Thin plate single crystal manufacturing apparatus and thin plate single crystal manufacturing method

Abstract

To provide a thin plate-like single crystal manufacturing device that can manufacture a thin plate-like single crystal of which additive agent density has an optimum composition and is homogeneous continuously at low cost with high accuracy by making a large-sized raw material lump applicable while suppressing large output of an infrared ray, and to provide a thin plate-like single crystal manufacturing method.SOLUTION: A thin plate-like single crystal manufacturing device includes: infrared ray radiation means 20 for melting a surface of an upper side face 14 of a raw material lump 12; lifting means 30 for immersing a lower side face 34 of a thin plate-like seed single crystal 32 into a melt which is melted by the infrared ray radiation means and acquired at a surface of the upper side face of the raw material lump and lifting upward the seed single crystal from an immersed state; and horizontal moving means 72 for moving a raw material lump in a horizontal direction. A manufacturing method manufactures a thin plate-like single crystal 40 continuously by pulling upward a seed single crystal via the lifting means and moving a raw material lump in the horizontal direction with the horizontal moving means at the same time while moving a melting region of upper side face of raw material lump in the horizontal direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an apparatus and method for producing a thin plate-shaped single crystal, which are capable of continuously producing a thin plate-shaped single crystal. [Background technology]

[0002] The present inventors have already developed an apparatus and method for producing thin plate single crystals that are capable of continuously producing thin plate single crystals. The thin plate-shaped single crystal manufacturing apparatus and method developed by the inventors involve irradiating the upper surface of a raw material block for manufacturing thin plate-shaped single crystals with infrared light (laser light) to melt it, and then immersing a thin plate-shaped seed single crystal in the resulting melt and pulling it up, thereby continuously manufacturing thin plate-shaped single crystals (Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent application No. 2021-002285 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the thin plate single crystal manufacturing apparatus and thin plate single crystal manufacturing method described in Patent Document 1, if the size of the raw material block is increased to continuously manufacture long thin plate single crystals, it is necessary to increase the output of infrared rays (laser light) to melt the upper surface of the larger raw material block, which could result in higher prices for the infrared irradiation means and lead to higher manufacturing costs.

[0005] Therefore, the present invention aims to provide a thin plate single crystal manufacturing apparatus and a thin plate single crystal manufacturing method that can apply large raw material blocks while suppressing the increase in infrared output, have an optimal and homogeneous additive concentration, and can produce thin plate single crystals continuously and with high precision at low cost. [Means for solving the problem]

[0006] The present invention has been invented to solve the problems in the prior art described above, The thin plate single crystal manufacturing apparatus of the present invention comprises: an infrared irradiation means for irradiating an upper surface of a raw material lump for producing a thin plate-shaped single crystal with infrared rays to melt the surface of the upper surface of the raw material lump; a lifting means for immersing a lower surface of a thin plate-shaped seed single crystal in the melt formed on the upper surface of the raw material lump by the infrared irradiation means, and lifting the seed single crystal upward from the immersed state; horizontally moving means for moving the raw material block in a horizontal direction; Equipped with the lower surface of the seed single crystal is immersed in the melt formed on the upper surface of the raw material lump by the infrared irradiation means via the lifting means, thereby starting the growth of the single crystal from the immersed lower surface of the seed single crystal; Furthermore, the seed single crystal is pulled upward via the lifting means, and at the same time, the raw material block is moved horizontally via the horizontal moving means, thereby continuously producing thin plate-shaped single crystals by moving the melting area on the upper surface of the raw material block horizontally.

[0007] Furthermore, the method for producing a thin plate-like single crystal of the present invention comprises the steps of: a melting step of irradiating an upper surface of a raw material lump for producing a thin plate-shaped single crystal with infrared rays via an infrared irradiation means to melt the surface of the upper surface of the raw material lump; a growing step of immersing a lower surface of a thin plate-shaped seed single crystal in the melt obtained on the upper surface of the raw material lump in the melting step via an elevating means, and starting the growth of a single crystal from the lower surface of the seed single crystal; a continuous production step in which the seed single crystal, from which single crystal growth has commenced, is pulled upward in the growth step, and at the same time the raw material lump is moved horizontally by a horizontal movement means, thereby continuously producing a thin plate-shaped single crystal while horizontally moving a melted region on the upper side surface of the raw material lump; It is characterized by having at least the following.

[0008] In this way, the thin plate single crystal is grown while the melt (melt zone) on the upper surface of the raw material lump is moved horizontally, so that the thin plate single crystal can be grown stably and continuously. Moreover, the number of components constituting the thin plate single crystal manufacturing apparatus is small, and thin plate single crystals with an optimal additive concentration and homogeneous composition can be manufactured at low cost and with high precision.

[0009] Furthermore, large raw material blocks can be used in the thickness direction and / or in the direction perpendicular to the thickness direction, and long, thin plate-shaped single crystals can be produced continuously, thereby achieving a significant reduction in production costs.

[0010] Furthermore, it is possible to produce thin plate-shaped single crystals with a homogeneous composition of so-called incongruent melting substances, such as decomposed melting substances and solid solution substances, with high precision. Furthermore, since the structure does not move the infrared irradiation means but moves the raw material block horizontally, even when large raw material blocks are used, there is no need to increase the output of the infrared irradiation means, which allows for reduction in manufacturing costs.

[0011] The thin plate single crystal manufacturing apparatus of the present invention is The infrared light emitted from the infrared light emitting means is a laser beam. Furthermore, the method for producing a thin plate-like single crystal of the present invention comprises the steps of: In the melting step, The infrared light emitted from the infrared light emitting means is a laser beam.

[0012] In this way, laser light can accurately heat a specified area of the raw material block, so the melt (melted area) can be reliably formed on the upper surface of the raw material block without the melt spilling over from the upper surface of the raw material block.

[0013] The infrared irradiating means are preferably installed on all four sides (e.g., every 90 degrees) of the raw material lump as the center when viewed from above. However, it is also possible to split the laser light irradiated from one infrared irradiating means and irradiate the raw material lump with the laser light from all four sides.

[0014] Furthermore, the number of infrared irradiation means is not limited to four directions (every 90 degrees), but may be, for example, two directions (every 180 degrees), and may be determined taking into consideration the size of the hollow rectangular irradiation area of the laser light described below and the output intensity of the infrared irradiation means, etc.

[0015] The thin plate single crystal manufacturing apparatus of the present invention is The shape of the laser light irradiation area is a hollow rectangular shape that is elongated in a horizontal direction perpendicular to the thickness direction of the raw material lump. If the shape of the laser beam irradiation area is a hollow rectangle, the entire upper surface of the raw material lump can be reliably melted.

[0016] The thin plate single crystal manufacturing apparatus of the present invention is a mounting table on which the raw material block is placed; a position control means for controlling the vertical position of the mounting table to a predetermined position; The present invention is characterized by comprising:

[0017] By being able to control the vertical position of the mounting table in this way, it becomes possible to use raw material blocks that are not only large horizontally but also large vertically.Furthermore, even if the liquid surface position of the melt in the raw material block drops as the thin plate-shaped single crystal is pulled, the position of the raw material block can be raised to maintain its original position, so that the liquid surface position of the melt can always be controlled to the same position.

[0018] Therefore, it is only necessary to fix the infrared radiation position at the same position at all times, and thin plate-shaped single crystals can be produced stably and continuously with a high yield. In addition, when infrared rays (laser light) traveling parallel to the surface of the raw material lump are irradiated perpendicularly to the upper surface of the raw material lump, the irradiation intensity of the infrared rays (laser light) does not change even if the liquid surface position of the molten raw material lump drops, so there is no need to perform position control to maintain the liquid surface position of the molten raw material lump constant.

[0019] The thin plate single crystal manufacturing apparatus of the present invention is The horizontal movement means a drive shaft provided on the bottom side of the position control means; a driving means for driving the drive shaft; Equipped with The device is characterized in that the driving shaft is driven via the driving means to move the placement table and the position control means in a horizontal direction, which is the thickness direction of the raw material block.

[0020] With this configuration, the mounting table and position control means can be reliably moved horizontally, and the melt (melted area) formed on the upper surface of the raw material block by irradiation with infrared rays (laser light) can be moved horizontally, allowing stable and continuous growth of thin plate-shaped single crystals.

[0021] The thin plate single crystal manufacturing apparatus of the present invention is The horizontal movement means In a case where the mounting table and the position control means are configured to move in a horizontal direction, which is a thickness direction of the raw material block, the positions of both ends of the upper surface of the raw material lump in a horizontal direction perpendicular to the thickness direction of the raw material lump and the positions of both ends of the hollow rectangular shape in a horizontal direction perpendicular to the thickness direction of the raw material lump are substantially the same; The size of the irradiation area of the laser light is set so that the horizontal length perpendicular to the thickness direction of the raw material block in the hollow rectangular shape is slightly smaller than the horizontal length perpendicular to the thickness direction of the raw material block on the upper side of the raw material block.

[0022] The method for producing a thin plate-like single crystal of the present invention further comprises: In the continuous production process, The raw material block is moved horizontally, i.e., in the thickness direction of the raw material block, by the horizontal movement means.

[0023] The method for producing a thin plate-like single crystal of the present invention further comprises: In the continuous production process, When the melting zone reaches one end of the raw material block in the thickness direction on the upper surface of the raw material block, the melting zone is then moved toward the other end of the raw material block in the thickness direction on the opposite side, and this is continuously repeated.

[0024] The method for producing a thin plate-like single crystal of the present invention further comprises: In the melting step, the shape of the irradiation area of the laser light is a hollow rectangular shape that is elongated in a horizontal direction perpendicular to the thickness direction of the raw material lump, the positions of both ends of the upper surface of the raw material lump in a horizontal direction perpendicular to the thickness direction of the raw material lump and the positions of both ends of the hollow rectangular shape in a horizontal direction perpendicular to the thickness direction of the raw material lump are substantially the same; The size of the irradiation area of the laser light is set so that the horizontal length perpendicular to the thickness direction of the raw material block in the hollow rectangular shape is slightly smaller than the horizontal length perpendicular to the thickness direction of the raw material block on the upper side of the raw material block.

[0025] In this way, by irradiating the upper surface of the raw material lump with hollow rectangular laser light so that the positions of both horizontal ends of the upper surface of the raw material lump, perpendicular to the thickness direction of the raw material lump, and the positions of both horizontal ends of the hollow rectangular irradiation area of the laser light, perpendicular to the thickness direction of the raw material lump, approximately coincide, the hollow rectangular band portion of the upper surface of the raw material lump that is irradiated with the laser light will melt first, and the central portion of the hollow rectangular portion that is not irradiated with the laser light will melt due to thermal conduction from the molten liquid in the square band portion that was melted first.

[0026] Therefore, the temperature of the central portion not irradiated with the laser beam can be controlled to be lower than the temperature of the rectangular band portion. As a method for forming the laser beam irradiation area into a hollow rectangular shape, for example, four linear (rectangular) laser beams can be irradiated from all sides onto the upper surface of the raw material lump to form a hollow rectangular shape.

[0027] Furthermore, the laser light may be irradiated onto the upper surface of the raw material lump from an obliquely upward direction or from directly above in a vertical direction, but it is preferable that the irradiation angle can be adjusted to the optimum angle depending on the thermal conductivity characteristics of the single crystal material and the thickness of the thin plate-shaped single crystal to be produced.

[0028] In order to continuously produce a thin plate-shaped single crystal by melting a raw material ingot, it is necessary to simultaneously continue melting the raw material ingot and solidifying it into a thin plate-shaped single crystal. However, melting the raw material ingot requires heating, and solidifying it into a thin plate-shaped single crystal requires cooling the melt.

[0029] Therefore, to enable the stable production of thin plate-shaped single crystals, it is essential to continue the contradictory actions of "heating" and "cooling" in a stable manner with good controllability. This can be achieved by irradiating the upper surface of the raw material lump with a laser beam having a hollow rectangular irradiation area as described above.

[0030] In other words, by creating a temperature distribution in the molten liquid (melting zone) on the upper surface of the raw material block such that the temperature of the central part not irradiated with laser light is lower than the temperature of the square band part, it is possible to stably and continuously grow a thin plate-shaped single crystal from this central part.

[0031] In addition, the thin plate single crystal manufacturing apparatus of the present invention has a horizontal movement means for moving the raw material block horizontally, so that one end of the hollow rectangular irradiation area can be approximately aligned with one end of the thickness direction of the upper side of the raw material block, and by moving the raw material block horizontally in this state, which is the thickness direction of the raw material block, the hollow rectangular irradiation area can be made to move toward the other end of the thickness direction of the upper side of the raw material block.

[0032] This allows the use of a large raw material block in the thickness direction, for example, and allows the continuous production of long, thin plate-shaped single crystals. Regarding the size of the raw material block, if the horizontal length of the hollow rectangular laser light irradiation area perpendicular to the thickness direction of the raw material block is "approximately the same" as the horizontal length perpendicular to the thickness direction of the raw material block, there is no restriction in principle on the thickness direction length of the raw material block.

[0033] The reason for using the word "approximately the same" here is that if the horizontal length of the laser light irradiation area of a completely hollow rectangular raw material block, which is perpendicular to the thickness direction, were to be made to match the horizontal length of the laser light irradiation area of the raw material block, that is, if the sizes were to be matched as closely as possible, there is a risk that when the upper surface of the raw material block melts due to the irradiation of the laser light and a molten liquid (molten area) is formed, the molten liquid may spill from the upper surface of the raw material block.

[0034] Therefore, in practice, by setting the horizontal length of the hollow rectangular laser light irradiation area perpendicular to the thickness direction of the raw material lump to be ``slightly smaller'' than the horizontal length perpendicular to the thickness direction of the raw material lump, the melt can be held to the upper surface of the raw material lump by surface tension without spilling over from one end to the other end of the upper surface of the raw material lump in the horizontal direction perpendicular to the thickness direction.

[0035] Of course, when the horizontal moving means moves the raw material block in its thickness direction, the position of one horizontal end of the raw material block on its upper surface, i.e., the position of one horizontal end of the raw material block in the thickness direction of the hollow rectangular laser beam irradiation area, should be "approximately coincident." In other words, if the two ends were perfectly coincident, as described above, the melt obtained by the laser beam irradiation may spill over the upper surface of the raw material block. For this reason, it is preferable that once the one horizontal end of the hollow rectangular laser beam irradiation area in the thickness direction of the raw material block reaches a position slightly short of the one horizontal end of the raw material block in the thickness direction of the raw material block, the raw material block should not be moved any further. The same applies to the other end on the opposite side of the one end.

[0036] Since the size of the hollow rectangular laser beam irradiation area and the size of the melt (melt area) formed by the laser beam irradiation are interrelated, if the laser beam output is increased, the size of the melt (melt area) will increase even if the size of the irradiation area is the same. Therefore, since it is difficult to determine the optimal size of the laser beam irradiation area in advance, it is important to first actually irradiate the laser beam onto the upper surface of the raw material lump to form a melt (melt area), and then determine the size of the hollow rectangular irradiation area while observing both the laser beam output and the shape so that no unmelted material remains and the melt (melt area) does not spill over from the upper surface of the raw material lump. By repeating the horizontal movement of the melting zone in this manner, it is possible to continuously produce long, thin plate-shaped single crystals using a large horizontally extending lump of raw material.

[0037] The thin plate single crystal manufacturing apparatus of the present invention is The horizontal movement means a drive shaft provided on the bottom side of the position control means; a driving means for driving the drive shaft; Equipped with The present invention is characterized in that the driving shaft is driven via the driving means to move the placement table and the position control means in a horizontal direction that is perpendicular to the thickness direction of the raw material block.

[0038] The thin plate single crystal manufacturing apparatus of the present invention is The horizontal movement means In a case where the mounting table and the position control means are configured to move in a horizontal direction that is a direction perpendicular to the thickness direction of the raw material lump, the positions of both ends of the upper surface of the raw material lump in the horizontal direction, which is the thickness direction of the raw material lump, and the positions of both ends of the hollow rectangular shape in the horizontal direction, which is the thickness direction of the raw material lump, are substantially aligned; The size of the irradiation area of the laser light is set so that the horizontal length, which is the thickness direction of the raw material block in the hollow rectangular shape, is slightly smaller than the horizontal length, which is the thickness direction of the raw material block at the upper side of the raw material block.

[0039] The method for producing a thin plate-like single crystal of the present invention further comprises: In the continuous production process, The raw material lump is moved in a horizontal direction, which is a direction perpendicular to the thickness direction of the raw material lump, by the horizontal movement means.

[0040] The method for producing a thin plate-like single crystal of the present invention further comprises: In the continuous production process, When the melting zone reaches one end of the upper surface of the raw material block in a direction perpendicular to the thickness direction of the raw material block, the melting zone is then moved toward the other end on the opposite side in a direction perpendicular to the thickness direction of the raw material block, and this is continuously repeated.

[0041] The method for producing a thin plate-like single crystal of the present invention further comprises: In the melting step, the shape of the irradiation area of the laser light is a hollow rectangular shape that is elongated in a horizontal direction perpendicular to the thickness direction of the raw material lump, the positions of both ends of the upper surface of the raw material lump in the thickness direction of the raw material lump are substantially the same as the positions of both ends of the hollow rectangular shape in the thickness direction of the raw material lump, and The size of the irradiation area of the laser light is set so that the horizontal length, which is the thickness direction of the raw material block in the hollow rectangular shape, is slightly smaller than the horizontal length, which is the thickness direction of the raw material block at the upper side of the raw material block.

[0042] In this way, even if the raw material block is moved in a direction perpendicular to the thickness direction of the raw material block, it is possible to continuously produce a long, thin plate-shaped single crystal in the same manner as described above. Here, it is preferable to use a raw material block that is large in the direction perpendicular to the thickness direction of the raw material block.

[0043] The thin plate single crystal manufacturing apparatus of the present invention is The horizontal movement means a drive shaft provided on the bottom side of the position control means; a driving means for driving the drive shaft; Equipped with The device is characterized in that by driving the drive shaft via the drive means, the placement table and the position control means are moved horizontally in the thickness direction of the raw material block and / or in the horizontal direction perpendicular to the thickness direction of the raw material block.

[0044] The method for producing a thin plate-like single crystal of the present invention further comprises: In the continuous production process, The raw material block is moved by the horizontal movement means in a horizontal direction that is the thickness direction of the raw material block and in a horizontal direction that is perpendicular to the thickness direction of the raw material block.

[0045] The method for producing a thin plate-like single crystal of the present invention further comprises: In the continuous production process, When the melting zone reaches one end of the upper surface of the raw material block in a horizontal direction perpendicular to the thickness direction of the raw material block, the melting zone is moved in the thickness direction of the raw material block by a predetermined length, and then the melting zone is moved toward the other end of the upper surface of the raw material block in a horizontal direction perpendicular to the thickness direction of the raw material block, Next, the melting zone is moved again toward one end of the raw material lump in a horizontal direction perpendicular to the thickness direction, and this is carried out continuously over the entire upper surface of the raw material lump.

[0046] The method for producing a thin plate-like single crystal of the present invention further comprises: In the melting step, The shape of the laser light irradiation area is a hollow rectangular shape that is elongated in a horizontal direction perpendicular to the thickness direction of the raw material lump.

[0047] In this way, by moving the raw material block in the thickness direction of the raw material block and also in a direction perpendicular to the thickness direction of the raw material block, it is possible to continuously produce long, thin plate-shaped single crystals. Furthermore, since it is possible to use a large raw material block both in the thickness direction and in the direction perpendicular to the thickness direction, it is possible to continuously produce a long thin plate-shaped single crystal.

[0048] The thin plate single crystal manufacturing apparatus of the present invention is The horizontal movement speed of the mounting table and the position control means is It is characterized by being in the range of 0.005 mm / min to 100 mm / min.

[0049] Furthermore, the method for producing a thin plate-like single crystal of the present invention comprises the steps of: In the continuous production process, The raw material block is moved horizontally by the horizontal movement means at a moving speed within a range of 0.005 mm / min to 100 mm / min.

[0050] In particular, if the horizontal movement speed is within this range, thin plate-shaped single crystals can be produced from the molten zone formed on the upper surface of the raw material mass, and the consumed raw material can always be supplied from the horizontal direction, thereby maintaining the size and composition of the molten zone uniform.

[0051] Therefore, the scheme of the "solvent transfer method" can be maintained, and the thin plate-shaped single crystal can be stably and continuously grown while maintaining the uniform composition of the produced thin plate-shaped single crystal.

[0052] As the raw material mass moves, melting and solidification of the raw material continues on the upper surface of the raw material mass. The solidification consists of a portion that solidifies as the thin plate single crystal is produced, and the remaining portion that solidifies as the molten region moves with the movement of the raw material mass. In the solidified portion on the upper surface of the raw material mass, if the moving speed of the raw material mass, i.e., the moving speed of the molten region, is too fast, cell growth may occur.

[0053] If cell growth occurs, a lamellar structure will form in the solidified portion, making it difficult to achieve uniform melting the next time the material is melted, which may result in compositional variations in the product. Therefore, it is preferable that the moving speed be within a range in which cell growth does not occur.

[0054] When silicon is used as the raw material mass, the moving speed is preferably set within a range of 0.5 mm / min to 50 mm / min. On the other hand, when a material with low thermal conductivity, such as an oxide other than silicon, is used as the raw material mass, the moving speed of the raw material mass is preferably set within a range of 0.05 mm / min to 0.5 mm / min, since the pulling (winding) speed of the thin plate-shaped single crystal is slower than that of silicon.

[0055] Furthermore, when a multi-component oxide material is used as the raw material mass, the pulling (winding) speed of the thin plate-shaped single crystal is slower than when a material with low thermal conductivity, such as an oxide other than silicon, is used, so the moving speed of the raw material mass is preferably set within the range of 0.005 mm / min to 0.05 mm / min. On the other hand, when a material with high thermal conductivity, such as a metal material, is used, the moving speed of the raw material mass is preferably set within the range of 1 mm / min to 100 mm / min.

[0056] That is, since the optimum pulling (winding) speed for the thin plate-shaped single crystal varies depending on the material of the raw material lump, the moving speed of the raw material lump should be set in accordance with the material of the raw material lump used.

[0057] The thin plate single crystal manufacturing apparatus of the present invention is The horizontal movement means It is characterized by being a linear actuator.

[0058] If the horizontal movement means is a linear actuator that converts the rotational motion of an electric motor into linear motion, it is easy to adjust the movement speed when moving the position control means horizontally, and vibration is less likely to occur, so the melt on the upper surface of the raw material lump does not spill over from the upper surface, and thin plate-shaped single crystals can be grown stably and continuously.

[0059] The thin plate single crystal manufacturing apparatus of the present invention is The lifting means is a winding means for continuously winding the produced thin plate-like single crystal into a roll, The winding means a winding shaft for continuously winding the thin plate-like single crystal; A rotating means for rotating the winding shaft; Equipped with The seed single crystal is suspended from the winding shaft via a plurality of thin wires.

[0060] If the winding means is configured in this manner, the continuously produced thin plate single crystals can be reliably wound around the winding shaft, and the thin plate single crystal manufacturing apparatus does not become larger than necessary.

[0061] Furthermore, since the produced thin plate single crystal is in a roll form, it can be easily transported during shipping, improving the handling properties. Furthermore, if the seed single crystal is suspended by a thin wire that is heat-resistant and has high strength, the continuously produced thin plate-shaped single crystal can be reliably wound around a winding shaft.

[0062] The thin plate single crystal manufacturing apparatus of the present invention is the winding speed of the thin plate-shaped single crystal by the winding means is It is characterized by being in the range of 0.005 mm / min to 100 mm / min.

[0063] If the thin plate single crystal is wound at such a winding speed, it can be wound reliably without damaging the thin plate single crystal, and therefore, thin plate single crystal can be produced with a good yield.

[0064] When silicon is used as the raw material lump, the winding speed of the thin plate-shaped single crystal is preferably set within the range of 0.5 mm / min to 50 mm / min. On the other hand, when a material with low thermal conductivity, such as an oxide other than silicon, is used as the raw material lump, the pulling (winding) speed of the thin plate-shaped single crystal is slower than that of silicon, so the winding speed is preferably set within the range of 0.05 mm / min to 0.5 mm / min.

[0065] Furthermore, when a multi-component oxide material is used as the raw material mass, the pulling (winding) speed of the thin plate single crystal is even slower than when a material with low thermal conductivity, such as an oxide other than silicon, and therefore the winding speed is preferably set within the range of 0.005 mm / min to 0.05 mm / min. On the other hand, when a material with high thermal conductivity, such as a metal material, is used, the winding speed is preferably set within the range of 1 mm / min to 100 mm / min.

[0066] That is, the optimum pulling (winding) speed for the thin plate-shaped single crystal varies depending on the material of the raw material lump, so the winding speed should be set in accordance with the material of the raw material lump used.

[0067] The method for producing a thin plate-like single crystal of the present invention further comprises: After the continuous manufacturing process, a winding step of winding the continuously produced thin plate-like single crystal into a roll; The present invention is characterized by further comprising: By including such a winding step, the continuously produced thin plate-shaped single crystal can be reliably wound into a roll, and thin plate-shaped single crystal can be produced efficiently.

[0068] The method for producing a thin plate-like single crystal of the present invention further comprises: In the winding step, The winding speed of the thin plate-like single crystal is characterized by being within the range of 0.005 mm / min to 100 mm / min.

[0069] If the thin plate single crystal is wound at such a winding speed, it can be wound reliably without damaging the thin plate single crystal, and therefore, thin plate single crystal can be produced with a good yield.

[0070] When silicon is used as the raw material lump, the winding speed of the thin plate-shaped single crystal is preferably set within the range of 0.5 mm / min to 50 mm / min. On the other hand, when a material with low thermal conductivity, such as an oxide other than silicon, is used as the raw material lump, the pulling (winding) speed of the thin plate-shaped single crystal is slower than that of silicon, so the winding speed is preferably set within the range of 0.05 mm / min to 0.5 mm / min.

[0071] Furthermore, when a multi-component oxide material is used as the raw material mass, the pulling (winding) speed of the thin plate-shaped single crystal is even slower than when a material with low thermal conductivity, such as an oxide other than silicon, is used, so the winding speed is preferably set within the range of 0.005 mm / min to 0.05 mm / min. On the other hand, when a material with high thermal conductivity, such as a metal material, is used, the winding speed is preferably set within the range of 1 mm / min to 100 mm / min. In other words, the optimal pulling (winding) speed for the thin plate-shaped single crystal varies depending on the raw material mass material, so the winding speed should be set according to the raw material mass material used.

[0072] The thin plate single crystal manufacturing apparatus of the present invention is In the seed single crystal, The thickness of the part where the thin wire is attached is The size is characterized by being equal to or smaller than the thickness of the thin plate-like single crystal to be produced.

[0073] In this way, if the thickness of the part of the seed single crystal to which the thin wire is attached is set to a size equal to or smaller than the thickness of the thin plate-shaped single crystal to be produced, it is possible to reliably prevent the surface of the thin plate-shaped single crystal from coming into contact with the thin wire and causing damage when the thin plate-shaped single crystal is wound around the winding shaft.

[0074] The thin plate single crystal manufacturing apparatus of the present invention is When the material of the raw material lump is silicon, the thickness of the thin plate-shaped single crystal is within a range of 30 μm to 500 μm.

[0075] When the raw material ingot is silicon, if the thickness is as described above, a high purity thin plate single crystal can be continuously produced and wound up to achieve a long length. Furthermore, by optimally adjusting the inclination angle of the laser light irradiated onto the upper surface of the raw material lump relative to the horizontal direction and the spacing between the irradiated laser light, it is possible to produce even thinner or thicker thin plate-shaped single crystals.

[0076] Furthermore, even when an oxide material or a metal material other than silicon is used as the raw material block material, a thin plate-shaped single crystal having the desired thickness can be produced by optimally adjusting the inclination angle of the laser light irradiated onto the upper surface of the raw material block relative to the horizontal direction and the spacing between the irradiated laser light.

[0077] The thin plate single crystal manufacturing apparatus of the present invention is The present invention is characterized in that an auxiliary heating member for preheating the raw material lump is provided around the raw material lump.

[0078] By providing such an auxiliary heating member, the amount of infrared (laser light) irradiation can be reduced by preheating the raw material lump to a temperature lower than the melting point. Therefore, even if the size of the raw material lump is increased, there is no need to increase the output of the infrared irradiating means more than necessary, and production costs can be reduced.

[0079] The thin plate single crystal manufacturing apparatus of the present invention is The auxiliary heating member is further provided with a heat insulating material on its outer side. If a heat insulating material is provided on the outside of the auxiliary heating member in this way, the energy required for heating to a temperature lower than the melting point by the auxiliary heating member can be significantly reduced.

[0080] The thin plate single crystal manufacturing apparatus of the present invention is On the upper surface of the raw material lump, The method is characterized in that a required amount of a liquid phase (referred to as a solvent phase) that coexists in equilibrium with the composition of the thin plate-like single crystal to be produced is initially placed.

[0081] In this case, the "required amount" is the same as the volume of the molten area formed on the upper surface of the raw material lump by irradiating it with the laser light. In this way, by initially placing a required amount of liquid phase composition that coexists in equilibrium with the composition of the thin plate-shaped single crystal to be produced on the upper surface of the raw material mass, it is possible to maintain the so-called solvent transfer method scheme, and thus thin plate-shaped single crystals with a homogeneous and optimal composition can be continuously produced.

[0082] However, if the composition fluctuates due to evaporation from the formed molten region, it is possible to produce a high-quality thin plate single crystal with a homogeneous composition by adding the same amount of the component as the evaporated amount to the raw material mass in advance and producing the thin plate single crystal while always maintaining the composition and amount constant.

[0083] Furthermore, if the specified component composition changes due to evaporation, it is possible to produce thin plate-shaped single crystals of the specified composition by supplying a gas that can replenish the component through reaction into the atmosphere. For example, when producing N-type silicon single crystals doped with phosphorus, it is well known to use phosphine (PH3) gas.

[0084] The method for producing a thin plate-like single crystal of the present invention further comprises: In the melting step, When the thin plate-shaped single crystal to be produced is a decomposed melt substance, a required amount of a liquid phase (called a solvent phase) that coexists in equilibrium with the composition of the decomposed melt substance is first placed on the upper surface of the raw material mass.

[0085] Furthermore, the method for producing a thin plate-like single crystal of the present invention comprises the steps of: In the melting step, When the thin plate-like single crystal to be produced is a solid solution material containing an additive, a required amount of a liquid phase (called a solvent phase) that coexists in equilibrium with the composition of the solid solution is first placed on the upper surface of the raw material mass.

[0086] In this case, the "required amount" is equal to the volume of the molten area formed on the upper surface of the raw material lump by irradiating it with laser light. In the molten zone that is initially formed on the upper surface of the raw material block, the supply of new raw material and solidification from the molten zone continue simultaneously as the raw material block moves. The solidification from the molten zone consists of a portion that solidifies as the thin plate-shaped single crystal is produced and the remaining portion that solidifies as the molten zone moves.

[0087] This allows the raw material block to melt and solidify simultaneously, so the concentration of additives in the resulting product (thin plate single crystal) becomes the same as that in the raw material block, making it homogeneous. This scheme is called the "solvent transfer method," and is the only means by which the "melt method" can be used to produce single crystal products (thin plate single crystals) with homogeneous composition.

[0088] In this way, by initially placing a required amount of liquid phase composition that coexists in equilibrium with the composition of the thin plate-shaped single crystal to be produced on the upper surface of the raw material mass, thin plate-shaped single crystals that are homogeneous and have an optimal composition can be continuously produced.

[0089] However, if the composition fluctuates due to evaporation from the formed molten region, it is possible to produce a high-quality thin plate single crystal with a homogeneous composition by adding the same amount of the component as the evaporated amount to the raw material mass in advance and producing the thin plate single crystal while always maintaining the composition and amount constant. [Effects of the Invention]

[0090] According to the thin plate single crystal manufacturing apparatus and method of the present invention, the raw material block is moved horizontally using a horizontal movement means, and the melt (molten zone) on the upper surface of the raw material block is moved horizontally while the thin plate single crystal is grown.This means that large raw material blocks can be used without increasing the infrared output, and thin plate single crystals with an optimal additive concentration and uniformity can be manufactured continuously and with high precision at low cost.

[0091] Furthermore, by controlling the position of the molten region formed on the upper surface of the raw material lump to always be at the same position, it becomes possible to use a raw material lump that is large in height, and manufacturing costs can be significantly reduced. [Brief explanation of the drawings]

[0092] [Figure 1] FIG. 1 is a schematic diagram of a thin plate single crystal manufacturing apparatus according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a diagram showing a hollow rectangular irradiation area formed by four laser beams irradiated from four infrared irradiation means. [Figure 3] FIG. 3 is a conceptual diagram showing a state in which a raw material ingot is viewed from above in the thin plate single crystal manufacturing apparatus according to the first embodiment of the present invention. [Figure 4] FIG. 4 is another schematic diagram of the thin plate single crystal manufacturing apparatus according to the first embodiment of the present invention. [Figure 5] FIG. 5 is a diagram for explaining the state of the melt (melt zone) formed on the upper side of the raw material ingot in the thin plate single crystal manufacturing apparatus shown in FIG. [Figure 6] FIG. 6 is a diagram for explaining the state of the melt (melt zone) formed on the upper side of the raw material ingot in the thin plate single crystal manufacturing apparatus shown in FIG. [Figure 7] FIG. 7 is a schematic perspective view for explaining the state of the raw material lump, the seed single crystal, and the thin plate-shaped single crystal in the first embodiment of the present invention. [Figure 8]FIG. 8 is a diagram for explaining the movement of the raw material block by the horizontal direction moving means in the thin plate single crystal manufacturing apparatus shown in FIG. [Figure 9] FIG. 9 is a schematic diagram showing the state in which the raw material lump is moved to one side in the thickness direction of the raw material lump by the horizontal direction moving means in the thin plate single crystal manufacturing apparatus shown in FIG. [Figure 10] FIG. 10 is a diagram for explaining the movement of the raw material block by the horizontal direction moving means in the thin plate single crystal manufacturing apparatus shown in FIG. [Figure 11] FIG. 11 is a schematic diagram showing the state in which the raw material lump has been moved to the other side in the thickness direction of the raw material lump by the horizontal direction moving means in the thin plate single crystal manufacturing apparatus shown in FIG. [Figure 12] FIG. 12 is a schematic diagram of a thin plate single crystal manufacturing apparatus according to the second embodiment of the present invention. [Figure 13] FIG. 13 is a cross-sectional view of the main part of the thin plate single crystal manufacturing apparatus shown in FIG. [Figure 14] FIG. 14 is a schematic diagram showing a state in which the raw material lump is moved upward by the position control means in the thin plate single crystal manufacturing apparatus according to the second embodiment of the present invention. [Figure 15] FIG. 15 is a schematic diagram of a thin plate single crystal manufacturing apparatus according to the third embodiment of the present invention. [Figure 16] FIG. 16 is a conceptual diagram showing a state in which a raw material ingot is viewed from above in a thin plate single crystal manufacturing apparatus according to the third embodiment of the present invention. [Figure 17] FIG. 17 is a schematic diagram of a thin plate single crystal manufacturing apparatus according to the fourth embodiment of the present invention. [Figure 18] FIG. 18 is a conceptual diagram showing a state in which a raw material ingot is viewed from above in a thin plate single crystal manufacturing apparatus according to the fourth embodiment of the present invention. [Figure 19] FIG. 19 is a diagram for explaining the movement of the raw material lump by the horizontal direction moving means in the thin plate single crystal manufacturing apparatus according to the fourth embodiment of the present invention shown in FIG. [Figure 20]FIG. 20 is a diagram for explaining the movement of the raw material lump by the horizontal direction moving means in the thin plate single crystal manufacturing apparatus according to the fourth embodiment of the present invention shown in FIG. [Figure 21] FIG. 21 is a conceptual diagram showing a state in which a raw material ingot is viewed from above in an apparatus for producing a thin plate-shaped single crystal in the fifth embodiment of the present invention. [Figure 22] FIG. 22 is a schematic perspective view for explaining the state of a raw material lump, a seed single crystal, and a thin plate-shaped single crystal in the fifth embodiment of the present invention. [Figure 23] FIG. 23 is a schematic diagram of a thin plate single crystal manufacturing apparatus according to the sixth embodiment of the present invention. [Figure 24] FIG. 24 is a schematic diagram of another thin plate single crystal manufacturing apparatus according to the sixth embodiment of the present invention. [Figure 25] FIG. 25 is a schematic diagram of an apparatus for producing a thin plate-shaped single crystal according to the seventh embodiment of the present invention. [Figure 26] FIG. 26 is an enlarged view of the essential parts of the thin plate single crystal manufacturing apparatus according to the seventh embodiment of the present invention shown in FIG. [Figure 27] FIG. 27 is a schematic diagram showing each step of the method for producing a thin plate-shaped single crystal of the present invention. [Figure 28] FIG. 28 is a schematic diagram showing each step of the method for producing a thin plate-shaped single crystal of the present invention. [Figure 29] FIG. 29 is a schematic diagram showing each step of the method for producing a thin plate-shaped single crystal of the present invention. [Figure 30] FIG. 30 is a schematic diagram of an apparatus for producing a thin plate-shaped single crystal according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0093] The thin plate single crystal manufacturing apparatus and thin plate single crystal manufacturing method of the present invention will be described in more detail below with reference to the drawings. The thin plate single crystal manufacturing apparatus and method of the present invention are capable of applying large raw material blocks while suppressing the use of high infrared output, and are intended to produce thin plate single crystals having an optimal and homogeneous solid solution composition containing additives, etc., continuously and with high precision at low cost.

[0094] <Thin plate single crystal manufacturing equipment 10> [First embodiment] 1, in the apparatus 10 for producing a thin plate-shaped single crystal according to the first embodiment of the present invention, a raw material lump 12 for producing a thin plate-shaped single crystal is placed on a mounting table 82 disposed in a chamber 80. The raw material lump 12 has a rectangular parallelepiped shape.

[0095] An infrared irradiation means 20 is provided at the top of the chamber 80 to irradiate the upper surface 14 of the rectangular parallelepiped raw material lump 12 with infrared rays 16, thereby melting the surface of the upper surface 14 and obtaining a melt 18 (molten region). Although the infrared irradiation means 20 are shown provided on the left and right of the raw material lump 12 in the figure, in reality, four infrared irradiation means 20 are arranged on all four sides of the periphery of the raw material lump 12, i.e., above, below, left, and right, as viewed from above, so that the infrared rays 16 are irradiated onto the upper surface 14 of the raw material lump 12 from all directions (for convenience of drawing in FIG. 1, the infrared irradiation means 20, reflectors 24 described below, and infrared rays 16 arranged in the front-to-back directions of the raw material lump 12 are not shown).

[0096] The infrared rays 16 emitted from each of these four infrared irradiating means 20 are preferably laser beams 16a. 2, the irradiation area A of the laser beam 16a is a hollow rectangular shape elongated in the horizontal direction (vertical direction in FIG. 2), and the four sides of the rectangle, i.e., two long sides and two short sides, are formed by four laser beams 16a with rectangular cross sections irradiated from four infrared irradiation means 20. Note that the width E of the laser beam 16a is preferably set within a range of 3 mm to 6 mm when producing a thin plate-shaped single crystal 40 with a thickness of about several hundred μm.

[0097] If the width E of the laser beam 16a is made too large, the output of the laser beam 16a will need to be increased, leading to increased costs. Conversely, if the width E of the laser beam 16a is made too small, the output of the laser beam 16a will need to be increased to form the desired melted region 18. If the output of the laser beam 16a is increased, the temperature of the melt 18 on the upper surface 14 of the raw material ingot 12 irradiated with the laser beam 16a will rise too high, tending to cause intense evaporation and the like, making it difficult to stably produce the thin plate-shaped single crystal 40.

[0098] Furthermore, the distance F between adjacent laser beams 16a in the thickness direction W of the raw material lump 12 is preferably set within a range of 2 mm to 10 mm. If the distance F between adjacent laser beams 16a in the thickness direction W of the raw material lump 12 in the irradiation area A is too small, it becomes difficult to control the temperature of the melt 18 when pulling up (winding up) the thin plate-shaped single crystal 40. Conversely, if the distance F between adjacent laser beams 16a is too large, it becomes necessary to increase the output of the laser beams 16a.

[0099] It is preferable that the laser beam 16a is aligned with the upper surface 14 of the raw material block 12 so that a hollow rectangular irradiation area A elongated in the horizontal direction is formed, as shown in Figure 3.

[0100] In this case, if the thickness direction of the raw material block 12 is defined as "W" and the direction (horizontal direction) perpendicular to the thickness direction of the raw material block 12 is defined as "D," it is preferable that the positions of both ends of the upper surface 14 of the raw material block 12 in the direction (horizontal direction) D perpendicular to the thickness direction of the raw material block 12 and the positions of both ends of the hollow rectangular irradiation area A in the direction (horizontal direction) D perpendicular to the thickness direction of the raw material block 12 are "approximately aligned."

[0101] It is preferable to set the size of the irradiation area A of the laser light 16a so that the length in the direction (horizontal direction) D perpendicular to the thickness direction of the raw material block 12 in the hollow rectangular shape is slightly smaller than the length in the direction (horizontal direction) D perpendicular to the thickness direction of the raw material block 12 at the upper surface 14 of the raw material block 12.

[0102] The reason for using the expression "approximately the same" here is that if the length of the irradiation area A of the laser light 16a, which is completely hollow and rectangular, in the direction (horizontal direction) D perpendicular to the thickness direction of the raw material block 12 is made to match the length of the irradiation area A of the laser light 16a in the direction (horizontal direction) perpendicular to the thickness direction of the raw material block 12, that is, if the sizes are matched as closely as possible, there is a risk that when the upper surface 14 of the raw material block 12 melts due to the irradiation of the laser light 16a and a molten liquid 18 (molten area) is formed, the molten liquid 18 may spill from the upper surface 14 of the raw material block 12.

[0103] Therefore, in practice, by setting the length of the irradiation area A of the hollow rectangular laser light 16a in the direction D perpendicular to the thickness direction of the raw material block 12 (horizontal direction) to be "slightly smaller" than the length of the direction D perpendicular to the thickness direction of the raw material block 12, the melt 18 can be held on the upper surface 14 of the raw material block 12 by surface tension without spilling over from one end to the other end in the direction D perpendicular to the thickness direction of the upper surface 14 of the raw material block 12.

[0104] In addition, since the size of the irradiation area A of the hollow rectangular laser beam 16a and the size of the melt 18 (melted area) formed by the irradiation of the laser beam 16a are mutually related, even if the size of the irradiation area A is the same, if the output of the laser beam 16a is increased, the size of the melt 18 (melted area) will become larger.

[0105] Therefore, it is difficult to optimally determine the size of the irradiation area A of the laser beam 16a in advance. For this reason, it is important to first actually irradiate the upper surface 14 of the raw material lump 12 with the laser beam 16a to form the melt 18 (melted area), and then determine the size of the irradiation area A of the laser beam 16a while observing both the size of the hollow rectangular shape formed by the laser beam 16a so that no unmelted residue remains and the melt 18 (melted area) does not spill over from the upper surface 14 of the raw material lump 12, and the output of the laser beam 16a.

[0106] Here, the laser light 16a emitted from the infrared irradiation means 20 may be incident into the chamber 80 in any manner, but it is preferable that it be incident into the chamber 80 through a window 22 provided at the top of the chamber 80 via a reflecting mirror 24 and be irradiated onto the upper surface 14 of the raw material lump 12 inside the chamber 80.

[0107] At this time, the laser beam 16a is irradiated onto the upper surface 14 of the raw material lump 12 from an obliquely upward direction as shown in Fig. 1, but it may also be irradiated onto the upper surface 14 of the raw material lump 12 from directly above in a vertical direction as shown in Fig. 4. The laser beam 16a irradiated onto the upper surface 14 of the raw material lump 12 may be controlled to an optimum irradiation angle depending on the thermal conductivity of the material of the raw material lump 12 and the thickness of the thin plate-shaped single crystal 40 to be produced.

[0108] As a result, when a hollow rectangular laser beam 16a as shown in Figure 2 is irradiated onto the upper surface 14 of the raw material block 12, the portion irradiated with the laser beam 16a (rectangular band portion B of irradiation area A) melts first as shown in Figure 3, and the hollow rectangular central portion C not hit by the laser beam 16a melts due to thermal conduction from the previously melted rectangular band portion B and the melt 18 formed in the vicinity of its periphery.

[0109] Therefore, the temperature of the central portion C not hit by the laser light 16a can be controlled to be lower than the temperature of the portion (square band portion B) irradiated by the laser light 16a, and by providing such a temperature distribution in the melt 18 (melting zone) on the upper surface 14 of the raw material lump 12, stable and continuous growth of a thin plate-shaped single crystal 40 can be achieved from the center of this melt 18 (melting zone).

[0110] That is, as shown in Figures 5 and 6, by irradiating the upper surface 14 of the raw material lump 12 with a hollow rectangular laser beam 16a, a melt 18 is formed in the rectangular band portion B and in the vicinity of the rectangular band portion B of the hollow rectangular irradiation area A to a greater depth than in the central portion C, and a melt 18 is formed in the central portion C that is shallower and has a lower temperature than the melt 18 formed around the central portion C.

[0111] Meanwhile, above the chamber 80, there is provided a lifting means 30 which immerses the lower surface 34 of a thin plate-shaped seed single crystal 32 into the melt 18 (molten zone) obtained on the surface of the upper surface 14 of the raw material block 12 by melting it with the infrared irradiation means 20, and pulls the seed single crystal 32 upward from the immersed state, and further pulls upward the thin plate-shaped single crystal 40 produced together with the seed single crystal 32.

[0112] The lifting means 30 is not particularly limited in structure, but is preferably, for example, a winding means 50 that continuously winds up the produced thin plate single crystal 40 in the form of a roll. Specifically, it has a winding shaft 36 that continuously winds up the produced thin plate single crystal 40, and a rotating means 38 that rotates the winding shaft 36. In the figure, the reference numeral 44 denotes a rotating roller that serves as a guide when continuously winding up the thin plate single crystal 40 around the winding shaft 36.

[0113] 7 , the size T1 of the lower surface 34 of the seed single crystal 32 in the longitudinal direction (direction D perpendicular to the thickness direction of the raw material lump 12) is set to be slightly smaller than the size T2 of the upper surface 14 of the raw material lump 12 in the direction D perpendicular to the thickness direction of the raw material lump 12. For example, as a specific relationship between the sizes, the size T2 of the upper surface 14 of the raw material lump 12 in the direction D perpendicular to the thickness direction of the raw material lump 12 is set to be several mm or more larger than the size T1 of the lower surface 34 of the seed single crystal 32 in the longitudinal direction (direction perpendicular to the thickness direction of the seed single crystal 32). In other words, the size is set so that the entire lower surface 34 of the seed single crystal 32 can be immersed in the melt 18.

[0114] The melt 18 (melting zone) formed on the upper surface 14 of the raw material lump 12, into which the seed single crystal 32 is immersed, by the infrared irradiation means 20 moves the raw material lump 12 from the state shown in Figure 8(a) in the thickness direction W of the raw material lump 12 (to the right in Figure 8(a)) by the horizontal movement means 72, and accordingly, as shown in Figure 8(b), the melt 18 (melting zone) moves to the left (the opposite direction to the moving direction of the raw material lump 12). In other words, on the surface of the raw material lump 12, melting progresses in the moving direction of the melt 18 (melting zone), and at the same time, solidification of the melt 18 progresses in the opposite direction to the moving direction of the melt 18 (melting zone).

[0115] The horizontal movement means 72 comprises a drive shaft 74 provided on the bottom side of the position control means 84 as shown in Figure 1, and a drive means 76 such as a motor that drives the drive shaft 74.By driving the drive shaft 74 via the drive means 76, the loading table 82 on which the raw material lump 12 is placed and the position control means 84 that controls the vertical position of the loading table 82 to a predetermined position can be moved in the thickness direction W of the raw material lump 12.

[0116] The position control means 84 is capable of changing the vertical position of the mounting table 82 by driving a drive shaft 86 installed below the mounting table 82 via a drive means 88 such as a motor. However, the present invention is not limited to this structure, and known means such as an air cylinder may also be used.

[0117] The horizontal movement speed of the mounting table 82 and the position control means 84 by the horizontal movement means 72 is preferably within the range of 0.005 mm / min to 100 mm / min. When silicon is used as the raw material lump 12, the moving speed is preferably set within a range of 0.5 mm / min to 50 mm / min. On the other hand, when a material with low thermal conductivity, such as an oxide other than silicon, is used as the raw material lump 12, the pulling (winding) speed of the thin plate-shaped single crystal 40 becomes slower than that of silicon, so the moving speed of the raw material lump 12 is preferably set within a range of 0.05 mm / min to 0.5 mm / min.

[0118] Furthermore, when a multi-component oxide material is used as raw material lump 12, the pulling (winding) speed of thin plate-shaped single crystal 40 is slower than when a material with low thermal conductivity, such as an oxide other than silicon, is used, so the moving speed of raw material lump 12 is preferably set within the range of 0.005 mm / min to 0.05 mm / min. On the other hand, when a material with high thermal conductivity, such as a metal material, is used, the moving speed of raw material lump 12 is preferably set within the range of 1 mm / min to 100 mm / min.

[0119] However, even if the moving speed of the raw material lump 12 is within the above range, if the formation of a lamellar structure due to cell growth is observed in the area that solidifies as the raw material lump 12 moves, it is desirable to reduce the moving speed to a speed that allows stable melting and solidification of the raw material.

[0120] It is preferable that the horizontal movement means 72 be a linear actuator that converts the rotational motion of an electric motor into linear motion. Such a linear actuator makes it easy to adjust the speed at which the position control means 84 is moved horizontally, and is less likely to vibrate, so that the melt 18 (molten zone) on the upper surface 14 of the raw material lump 12 does not spill over from the upper surface 14, and the thin plate-shaped single crystal 40 can be stably and continuously grown while being held in place by surface tension.

[0121] In addition to linear actuators, the structure is not particularly limited to a linear actuator, and may be, for example, a structure in which the position control means 84 moves horizontally on a roller conveyor (not shown), as long as it can move the raw material block 12 horizontally without the molten liquid 18 (molten area) on the upper surface 14 of the raw material block 12 spilling over from the upper surface 14, similar to a linear actuator.

[0122] Then, when the melt 18 (molten zone) formed by irradiation with the hollow rectangular laser light 16a reaches one end of the raw material block 12, as shown in Figures 8(c) and 9, the direction of movement of the raw material block 12 is reversed and it is moved to the left (towards the other end of the raw material block 12) as shown in Figure 10(a).

[0123] Furthermore, as shown in Figure 10(b), the raw material block 12 is moved in a leftward direction (towards the other end of the raw material block 12), and when the melt 18 (melted zone) again reaches the other end of the raw material block 12 as shown in Figures 10(c) and 11, the raw material block 12 is again reversed and moved in a rightward direction (towards one end of the raw material block 12), and this left-right reversal is continued continuously.

[0124] In this way, by moving the position of the raw material block 12 horizontally to the left and right (in the thickness direction W of the raw material block 12) using the horizontal movement means 72, the raw material block 12 can be melted and solidified sequentially even if the size of the raw material block 12 is increased in the thickness direction W of the raw material block 12. Therefore, in principle, there is no size limit in the thickness direction W of the raw material block 12, and a raw material block 12 large in the thickness direction can be used.

[0125] Of course, when the horizontal movement means 72 moves the raw material block 12 in the thickness direction W of the raw material block 12, the position of one horizontal end of the raw material block 12 in the thickness direction W of the raw material block 12 on the upper surface 14 of the raw material block 12 will be made to "approximately coincide" with the position of one horizontal end of the raw material block 12 in the thickness direction W of the raw material block 12 in the hollow rectangular irradiation area A of the laser light 16a.In other words, as described above, if both ends are made to completely coincide, there is a risk that the melt 18 obtained by irradiation with the laser light 16a will spill over from the upper surface 14 of the raw material block 12.

[0126] For this reason, when one end of raw material lump 12 in the horizontal direction, i.e., thickness direction W, of irradiation area A of hollow rectangular laser beam 16a reaches a position slightly before the one end of raw material lump 12 in the horizontal direction, i.e., thickness direction W, it is preferable not to move raw material lump 12 any further than this position. The same applies to the other end on the opposite side of the one end.

[0127] In this way, the lower surface 34 of the seed single crystal 32 is immersed in the center of the melt 18 (melting zone) that is continuously obtained while moving on the upper surface 14 of the raw material lump 12 via the lifting means 30 (winding means 50).At the interface between the lower surface 34 of the immersed seed single crystal 32 and the melt 18, heat is transferred upward through the seed single crystal 32 by thermal conduction, lowering the interface temperature and starting the growth of the single crystal.

[0128] The seed single crystal 32 is pulled upward by the lifting means 30 in accordance with the growth rate of the single crystal, and the position of the solid-liquid interface between the single crystal and the melt 18 is kept constant, thereby enabling stable and continuous production of the thin plate-shaped single crystal 40. The winding speed of the thin plate-shaped single crystal 40 by the winding means 50 is preferably within the range of 0.005 mm / min to 100 mm / min.

[0129] When silicon is used as the raw material lump 12, the winding speed of the thin plate-shaped single crystal 40 is preferably set within a range of 0.5 mm / min to 50 mm / min. On the other hand, when a material with low thermal conductivity, such as an oxide other than silicon, is used as the raw material lump 12, the pulling (winding) speed of the thin plate-shaped single crystal 40 is slower than that of silicon, so the winding speed is preferably set within a range of 0.05 mm / min to 0.5 mm / min.

[0130] Furthermore, when a multi-component oxide material is used as the raw material ingot 12, the pulling (winding) speed of the thin plate-shaped single crystal 40 is even slower than when a material with low thermal conductivity, such as an oxide other than silicon, is used, so the winding speed is preferably set within the range of 0.005 mm / min to 0.05 mm / min. On the other hand, when a material with high thermal conductivity, such as a metal material, is used, the winding speed is preferably set within the range of 1 mm / min to 100 mm / min.

[0131] That is, the optimum pulling (winding) speed for the thin plate-shaped single crystal 40 varies depending on the material of the raw material ingot 12, so the winding speed should be set in accordance with the material of the raw material ingot 12 used.

[0132] The thickness of the thin plate-shaped single crystal 40 produced can be adjusted in a steady state by the temperature of the melt 18 and the pulling (winding) speed of the seed single crystal 32, and can be about 30 μm to 500 μm, for example, when the material of the raw material lump 12 is silicon. However, if the thickness of the thin plate-shaped single crystal 40 exceeds 500 μm, the winding means 50 becomes large, so if the thickness exceeds 500 μm, it can be pulled upward without being wound to produce a product.

[0133] Furthermore, by optimally adjusting the inclination angle of the laser beam 16a irradiated onto the upper surface 14 of the raw material lump 12 relative to the horizontal direction and the spacing between the irradiated laser beams 16a, it is possible to produce thin plate-shaped single crystals 40 that are even thinner or thicker than this.

[0134] Furthermore, even if an oxide material or a metal material other than silicon is used as the material for the raw material lump 12, a thin plate-shaped single crystal 40 having the desired thickness can be produced by optimally adjusting the inclination angle of the laser light 16a irradiated onto the upper surface 14 of the raw material lump 12 relative to the horizontal direction and the spacing between the irradiated laser light 16a.

[0135] There is a correlation between the temperature of the melt 18 and the pulling (coiling) speed of the thin plate-shaped single crystal 40. That is, when the temperature of the melt 18 is high, the amount of cooling required for the growth of the thin plate-shaped single crystal 40 increases, so the pulling (coiling) speed of the thin plate-shaped single crystal 40 is slowed down, and when the temperature of the melt 18 is low, the pulling (coiling) speed of the thin plate-shaped single crystal 40 is increased, thereby improving the productivity of the thin plate-shaped single crystal 40. However, if the pulling (coiling) speed is too fast, so-called "cell growth" is likely to occur, and the crystal properties of the thin plate-shaped single crystal 40 will deteriorate, so it is preferable to adjust the pulling (coiling) speed of the thin plate-shaped single crystal 40 appropriately.

[0136] The thickness V2 of the seed single crystal 32 immersed in the melt 18 and the width (size) in the direction perpendicular to the thickness V2 are not particularly limited, and may be set appropriately according to the size of the thin plate single crystal manufacturing apparatus 10.

[0137] For example, when the thickness of the seed single crystal 32 is set to about 300 μm to 500 μm, the temperature of the melt 18 and the pulling (winding) speed of the thin plate-shaped single crystal 40 can be adjusted to continuously produce a thin plate-shaped single crystal 40 of the desired thickness.

[0138] Furthermore, in this specification, the thickness of the thin plate-like single crystal 40 and the thickness of the seed single crystal 32 are illustrated as being different, but this is done intentionally so that the thin plate-like single crystal 40 and the seed single crystal 32 can be distinguished in the drawing, and does not particularly limit the relationship between the thicknesses of the two.

[0139] When winding the thin plate-shaped single crystal 40, it is preferable to hang the seed single crystal 32 on the winding shaft 36 of the winding means 50 via a plurality of (three in FIG. 7 ) heat-resistant, high-strength thin wires 52. In particular, if the thickness V1 of the portion of the seed single crystal 32 where the thin wires 52 are attached is set to be equal to or less than the thickness V2 of the seed single crystal 32, it is possible to reliably prevent the surface of the thin plate-shaped single crystal 40 from coming into contact with the thin wires 52 and causing damage when the thin plate-shaped single crystal 40 is wound around the winding shaft 36.

[0140] The method for attaching the thin wire 52 to the seed single crystal 32 is not particularly limited, but it is preferable to provide, for example, through holes (not shown) at several locations at the end of the seed single crystal 32 for tying the thin wire 52, and to provide grooves (not shown) on both sides of the seed single crystal 32 so as to connect to these through holes, so that when the thin wire 52 is tied to the seed single crystal 32, the thin wire 52 fits into these grooves and does not protrude outward from the seed single crystal 32. By doing so, it is possible to reliably prevent the surface of the thin plate-like single crystal 40 from coming into contact with the thin wire 52 and causing damage when the thin plate-like single crystal 40 is wound up.

[0141] In addition, in the thin plate single crystal manufacturing apparatus 10 of the present invention, it is preferable to provide, between the lifting means 30 and the raw material block 12, an anti-vibration member 60 that prevents the continuously manufactured thin plate single crystals 40 from shaking and keeps them within a predetermined range to prevent the growth position from shifting, and a shielding member 62 that blocks the radiant heat emitted from the melt 18 so that it does not reach the continuously manufactured thin plate single crystals 40.

[0142] By providing the anti-vibration member 60, it is possible to prevent the produced thin plate-shaped single crystal 40 from vibrating too much from side to side, which would cause the growth position to shift, and it is possible to stably and continuously produce high-quality thin plate-shaped single crystal 40.

[0143] Furthermore, the provision of the shielding member 62 can increase the production rate of the thin plate-shaped single crystal 40. That is, the method of melting the raw material ingot 12 and solidifying it into a single crystal is called the "melt method," and the growth rate of the single crystal in this melt method can be increased by efficiently dissipating the latent heat of crystallization released when the crystal solidifies through thermal conduction within the single crystal in contact with the melt 18.

[0144] Therefore, for example, if a shielding member 62 is provided so as not to block the optical path of the infrared rays 16 (laser light 16a), the amount of radiant heat reaching the thin plate-shaped single crystal 40 can be reduced, and the crystallization latent heat can be efficiently discharged by not increasing the temperature of the thin plate-shaped single crystal 40, thereby improving the manufacturing efficiency of the thin plate-shaped single crystal 40.

[0145] In this way, by using the thin plate single crystal manufacturing apparatus 10 of the present invention, thin plate single crystals 40 can be manufactured continuously, but as the thin plate single crystals 40 are manufactured continuously, the position of the upper surface 14 of the raw material ingot 12 will drop. If this happens, it is necessary to control the irradiation position of the infrared rays 16 (laser light 16a) from the infrared irradiation means 20 so that it is the desired position.

[0146] In this embodiment, instead of controlling the irradiation position of the infrared rays 16, a table 82 on which the raw material lump 12 is placed is provided with a position control means 84 for controlling the vertical position of the table 82.

[0147] By providing such a position control means 84, even if the position of the upper surface 14 of the raw material lump 12 drops as the continuously produced thin plate-shaped single crystal 40 is pulled up, the loading table 82 can be raised to maintain the position of the upper surface 14 of the raw material lump 12 at the same position as its original position, and the liquid surface position of the melt 18 can always be kept at the same position.

[0148] Therefore, it is sufficient to always irradiate the same position with infrared rays 16, thereby enabling stable, high-yield continuous production of thin plate-shaped single crystals 40. Here, when laser light 16a is irradiated perpendicularly from directly above raw material lump 12 onto upper surface 14 of raw material lump 12, as in the thin plate-shaped single crystal production apparatus 10 shown in Figures 4 and 6, the temperature of melt 18 does not change even if the position of upper surface 14 of raw material lump 12 fluctuates in the vertical direction, so there is no need to control the vertical position of upper surface 14 of raw material lump 12.

[0149] The raw material lump 12 used in the above-described thin plate single crystal manufacturing apparatus 10 has the same composition as the material of the thin plate single crystal 40 to be manufactured. However, if the material of the thin plate single crystal 40 is a decomposed melting substance, the desired thin plate single crystal 40 cannot be obtained even if the raw material lump 12 is melted and solidified as is in the thin plate single crystal manufacturing apparatus 10 of the present invention.

[0150] A required amount of a liquid phase (referred to as a solvent phase) that coexists in equilibrium with the composition of the material of the thin plate-shaped single crystal 40 to be produced is first placed on the upper surface 14 of the raw material lump 12, and this is then melted. In this case, the "required amount" is the same as the volume of the melt (melted region) 18 formed on the upper surface 14 of the raw material lump 12 by irradiation with infrared rays 16 (laser light 16a). In this way, an amount of solvent equivalent to the amount of the melt phase formed by irradiation with laser light 16a is placed on the upper surface 14 of the raw material lump 12.

[0151] When the thin plate-shaped single crystal 40 is produced in this manner, the amount of raw material newly supplied to the melting zone 18 as the raw material block 12 moves is equal to the amount that solidifies as the thin plate-shaped single crystal 40, and the amount that solidifies in the melting zone 18 as the raw material block 12 moves, so the amount and composition of the solvent do not change from start to finish, and it appears as if the solvent phase is dissolving the raw material block 12, solidifying and moving while precipitating a single crystal.

[0152] This scheme is called the “solvent migration method.” When the thin plate-shaped single crystal 40 obtained by the thin plate-shaped single crystal manufacturing apparatus 10 of the present invention is a decomposed melt substance or a solid solution substance containing additives, it is important to use this “solvent migration method” in order to make the concentration of the additives in the obtained thin plate-shaped single crystal 40 uniform.

[0153] Thus, according to the present invention, by moving the raw material block 12 horizontally using the horizontal moving means 72, the melt (molten zone) 18 on the upper surface 14 of the raw material block 12 is moved horizontally while growing the thin plate-shaped single crystal 40.Therefore, a large raw material block 12 can be used without increasing the output of the infrared rays 16, and thin plate-shaped single crystals 40 having an optimal additive concentration and a homogeneous composition can be produced continuously and with high precision at low cost.

[0154] [Second embodiment] Next, a second embodiment of the thin plate single crystal manufacturing apparatus 10 of the present invention will be described. 12 to 14 show a thin plate single crystal manufacturing apparatus 10 according to the second embodiment of the present invention.

[0155] The thin plate-shaped single crystal manufacturing apparatus 10 shown in Figures 12 to 14 has basically the same configuration as the thin plate-shaped single crystal manufacturing apparatus 10 of the first embodiment shown in Figures 1 to 11, so the same components are given the same reference numbers and detailed descriptions are omitted, and only the differences are described.

[0156] As shown in Figures 12 to 14, the thin plate-shaped single crystal manufacturing apparatus 10 in the second embodiment of the present invention differs from the thin plate-shaped single crystal manufacturing apparatus 10 in the first embodiment in that an auxiliary heating element 64 for preheating the raw material block 12 is provided around the raw material block 12, and an insulating material 66 is further provided outside the auxiliary heating element 64.

[0157] As shown in Figure 13, the auxiliary heating member 64 and the insulating material 66 are preferably arranged to the side of the position control means 84 so as to completely cover the raw material lump 12 when the raw material lump 12 is placed on the loading table 82.

[0158] In this way, by providing the auxiliary heating member 64 and the insulating material 66 to the side of the position control means 84, as shown in Figure 14, when the raw material block 12 is moved upward by the position control means 84 as the upper surface 14 of the raw material block 12 melts, the height positions of the auxiliary heating member 64 and the insulating material 66 can be maintained at the same position.

[0159] Furthermore, since the position control means 84 and the horizontal movement means 72 are naturally connected, the auxiliary heating member 64 and the insulating material 66 can also be moved in accordance with the horizontal movement of the raw material block 12 by the horizontal movement means 72, so that the raw material block 12 can always be kept in a heated state.

[0160] It is preferable that the raw material lump 12 is heated by the auxiliary heating member 64 to a temperature lower than the melting point of the raw material lump 12 . Before the upper surface 14 of the raw material lump 12 is irradiated with the infrared rays 16 (laser light 16a) emitted from the infrared irradiation means 20, the temperature of the raw material lump 12 is preheated to a temperature lower than the melting point via the auxiliary heating member 64, thereby reducing the amount of irradiation of the infrared rays 16 (laser light 16a). Therefore, even if the size of the raw material lump 12 is increased, there is no need to increase the output of the infrared irradiation means 20 more than necessary, and manufacturing costs can be reduced. Furthermore, if a heat insulating material 66 is provided on the outside of the auxiliary heating member 64, the energy required for heating the auxiliary heating member 64 to a temperature lower than the melting point can be saved.

[0161] [Third embodiment] Next, a third embodiment of the thin plate single crystal manufacturing apparatus 10 of the present invention will be described. 15 and 16 show a thin plate single crystal manufacturing apparatus 10 according to a third embodiment of the present invention.

[0162] The thin plate-shaped single crystal manufacturing apparatus 10 shown in Figures 15 and 16 has basically the same configuration as the thin plate-shaped single crystal manufacturing apparatus 10 of the first embodiment shown in Figures 1 to 11, so the same components are given the same reference numbers and detailed descriptions are omitted, and only the differences are described.

[0163] The thin plate-shaped single crystal manufacturing apparatus 10 in the third embodiment of the present invention differs from the thin plate-shaped single crystal manufacturing apparatus 10 in the first embodiment in that, as shown in Figures 15 and 16, a horizontal movement means 72 is provided on the front side of the bottom lateral side of the position control means 84, and a large raw material block 12 is used in a direction D perpendicular to the thickness direction of the raw material block 12.

[0164] That is, the thin plate-shaped single crystal manufacturing apparatus 10 in the third embodiment is configured to continuously manufacture thin plate-shaped single crystals 40 by moving the raw material block 12 in a direction (horizontal direction) D perpendicular to the thickness direction of the raw material block 12 via a horizontal movement means 72, thereby moving the melt (melting zone) 18 provided on the upper surface 14 of the raw material block 12 in a direction D perpendicular to the thickness direction of the raw material block 12 (up and down directions of the arrow in Figure 16).

[0165] Here, it is preferable to align the laser light 16a irradiated onto the upper surface 14 of the raw material block 12 so that a hollow rectangular irradiation area A that is elongated in the horizontal direction (up and down direction in Figure 16) on the upper surface 14 of the large raw material block 12 in direction D perpendicular to the thickness direction of the raw material block 12, as shown in Figure 16.

[0166] In this case, it is preferable that the hollow rectangular irradiation area A is such that the positions of both ends of the raw material block 12 in the thickness direction W on the upper surface 14 of the raw material block 12 are "approximately aligned" with the positions of both ends of the raw material block 12 in the thickness direction W in the hollow rectangular shape.

[0167] It is preferable to set the size of the irradiation area of the laser light 16a so that the length in the thickness direction W of the raw material block 12 in the hollow rectangular shape is slightly smaller than the length in the thickness direction W of the raw material block 12 at the upper surface 14 of the raw material block 12.

[0168] The reason for using the word "approximately the same" here is that, as explained in the first embodiment, if the length in the thickness direction W of the raw material lump 12 in the irradiation area A of the laser light 16a, which is completely hollow and rectangular, were to be made to match the length in the thickness direction W of the raw material lump 12, that is, if the sizes were to be matched as closely as possible, there is a risk that when the upper surface 14 of the raw material lump 12 melts due to the irradiation of the laser light 16a and a molten liquid 18 (molten area) is formed, the molten liquid 18 may spill from the upper surface 14 of the raw material lump 12.

[0169] Therefore, in practice, by setting the length of the irradiation area A of the hollow rectangular laser light 16a in the thickness direction W of the raw material lump 12 to be "slightly smaller" than the length of the thickness direction W of the raw material lump 12, the melt 18 can be reliably melted from one end to the other end in a direction D perpendicular to the thickness direction of the upper surface 14 of the raw material lump 12 without spilling over from the upper surface 14 of the raw material lump 12, while keeping the melt 18 held on the upper surface 14 of the raw material lump 12 by surface tension.

[0170] After irradiating the upper surface 14 of the raw material block 12 with laser light 16a to form a melt (melted zone) 18, the raw material block 12 is moved in a direction D (downward in Figure 16) perpendicular to the thickness direction of the raw material block 12 using a horizontal movement means 72, forming a melt (melted zone) 18 until it reaches one end of the raw material block 12 in the direction D perpendicular to the thickness direction of the raw material block 12, and this process can be repeated.

[0171] In this way, even if the raw material block 12 is large in the direction D perpendicular to the thickness direction of the raw material block 12, by providing the horizontal movement means 72 on the front side of the bottom side of the position control means 84, it is possible to produce thin plate-shaped single crystals 40 having an optimal additive concentration and a homogeneous composition at low cost, continuously, and with high precision.

[0172] [Fourth embodiment] Next, a fourth embodiment of the thin plate single crystal manufacturing apparatus 10 of the present invention will be described. 17 to 20 show a thin plate single crystal manufacturing apparatus 10 according to a fourth embodiment of the present invention.

[0173] The thin plate-shaped single crystal manufacturing apparatus 10 shown in Figures 17 to 20 has basically the same configuration as the thin plate-shaped single crystal manufacturing apparatus 10 of the first embodiment shown in Figures 1 to 11, so the same components are given the same reference numbers and detailed explanations are omitted, and only the differences are explained.

[0174] As shown in Figures 17 and 18, the thin plate-shaped single crystal manufacturing apparatus 10 in the fourth embodiment of the present invention differs from the thin plate-shaped single crystal manufacturing apparatus 10 in the first embodiment in that horizontal movement means 72 are provided on the left and right sides of the bottom side of the position control means 84 (on the right side in Figure 17), and also on the front side of the bottom side of the position control means 84, and large raw material blocks 12 are used in both the thickness direction W of the raw material block 12 and the direction D perpendicular to the thickness direction.

[0175] If two horizontal movement means 72 are provided in this way, the raw material lump 12 can be freely moved in a desired horizontal direction, so that a large raw material lump 12 can be used.

[0176] In addition, when two horizontal movement means 72 are provided in this manner, as shown in Figure 18, a large lump of raw material 12 can be used in both the thickness direction W of the lump of raw material 12 and the direction D perpendicular to the thickness direction.For example, as shown in Figure 19(a), first, the irradiation area A of the laser light 16a is aligned near the lower left corner of the lump of raw material 12 to form a melt (melted area) 18 on the upper surface 14 of the lump of raw material 12, and from this position, the horizontal movement means 72b provided on the front side of the bottom side of the position control means 84 is used to move the lump of raw material 12 from one end to the other end in the direction D perpendicular to the thickness direction of the lump of raw material 12, thereby achieving the state shown in Figure 19(b).

[0177] Next, horizontal movement means 72a, provided on the left and right sides of the bottom of position control means 84 (on the right side in FIG. 17), move raw material lump 12 in thickness direction W of raw material lump 12 to the state shown in 19(c). The movement distance of raw material lump 12 at this time is set to a value smaller than the size in the thickness direction of molten region 18 formed by irradiated region A by laser light 16a, and the movement speed is set to a range in which cell growth does not occur when molten region 18 solidifies as it moves. The specific movement amount and movement speed are determined to match the production conditions of thin plate-shaped single crystal 40.

[0178] Next, as shown in Figure 20(a), horizontal movement means 72b provided on the front side of the bottom side of position control means 84 again moves raw material lump 12 toward the other end in direction D perpendicular to the thickness direction of raw material lump 12. When melting zone 18 reaches the other end, horizontal movement means 72a provided on the left and right sides of the bottom side of position control means 84 (right side in Figure 17) further moves raw material lump 12 a predetermined distance in the thickness direction W of raw material lump 12, as shown in Figure 20(b).

[0179] Next, as shown in Figure 20(c), the raw material block 12 is moved from the other end to the one end in a direction D perpendicular to the thickness direction of the raw material block 12 using a horizontal movement means 72b provided on the front side of the bottom side of the position control means 84, thereby melting the entire area of the upper surface 14 of the raw material block 12.

[0180] By repeating this movement depending on the size of the upper surface 14 of the raw material lump 12, the molten region 18 formed on the upper surface 14 of the raw material lump 12 is moved horizontally relative to the large raw material lump 12 in both the thickness direction W of the raw material lump 12 and the direction D perpendicular to the thickness direction, thereby continuously producing thin plate-shaped single crystals 40. Thus, thin plate-shaped single crystals 40 can be continuously produced.

[0181] In the fourth embodiment, two horizontal movement means 72a and horizontal movement means 72b are provided so that the raw material block 12 can be moved in either horizontal direction, but this configuration is not limited to this and a known horizontal movement table or the like may also be used.

[0182] [Fifth embodiment] Next, a fifth embodiment of the thin plate single crystal manufacturing apparatus 10 of the present invention will be described. 21 and 22 show a thin plate single crystal manufacturing apparatus 10 according to a fifth embodiment of the present invention.

[0183] The thin plate-shaped single crystal manufacturing apparatus 10 shown in Figures 21 and 22 is basically configured in the same manner as the thin plate-shaped single crystal manufacturing apparatus 10 of the first embodiment shown in Figures 1 to 11, so the same components are given the same reference numbers and detailed descriptions thereof are omitted, and only the differences are described.

[0184] The thin plate-shaped single crystal manufacturing apparatus 10 in the fifth embodiment of the present invention differs from the thin plate-shaped single crystal manufacturing apparatus 10 in the first embodiment in that the shape of the raw material block 12 is a horizontally inclined cylindrical shape, as shown in Figures 21 and 22.

[0185] That is, in the thin plate-shaped single crystal manufacturing apparatus 10 of the first embodiment, a rectangular prism-shaped raw material block 12 is used, but even if a cylindrical raw material block 12 is used that is laid on its side, thin plate-shaped single crystals 40 can be continuously manufactured.

[0186] In this case, the cylindrical raw material block 12 is placed on its side on the mounting table 82, and the longitudinal direction of the raw material block 12 (direction D perpendicular to the thickness direction of the raw material block 12) is aligned with direction D perpendicular to the thickness direction of the seed single crystal 32.In this state, laser light 16a is started to be irradiated onto the upper surface 14 of the raw material block 12, and the seed single crystal 32 is immersed in the melt (melt zone) 18 formed at the most protruding part (top of the circle) of the upper surface 14 of the raw material block 12 and pulled upward, thereby starting the growth of the thin plate-shaped single crystal 40.

[0187] Because the cross section of the raw material ingot 12 is circular, the extent of the molten region 18 of the raw material ingot 12 gradually increases as the thin plate-shaped single crystal 40 grows, reaching a maximum when half of the width of the cylindrical raw material ingot 12 (the upper half in the cross section) has been melted, and then gradually decreasing. When most of the raw material ingot 12 has melted and solidified, the production of the thin plate-shaped single crystal 40 is complete.

[0188] The end position in the thickness direction W of the melted area 18 formed by the irradiation area A of the laser beam 16a on the upper surface 14 of the raw material lump 12 must coincide with the end position in the thickness direction W of the upper surface 14 of the raw material lump 12. In this case, the position of the irradiation area A of the laser beam 16a can be set in the same way as when a large raw material lump 12 is used in both the thickness direction W and the direction D perpendicular to the thickness direction, as described in the fourth embodiment.

[0189] The cylindrical raw material lump 12 that has been laid on its side can be divided into two cylindrical raw material lump 12 by cutting the curved portion of the U-shaped single crystal produced by the Siemens process. Since the size of the upper surface 14 of the cylindrical raw material lump 12 changes from moment to moment, it is preferable to program the irradiation of the laser light 16a in advance and to form a melt (melted area) 18 in conjunction with the horizontal movement means 72.

[0190] [Sixth embodiment] Next, a sixth embodiment of the thin plate single crystal manufacturing apparatus 10 of the present invention will be described. 23 and 24 show a thin plate single crystal manufacturing apparatus 10 according to a sixth embodiment of the present invention.

[0191] The thin plate-shaped single crystal manufacturing apparatus 10 shown in Figures 23 and 24 has basically the same configuration as the thin plate-shaped single crystal manufacturing apparatus 10 of the first embodiment shown in Figures 1 to 11, so the same components are given the same reference numbers and detailed descriptions are omitted, and only the differences are described.

[0192] The sixth embodiment of the thin plate-shaped single crystal manufacturing apparatus 10 of the present invention differs from the first embodiment of the thin plate-shaped single crystal manufacturing apparatus 10 in that the chamber 80 is equipped with a gas introduction device 90 that fills the chamber 80 with an ambient gas containing an additive, as shown in Figures 23 and 24.

[0193] A gas introduction device 90 is provided on the upper side of the chamber 80, and atmospheric gas is introduced from the gas introduction device 90 into the chamber 80 via an introduction pipe 92. An exhaust pipe 94 is provided on the lower side of the chamber 80, and the atmospheric gas can be exhausted from this exhaust pipe 94 to the outside of the chamber 80.

[0194] This allows the chamber 80 to be kept filled with an atmospheric gas suitable for producing the thin plate-shaped single crystal 40, and allows for the continuous production of high-quality thin plate-shaped single crystals 40 with a uniform additive concentration.

[0195] The atmospheric gas may be prepared according to the characteristics of the material of the thin plate-shaped single crystal 40 to be manufactured. For example, when manufacturing an N-type silicon thin plate-shaped single crystal 40, it is preferable to introduce high-purity argon gas containing an optimal concentration of phosphine (PH3) into the chamber 80 as the atmospheric gas.

[0196] Also, as shown in FIG. 24, for example, a cover member 42 may be provided below a window 22 for guiding infrared rays 16 (laser light 16a) irradiated from the infrared irradiation means 20 into the chamber 80, and atmospheric gas may be actively introduced from a gas introduction device 90 into the space separated by the chamber 80 and the cover member 42.

[0197] By introducing atmospheric gas into the space separated by the chamber 80 and the cover member 42 in this manner, it is possible to prevent evaporation products from the melt 18 from adhering to the window 22, and it is possible to stably and continuously produce high-quality thin plate-shaped single crystals 40 with a homogeneous additive concentration with good yield.

[0198] [Seventh embodiment] Next, a seventh embodiment of the thin plate single crystal manufacturing apparatus 10 of the present invention will be described. 25 and 26 show a thin plate single crystal manufacturing apparatus 10 according to the seventh embodiment of the present invention.

[0199] The thin plate-shaped single crystal manufacturing apparatus 10 shown in Figures 25 and 26 has basically the same configuration as the thin plate-shaped single crystal manufacturing apparatus 10 of the first embodiment shown in Figures 1 to 11, so the same components are given the same reference numbers and detailed descriptions are omitted, and only the differences are described.

[0200] 25 and 26, the apparatus 10 for producing a thin plate-shaped single crystal in the seventh embodiment of the present invention differs from the apparatus 10 for producing a thin plate-shaped single crystal in the first embodiment in that the chamber 80 is provided with a gas introduction device 90 for filling the chamber 80 with an atmospheric gas containing additives, and in that a plurality of lifting means 30 (two in FIG. 25) are provided above the raw material lump 12. The explanation regarding the provision of the gas introduction device 90 is the same as that given in the sixth embodiment.

[0201] Specifically, two lifting means 30 (winding means 50) are provided side by side on the left and right sides at the top of the chamber 80, and seed single crystals 32, 32 are immersed in the molten liquid 18 on the upper surface 14 of the raw material block 12, and then pulled upward by the lifting means 30, 30 (winding means 50, 50), respectively, thereby producing thin plate-shaped single crystals 40, 40, respectively. In this way, if a plurality of lifting means 30 are provided above the raw material lump 12, the production efficiency of the thin plate-shaped single crystal 40 can be significantly improved compared to when only one lifting means 30 is provided.

[0202] <Method for producing thin plate-shaped single crystals> Next, a method for producing a thin plate single crystal using the thin plate single crystal production apparatus 10 of the present invention will be described.

[0203] 27(a), a raw material lump 12 is placed on a mounting table 82 in a chamber 80, the chamber 80 is sealed, and a seed single crystal 32 is placed above the upper surface 14 of the raw material lump 12 so that the longitudinal direction (direction D perpendicular to the thickness direction) of the raw material lump 12 coincides with the longitudinal direction (direction D perpendicular to the thickness direction) of the thin plate-shaped seed single crystal 32. The seed single crystal 32 is suspended from a winding shaft 36 of a winding means 50 via a thin wire 52.

[0204] The atmosphere in the chamber 80 is evacuated to a vacuum through an exhaust pipe 94, and an atmospheric gas suited to the characteristics of the material of the thin plate-shaped single crystal 40 to be produced is introduced into the chamber 80 through an introduction pipe 92 of a gas introduction device 90.

[0205] Next, as shown in FIG. 27(b), infrared rays 16 (laser light 16a) are irradiated onto the vicinity of the corners of the upper surface 14 of the raw material lump 12 via infrared irradiation means 20, thereby partially melting the upper surface 14.

[0206] The shape of the irradiation area A of the infrared ray 16 (laser light 16a) is a horizontally elongated hollow rectangle, and the laser light 16a is aligned with and irradiated onto the upper surface 14 of the raw material block 12 so as to form this horizontally elongated hollow rectangular irradiation area A.

[0207] As a result, a melt 18 (melted region) is formed on the upper surface 14 of the raw material lump 12 by irradiation with the laser beam 16a, and the central portion of the melt 18 (melted region) that is not irradiated by the laser beam 16a is melted by thermal conduction from the melt 18 near the previously melted square band portion B of the irradiation region A. At the same time, the raw material lump 12 is moved at a predetermined speed in the thickness direction W of the raw material lump 12 and in a direction D perpendicular to the thickness direction via the horizontal movement means 72a and horizontal movement means 72b, until the corners of the upper surface 14 of the raw material lump 12 are completely covered with the melted region 18.

[0208] Next, as shown in Figure 27(c) and Figure 19(a), the lower surface 34 of a thin plate-shaped seed single crystal 32 is immersed in the center of the melt 18 (melting zone) obtained on the upper surface 14 of the raw material lump 12 via a lifting means 30 (winding means 50), and single crystal growth begins from the lower surface 34 of the seed single crystal 32.

[0209] Furthermore, as shown in FIG. 28(a), the seed single crystal 32 is pulled upward by the lifting means 30 (winding means 50), and thin plate-shaped single crystals 40 are continuously produced. Next, the raw material lump 12 is moved at a predetermined speed in a direction D perpendicular to the thickness direction by the horizontal movement means 72b. When the melting zone 18 reaches the end of the direction D perpendicular to the thickness direction of the raw material lump 12, the raw material lump 12 is moved at a predetermined speed by the horizontal movement means 72a for a predetermined length, and then the raw material lump 12 begins to move again toward the opposite end in the direction D perpendicular to the thickness direction by the horizontal movement means 72b, and this process is repeated over the entire upper surface 14 of the raw material lump 12 (Figure 28(b) and Figures 19(b) to 20(c)).

[0210] 28(c), as the thin plate-shaped single crystal 40 is continuously produced, the position of the mounting table 82 is moved upward via the position control means 84. As a result, even if the position of the melt 18 in the raw material lump 12 drops as it is pulled up, the position of the raw material lump 12 is controlled to maintain its original position, and the liquid surface of the melt 18 is always kept at the same position.

[0211] Here, when laser light 16a is irradiated vertically from directly above raw material lump 12 onto upper surface 14 of raw material lump 12, as in the thin plate single crystal manufacturing apparatus 10 shown in Figures 4 and 6, the temperature of melt 18 does not change even if the position of upper surface 14 of raw material lump 12 fluctuates, so there is no need to control the position of upper surface 14 of raw material lump 12 to a constant position.

[0212] Next, as shown in Figure 29(a), the amount of infrared rays 16 (laser light 16a) emitted by the infrared irradiation means 20 is increased to raise the temperature of the melt 18, and finally, as shown in Figure 29(b), the thin plate-shaped single crystal 40 is separated from the melt 18, the continuously produced thin plate-shaped single crystal 40 is wound up by the lifting means 30 (winding means 50), and the irradiation of infrared rays 16 (laser light 16a) by the infrared irradiation means 20 is finished, thereby completing the production of the thin plate-shaped single crystal 40. [Example]

[0213] [Example 1] Using the thin plate single crystal manufacturing apparatus 10 of the present invention, a thin plate single crystal 40 of N-type silicon doped with phosphorus was manufactured.

[0214] The raw material lump 12 used was a rectangular parallelepiped lump 12 having a width of 400 mm, a thickness of 500 mm, and a height of 500 mm. On the other hand, a silicon seed single crystal 32 having a (111) plane and measuring 350 mm in width, 0.3 mm in thickness, and 100 mm in height was used as the thin plate-shaped seed single crystal 32. Silicon has the property of easily producing flat surfaces called facets in the (111) plane direction, and this flat surface was used as the plate surface of the seed single crystal 32. The seed single crystal 32 was attached in advance to the winding shaft 36 of the winding means 50 via three thin wires 52.

[0215] First, the raw material block 12 was placed on the table 82 in the chamber 80, and the chamber 80 was closed to create a vacuum inside the chamber. Then, an atmospheric gas was introduced into the chamber 80. High purity argon gas was used as the atmospheric gas, and a necessary amount of phosphine (PH3) gas was added to add phosphorus.

[0216] Laser light 16a with a rectangular cross section, 6 mm wide and 382 mm long, was irradiated onto the upper surface 14 of this raw material lump 12 from the left and right sides at an inclination angle of 80 degrees from the horizontal, with one side of the laser light 16a being 3 mm away from one end of the thickness direction W of the raw material lump 12, and the other side of the laser light 16a being irradiated at a position 6 mm away from the one side of the laser light 16a.

[0217] At the same time, laser light 16a having a rectangular cross section, 6 mm wide and 18 mm long, was irradiated onto both ends of raw material block 12 in direction D perpendicular to the thickness direction, at an angle of 80 degrees from the horizontal, 3 mm away from both ends, as the short side portion of square band portion B of irradiation area A of laser light 16a.

[0218] The shape of the irradiation area A of the laser beam 16a was a horizontally elongated hollow rectangle as a whole due to the four laser beams 16a irradiated from the four infrared irradiation means 20. As a result, a rectangular melt 18 (melted area) was formed on the upper surface 14 of the raw material lump 12.

[0219] At the same time, the raw material block 12 began to move horizontally toward one end of the thickness direction W of the raw material block 12 at a speed of 1 mm / min, and when the melting zone 18 reached one end, it was reversed and moved toward the other end in the opposite direction at a speed of 1 mm / min in the same manner, and this was repeated.

[0220] The winding shaft 36 of the winding means 50 was rotated, and the underside 34 of the seed single crystal 32 was immersed in the center of the melt 18 obtained by melting with the laser light 16a. A thin plate-like single crystal 40 was grown from the underside 34 of the seed single crystal 32. Then, the winding shaft 36 was rotated in the opposite direction, and the seed single crystal 32 was pulled upward at a speed of 5 mm / min. The thin plate-like single crystal 40 was continuously wound in a roll around the winding shaft 36 at the top, producing a long thin plate-like single crystal 40 having a length of more than 10 m.

[0221] The seed single crystal 32 was set on the winding shaft 36 of the winding means 50 by a thin carbon fiber wire 52 having a diameter of about 0.05 mm, and the seed single crystal 32 was moved up and down by controlling the rotation direction and rotation speed of the winding shaft 36 with the rotating means 38.

[0222] When the seed single crystal 32 is immersed in the center of the melt 18 (melting area) on the upper surface 14 of the raw material lump 12, crystallization begins immediately, and the immersed part of the seed single crystal 32 becomes thicker, but it was confirmed that if left as is, the thickened part melts and becomes thinner.

[0223] In this state, the seed single crystal 32 was pulled upward, the thickness of the produced thin plate-like single crystal 40 was confirmed with a camera, and the thickness was controlled to 0.3 mm while adjusting the pulling (winding) speed and the irradiation intensity of the laser beam 16a, and the winding shaft 36 was rotated, and the thin plate-like single crystal 40 was continuously wound around the winding shaft 36. During this time, the raw material lump 12 was continuously moved at a speed of 1 mm / min, and when the melt 18 (melted region) reached one end of the raw material lump 12 in the thickness direction W, it was turned over and moved toward the other end, and this operation was carried out continuously.

[0224] It was confirmed that slowing down the pulling (winding) speed of the seed single crystal 32 resulted in a thicker thin plate-like single crystal 40, and that speeding up the pulling (winding) speed resulted in a thinner thin plate-like single crystal 40. The temperature of the melt 18 was adjusted so that a thin plate-like single crystal 40 with a thickness of 0.3 mm could be continuously pulled up at a speed of 30 mm per minute.

[0225] Here, as the thin plate-shaped single crystal 40 is pulled up, the liquid surface position of the melt 18 of the raw material lump 12 drops, so the position of the mounting table 82 on which the raw material lump 12 is placed is controlled to a predetermined position via a position control means 84 so that the liquid surface position of the melt 18 of the raw material lump 12 is always kept at the same position as the original position.

[0226] The thin plate-like single crystal 40 thus produced, which was longer than 10 m, had a thickness of 0.3 mm and a width of 374 to 378 mm, was confirmed by secondary ion mass spectrometry (SIMS).

[0227] As a result, it was confirmed that the concentration of the additive phosphorus was optimal, uniform, and of high quality, confirming the superiority of the thin plate single crystal manufacturing apparatus 10 and thin plate single crystal manufacturing method of the present invention.

[0228] Next, a summary of the above-described thin plate single crystal manufacturing apparatus 10 of the present invention and the thin plate single crystal manufacturing method using this thin plate single crystal manufacturing apparatus 10 will be explained. The most significant factor that enables the thin plate-shaped single crystal manufacturing apparatus 10 and thin plate-shaped single crystal manufacturing method of the present invention to continuously and stably manufacture thin plate-shaped single crystals 40 is that the melting of the raw material mass 12 and the single crystallization from the resulting melt 18 can be largely controlled independently.

[0229] Furthermore, a horizontal direction moving means 72 (72a, 72b) is used to continuously move the raw material lump 12 in a horizontal direction, thereby making it possible to handle large raw material lump 12. That is, heating is required to melt the raw material ingot 12 to obtain the melt 18, but cooling is required to solidify and crystallize the melt 18, and the two are contradictory.

[0230] Therefore, in the present invention, the laser light 16a is not irradiated directly onto the portion where crystallization occurs (the center of the melt 18), but rather onto the portion other than the portion where crystallization occurs (the peripheral region excluding the center of the melt 18), thereby partially melting the upper surface 14 of the raw material lump 12 and conducting the heat of the melt 18 to the portion where crystallization occurs (the center), thereby forming the melt 18 (melted region) on the upper surface 14 of the raw material lump 12.

[0231] As a result, the temperature of the portion (center portion) where crystallization is to occur becomes lower than the temperature of the portion that is melted by irradiation with the laser light 16a, facilitating crystallization. When the seed single crystal 32 is immersed in the center of the melt 18, the heat of the melt 18 is transferred to the underside 34 of the immersed seed single crystal 32, causing the temperature of the melt 18 in contact with the underside 34 to drop, and crystallization progresses rapidly. After being left for a while, the amount of heat escaping through the seed single crystal 32 reaches a steady state, and the parts that had solidified rapidly up to that point gradually melt due to the heat from the surrounding melt 18, and return to a steady state.

[0232] When the seed single crystal 32 is pulled up (wound up) in this state, the seed single crystal 32 moves to a low temperature area, and crystallization proceeds on the lower surface 34 in contact with the melt 18 . If the pulling speed (winding speed) of the seed single crystal 32 is increased and crystallization cannot keep up, the thickness of the produced thin plate-like single crystal 40 will become thin, and if the pulling speed (winding speed) is slowed, crystallization will proceed and the thickness of the thin plate-like single crystal 40 will increase.

[0233] Therefore, if the temperature of the melt 18 is controlled to be low, crystallization becomes easier and the thickness of the thin plate-like single crystal 40 increases, so that even if the pulling speed (winding speed) is increased, thin plate-like single crystals 40 of a predetermined thickness can be continuously produced.

[0234] Increasing the pulling speed (winding speed) of the seed single crystal 32 can improve the production efficiency of the thin plate-shaped single crystal 40, but increasing the speed too much increases the possibility of cell growth. If cell growth occurs, the concentration of the additive phosphorus will fluctuate significantly locally, deteriorating the properties of the single crystal. Therefore, it is important to continuously produce the thin plate-shaped single crystal 40 by accelerating the pulling speed (winding speed) as much as possible while suppressing cell growth.

[0235] Furthermore, the present invention has made it possible for the first time to produce high-quality thin plate single crystals 40 with a homogeneous composition even for so-called incongruent melting substances, such as decomposed melting substances and solid solution single crystals. Such thin plate single crystals 40 with a homogeneous composition of incongruent melting substances have been considered impossible to produce using conventional manufacturing methods.

[0236] That is, in the so-called "melt method" in which raw materials are melted to form a melt, which is then solidified to produce single crystals, in order to produce single crystals of homogeneous composition from these incongruent melt substances, there is no other method in principle than to apply the so-called "solvent transfer method," in which a raw material lump of the desired composition is produced first, and then a solvent of a solvent composition that coexists in equilibrium with the desired composition is used to dissolve the raw material lump and simultaneously precipitate single crystals from the solvent.

[0237] In the present invention, a required amount of solvent phase components is placed on the upper surface 14 of the raw material ingot 12, and then irradiated with infrared rays 16 to melt the components and form a solvent portion. The solvent portion is then moved horizontally, and new raw material is supplied to the solvent portion, and thin plate-like single crystals 40 are produced from the solvent portion and solidified simultaneously. This applies the "solvent movement method," making it possible to produce thin plate-like single crystals 40 of a homogeneous composition.

[0238] In the case of N-type silicon, phosphorus is added as an additive, but phosphorus evaporates from the melt 18, and the concentration in the melt 18 becomes thinner over time. Therefore, phosphine (PH3) was added to the atmosphere to manufacture (grow) the thin plate-shaped single crystal 40.

[0239] In this case, phosphine (PH3) reacts with the silicon melt, dissolving phosphorus into the melt. There is a concentration difference between the phosphorus concentration in the melt and the phosphorus concentration in the solidified thin plate single crystal 40 according to a concentration ratio defined by the distribution coefficient, and if the phosphorus concentration in the melt is kept constant at a predetermined concentration, the phosphorus concentration in the thin plate single crystal 40 will also be kept constant.

[0240] The phosphorus concentration in the melt was set so that the phosphorus concentration in this thin plate-like single crystal 40 would be the optimum concentration, and the concentration of phosphine (PH3) in the atmosphere was set so that the phosphorus concentration would be maintained.

[0241] The thin plate single crystal manufacturing apparatus 10 of the present invention and the thin plate single crystal manufacturing method using this thin plate single crystal manufacturing apparatus 10 have been described above, but the present invention is not limited to the above-described embodiment.

[0242] For example, although the first to seventh embodiments of the thin plate single crystal manufacturing apparatus 10 have been described separately above, these may be appropriately combined to form the thin plate single crystal manufacturing apparatus 10 of the present invention.

[0243] Furthermore, in the above-mentioned thin plate single crystal manufacturing apparatus 10, the infrared irradiation means 20 are provided on all four sides (for example, every 90 degrees) of the raw material block 12 as the center in a top view so that the laser light 16a irradiated from the infrared irradiation means 20 can form a hollow rectangular irradiation area A. However, this is not limited to this, and the laser light 16a irradiated from one infrared irradiation means 20 may be divided and the laser light 16a may be irradiated onto the raw material block 12 from all four sides.

[0244] Furthermore, the number of infrared irradiation means 20 is not limited to four directions (every 90 degrees) but may be, for example, two directions (every 180 degrees), and may be determined taking into consideration the size of the hollow rectangular irradiation area A of the laser light 16a and the output intensity of the infrared irradiation means 20, etc.

[0245] Furthermore, as long as the laser light 16a can be irradiated so as to form a horizontally elongated hollow rectangular irradiation area A that matches the peripheral area excluding the center of the upper surface 14 of the raw material block 12, the cross-sectional shape of the laser light 16a irradiated from one infrared irradiation means 20 is not limited to a rectangle.

[0246] In other words, a laser beam 16a having a U-shaped cross section may be irradiated onto the upper surface 14 of the raw material block 12 from the left and right sides, and the two laser beams 16a, 16a having a U-shaped cross section may form an irradiation area A having a horizontally elongated hollow rectangular cross section.

[0247] Furthermore, in the above-described thin plate single crystal manufacturing apparatus 10, the infrared rays 16 (laser light 16a) emitted from the infrared irradiating means 20 are configured to be introduced into the chamber 80 via a reflecting mirror 24, but as shown in Figure 30, the infrared rays may be configured to be introduced directly into the chamber 80 without passing through the reflecting mirror 24. Whether or not the reflecting mirror 24 is required can be determined appropriately in consideration of the configuration, size, etc. of the thin plate single crystal manufacturing apparatus 10.

[0248] Furthermore, the thickness of the thin plate-like single crystal 40 to be produced has been described as being approximately 30 μm to 500 μm, but in principle it is possible to produce a thickness greater than this, for example, 5000 μm or more, and the thickness is not limited to the above range.

[0249] Furthermore, the thickness of the seed single crystal 32 to be immersed in the melt 18 has been described as, for example, about 300 μm to 500 μm, but in principle, it is also possible to produce a thin plate-shaped single crystal 40 with a thickness outside this range, and the thickness is not limited to the above range.

[0250] Furthermore, when producing thin plate-shaped single crystal 40 of N-type silicon doped with phosphorus, phosphine (PH3) is added to the atmosphere as described above, and the phosphine (PH3) reacts with the silicon melt, causing the phosphorus to dissolve in the melt, thereby producing thin plate-shaped single crystal 40 of N-type silicon doped with phosphorus. However, this is not limited to this, and it is also possible to produce raw material block 12 by adding from the beginning the amount of additive (phosphorus) that will be lost due to evaporation to the originally required amount of additive (phosphorus).

[0251] As described above, the thin plate single crystal manufacturing apparatus 10 and the thin plate single crystal manufacturing method of the present invention can be modified in various ways without departing from the object of the present invention. [Explanation of symbols]

[0252] 10 Thin plate single crystal manufacturing equipment 12 Raw material lump 14 Top side 16 Infrared 16a Laser light 18 Melt (Melting Zone) 20 Infrared irradiation means 22 Windows 24 Reflector 30 Lifting means 32 Seed single crystal 34 Lower side 36 Winding shaft 38 Rotating means 40 Thin plate single crystal 42 Cover member 44 rotating rollers 50 Winding means 52 Thin line 60 Anti-vibration member 62 Shielding member 64 Auxiliary heating element 66 Insulation 72 Horizontal movement means 72a Horizontal movement means 72b Horizontal means of movement 74 Drive shaft 76 Driving means 80 Chambers 82 Mounting table 84 Position control means 86 Drive shaft 88 Driving means 90 Gas introduction device 92 Introductory tube 94 Discharge pipe A Irradiation area B Square band part C center part D: Orthogonal to the thickness direction of the raw material block E Laser beam width F Distance between laser beams T1: The size of the bottom surface of the seed single crystal in the longitudinal direction (the direction perpendicular to the thickness direction) T2: The size of the upper surface of the raw material block in the direction perpendicular to the thickness direction V1 Thickness of the seed single crystal at the part where the thin wire is attached V2 Seed single crystal thickness W: thickness direction of raw material block

Claims

1. an infrared irradiation means for irradiating an upper surface of a raw material lump for producing a thin plate-shaped single crystal with infrared rays to melt the surface of the upper surface of the raw material lump; a lifting means for immersing a lower surface of a thin plate-shaped seed single crystal in the melt formed on the upper surface of the raw material lump by the infrared irradiation means, and lifting the seed single crystal upward from the immersed state; horizontally moving means for moving the raw material block in a horizontal direction; Equipped with the lower surface of the seed single crystal is immersed in the melt formed on the upper surface of the raw material lump by the infrared irradiation means via the lifting means, thereby starting the growth of the single crystal from the immersed lower surface of the seed single crystal; Furthermore, the thin plate single crystal manufacturing apparatus is characterized in that it is configured so that the seed single crystal is pulled upward via the lifting means, and at the same time the raw material block is moved horizontally via the horizontal moving means, thereby continuously producing thin plate single crystals by moving the melting area on the upper surface of the raw material block horizontally.

2. 2. The thin plate single crystal manufacturing apparatus according to claim 1, wherein the infrared rays emitted from said infrared ray irradiating means are laser light.

3. 3. The thin plate single crystal manufacturing apparatus according to claim 2, wherein the shape of the laser beam irradiation area is a hollow rectangular shape that is elongated in a horizontal direction perpendicular to the thickness direction of the raw material lump.

4. a mounting table on which the raw material block is placed; a position control means for controlling the vertical position of the mounting table to a predetermined position; 4. The thin plate single crystal manufacturing apparatus according to claim 3, further comprising:

5. The horizontal movement means a drive shaft provided on the bottom side of the position control means; a driving means for driving the drive shaft; Equipped with The thin plate single crystal manufacturing apparatus according to claim 4, characterized in that the mounting table and the position control means are configured to move in a horizontal direction, which is the thickness direction of the raw material block, by driving the drive shaft via the drive means.

6. The horizontal movement means In a case where the mounting table and the position control means are configured to move in a horizontal direction, which is a thickness direction of the raw material block, the positions of both ends of the upper surface of the raw material lump in a horizontal direction perpendicular to the thickness direction of the raw material lump and the positions of both ends of the hollow rectangular shape in a horizontal direction perpendicular to the thickness direction of the raw material lump are substantially the same; The thin plate single crystal manufacturing apparatus described in claim 5, characterized in that the size of the laser light irradiation area is set so that the horizontal length perpendicular to the thickness direction of the raw material block in the hollow rectangular shape is slightly smaller than the horizontal length perpendicular to the thickness direction of the raw material block on the upper side of the raw material block.

7. The horizontal movement means a drive shaft provided on the bottom side of the position control means; a driving means for driving the drive shaft; Equipped with The thin plate single crystal manufacturing apparatus of claim 4, characterized in that the driving shaft is driven via the driving means to move the mounting table and the position control means in a horizontal direction that is perpendicular to the thickness direction of the raw material block.

8. The horizontal movement means In a case where the mounting table and the position control means are configured to move in a horizontal direction that is a direction perpendicular to the thickness direction of the raw material lump, the positions of both ends of the upper surface of the raw material lump in the horizontal direction, which is the thickness direction of the raw material lump, and the positions of both ends of the hollow rectangular shape in the horizontal direction, which is the thickness direction of the raw material lump, are substantially aligned; The thin plate single crystal manufacturing apparatus described in claim 7, characterized in that the size of the laser light irradiation area is set so that the horizontal length, which is the thickness direction of the raw material block in the hollow rectangular shape, is slightly smaller than the horizontal length, which is the thickness direction of the raw material block at the upper side of the raw material block.

9. The horizontal movement means a drive shaft provided on the bottom side of the position control means; a driving means for driving the drive shaft; Equipped with The thin plate single crystal manufacturing apparatus described in claim 4, characterized in that the mounting table and the position control means are configured to move in a horizontal direction which is the thickness direction of the raw material block and / or in a horizontal direction which is perpendicular to the thickness direction of the raw material block by driving the drive shaft via the drive means.

10. The horizontal movement speed of the mounting table and the position control means is 10. The thin plate single crystal manufacturing apparatus according to claim 4, wherein the speed is in the range of 0.005 mm / min to 100 mm / min.

11. The horizontal movement means 11. The thin plate single crystal manufacturing apparatus according to claim 4, wherein the thin plate single crystal manufacturing apparatus is a linear actuator.

12. The lifting means is a winding means for continuously winding the produced thin plate-like single crystal into a roll, The winding means a winding shaft for continuously winding the thin plate-like single crystal; A rotating means for rotating the winding shaft; Equipped with 12. The thin plate-shaped single crystal manufacturing apparatus according to claim 1, wherein the seed single crystal is suspended from the winding shaft via a plurality of thin wires.

13. the winding speed of the thin plate-shaped single crystal by the winding means is 13. The thin plate single crystal manufacturing apparatus according to claim 12, wherein the speed is in the range of 0.005 mm / min to 100 mm / min.

14. In the seed single crystal, The thickness of the part where the thin wire is attached is 14. The thin plate single crystal manufacturing apparatus according to claim 12, wherein the size of the thin plate single crystal is equal to or smaller than the thickness of the thin plate single crystal to be manufactured.

15. 15. The thin plate single crystal manufacturing apparatus according to claim 1, wherein when the raw material block is silicon, the thickness of the thin plate single crystal is in the range of 30 μm to 500 μm.

16. 16. The thin plate single crystal manufacturing apparatus according to claim 1, wherein an auxiliary heating member for preheating the raw material lump is provided around the raw material lump.

17. 17. The thin plate single crystal manufacturing apparatus according to claim 16, wherein a heat insulating material is further provided on the outside of said auxiliary heating member.

18. On the upper surface of the raw material lump, The thin plate-shaped single crystal manufacturing apparatus according to any one of claims 1 to 17, characterized in that a required amount of a liquid phase composition that coexists in equilibrium with the composition of the thin plate-shaped single crystal to be manufactured is initially placed.

19. a melting step of irradiating an upper surface of a raw material lump for producing a thin plate-shaped single crystal with infrared rays via an infrared irradiation means to melt the surface of the upper surface of the raw material lump; a growing step of immersing a lower surface of a thin plate-shaped seed single crystal in the melt obtained on the upper surface of the raw material lump in the melting step via an elevating means, and starting the growth of a single crystal from the lower surface of the seed single crystal; a continuous production step in which the seed single crystal, from which single crystal growth has commenced, is pulled upward in the growth step, and at the same time the raw material lump is moved horizontally by a horizontal movement means, thereby continuously producing a thin plate-shaped single crystal while horizontally moving a melted region on the upper side surface of the raw material lump; A method for producing a thin plate-shaped single crystal, comprising at least the steps of:

20. In the melting step, 20. The method for producing a thin plate-shaped single crystal according to claim 19, wherein the infrared rays irradiated from the infrared irradiating means are laser light.

21. In the continuous production process, 21. The method for producing a thin plate-shaped single crystal according to claim 20, wherein the raw material lump is moved horizontally, i.e., in the thickness direction of the raw material lump, by the horizontal movement means.

22. In the continuous production process, A method for producing a thin plate-shaped single crystal as described in claim 21, characterized in that when the melting zone reaches one end of the raw material block on the upper surface thereof in the thickness direction, the melting zone is then moved toward the other end of the raw material block on the opposite side in the thickness direction, and this is continuously repeated.

23. In the melting step, the shape of the irradiation area of the laser light is a hollow rectangular shape that is elongated in a horizontal direction perpendicular to the thickness direction of the raw material lump, the positions of both ends of the upper surface of the raw material lump in a horizontal direction perpendicular to the thickness direction of the raw material lump and the positions of both ends of the hollow rectangular shape in a horizontal direction perpendicular to the thickness direction of the raw material lump are substantially the same; A method for producing a thin plate-shaped single crystal as described in claim 21 or 22, characterized in that the size of the irradiation area of the laser light is set so that the horizontal length perpendicular to the thickness direction of the raw material lump in the hollow rectangular shape is slightly smaller than the horizontal length perpendicular to the thickness direction of the raw material lump on the upper surface of the raw material lump.

24. In the continuous production process, 21. The method for producing a thin plate-shaped single crystal according to claim 20, wherein the raw material block is moved in a horizontal direction, which is a direction perpendicular to the thickness direction of the raw material block, via the horizontal movement means.

25. In the continuous production process, A method for producing a thin plate-shaped single crystal as described in claim 24, characterized in that when the melting zone reaches one end of the upper surface of the raw material block in a direction perpendicular to the thickness direction of the raw material block, the melting zone is then moved toward the other end on the opposite side in a direction perpendicular to the thickness direction of the raw material block, and this is continuously repeated.

26. In the melting step, the shape of the irradiation area of the laser light is a hollow rectangular shape that is elongated in a horizontal direction perpendicular to the thickness direction of the raw material lump, the positions of both ends of the upper surface of the raw material lump in the thickness direction of the raw material lump are substantially the same as the positions of both ends of the hollow rectangular shape in the thickness direction of the raw material lump, and A method for producing a thin plate-shaped single crystal as described in claim 24 or 25, characterized in that the size of the irradiation area of the laser light is set so that the horizontal length, which is the thickness direction of the raw material block in the hollow rectangular shape, is slightly smaller than the horizontal length, which is the thickness direction of the raw material block at the upper side of the raw material block.

27. In the continuous production process, A method for producing a thin plate-shaped single crystal as described in claim 20, characterized in that the raw material block is moved horizontally in the thickness direction of the raw material block and in a horizontal direction perpendicular to the thickness direction of the raw material block via the horizontal movement means.

28. In the continuous production process, When the melting zone reaches one end of the upper surface of the raw material block in a horizontal direction perpendicular to the thickness direction of the raw material block, the melting zone is moved in the thickness direction of the raw material block by a predetermined length, and then the melting zone is moved toward the other end of the upper surface of the raw material block in a horizontal direction perpendicular to the thickness direction of the raw material block, The method for producing a thin plate-shaped single crystal as described in claim 27, characterized in that the melting zone is then moved again toward one end of the raw material block in a horizontal direction perpendicular to the thickness direction, and this is performed continuously over the entire upper surface of the raw material block.

29. In the melting step, 29. A method for producing a thin plate-shaped single crystal according to claim 27 or 28, wherein the shape of the irradiation area of the laser light is a hollow rectangular shape that is elongated in a horizontal direction perpendicular to the thickness direction of the raw material lump.

30. In the continuous production process, 30. The method for producing a thin plate-shaped single crystal according to any one of claims 19 to 29, wherein the moving speed of the raw material block when moving it horizontally via the horizontal moving means is within a range of 0.005 mm / min to 100 mm / min.

31. After the continuous manufacturing process, a winding step of winding the continuously produced thin plate-like single crystal into a roll; The method for producing a thin plate-shaped single crystal according to any one of claims 19 to 30, further comprising:

32. In the winding step, 32. The method for producing a thin plate-shaped single crystal according to claim 31, wherein the winding speed of the thin plate-shaped single crystal is within a range of 0.005 mm / min to 100 mm / min.

33. In the melting step, 33. The method for producing a thin plate-shaped single crystal according to any one of claims 19 to 32, wherein, when the thin plate-shaped single crystal to be produced is a decomposed melt substance, a required amount of a liquid phase composition that coexists in equilibrium with the composition of the decomposed melt substance is initially placed on the upper surface of the raw material block.

34. In the melting step, 33. The method for producing a thin plate-shaped single crystal according to any one of claims 19 to 32, wherein, when the thin plate-shaped single crystal to be produced is a solid solution material containing an additive, a required amount of a liquid phase composition that coexists in equilibrium with the composition of the solid solution material is initially placed on the upper surface of the raw material block.

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