second gas exhaust unit 217. The raw material supply control device 5 of the control device 4 performs a raw material supply step of supplying the silicon raw material R to the silicon melt M generated in the initial melt generating step in order to increase the amount of the silicon melt M in the crucible 22 (step S2). The growth control unit 47 performs a growth step of growing a silicon single crystal SM by immersing the seed crystal SC in the silicon melt M to which the dopant has been added and then pulling it up (step S3).

[0038] 5, in the raw material supply process of step S2, supply start control unit 45 of raw material supply control device 5 controls gate valve driving unit 275 to close gate valve 213 (step S11). By the process of step S11, pulling chamber 212 is isolated from main chamber 211, which has an inert gas atmosphere. The supply start control unit 45 closes the gate valve 213 and simultaneously controls the second gas supply control unit 273 to supply the inert gas Gf into the main chamber 211. The supply start control unit 45 controls the first gas supply control unit 271 to stop the supply of the inert gas Gf into the pull chamber 212. After the pressure inside the pull chamber 212 is set to atmospheric pressure, an operator or an attachment / detachment device (not shown) attaches the raw material supply device 3 loaded with the silicon raw material R to the lower end of the wire 261 at the attachment / detachment position (step S12).

[0039] After the installation of the raw material supply device 3 is completed, the supply start control unit 45 controls the first gas supply control unit 271 to supply the inert gas Gf into the pull chamber 212, and also controls the first gas discharge control unit 272 to discharge the inert gas Gf from the pull chamber 212, thereby reducing the pressure inside the pull chamber 212. The supply start control unit 45 drives the motor 263 to lower the raw material supply device 3 to the standby position above the gate valve 213, and then controls the gate valve driving unit 275 to open the gate valve 213 (step S13). The supply start control unit 45 opens the gate valve 213 and simultaneously controls the second gas supply control unit 273 to stop the supply of the inert gas Gf from the second gas supply unit 216 into the main chamber 211. Furthermore, the supply start control unit 45 controls the first gas exhaust control unit 272 to stop the exhaust of the inert gas Gf from the first gas exhaust unit 215, and controls the second gas exhaust control unit 274 to adjust the gas exhaust amount so that the pressure inside the main chamber 211 becomes a pressure suitable for supplying the silicon raw material R.

[0040] The supply start control unit 45 acquires the weight detection result of the load cell 264 as the initial weight (step S14). If the weight of the charge pipe 31 is W1, the weight of the open / close member 32 is W2, and the total weight of the silicon raw material R loaded into the raw material supply device 3 is W3, the initial weight is W4, which is obtained by adding the weights W1, W2, and W3, as shown in FIG. The supply start control unit 45 may acquire the initial weight before lowering the raw material supply device 3 to the standby position, or may acquire the initial weight after lowering the raw material supply device 3 to the standby position above the gate valve 213 and before opening the gate valve 213.

[0041] The supply start control unit 45 drives the motor 263 to wind down the wire 261, and lowers the raw material supply device 3 to the supply position, thereby starting the supply of the silicon raw material R (step S15). The processing of steps S11 to S15 constitutes a supply start step. In step S15, as shown in the upper left diagram of Fig. 7, raw material supplying device 3 descends with lower end opening 331 closed by bottom lid 36, protruding portion 342 separated from charge tube stopper 212A, and bottom lid stopper 39 separated from closing portion 341. When raw material supplying device 3 descends as motor 263 is further driven, at time T1, as shown in the upper center diagram of Fig. 7, protruding portion 342 abuts against and is latched on charge tube stopper 212A, and bottom lid stopper 39 separated from closing portion 341.

[0042] From time T1, when motor 263 is further driven, only open / close member 32 descends while charge tube 31 is supported by charge tube stopper 212A. This descent of only open / close member 32 opens lower end opening 331 of charge tube 31, causing raw silicon material R in charge tube 31 to fall. In this state, as shown in FIG. 6, the weight detected by load cell 264 gradually decreases from weight W4. The open / close member 32 further descends, and at time T2, as shown in the upper right diagram of Fig. 7, the bottom cover stopper 39 abuts against the closing portion 341, and the raw material supplying device 3 reaches the supply position. The supply start control unit 45 then stops driving the motor 263. In this state, the charge tube 31 is supported by the charge tube stopper 212A, and the open / close member 32 is supported by the charge tube 31. Therefore, the weight detected by the load cell 264 becomes 0 regardless of whether or not the silicon raw material R remains in the charge tube 31. The weight deviation (hereinafter, sometimes simply referred to as "weight deviation") based on the weight W4 of the raw material supplying device 3 loaded with the silicon raw material R becomes -W4 (= 0 - W4). Thereafter, if the silicon raw material R remains in the charge pipe 31, all of the silicon raw material R in the charge pipe 31 is supplied to the silicon melt M over time, as shown in the lower left diagram of FIG.

[0043] When a predetermined time has elapsed since time T2, at time T3, as shown in FIG. 5, the supply termination control unit 46 drives the motor 263 to wind up the wire 261, thereby raising the raw material supply device 3 until the support of the raw material supply device 3 by the charge pipe stopper 212A is released (step S16). The waiting period P from time T2 to time T3 is a period during which all of the silicon raw material R in the raw material supply apparatus 3 is estimated to fall into the silicon melt M before the raw material supply apparatus 3 starts to rise, and is preferably set according to the amount of silicon raw material R charged. The waiting period P may also be a period during which all of the silicon raw material R in the raw material supply apparatus 3 is estimated to fall into the silicon melt M after the raw material supply apparatus 3 starts to rise and before the lower-end opening 331 is closed. For example, if the amount of silicon raw material R charged is estimated to be such that all of the silicon raw material R will fall into the silicon melt M before the lower-end opening 331 is closed, even if the opening / closing member 32 starts to rise immediately after the bottom cover stopper 39 abuts against the closing portion 341, the waiting period P may be 0 seconds. In other words, the opening / closing member 32 may start to rise at time T2.

[0044] As the motor 263 is driven, the opening / closing member 32 rises from time T3, and at time T4, as shown in the diagram in the lower center of Figure 7, the lower end opening 331 is closed by the bottom lid 36 due to the abutment of the blocking portion 341 and the guide tube lid body 38, the protrusion 342 abuts against the charge tube stopper 212A, and the bottom lid stopper 39 is separated from the blocking portion 341. When the opening / closing member 32 is further raised, the weight detected by the load cell 264 gradually increases.

[0045] When the open / close member 32 is further raised, at time T5, the protrusion 342 moves away from the charge pipe stopper 212A, as shown in the lower right diagram of FIG. In this state, when all of the silicon raw material R loaded in the raw material supply device 3 is supplied to the silicon melt M, i.e., when no clogging of the silicon raw material R occurs, the weight detected by the load cell 264 becomes the weight obtained by adding the weight W1 and the weight W2, i.e., the weight of only the raw material supply device 3, as shown by the solid line in Figure 6, and does not change thereafter. On the other hand, there may be cases where a plurality of pieces of silicon raw material R get caught between the lower end opening 331 and the bottom cover 36, causing clogging of the silicon raw material R and leaving the silicon raw material R in the raw material supply device 3. In this case, if the total weight of the silicon raw material R remaining in the raw material supply device 3 is Wt, the weight detected by the load cell 264 will be the weight obtained by adding the weights W1, W2, and Wt, as shown by the dashed line in Fig. 6, that is, a weight that is heavier than the weight of the raw material supply device 3 alone, and will not change thereafter. After time T5, the weight deviation is as follows: If a blockage occurs: -W3 (=W1 + W2 - W4) If no clogging occurs: -W3+Wt (=W1+W2+Wt-W4)

[0046] When a predetermined time has elapsed from time T5, that is, when time T6 arrives, as shown in FIG. 5, supply end control unit 46 acquires the weight detection result from load cell 264 (step S17). The supply end control unit 46 determines whether or not the weight deviation coincides with the weight of the raw material supply device 3 alone, that is, the value corresponding to the specified weight (step S18). When it is determined that the weight deviation coincides with the value corresponding to the weight of only the raw material supply device 3 (step S18: YES), the supply end control unit 46 determines that the supply of the silicon raw material R has ended (step S19).

[0047] The supply end control unit 46 drives the motor 263 to raise the raw material supply device 3 to the attachment / detachment position, and controls the gate valve driving unit 275 to close the gate valve 213 (step S20). The processing of steps S16 to S20 constitutes a supply ending step. The supply termination control unit 46 closes the gate valve 213 and simultaneously controls the second gas supply control unit 273 to supply the inert gas Gf into the main chamber 211. The supply termination control unit 46 controls the first gas supply control unit 271 to stop the supply of the inert gas Gf into the pull chamber 212. After the pressure inside the pull chamber 212 is set to atmospheric pressure, the operator or the attaching / detaching device detaches the raw material supply device 3 from the wire 261 (step S21). Thereafter, an operator or an attachment / detachment device attaches a dopant addition device (not shown) to the wire 261, and a dopant is added to the silicon melt M. Then, an operator or an attachment / detachment device attaches a seed crystal SC to the wire 261 instead of the dopant addition device, and the growth process of step S3 is performed.

[0048] On the other hand, when the supply termination control unit 46 determines that the weight deviation does not match the value corresponding to the weight of the raw material supply device 3 alone (step S18: NO), it determines that a blockage of the silicon raw material R has occurred between the lower end opening 331 and the bottom lid 36, and performs an open / close member lifting / lowering step (described later) in which the open / close member 32 is raised and lowered to clear the blockage of the silicon raw material R. As shown in Fig. 8, the supply termination control unit 46 determines whether the open / close member lifting / lowering step has been performed a set number of times (step S22). The set number of times is not particularly limited, but is set to a number at which it can be estimated that the blockage of the silicon raw material R will be cleared by the open / close member lifting / lowering step. When it is determined that the opening / closing member lifting / lowering process has not been performed the set number of times (step S22: NO), the supply end control unit 46 performs the opening / closing member lifting / lowering process (step S23).

[0049] In the opening / closing member lifting process of step S23, for example, the supply end control unit 46 controls the motor 263 to lower the opening / closing member 32 to open the bottom end opening 331 of the charge tube 31, and then lift the opening / closing member 32, as shown in the upper right diagram of FIG. 7. At this time, the opening / closing member 32 may be lifted after the bottom cover stopper 39 abuts against the closing portion 341, or may be lifted before the bottom cover stopper 39 abuts against the closing portion 341. In step S23, the process of changing the opening size of the bottom end opening 331 is performed one or more times. After the process of step S23, the supply end control unit 46 acquires the weight detection result of the load cell 264 as shown in FIG. 6 (step S17).

[0050] On the other hand, if the supply termination control unit 46 determines that the opening / closing member lifting and lowering process has been performed the set number of times (step S22: YES), it issues an error notification indicating that the blockage has not been cleared (step S24) and terminates the raw material supply process as shown in Figure 6. In step S24, the supply termination control unit 46, for example, displays an abnormality on the display unit 42 or outputs a sound indicating the abnormality from a speaker (not shown). When the operator confirms the abnormality, for example, the operator switches the silicon single crystal production system 1 to manual operation and detaches the raw material supply device 3 from the wire 261. In addition, after notifying of an abnormality in step S24, the supply termination control unit 46 may perform the processing of step S20 without switching the silicon single crystal manufacturing system 1 to manual operation, thereby raising the raw material supply device 3 to the attachment / detachment position.

[0051] <Advantages of the First Embodiment> According to the first embodiment, the following effects can be achieved. (1) The raw material supply control device 5 lowers the opening / closing member 32 of the raw material supply device 3 relative to the charge tube 31 so as to open the lower end opening 331, thereby supplying the silicon raw material R to the silicon melt M, and determines that the supply of the silicon raw material R has been completed based on the detection result of the load cell 264. Specifically, after the protruding portion 342 abuts against the charge tube stopper 212A, the raw material supply control device 5 lowers the opening / closing member 32 until the bottom cover stopper 39 abuts against the closing portion 341, and then raises the opening / closing member 32 until the bottom cover stopper 39 moves away from the closing portion 341 and the protruding portion 342 moves away from the charge tube stopper 212A. Then, when the weight deviation matches a value corresponding to the weight of the raw material supply device 3 alone, the raw material supply control device 5 determines that the supply of the silicon raw material R has been completed. Therefore, the operator does not need to visually check the raw material supply device 3, which eliminates the risk of an increase in the burden of monitoring work and variations in judgment based on the operator's sensory evaluation. Furthermore, even if the cylindrical portion 33 of the charge tube 31 becomes cloudy, the end of supply of the silicon raw material R can be appropriately determined.

[0052] (2) When clogging of the silicon raw material R occurs and the weight deviation does not match the value corresponding to the weight of the raw material supply device 3 alone, the raw material supply control device 5 performs the opening / closing member lifting / lowering step. Therefore, even if clogging of the silicon raw material R occurs, all of the silicon raw material R can be supplied to the silicon melt M.

[0053] (3) The raw material supply control device 5 performs the process of determining whether the supply of silicon raw material R has been completed based on the detection result of the load cell 264 and the process of raising and lowering the opening and closing member a set number of times, but if the weight deviation does not match the value corresponding to the weight of the raw material supply device 3 alone, it will report an abnormality. This allows the operator to quickly carry out recovery work.

[0054] (4) The raw material supply control device 5 determines whether the supply of the silicon raw material R has been completed using the load cell 264 that detects the weight of the silicon single crystal SM being grown. Therefore, there is no need to provide the silicon single crystal production system 1 with a weight detection unit used only to determine the end of supply of the silicon raw material R, and the configuration of the silicon single crystal production system 1 can be simplified.

[0055] [Second embodiment] <Configuration of silicon single crystal production system> Next, the configuration of a silicon single crystal production system according to a second embodiment of the present invention will be described. The silicon single crystal production system 1A of the second embodiment shown in Fig. 1 differs from the silicon single crystal production system 1 of the first embodiment in a control device 4A constituting a silicon single crystal production apparatus 2 and a raw material supply device 3A shown in Figs. 9(A) and (B). Hereinafter, the same components as those in the first embodiment are given the same reference numerals and names, and descriptions thereof will be simplified or omitted.

[0056] The raw material supplying device 3A differs from the raw material supplying device 3 of the first embodiment in that an opening / closing member 32A is provided instead of the opening / closing member 32. The opening / closing member 32A differs from the opening / closing member 32 of the first embodiment in that it does not include the bottom cover stopper 39. Unlike the opening / closing member 32 of the first embodiment, the opening / closing member 32A configured in this manner is not restricted from descending relative to the charge pipe 31.

[0057] As shown in FIG. 3, the control unit 44A constituting the control device 4A includes a supply start control unit 45A, a supply end control unit 46A, and a growth control unit 47. The supply start control unit 45A and the supply end control unit 46A constitute a raw material supply control device 5A, and control the supply of the silicon raw material R to the silicon melt M.

[0058] The supply start control unit 45A lowers the raw material supply device 3A loaded with the silicon raw material R to the supply position, and then supplies the silicon raw material R to the silicon melt M. At this time, the supply start control unit 45A lowers the opening / closing member 32A until the opening size of the lower end opening 331 reaches a set value after the protrusion 342 abuts against the charge pipe stopper 212A.

[0059] The supply termination control unit 46A determines that the supply of the silicon raw material R to the silicon melt M has been completed based on the weight detected by the load cell 264. At this time, the supply termination control unit 46A determines that the supply has been completed when the weight detected by the load cell 264 matches a specified weight while the opening / closing member 32A is not raised. The specified weight in the second embodiment is the weight of only the opening / closing member 32A.

[0060] <Silicon single crystal manufacturing method> Next, a method for producing a silicon single crystal will be described. Hereinafter, the same processes as those in the first embodiment are denoted by the same reference numerals and names, and the description thereof will be simplified or omitted.

[0061] As shown in FIG. 4, the silicon single crystal production method of the second embodiment differs from the silicon single crystal production method of the first embodiment in that a raw material supply step of step S4 is performed instead of the raw material supply step of step S2.

[0062] 10, in the raw material supply process of step S4, the processes of steps S11 to S13 of the first embodiment are performed. After the process of step S13, the supply start control unit 45A of the raw material supply control device 5A acquires the weight detection result of the load cell 264 as the initial weight (step S14). If the weight of the charge pipe 31 is W1, the weight of the open / close member 32 is W2, and the total weight of the silicon raw material R loaded into the raw material supply device 3 is W3, the initial weight is W4, which is obtained by adding the weights W1, W2, and W3, as shown in FIG.

[0063] The supply start control unit 45A starts the supply of silicon raw material R by driving the motor 263 to lower the raw material supply device 3A to a supply position where the lowering is restricted by the charge pipe stopper 212A and the lower end opening 331 is opened (step S31). The processing of steps S11 to S14 and S31 constitutes a supply start step.

[0064] In step S31, raw material supplying device 3A descends with lower end opening 331 closed by bottom lid 36 and protrusion 342 separated from charge pipe stopper 212A, as shown in the upper left diagram of Fig. 12. When raw material supplying device 3A descends as motor 263 is further driven, at time T11, protrusion 342 comes into contact with charge pipe stopper 212A, as shown in the upper center diagram of Fig. 12.

[0065] As motor 263 continues to drive from time T11, only opening / closing member 32A descends while charge tube 31 is supported by charge tube stopper 212A. When raw material supplying device 3A reaches a supply position where the opening size of bottom opening 331 reaches a set value, as shown in the upper right diagram of FIG. 12, supply start control unit 45A stops driving motor 263. When bottom opening 331 of charge tube 31 opens, raw material silicon R in charge tube 31 falls, and as shown in FIG. 11, the weight detected by load cell 264 gradually decreases from weight W4. Then, at time T12, as shown in the lower left diagram of FIG. 12, all of the raw material silicon R loaded in raw material supplying device 3A is supplied to silicon melt M. The weight detected by load cell 264 then becomes weight W2, i.e., the weight of opening / closing member 32A only, as shown by the solid line, and remains unchanged thereafter. On the other hand, there may be cases where the silicon raw material R becomes clogged between the lower end opening 331 and the bottom lid 36, and the silicon raw material R remains in the raw material supplying device 3A. In this case, if the total weight of the silicon raw material R remaining in the raw material supplying device 3A is Wt, the weight detected by the load cell 264 after time T12 will be the weight obtained by adding the weight W2 and the weight Wt, as shown by the dashed line, that is, a weight that is heavier than the weight of the opening / closing member 32A alone, and will not change thereafter. After time T12, the weight deviation in the state where the opening / closing member 32A is stopped is as follows. If a blockage occurs: -(W1+W3)(=W2-W4) If no clogging occurs: -(W1+W3)+Wt(=W2+Wt-W4)

[0066] At time T13, which is a predetermined time after time T12, the supply end control unit 46A acquires the weight detection result from the load cell 264, as shown in FIG. 10 (step S17). A waiting period P1 from time T12 to time T13 is set in the same manner as the waiting period P in the first embodiment, and may be 0 seconds.

[0067] The supply end control unit 46A determines whether or not the weight deviation coincides with the weight of the opening / closing member 32A alone, that is, the value corresponding to the specified weight (step S32). When the supply end control unit 46A determines that the weight deviation matches the value corresponding to the weight of only the opening / closing member 32A (step S32: YES), it determines that the supply of the silicon raw material R has ended (step S33).

[0068] For example, at time T14, the supply end control unit 46A drives the motor 263 to raise the raw material supply device 3A to the attachment / detachment position, and controls the gate valve driving unit 275 to close the gate valve 213 (step S20). The processes of steps S17, S32, S33, and S20 constitute a supply ending step. When the motor 263 is driven and the open / close member 32 rises, the protrusion 342 moves away from the charge pipe stopper 212A, as shown in the lower right diagram of Figure 12. The weight detected by the load cell 264 thereafter is the weight obtained by adding the weights W1 and W2, that is, the weight of only the raw material supply device 3, as shown by the solid line. The weight deviation at this time is -W3.

[0069] Thereafter, the process of step S21 in the first embodiment is performed, and then the growing step of step S3 is performed.

[0070] On the other hand, if the supply termination control unit 46A determines that the weight deviation does not match the value corresponding to the weight of the opening / closing member 32A alone (step S32: NO), it determines whether the opening / closing member lifting / lowering process has been performed a set number of times (step S22), as shown in Figure 8. When it is determined that the opening / closing member lifting / lowering process has not been performed the set number of times (step S22: NO), the supply end control unit 46A performs the opening / closing member lifting / lowering process (step S34).

[0071] In the opening / closing member raising / lowering process of step S34, the supply end control unit 46A may control the motor 263 to lower and then raise the opening / closing member 32 from the state shown in the lower left diagram of Fig. 7, or may raise and then lower the opening / closing member 32. In step S34, the process of changing the opening size of the lower end opening 331 is performed one or more times. After the process of step S34, the supply end control unit 46A acquires the weight detection result of the load cell 264 as shown in FIG. 10 (step S17).

[0072] On the other hand, if the supply end control unit 46A determines that the opening / closing member lifting and lowering process has been performed the set number of times (step S22: YES), it issues an abnormality notification (step S24) and ends the raw material supply process as shown in FIG. 10.

[0073] <Effects of the second embodiment> According to the second embodiment, in addition to the same effects as those (2) to (4) of the first embodiment, the following effects can be achieved. (5) After the protrusion 342 abuts against the charge pipe stopper 212A, the raw material supply control device 5A lowers the opening / closing member 32A to open the lower end opening 331, thereby supplying the silicon raw material R to the silicon melt M, and when the weight deviation matches the value corresponding to the weight of the opening / closing member 32A alone without raising the opening / closing member 32A, it determines that the supply of the silicon raw material R has ended. Therefore, for the same reason as in (1) of the first embodiment, the end of the supply of the silicon raw material R can be determined easily and appropriately.

[0074] [Variations] In the first embodiment, the end of supply of silicon raw material R is determined based on the weight deviation, but the process of acquiring the initial weight in step S14 may not be performed, and the end of supply may be determined in step S18 based on whether the detection result of the load cell 264 matches the weight of only the raw material supply device 3. Similarly, in the second embodiment, the process of acquiring the initial weight in step S14 may not be performed, and the end of supply may be determined in step S32 based on whether the detection result of the load cell 264 matches the weight of only the open / close member 32A.

[0075] In the first and second embodiments, if the first processing of steps S18 and S32 determines that the weight deviation does not match the value corresponding to the specified weight (the weight of the raw material supply device 3 only, or the weight of the opening / closing member 32A only), the abnormality notification processing of step S24 may be performed without performing the opening / closing member lifting / lowering process of step S23, or the raw material supply device 3 may be raised to the attachment / detachment position by performing the processing of step S20. In the first and second embodiments, if it is determined in the processing of step S22 that the opening / closing member raising / lowering process has been performed the set number of times, the raw material supply device 3 may be raised to the detachable position by performing the processing of step S20 without performing the abnormality notification processing of step S24. In the first and second embodiments, a silicon single crystal SM to which no dopant is added may be produced.

[0076] Although the load cell 264 for detecting the weight of the silicon single crystal SM being grown is used to determine the end of supply of the silicon raw material R, a weight detection unit other than the load cell 264 may also be used. An example of such a weight detection unit is a weighing scale on which the drum 262 is placed. [Explanation of symbols]

[0077] 1,1A...silicon single crystal manufacturing system, 3,3A...raw material supply device, 5,5A...raw material supply control device, 21...chamber, 22...crucible, 26...pulling section, 31...charge tube, 32,32A...opening / closing member, 33...tubular section, 35...shaft, 36...bottom lid, 39...bottom lid stopper, 45,45A...supply start control section, 46,46A...supply end control section, 47...growth control section, 212A...charge tube stopper, 261...wire, 262...drum, 263...motor, 264...load cell (weight detection section), 331...lower end opening, 341...closing section, 342...protrusion, M...silicon melt R...silicon raw material, SC...seed crystal, SM...silicon single crystal.

Claims

1. A raw material supply method for supplying a silicon raw material to a silicon melt in a crucible disposed in a chamber using a raw material supply device having a cylindrical charge tube and an opening / closing member for opening and closing a bottom end opening of the charge tube, comprising: a supply start step of attaching the raw material supply device loaded with the silicon raw material to one end of a wire and lowering the opening / closing member relative to the charge pipe to open the lower end opening, thereby supplying the silicon raw material to the silicon melt; and a supply completion step of determining that the supply of the silicon raw material has been completed based on the weight of the raw material supply device attached to the one end side of the wire detected by a weight detection unit.

2. 2. The raw material supply method according to claim 1, the charge pipe comprises a cylindrical portion having the lower end opening, a closing portion closing an upper end of the cylindrical portion, and a protruding portion protruding from an outer peripheral surface of the cylindrical portion or the closing portion, the opening / closing member includes a shaft that is inserted into the closing portion and has an upper end attached to the one end side of the wire, and a bottom cover that is fixed to a lower end of the shaft and opens and closes the lower end opening, a charge pipe stopper that abuts against a lower end of the protrusion to restrict descent of the charge pipe, the supply starting step supplies the silicon raw material by lowering the opening / closing member relative to the charge pipe so as to open the lower end opening after the protrusion abuts against the charge pipe stopper.

3. 3. The raw material supply method according to claim 2, a bottom cover stopper that abuts against an upper end of the closing portion to restrict descent of the bottom cover relative to the charge pipe, the supply starting step includes: supplying the silicon raw material by lowering the opening / closing member after the protruding portion abuts against the charge pipe stopper until the bottom cover stopper abuts against the closing portion; the supply completion step includes lifting the opening / closing member until the bottom cover stopper is separated from the closing portion and the protruding portion is separated from the charge pipe stopper, and determining that the supply of the silicon raw material is completed when a weight detection result by the weight detection unit matches a specified weight; The raw material supply method, wherein the specified weight is the weight of the raw material supply device only.

4. 3. The raw material supply method according to claim 2, the supply termination step includes determining that the supply of the silicon raw material has been terminated when a weight detection result from the weight detection unit matches a specified weight in a state in which the opening / closing member is not raised; The specified weight is the weight of the opening and closing member only.

5. 5. The raw material supply method according to claim 3 or 4, If the weight detection result does not match the specified weight in the supply completion step, an opening / closing member lifting step is performed to raise and lower the opening / closing member, and then the supply completion step is performed.

6. 6. The raw material supply method according to claim 5, A raw material supply method, wherein if the weight detection result does not match the specified weight even after the supply completion step and the open / close member lifting and lowering step have been performed a set number of times, an abnormality is reported.

7. 2. The raw material supply method according to claim 1, A drum is fixed to the other end of the wire, and the drum rotates by driving a motor to wind up or down the wire. the weight detection unit is a load cell that detects a load acting on the motor, thereby detecting a weight of the raw material supply device attached to the one end of the wire, The supply starting step and the supply ending step control the motor to move the material supply device.

8. a raw material supplying step of supplying the silicon raw material to the silicon melt by the raw material supplying method according to claim 1; a growing step of growing a silicon single crystal by the CZ method using the silicon melt.

9. A raw material supply control device that supplies a silicon raw material to a silicon melt in a crucible disposed in a chamber using a raw material supply device that has a cylindrical charge tube and an opening / closing member that opens and closes a bottom end opening of the charge tube, the raw material supply control device being disposed in the chamber, a supply start control unit that supplies the silicon raw material to the silicon melt by lowering the opening / closing member of the raw material supply device, which is loaded with the silicon raw material and attached to one end of a wire, relative to the charge pipe so as to open the lower end opening; a supply termination control unit that determines that the supply of the silicon raw material has been terminated based on the weight of the raw material supply device attached to the one end side of the wire detected by a weight detection unit.

10. The raw material supply control device according to claim 9, the charge pipe comprises a cylindrical portion having the lower end opening, a closing portion closing an upper end of the cylindrical portion, and a protruding portion protruding from an outer peripheral surface of the cylindrical portion or the closing portion, the opening / closing member includes a shaft that is inserted into the closing portion and has an upper end attached to the one end side of the wire, and a bottom cover that is fixed to a lower end of the shaft and opens and closes the lower end opening, a charge pipe stopper that abuts against a lower end of the protrusion to restrict descent of the charge pipe, the supply start control unit lowers the opening / closing member relative to the charge pipe so as to open the lower end opening after the protrusion abuts against the charge pipe stopper, thereby supplying the silicon raw material.

11. The raw material supply control device according to claim 10, a bottom cover stopper that abuts against an upper end of the closing portion to restrict descent of the bottom cover relative to the charge pipe, the supply start control unit supplies the silicon raw material by lowering the opening / closing member until the bottom cover stopper abuts on the closing portion after the protruding portion abuts on the charge pipe stopper, and the supply termination control unit raises the shaft until the bottom cover stopper is separated from the closing portion and the protruding portion is separated from the charge pipe stopper, and when a weight detection result from the weight detection unit matches a specified weight, determines that the supply of the silicon raw material is terminated; The specified weight is the weight of the raw material supply device only.

12. The raw material supply control device according to claim 10, the supply termination control unit determines that the supply of the silicon raw material has been terminated when the weight detection result of the weight detection unit matches a specified weight while the opening / closing member is not raised, The specified weight is the weight of the opening and closing member only.

13. The raw material supply control device according to claim 11 or 12, When it is determined that the weight detection result does not match the specified weight, the supply termination control unit performs an opening / closing member lifting and lowering process to raise and lower the opening / closing member, and then determines whether the supply of the silicon raw material has been terminated based on the weight detection result.

14. The raw material supply control device according to claim 13, The supply termination control unit is configured to notify an abnormality if the weight detection result does not match the specified weight even after performing the step of determining whether the supply of the silicon raw material has been completed and the step of raising and lowering the opening / closing member a set number of times.

15. The raw material supply control device according to claim 9, A drum is fixed to the other end of the wire, and the drum rotates by driving a motor to wind up or down the wire. the weight detection unit is a load cell that detects a load acting on the motor, thereby detecting a weight of the raw material supply device attached to the one end of the wire, The supply start control unit and the supply end control unit control the motor to move the raw material supply device.

16. The raw material supply control device according to any one of claims 9 to 12; The raw material supply device; the wire to one end of which the raw material supply device or the seed crystal is attached; The weight detection unit; a growth control unit that grows a silicon single crystal by the CZ method by immersing the seed crystal attached to the one end of the wire in the silicon melt and then pulling it up.

17. The raw material supply control device according to claim 15; The raw material supply device; a pulling unit having the wire, the drum, and the motor, the wire having the raw material supply device or the seed crystal attached to one end thereof; The load cell; a growth control unit that grows a silicon single crystal by the CZ method by immersing the seed crystal attached to the one end of the wire in the silicon melt and then pulling it up.

Images