JP5282801B2 - Single crystal manufacturing apparatus and manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus and a method for producing a single crystal, by means of which a single crystal with uniform composition distribution is stably obtained even when a highly volatile material such as MoO<SB POS="POST">3</SB>is used. <P>SOLUTION: The method for producing a single crystal includes a step in which: a raw material 7 of a raw material melt 8 is filled in the inside of a crucible 11, and at the same time, an opening 11b of the crucible 11 is closed by a lid 17 having a protrusion of which the tip can be immersed in the raw material melt 8; the raw material melt 8 is obtained by heating and melting the raw material 7 and at the same time, the liquid level of the raw material melt 8 in the crucible 11 is detected; the lid 17 is heated, and at the same time the distance between the lid 17 and the liquid level is set to be a predetermined value by a lid moving means 21; and a seed is brought into contact with the raw material melt 8 leaked out from a through-hole 11a and the seed is pulled down along a predetermined pull down axis, wherein the distance is kept at the predetermined value in the pulling down step. <P>COPYRIGHT: (C)2013,JPO&amp;INPIT

Description

  The present invention relates to a single crystal manufacturing apparatus and a single crystal manufacturing method for manufacturing a single crystal by a pulling method for obtaining a desired crystal material while drawing a raw material melt from a hole provided in a crucible bottom. More specifically, a single crystal suitable for obtaining a fiber-like single crystal exemplified by an oxide single crystal used in so-called next-generation semiconductor power devices such as an IGBT (Insulated Gate Bipolar Transistor) inverter, FET, and high-speed switching element. The present invention relates to a crystal manufacturing apparatus and a single crystal manufacturing method.

  A lead hole is formed in the bottom of the crucible holding the heated and melted raw material, and a crystal nucleus (hereinafter referred to as a seed) is brought into contact with the raw material melt that leaks from the hole, with the leakage of the raw material from the hole. A so-called pulling-down method is known in which a single crystal that grows using the seed as a nucleus is obtained by pulling down the seed. A single crystal obtained by this method has a smaller crystal diameter than that of a single crystal obtained by a so-called pulling method represented by a conventionally known CZ method. However, as a method for obtaining a single crystal having a short time required for crystal growth and excellent in crystallinity at a low cost as compared with the CZ method, it is necessary to modify the actual manufacturing equipment in terms of hardware and various single units. Application to crystals has been studied. For example, Patent Document 1 discloses a configuration for continuously obtaining longer single crystals even in a single crystal manufacturing apparatus using a crucible with a small internal capacity by enabling raw materials to be appropriately supplied to the crucible. Has been.

Here, for example, conventional IGBTs using Si have a heat-resistant temperature of around 175 ° C., for example, when a vehicle-mounted product is intended to be used, the required heat-resistant temperature can reach 200 ° C. Therefore, there is a problem that it cannot be implemented. For this reason, development of next-generation semiconductors using materials capable of supporting high temperatures such as SiC, AlN, or inexpensive MoO ₃ capable of supporting high temperatures has been actively conducted. In the development of such next-generation semiconductors, obtaining a so-called bulk single crystal of high-quality MoO ₃ is an important factor.

JP 2008-150223 A

For example, there is MoO ₃ as a material expected for high-temperature applications, but at present, high-quality bulk crystals cannot be obtained because it can only be obtained by vapor phase growth. This is also attributed to the low boiling point of MoO3. That is, when an attempt is made to obtain a crystalline material from the melt by holding the melt composed of the composition in the crucible, a part of the melt volatilizes, resulting in non-uniformity in the melt concentration distribution, which is stable. This is because the crystal growth is difficult. Therefore, even if an attempt is made to obtain a single crystal material having the above composition by the pulling-down method, the characteristics of the material used for crystal growth by the volatilization-evaporation of the raw material melt inside the crucible, temperature distribution and other characteristics are not stable, In practice, stable crystal pulling operation was difficult. Even if a bulk crystal material is obtained, its quality is not stable, and as a result, it is difficult to improve the quality.

  The present invention has been made in view of the above situation, and can stably obtain a single crystal having a uniform composition distribution even when a highly volatile material as described above is used. An object of the present invention is to provide a single crystal manufacturing apparatus and a manufacturing method thereof.

  In order to solve the above problems, a single crystal manufacturing apparatus according to the present invention has a cylindrical shape that becomes a closed portion with a closed bottom, and has a through hole that penetrates the closed portion from the inside of the cylindrical shape to the outside. The raw material melt held in the crucible is leaked from the through hole, and the seed that determines the crystal orientation when the raw material melt is crystallized is brought into contact with the leaked raw material melt, and the seed is used as a predetermined pulling shaft. A single crystal manufacturing apparatus for obtaining a single crystal that grows with a seed as a starting point by pulling down along the lid, closing the opening of the crucible and having a protrusion having a tip that can be immersed in the raw material melt, and a crucible for the raw material melt A liquid level detector for detecting the position of the liquid level in the inside, a lid moving means for moving the lid relative to the liquid level, and a heating means for heating the lid. Keep the tip immersed in the raw material melt It is characterized by performing the relative movement to.

In the single crystal manufacturing apparatus described above, the contact angle θo indicating wettability between the raw material melt and the surface of the lid, and the contact angle θi indicating wettability between the raw material melt and the inner peripheral surface of the crucible Preferably satisfies θi ≧ θo. Alternatively, there is an angle θcont formed between the surface of the tip when the tip of the protrusion is immersed in the raw material melt and the liquid surface of the raw material melt, and a contact angle θo ₁ indicating wettability between the raw material melt and the surface of the protrusion. , Θcont <θo ₁ is preferably satisfied. Moreover, it is more preferable that the single crystal manufacturing apparatus further includes a liquid sealing material disposed between the lid and the inner peripheral surface of the crucible to close the gap. Moreover, it is more preferable that the heating means maintain the temperature of the lid higher than the temperature of the crucible holding the raw material melt.

  In order to solve the above problems, the method for producing a single crystal according to the present invention has a cylindrical shape that becomes a closed portion with a closed bottom, and has a through hole that penetrates the closed portion from the inside of the cylindrical shape to the outside. The raw material melt held inside the crucible is leaked from the through-hole, the seed that determines the crystal orientation when the raw material melt is crystallized is brought into contact with the leaked raw material melt, and the seed is pulled down to a predetermined pulling axis. A single crystal manufacturing method for obtaining a single crystal that grows with a seed as a base point by pulling down along the surface of the crucible, wherein the crucible is filled with the raw material of the raw material melt, and a protrusion whose tip can be immersed in the raw material melt The lid of the crucible is closed, the raw material is heated and melted to obtain the raw material melt, the position of the liquid level in the crucible of the raw material melt is detected, the lid is heated, and the lid moving means Interval It has a step of bringing the seed into contact with the raw material melt leaked from the through hole and lowering the seed along a predetermined pulling axis, and the interval is maintained at the predetermined value in the step of lowering Yes.

  In the single crystal manufacturing method described above, the predetermined value is preferably changed according to the step of reducing. Alternatively, it is more preferable that the temperature of the lid is changed according to the step of pulling down.

According to the present invention, it is possible to stably obtain a single crystal having a uniform composition distribution even when a highly volatile material such as MoO ₃ or a material having a low melting point and a boiling point is used. It becomes possible.

It is a figure which shows these schematic structures including the partial cross section about the main structure of the single crystal pulling-down apparatus which concerns on one Embodiment of this invention seen from the side. FIG. 2 shows a further embodiment of the invention in a manner similar to FIG. It is a figure which expands the area | region A in FIG. 2, and shows further embodiment. It is a figure which expands the area | region A in FIG. 2, and shows a different form from FIG. 3A. It is a figure which shows schematic structure of the single crystal manufacturing apparatus containing the structure shown in FIG.

  An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram showing an outline of the main components of a pulling apparatus, which is a single crystal manufacturing apparatus according to an embodiment of the present invention, as viewed from the side. The pulling device 1 according to this embodiment includes a crucible 11, an after heater 13, a heating coil 15, a heating lid 17, a lid lifting / lowering unit 21, and a liquid level detection unit 23. The crucible 11 has a cylindrical shape with a closed bottom surface (lower end) and is made of carbon or a high melting point metal (for example, Re, Ir, W, Ta, Mo, Pt, or an alloy thereof). . At the center of the bottom surface of the crucible 11, a through hole 11 a is provided along the central axis of the crucible so as to penetrate the bottom surface, which is a closed portion of the cylinder, from the inside of the crucible 11 to the outside. The heating coil 15 has a spiral structure coaxial with the crucible 11. The heating coil 15 emits a high frequency toward the crucible 11 or the like, and utilizes the so-called high frequency induction phenomenon to heat (heat generation) the raw material 7 or the raw material melt 8 held inside the crucible 11 or the crucible 11, and the raw material Melting is taking place.

  The seed 5 (see FIG. 4) is arranged so that the end surface faces the opening forming surface of the crucible through hole 11a. When the crystallization of the raw material melt 8 progresses in contact with the raw material melt 8, the seed 5 serves to form crystal nuclei and determine the crystal orientation. That is, the seed 5 serves as a growth base point during single crystal growth. The seed 5 is supported by a seed holder (not shown) that extends along the central axis of the crucible 11 and can move up and down along the central axis, and is arranged vertically below the through hole. . The seed holder is moved up and down by the pulling mechanism 31. The raw material melt 8 leaked from the crucible 11 comes into contact with a contact surface (a flat surface provided at the upper part) with the raw material melt 8 in the seed 5 to start crystallization, and the seed 5 is aligned along the above-described central axis. By pulling it down, it promotes crystal growth and growth. In this embodiment, the raw material melt 8 has a small contact angle with respect to the material of the crucible 11 and good so-called wettability. Therefore, when the raw material melt 8 leaks from the crucible through-hole 11a to the lower part of the crucible 11, A solid-liquid boundary (growing part 8a) having the same cross-sectional area as the opening hole forming end face is formed. A single crystal 9 is grown continuously below the growing portion 8a.

  Below the crucible 11, a cylindrical after-heater 13 that contacts the vicinity of the outer periphery of the lower end of the crucible 11 and supports the crucible 11 is disposed. The after heater 13 is made of the same material as that of the crucible and is arranged so as to be coaxial with the crucible 11. When the raw material is heated, the after-heater 13 also generates heat by high-frequency induction, and the raw material melt that leaks from the lower end of the crucible 11 can be heated. Further, the length of the after heater 13 is such that when the crucible 11 arranged at the center in the longitudinal direction of the heating coil 15 and the after heater 13 are arranged in contact with each other, the effective heating area in the heating coil 15 is set. The after heater 13 is set to be accommodated. By installing the after heater 13, the soaking area in the pulling-down direction can be expanded, and the conditions for crystal growth can be made wider.

  In this invention, it has the lid | cover which has an external shape so that it can insert in the axial direction of this crucible 11 with respect to the opening 11b of the upper part of the crucible 11. FIG. The lid includes a heater so that temperature management such as heating can be performed independently of the crucible 11, and is hereinafter referred to as a heating lid 17. The heating lid 17 is connected to a heating unit 20 such as a heating control device provided outside. The heating lid 17 is supported by an elevating unit 21 that elevates and lowers the heating lid 17 in a direction along the pulling axis. The heating lid 17 has a cone portion 18 that protrudes in the crucible 11 in parallel with the pulling-down axis direction. The cone portion 18 is in contact with the raw material melt 8 at the tip portion in the protruding direction. In the illustrated configuration, a case where a plurality of cone portions 18 are annularly arranged in the circumferential direction around the pulling shaft is shown. For example, as shown in FIG. It may be configured to have.

For example, the raw material melt 8 made of a highly volatile material such as MoO ₃ to be obtained by the present invention often has very good wettability with respect to the material of the crucible 11. Volatile raw materials adhere to the lid and usually solidify on the surface. By adopting a mode in which the lid is heated as in the present invention, it is possible to promote remelting of the solidified raw material. However, for example, in the case of a raw material melt having good wettability with respect to all materials used for the crucible or the lid, it may not be easy to drop it into the crucible 11 while adhering as a liquid to the surface of the lid. By disposing the cone portion 18 connecting the raw material melt 8 and the lower surface of the lid 17 on the lower surface of the heating lid 17 as in the present invention, the raw material wets from the surface of the raw material melt 8 along the surface of the cone portion 18. The melt 8 and the raw material melt remelted on the lower surface of the heating lid 17 come into contact with each other and can be mixed with each other.

  In the present invention, the liquid level detection unit 23 for measuring the liquid level of the raw material melt 8 stored in the crucible 11 is provided. The liquid level detection unit 23 may be obtained from, for example, the amount of the raw material 7 filled in the crucible 11 and the amount of the raw material melt lowered, and the liquid level can be observed from the information of the crucible 11 by ultrasonic waves or light. Various known liquid level measurement techniques, such as measuring the height, can be applied. The position of the liquid level of the raw material melt 8 obtained by the liquid level detection unit 23 is transmitted to the liquid level control unit 25. The liquid level control unit 25 is connected to the elevating unit 21, and the elevating unit 21 is heated based on the obtained liquid level so that the distance between the liquid level, the lower surface of the heating lid 17 and the liquid level is constant. 17 is controlled. By arranging the configuration, the volume of the space substantially closed by the inner wall of the crucible 11, the liquid surface of the raw material melt 8, the lower surface of the heating lid 17, and the surface of the cone portion 18 is always kept constant, thereby the heating lid. The amount of the raw material melt 8 adhering to the lower surface 17 and the surface of the cone portion 18 is always constant. As a result, the amount of the raw material melt 8 supplied to the crystal growth is supplied from the crucible 11 for crystal growth. The composition of the raw material melt 8 is kept constant.

  The contact angle θo indicating the wettability between the raw material melt 8 and the surface of the heating lid 17 (including the surface of the cone portion 18 but hereinafter referred to as the surface of the heating lid 17). Preferably satisfies θi ≧ θo with respect to the contact angle θi related to the wettability with the inner peripheral surface of the crucible 17, that is, the wettability is good. By satisfying the condition, the diffusion of the raw material melt between the lid surface and the liquid surface of the raw material melt 8 will preferentially proceed, and the composition change of the raw material melt 8 due to volatilization can be made more quickly and reliably. Will be suppressed. In addition, the angle θcont formed by the tip surface and the liquid surface when the tip of the cone portion 18 contacts the liquid surface of the raw material melt 8 is determined when the raw material melt 8 is dropped on the surface of the cone portion 18. The so-called contact angle θo preferably satisfies θcont <θo. That is, it is more preferable that the projection surface of the cone portion 18 is immersed at an angle close to perpendicular to the surface of the raw material melt 8.

  Further, a modification of the previously operated embodiment is shown in FIG. 2, FIG. 3A or FIG. 3B. FIG. 2 shows only the crucible 11, the heating lid 17 and the raw material melt 8 shown in FIG. 1 in the same manner as in FIG. 1, and the region related to the modified portion of the previous embodiment in FIG. Is indicated by a circle A. 3A and 3B schematically show the area A in an enlarged manner. In the previous embodiment, it has been described that the heating lid 17 can be inserted into the upper opening 11b of the crucible 11. However, since the raw material melt 8 having good wettability with respect to the crucible material is used, the outer periphery of the heating lid 17 is used. Even if the gap between the portion and the inner peripheral wall of the crucible 11 is narrowed, the raw material melt 8 gets wet along the inner peripheral wall. Further, if the gap between the heating lid 17 and the inner wall of the crucible 11 is made too narrow in order to prevent this, there is a concern that these may come into contact with each other to generate impurities made of the material of the crucible 11.

  In this modification, the liquid sealing material 24 (24a, 24b) is disposed in the gap (see FIGS. 3A and 3B). The presence of the liquid sealing material 24 prevents unnecessary raw material melt 8 from rising through the gap, and further prevents leakage to the outside of the crucible 11. As shown in FIG. 3A, the liquid sealing material 24 may be arranged such that a highly viscous material 24a has a shape like a so-called O-ring having a substantially circular cross section. Alternatively, as shown in FIG. 3B, the material may be arranged so that the gap between the inner peripheral surface of the crucible 11 and the outer peripheral surface of the heating lid 17 is filled with a low-viscosity material 24b. Further, since the heating lid 17 moves with respect to the crucible 11, the same member has an inner peripheral surface of the crucible 11, a lower surface of the heating lid 17, so that there is no possibility of generating foreign matter due to friction and sliding between them. And it is preferable to comprise from the liquid material with low wettability with respect to the raw material melt 8.

  The temperature at which the heating lid 17 is heated by the heating unit 20 is preferably set higher than the holding temperature of the raw material organic 8 inside the crucible 11. The temperature of the material vaporized from the surface of the raw material melt 8 increases as the distance from the surface increases, and reaches the maximum temperature in the attached state. Therefore, it is necessary to remelt and apply energy to circulate the liquid surface. In the present invention, as described above, by maintaining the temperature of the heating lid 17 higher than the holding temperature of the raw material melt 8, this circulation phenomenon can be easily and suitably continued. By adding these configurations to the above-described embodiment, the concentration of the raw material melt 8 that contributes to the growth of the single crystal can be further stabilized, and a high-quality bulk single crystal can be obtained. .

  In addition, although the lid described in the above-described embodiments has a cylindrical shape, it may have a simple cylindrical shape. In addition, since the heating lid may have a lid body and a heating means for heating the lid separately, in the present invention, these are defined as a lid having a protrusion whose tip is immersed in the raw material melt and a heating means. Furthermore, although the structure which raises / lowers a lid | cover is illustrated in this invention, you may move the crucible side, Therefore, it is preferable that the movement of a lid | cover is grasped | ascertained as a relative movement. Furthermore, the temperature of the lid may be a temperature management mode in which it is changed according to the remaining amount of the raw material melt.

  Next, a method for actually growing a single crystal using the pulling apparatus having the configuration shown in FIG. 1 will be described. The inside of the crucible 11 is filled with the raw material 7, and the heating lid 17 is disposed so as to cover the opening 11b above the crucible 11. In this state, high frequency power is applied to the heating coil 15 to melt the raw material 7. At the same time, heating of the heating lid 17 is also started. After the raw material 7 is melted, the liquid level detection unit 23 detects the liquid level of the raw material melt 8, and the liquid level control unit 25 and the lid lifting / lowering unit 21 set the distance between the liquid level and the lower surface of the heating lid 17 to a predetermined value. To control. Then, after a predetermined time has elapsed, the state of the raw material melt 8 is stabilized, and the seed 5 is brought into contact with the raw material melt 8 leaking from the through hole 11a of the crucible 11. After confirming that the crystal growth has started from the contact portion between the raw material melt 8 and the seed 5, the seed 5 is pulled down along a predetermined pulling axis while observing the state of the growing portion 8a described above to grow a single crystal. Plan.

  At the time of lowering, the position of the melt surface is confirmed by the liquid level detection unit 23, the heating lid 17 is moved up and down by the liquid level control unit 25 and the lid lifting unit 21, and the interval between the liquid level and the lower surface of the heating lid 17 is increased. Continue to maintain a predetermined value. As a result, the concentration of the raw material melt 8 leaking through the crucible through hole 11a can be further stabilized, and a high-quality bulk single crystal can be obtained. Note that depending on the remaining amount of the raw material melt 8 in the crucible 11, a change may occur in the reflux mode of the volatile melt that flows back into the melt from the lower surface of the heating lid 17, and a change in the concentration or temperature state may also occur. It is done. In this case, the characteristics of the single crystal obtained according to the remaining amount of the raw material melt 8 in the crucible 11 are obtained in advance, and the predetermined value is gradually increased so as to suppress the change according to the characteristic change. It is also possible to change the style. In this case, it is preferable that the change mode or the like of the predetermined value is determined according to the change pattern stored in the liquid level control unit 25 or the designation by the operator.

  Next, a schematic configuration of the single crystal pulling apparatus including the configuration shown in FIG. 1 will be described. FIG. 4 shows a schematic configuration of a single crystal pulling apparatus according to an embodiment of the present invention as viewed from the side. As described above, the single crystal pulling device 1 is mainly composed of the seed 5, the crucible 11, the after heater 13, the heating coil 15, the heating lid 17 including the cone portion 18, the heating portion 20, the lid lifting and lowering portion 21, the liquid level. The detector 23 and the pull-down mechanism 31 are further provided with a control device including a heat retaining tube 27, an outer tube 28, a crucible stage 29, a CCD camera 35, and a liquid level control unit 25 (not shown in the figure). . The after heater 13 is supported by the upper surface of the annular crucible stage 29 at the lower end thereof. The crucible stage 29 (and the heat insulating tube 27) is made of a material having insulation properties against high frequency induction used for heating, such as ceramics and quartz. The heat insulating tube 27 is disposed inside the heating coil 15 and has a cylindrical shape surrounding the crucible 11, and suppresses the heat radiated from the crucible 11 to the outside. The crucible stage 29 is supported on the lower surface by an upper end portion of a cylindrical outer tube 28 made of the same material as the crucible stage 29. The crucible 11, the after heater 13, the heating coil 15, the heat insulating tube 25, the crucible stage 29, and the outer tube 28 are arranged so as to be coaxial, and the crystal pulling operation is performed along a pulling axis that coincides with the axis. Done.

  The seed 5 is held by a seed holder (not shown) disposed at the upper end of the pulling mechanism 31. The seed 5 can be moved up and down in accordance with the vertical movement of the pulling mechanism 31 in the axial direction. The CCD camera 35 is used for observing the formation state of the growing part 8a which is a solid-liquid boundary. The after heater 13 is provided with a through window (not shown) for observing the growing part 8a, and the CCD camera 35 can take an image of the growing part 8a through the through window. The image obtained from the CCD camera 35 is transmitted to the control device described above, the state of the growing unit 8a is determined based on the obtained image, and the pulling-down speed of the seed 5 is controlled according to the determination result. Is called. That is, the pull-down mechanism 31 is controlled in accordance with the image of the growing unit 8a, and operations such as deceleration, stop, or change to the lowering operation of the seed 5 and adjustment of the lowering speed are performed. Similarly, the raising / lowering position of the heating lid 17 is also controlled by the liquid level control unit 25 in accordance with the state of the growing section 8a.

  Note that the configuration described in the above-described single crystal pulling apparatus 1 is an example, and various modifications can be made depending on the raw materials, for example. Specifically, a cylindrical member made of a conductive material serving as a further heating element may be disposed between the crucible 11 and the heating coil 15. The crucible 11 itself may not be configured to generate heat, and the cylindrical member may be configured to generate heat. Alternatively, the structure may be such that the after heater 13 is eliminated, the after heater 13 has a double structure, or the positional relationship between the after heater and the heating coil 15 can be modified. It is also conceivable that the lowering operation is performed in a specific gas atmosphere such as an inert gas atmosphere or a gas atmosphere such as an oxidizing or fluorinated gas. Assuming such a case, the lowering device 1 is installed inside a sealable chamber, and an exhaust system and a gas introduction system are attached to the chamber to exhaust the internal space to a so-called vacuum state, It is preferable to make it possible to maintain a predetermined pressure with gas.

  In the present invention, when a bulk single crystal is grown using a highly volatile raw material melt, the temperature can be controlled and the top of the crucible 11 is covered with a lid having a protrusion whose tip can be immersed in the raw material melt surface. The opening 11b is closed, and the single crystal is grown while maintaining the distance between the lower surface of the lid and the melt surface at a predetermined value. As described above, according to the present invention, due to the action of the heating lid, in the case of using a raw material melt having volatility at a growth temperature at which it was considered difficult to grow a high-quality bulk single crystal. Even if it exists, it becomes possible to implement seed touch suitably and to grow a high-quality single crystal excellent in uniformity of composition and the like in each part.

  Note that in this specification, a structure for obtaining a rod-like single crystal is described. However, the present invention has various forms by modifying not only the crystal shape but also, for example, the shape of the crucible through hole when the raw material is leaked from the crucible, the surface shape of the lower end of the crucible where the raw material melt spreads, etc. It can also be applied to single crystal growth. In addition, the heating lid to which a protrusion is added and which can be moved up and down is also applicable as a crucible lid in a so-called pulling method exemplified by the CZ method.

DESCRIPTION OF SYMBOLS 1: Pulling-down apparatus, 5: Seed, 7: Raw material, 8: Raw material melt, 8a: Growing part, 9: Single crystal, 11: Crucible, 11a: Crucible through-hole, 11b: Crucible opening 13: After heater, 15: Heating coil, 17: heating lid, 18: cone portion, 20: heating portion, 21: lid lifting / lowering portion, 23: liquid level detecting portion, 24 (24a, 24b): liquid sealing material, 25: liquid level control unit, 27: heat insulation tube, 28: outer tube, 29: crucible stage, 31: pulling mechanism, 35: CCD camera

Claims (8)

Leakage of raw material melt held inside the crucible having a cylindrical shape that becomes a closed portion with a closed bottom portion and having a through hole that penetrates the closed portion from the inside of the cylindrical shape to the outside from the through hole A seed that determines a crystal orientation when the raw material melt is crystallized is brought into contact with the leaked raw material melt, and the seed is grown along a predetermined pulling axis to grow from the seed as a base point. A single crystal manufacturing apparatus for obtaining a crystal,
A lid having a protrusion that closes the opening of the crucible and whose tip can be immersed in the raw material melt;
A liquid level detector for detecting the position of the liquid level in the crucible of the raw material melt;
Lid moving means for moving the lid relative to the liquid surface;
Heating means for heating the lid,
The single crystal manufacturing apparatus according to claim 1, wherein the lid moving means performs the relative movement so as to maintain a state in which a tip of the protrusion is immersed in the raw material melt.   The contact angle θo indicating wettability between the raw material melt and the surface of the lid and the contact angle θi indicating wettability between the raw material melt and the inner peripheral surface of the crucible satisfy θi ≧ θo. The single crystal manufacturing apparatus according to claim 1, wherein The angle θcont formed by the surface of the tip and the surface of the raw material melt when the tip of the protrusion is immersed in the raw material melt, and contact indicating wettability between the raw material melt and the surface of the protrusion The single crystal manufacturing apparatus according to claim ₁ , wherein the angle θo ₁ satisfies θcont <θo ₁ .   4. The single crystal manufacturing apparatus according to claim 1, further comprising a liquid sealing material disposed between the lid and the inner peripheral surface of the crucible to close the gap.   5. The single crystal manufacturing apparatus according to claim 1, wherein the heating unit maintains a temperature of the lid higher than a temperature of the crucible holding the raw material melt. 6. Leakage of raw material melt held inside the crucible having a cylindrical shape that becomes a closed portion with a closed bottom portion and having a through hole that penetrates the closed portion from the inside of the cylindrical shape to the outside from the through hole A seed that determines a crystal orientation when the raw material melt is crystallized is brought into contact with the leaked raw material melt, and the seed is grown along a predetermined pulling axis to grow from the seed as a base point. A single crystal manufacturing method for obtaining a crystal,
The crucible is filled with the raw material of the raw material melt, and the crucible opening is closed with a lid having a protrusion whose tip can be immersed in the raw material melt,
The raw material is heated and melted to obtain the raw material melt, and the position of the liquid level in the crucible of the raw material melt is detected,
While heating the lid, a gap between the lid and the liquid level is set to a predetermined value by a lid moving means,
The step of bringing the seed into contact with the raw material melt leaked from the through hole and lowering the seed along the predetermined pulling axis;
The single crystal manufacturing method, wherein the predetermined value is maintained in the step of lowering the interval.   The method for producing a single crystal according to claim 6, wherein the predetermined value is changed according to the lowering step.   The method for producing a single crystal according to claim 6 or 7, wherein the temperature of the lid is changed according to the step of pulling down.

Images