JPH07277872A - Apparatus for producing semiconductor single crystal - Google Patents

Abstract

PURPOSE:To prevent vibration propagating to a single crystal under growth from below a supply pipe at the time of falling of liquid drops with an apparatus for producing the semiconductor single crystal using a continuous charging method melting a raw material crystal rod and supplying the liquid drops formed in such a manner to a melt. CONSTITUTION:The bottom end of the supply pipe 6 is closed by a bottom plate 6a constituted integrally with the supply pipe 6. This bottom plate 6a is provided with at least one piece of holes 6b for putting the melt into and out of the supply pipe 6 when the supply pipe 6 is immersed into the melt. These holes 6b are formed in positions deviating from the axial center of the supply pipe 6. The liquid drops of the raw material crystal rod melted by a raw material melting heater fall onto the melt surface in the supply pipe 6. The vibration by collision of the liquid drops against the melt surface propagates in respective directions within the melt but the melt of the liquid drop falling part is enclosed by the supply pipe 6 exclusive of the holes 6b and, therefore, the vibration hardly propagates outside. Then, surges are not generated on the melt surface on the outer side of the supply pipe 6 and the polycrystallization of the single crystal under growth is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor single crystal production apparatus for continuously producing a homogeneous semiconductor single crystal using a continuous charge method.

[0002]

2. Description of the Related Art A high-purity single crystal silicon is mainly used for a substrate of a semiconductor element, and one of the methods for producing this single crystal silicon is the Czochralski method (hereinafter referred to as the CZ method). In the CZ method, a graphite crucible is placed on the upper end of a crucible shaft installed in a chamber of a semiconductor single crystal manufacturing apparatus via a crucible receiver, and a quartz crucible housed in the graphite crucible is filled with polycrystalline silicon. The polycrystalline silicon is heated and melted by a heater provided around the graphite crucible to form a melt. Then, the seed crystal attached to the seed chuck is immersed in the melt, and the seed chuck is pulled up while the seed chuck and the graphite crucible are rotated in the same direction or in the opposite direction to grow single crystal silicon.

In recent years, the diameter of semiconductor wafers has increased,
With the demand for large-diameter wafers exceeding 8 inches, single crystal silicon having a diameter of 8 inches or more is becoming the mainstream. For this reason, the single crystal manufacturing equipment also becomes larger,
The throughput per cycle tends to increase. However, as the size of the single crystal manufacturing apparatus becomes larger, the time required for the single crystal growth step becomes longer, and before and after that, for example, the time required for melting the raw material polycrystal, and after taking out the grown single crystal silicon out of the furnace. The cooling time required for the crucible, the heater, etc. to reach a temperature at which they can be cleaned is longer than before. These are factors that reduce the productivity of single crystal silicon. Further, since the quartz crucible is deformed or cracked due to the heat load applied when the polycrystalline silicon is melted, it is replaced with a new one every time the single crystal silicon is pulled up.

As one of means for efficiently producing large-diameter single crystal silicon by the CZ method, a raw material is supplied into a crucible according to the amount of the pulled single crystal silicon, and the single crystal silicon is continuously pulled up. The charge method is used. FIG. 15 is a partial cross-sectional view schematically showing an example of a semiconductor single crystal manufacturing apparatus using the continuous charge method, and two sets of raw material supply mechanisms 20 are installed above the peripheral edge of the crucible 4. The raw material supply mechanism 20 melts rod-shaped polycrystalline silicon (hereinafter referred to as raw material crystal rod) 22 supported from the upper part of the chamber 21 and drops it into the melt 5. The raw material melting heater 23 and the raw material melting The protective cylinder 24 surrounds the heater 23 and a quartz supply pipe 25 attached to the lower end of the protective cylinder 24. The supply pipe 25
The lower end of the melt 5 is immersed in the melt 5
Is prevented from being propagated and vapor phase separation between the raw material supply part and the single crystal growth region is performed. Raw material crystal rod 22 is 1
The materials are alternately suspended in the raw material melting heater 23, and when the melting of the raw material crystal rods on one side is completed, the raw material crystal rods on the other side are melted and the raw material is continuously supplied. In addition,
26 is a main heater, 27 is a heat insulating cylinder, 28 is single crystal silicon being pulled up, and 29 is a crucible shaft.

[0005]

The above-described semiconductor single crystal manufacturing apparatus using the continuous charge method has the following problems conventionally. (1) In FIG. 15, the crucible 4 rotates with the rotation of the crucible shaft 29, but the raw material supply mechanism 20 is stationary. Therefore, since the supply pipe 25 attached to the lower end of the protection cylinder 24 also remains stationary, the melt 5 rotating with the crucible 4 is agitated by the supply pipe 25. Then, convection of the melt is obstructed to cause liquid surface vibration and melt temperature fluctuation, which makes it difficult to squeeze when forming the neck portion prior to the growth of single crystal silicon, and hinders dislocation-free crystallization. (2) By immersing the lower end of the supply pipe 25 in the melt 5, the vibration of the melt 5 caused by the falling droplets is prevented from propagating to the single crystal growth region. The vibration propagation from the surface of the melt 5 is blocked by the supply pipe 25, as shown in FIG.
As shown in FIG. 6, the vibration at the time of dropping the droplet propagates from below the supply pipe 25 and spreads to the single crystal growth region. When the single crystal being pulled receives the wave motion of the melt 5, it causes polycrystallization.
Therefore, the vibration propagation cannot be completely prevented only by immersing the lower end of the supply pipe 25 in the melt 5. (3) When a series of single crystal growth approaches the end and the supply of the raw material by melting the raw material crystal rod ends, the melt surface gradually descends and the lower end of the supply pipe 25 separates from the melt surface. However, since the melt 5 has a large surface tension, it adheres to the lower surface of the supply pipe 25 and is lifted as shown in FIG. The maximum height at which the melt 5 can be lifted is about 5 mm. When the melt surface further descends and the melt separates from the lower surface of the supply pipe 25, liquid surface vibration occurs as shown in FIG. 17 (b). This liquid level vibration causes polycrystallization of the single crystal during pulling. (4) Although quartz is generally used for the supply pipe 25,
The portion of the supply pipe 25 immersed in the melt 5 reacts with the melt 5 and is gradually eroded. When such a supply pipe 25 is used, when the supply of the raw material by the melting of the raw material crystal rod is completed and the melt surface descends to the eroded portion of the supply pipe 25,
As shown in FIG. 18, the contact angle between the melt 5 and the outer peripheral surface of the supply pipe 25 changes and liquid level vibration occurs. This liquid level vibration causes polycrystallization of the single crystal during pulling.

The present invention has been made by paying attention to the above-mentioned conventional problems. A first object of the present invention is to agitate the melt by a supply pipe attached to the lower end of the raw material replenishing mechanism and to hinder the convection of the melt. It is an object of the present invention to provide a semiconductor single crystal manufacturing apparatus. A second object of the present invention is to provide a semiconductor single crystal manufacturing apparatus that prevents the propagation of melt vibration that occurs when the droplets of the melted raw material crystal rod fall. A third object of the present invention is to provide a semiconductor single crystal manufacturing apparatus that does not generate liquid level oscillation when the melt surface descends and the lower end of the supply pipe separates, and fourthly, the eroded supply. An object of the present invention is to provide a semiconductor single crystal manufacturing apparatus capable of preventing liquid surface vibration caused by a change in contact angle between a tube and a melt surface.

[0007]

In order to achieve the first object, a semiconductor single crystal manufacturing apparatus according to the present invention is a crucible for filling a raw material of a semiconductor single crystal, and a crucible installed around the crucible. A main heater that melts the raw materials inside,
It has a pulling mechanism for immersing a seed crystal in the melt in the crucible and pulling up a single crystal, and a raw material supply mechanism for melting a raw material crystal rod by a raw material melting heater to supply the droplets into the crucible. In the semiconductor single crystal manufacturing apparatus provided above the peripheral portion of, the lower cross section of the supply pipe attached to the lower end of the cylindrical protective cylinder surrounding the raw material melting heater,
The supply pipe whose lower cross section is surrounded by a non-circular curve is characterized in that it has a shape surrounded by a non-circular curve, and the longitudinal direction of the lower cross section is parallel to the rotation direction of the crucible. And a configuration in which the resistance of the supply pipe to the melt rotating with the crucible is minimized.

Next, as a means for achieving the second object, the semiconductor single crystal manufacturing apparatus according to the present invention comprises a crucible for filling the raw material of the semiconductor single crystal, and a raw material in the crucible which is installed around the crucible. Having a main heater for melting, and a pulling mechanism for pulling a single crystal by immersing a seed crystal in the melt in the crucible, and melting the raw material crystal rod by the raw material melting heater to drop the droplet in the crucible. In a semiconductor single crystal manufacturing apparatus equipped with a raw material supply mechanism above a peripheral portion of a crucible, a supply pipe attached to a lower end of a cylindrical protective cylinder surrounding the raw material melting heater has a bottom plate closing the supply pipe at its lower end. And at least one on the bottom plate
Or a configuration in which at least one hole is provided in the bottom plate, in which the lower end is obliquely cut with respect to the axis of the supply pipe and the lower end is closed by a bottom plate. Alternatively, a bottom plate for closing the supply pipe may be provided in upper and lower two layers at the lower end of the supply pipe, and each bottom plate may be provided with at least one hole having a different opening position. Further, it is characterized in that holes provided in the bottom plate for closing these supply pipes are provided at positions deviated from the axis of the supply pipes.

As a means for achieving the third object, a semiconductor single crystal production apparatus according to the present invention is installed in a crucible for filling a raw material of a semiconductor single crystal and around the crucible, and melts the raw material in the crucible. A raw material having a main heater and a pulling mechanism for pulling a single crystal by immersing a seed crystal in the melt in the crucible, and melting the raw material crystal rod by a raw material melting heater to supply the droplets into the crucible In a semiconductor single crystal manufacturing apparatus provided with a supply mechanism above a peripheral portion of a crucible, a lower surface of a supply pipe attached to a lower end of a cylindrical protective cylinder surrounding the raw material melting heater is not orthogonal to an axis of the supply pipe. The structure is such that the supply pipe is cut obliquely, and in such a structure, the difference in length between the long axial part and the short axial part of the supply pipe is 5 mm or more, and the lower surface of the supply pipe is oblique to the axis. The cut the supply pipe, a short portion of the axial length of the supply pipe was be attached to the protective tube so as to be close to the inner wall of the crucible.

Further, in order to achieve the fourth object, a semiconductor single crystal manufacturing apparatus according to the present invention is provided with a crucible for filling a raw material of a semiconductor single crystal and a crucible surrounding the crucible and melting the raw material in the crucible. Having a main heater and a pulling mechanism for immersing the seed crystal in the melt in the crucible to pull up the single crystal, and melting the raw material crystal rod by the raw material melting heater to supply the droplet into the crucible. In a semiconductor single crystal manufacturing apparatus equipped with a raw material supply mechanism above the peripheral portion of a crucible, a slight gap is provided with respect to the supply pipe around the supply pipe attached to the lower end of a cylindrical protective cylinder that surrounds the raw material melting heater. A ring-shaped float is provided so as to surround and surround it.

In order to achieve the above first to fourth objects, each supply pipe attached to the lower end of the protective cylinder and the annular float surrounding the supply pipe are made of quartz or quartz whose surface is coated with silicon carbide. Alternatively, it is characterized by being made of silicon carbide or silicon nitride.

[0012]

In the semiconductor single crystal manufacturing apparatus, the present invention provides a means for achieving the first object of preventing the stirring of the melt by the supply pipe attached to the lower end of the raw material replenishing mechanism and the accompanying inhibition of the melt convection. Since the lower part of the supply pipe has a shape surrounded by a non-circular curve and is arranged in the direction in which the resistance to the melt is minimized, the melt rotating with the crucible passes through both sides of this supply pipe. However, no vortex is generated. Therefore, convection of the melt is not hindered, and it is possible to reduce liquid level vibration and melt temperature fluctuation due to immersion of the supply pipe.

Next, as a means for achieving the above-mentioned second object of preventing the vibration propagation of the melt generated when the droplets of the melted raw material crystal rod fall, the lower end of the supply pipe is closed by the bottom plate, At least one hole is provided on the bottom plate,
Alternatively, the lower end of the supply pipe is obliquely cut, the lower end is closed by a bottom plate, and at least one hole is provided in the bottom plate. Moreover, since the hole of the bottom plate is provided at a position deviated from the axial center of the supply pipe, by using the supply pipe having such a structure, vibration propagation of the melt generated when the raw material droplets are dropped can be supplied. Almost all, including vibrations propagating from below the tube, are blocked by the supply tube. Further, when the lower end of the supply pipe is closed by upper and lower two-layer bottom plates and each bottom plate is provided with at least one hole having a different opening position, it is possible to completely block the propagation of the vibration. Become.

The third aspect of the present invention is to prevent liquid level vibration that occurs when the melt surface descends and the lower surface of the supply pipe separates from the melt.
However, as a means for achieving this, the lower end of the supply pipe is cut obliquely, and the difference in length between the long part and the short part of the axial length of the supply pipe is Since the height is at least the maximum height which can be attached to the lower surface of the supply pipe and lifted, that is, at least 5 mm, the liquid at the lower end of the supply pipe is well drained against the melt having a large surface tension. Therefore, when the supply pipe is detached from the melt surface, the melt is not attached to the lower surface of the supply pipe and lifted up unlike the conventional case, and it is possible to prevent the occurrence of liquid level vibration. Further, by mounting the supply pipe so that a portion having a short axial length is close to the inner wall of the crucible, a predetermined gap is secured between the lower surface of the supply pipe and the bottom surface of the crucible when the crucible is raised. be able to.

Further, as a means for achieving the fourth object of preventing the vibration of the liquid surface caused by the change in the contact angle between the corroded supply pipe and the melt surface, a slight gap is provided between the supply pipe and the liquid pipe. An annular float surrounding the supply pipe is provided around the supply pipe. As a result, the liquid level vibration is blocked by the float and can be prevented from propagating to the single crystal growth region.

In the present invention, each supply pipe and an annular float surrounding the supply pipe are made of quartz or a quartz whose surface is coated with silicon carbide, or silicon carbide or silicon nitride. Since the supply pipe made of silicon carbide or silicon nitride or the supply pipe coated with silicon carbide is less corroded than the supply pipe made of quartz, the service life of the supply pipe can be extended.

[0017]

Embodiments of the semiconductor single crystal manufacturing apparatus according to the present invention will be described below with reference to the drawings. 1 to 3
Shows a supply pipe attached to the lower end of a cylindrical protective cylinder surrounding the raw material melting heater in the raw material supply mechanism provided above the peripheral portion of the crucible. FIG. 1 (a) shows claim 1.
FIG. 1B is a sectional view according to the first embodiment of FIG. 1, and FIG. 1B is a bottom view of FIG. Like the conventional one, the upper portion of the supply pipe 1 is provided with a flange 1a that can be hooked on the lower end of a cylindrical protective cylinder, and the cylindrical section 1b has an oval circular cross section. FIG. 2A is a side view according to the second embodiment of claim 1,
FIG. 2B is a bottom view of FIG. This supply pipe 2
The lower portion of the cylindrical portion 2b has a cross-sectional shape in which two opposing arc-shaped curves are combined. In addition, FIG.
3B is a side view according to the third embodiment of the present invention, and FIG. 3B is a bottom view of FIG. The lower portion of the cylindrical portion 3b of the supply pipe 3 has a so-called streamline shape having an arcuate head portion at one end in the major axis direction of its cross section and a sharp tail portion at the other end. The raw material crystal rod is melted by the raw material melting heater and drops in the supply pipe as droplets having a diameter of about 5 mm. The inner dimension in the minor axis direction in the lower cross section of the supply pipe shown in FIGS. The size is sufficiently large for the droplet.

FIG. 4 is an explanatory view of the supply pipe immersed in the melt, and illustrates the case where the supply pipe according to the third embodiment of the first aspect (see FIG. 3) is used. Supply pipe 3 Crucible 4
The inner peripheral portions are arranged at positions facing each other, and the lower ends thereof are immersed in the melt 5. At this time, the lower portion of the supply pipe 3 is attached to the protective cylinder such that the major axis direction thereof is parallel to the rotation direction of the crucible 4. Further, when the shape of both ends of the lower cross section in the major axis direction is different as in the supply pipe 3 according to the third embodiment, after the melt 5 rotating in the direction of the arrow passes through both side surfaces of the supply pipe 3, it is swirled. Is arranged in such a direction that does not generate In the case of FIG. 4, the melt 5 rotates counterclockwise, but the lower cross section of each of the supply pipes 3 is arranged with its arcuate head facing the upstream side. The supply pipes of any of the first to third embodiments have almost no resistance to the rotation of the melt, and the melt is not agitated. Therefore, convection of the melt is not hindered, and liquid level vibration and melt temperature fluctuation can be reduced.

FIG. 5 is a cross-sectional view of an embodiment of the supply pipe according to claims 3 and 6. The lower end of this supply pipe 6 is
It is closed by a bottom plate 6a formed integrally with the supply pipe 6, and when the supply pipe 6 is immersed in the melt, the melt flows into the supply pipe 6 or melts from the supply pipe 6. At least one hole 6b for letting out flows is provided. The hole 6b is provided at a position off the axis of the supply pipe 6.

FIG. 6 is a sectional view of an embodiment of the supply pipe according to claims 4 and 6, wherein the lower end of the supply pipe 7 is cut obliquely with respect to the axis and is closed by a bottom plate 7a.
At the lowest position of the bottom plate 7a, a hole 7b for allowing the melt to flow in and out is provided.

FIG. 7 is a sectional view of an embodiment of a supply pipe according to claims 5 and 6. The lower end of the supply pipe 8 is composed of upper and lower two layers of bottom plates 8a, 8b integrally formed with the supply pipe 8.
The bottom plates 8a, 8b are closed by at least one hole 8c, 8d having different opening positions.
Is provided. Both the holes 8c and 8d are provided at positions off the axis of the supply pipe 8.

FIG. 8 is an explanatory view showing a state of a supply pipe according to claims 3 and 6 as a typical example among the supply pipes according to claims 3 to 6 when a droplet is dropped. The droplet of the raw material crystal rod melted by the raw material melting heater falls on the melt surface in the supply pipe 6 whose lower end is immersed in the melt 5. The vibration caused by the collision of the droplet on the surface of the melt propagates in each direction in the melt, but the melt in the droplet drop portion is surrounded by the cylindrical portion of the supply pipe 6 and the bottom plate 6a except for the hole 6b. , Hardly propagated outside. Therefore, the melt surface outside the supply pipe 6 including the single crystal growth region does not have a wave motion due to the drop of droplets, and thus the single crystal under growth can be prevented from becoming polycrystal. It should be noted that when the supply pipe having the bottom plate of the upper and lower two layers shown in FIG. Further, in the case of the supply pipe according to claim 4 and claim 6 shown in FIG. 6, by attaching to the protective cylinder so that the portion of the supply pipe 7 having a short axial length is close to the inner wall of the crucible, It is possible to maintain the gap between the bottom surface of the supply pipe and the bottom surface of the crucible at a predetermined value when the crucible is raised.

FIG. 9 is a cross-sectional view of an embodiment of the supply pipe according to claims 7 to 9, showing a state where the lower end is immersed in the melt 5. The lower surface of the supply pipe 9 is obliquely cut so as not to be orthogonal to the axis of the supply pipe 9. The difference L between the long axial part and the short axial part of the supply pipe 9 is 5 mm or more, and the short axial part is attached to the protective cylinder so as to be close to the inner wall of the crucible 4. The shape and dimensions of the other parts are the same as those of the conventional supply pipe.

FIGS. 10 and 11 are explanatory views showing a state in which the supply of the raw material by the melting of the raw material crystal rod is completed and the melt surface is lowered. Since the lower surface of the supply pipe 9 is inclined with respect to the melt surface, the melt 5 runs off the lower surface well,
Even when the lower surface of the supply pipe 9 separates from the melt 5, as shown in FIG. 11, the amount of the melt adhered to the lower end of the supply pipe 9 and lifted up is very small. Therefore, from the melt surface to the supply pipe 9
When is removed, the liquid surface vibration hardly occurs, and the single crystal under growth is prevented from becoming polycrystal.

Also in the case of the supply pipe (see FIG. 6) based on the above-mentioned claim 4 and claim 6, the liquid running out at the time of leaving from the melt surface is good as in the above, and the claims 7 to 7 are also preferred. The same effect as that of the supply pipe based on 9 can be obtained.

FIG. 12 shows a first supply pipe according to claim 10.
In the sectional view of the example, the lower end is immersed in the melt. An annular float 11 is fitted on the outer circumference of the supply pipe 10 so as to be vertically movable with a slight gap between the float 11 and the outer circumference of the supply pipe 10. The cross section of the float 11 is U
It is shaped like a letter and is inserted from the upper end of the supply pipe 10 to receive the buoyancy of the melt 5. A flange that prevents the float 11 from falling off is provided at the lower end of the supply pipe 10.

FIG. 13 shows that in the raw material supply mechanism of the semiconductor single crystal manufacturing apparatus using the supply pipe 10 whose lower portion is eroded by the reaction with the melt, the raw material supply by the melting of the raw material crystal rod is completed, and the melt surface It is explanatory drawing which shows the state which fell.
Since the conventional supply pipe does not have a float, the contact angle between the melt and the outer peripheral surface of the corroded supply pipe changes and liquid level vibration occurs, but in the case of this embodiment, the float around the supply pipe 10 is generated. Since 11 is surrounded, the propagation of the liquid level vibration is blocked by the float 11 regardless of the change in the contact angle. Since the float 11 is always located on the melt surface, the effect of preventing the propagation of the liquid level vibration is maintained even if the melt surface further descends.

FIG. 14 shows a second supply pipe according to claim 10.
In the cross-sectional view of the embodiment, a float 13 having an L-shaped cross section is inserted and fitted into the supply pipe 12. By moving the fitting portion between the supply pipe 12 and the float 13 to the upper portion of the supply pipe 12, that is, a portion that is difficult to be eroded by the melt,
The vertical movement of the float 13 associated with the vertical movement of the melt surface is made smoother.

The supply pipe in the embodiment of claim 1, claim 3, claim 4, claim 5 or claim 7 and the supply pipe and float in the embodiment of claim 10 have been conventionally used. In addition to quartz, the surface of quartz is coated with silicon carbide, or is made of silicon carbide or silicon nitride. When silicon carbide or silicon nitride is used, it is less corroded than quartz and the service life can be extended.

[0030]

As described above, according to the present invention, the semiconductor single crystal manufacturing apparatus using the continuous charge method in which the raw material crystal rod is melted and its droplets are supplied to the melt from above the crucible is improved. Since the countermeasures were implemented for each of the four required issues, the following effects can be obtained. (1) The lower cross section of the supply pipe attached to the lower end of the raw material supply mechanism has a shape surrounded by a non-circular curve and is arranged so that the resistance to the melt is minimized. The agitation is significantly reduced, and vibration of the melt surface and melt temperature fluctuation, which have been problems in the past, are suppressed. Therefore, the neck portion is formed smoothly,
It becomes easy to grow a dislocation-free single crystal having excellent quality. (2) As a measure against vibration propagating from below the supply pipe when the droplets of the raw material fall, the bottom plate is provided at the lower end of the supply pipe to interrupt the propagation of the vibration. As a result, it is possible to suppress the generation of waves of the melt, which adversely affects the single crystal being pulled, as much as possible, and to eliminate the possibility of polycrystallization, so that it is possible to efficiently produce a high-quality semiconductor single crystal. (3) Further, the liquid level vibration that occurs when the lower end of the supply pipe separates from the melt surface when the supply of the raw material is completed and the lower surface of the melt descends, and the lower end of the supply pipe is inclined. It can be prevented by making the cut well. Therefore, it is possible to solve one of the causes of polycrystallizing the single crystal being pulled. (4) Liquid level vibration caused by erosion of the supply pipe also causes polycrystallization of the single crystal being pulled. Therefore, a float was provided around the supply pipe to prevent propagation of the vibration. As a result, the single crystal being pulled does not undergo liquid surface vibration, and polycrystallization does not occur. (5) Conventionally, about 30% of a single crystal produced by the continuous charge method was polycrystallized by vibration of the melt surface, but by applying the present invention, the defect rate can be reduced to 0%, and a single crystal is produced. The cost can be significantly reduced.

[Brief description of drawings]

FIG. 1 shows a supply pipe according to a first embodiment of claim 1,
(A) is sectional drawing, (b) is a bottom view of said (a).

2 shows a supply pipe according to a second embodiment of claim 1,
(A) is a side view, (b) is a bottom view of the (a).

FIG. 3 shows a supply pipe according to a third embodiment of claim 1,
(A) is a side view, (b) is a bottom view of the (a).

4 is an explanatory view of a lower portion of the supply pipe of FIG. 3 immersed in a melt.

FIG. 5 is a cross-sectional view of an embodiment of a supply pipe according to claim 3.

FIG. 6 is a cross-sectional view of an embodiment of a supply pipe according to claim 4.

FIG. 7 is a sectional view of an embodiment of a supply pipe according to claim 5;

FIG. 8 is an explanatory diagram showing a state of the supply pipe shown in FIG. 5 when a droplet is dropped.

FIG. 9 is a cross-sectional view of an embodiment of a supply pipe according to claims 7-9.

FIG. 10: The supply of the raw material by melting the raw material crystal rod is completed,
It is explanatory drawing which shows the state which the melt surface fell.

FIG. 11: The raw material supply by the melting of the raw material crystal rod is completed,
It is explanatory drawing which shows the state which the melt surface fell further.

FIG. 12 is a sectional view of a first embodiment of a supply pipe according to claim 10.

FIG. 13 is an explanatory view showing a state where the melt surface is lowered in the supply pipe of FIG.

FIG. 14 is a sectional view of a second embodiment of the supply pipe according to claim 10.

FIG. 15 is a partial cross-sectional view schematically showing an example of a semiconductor single crystal manufacturing apparatus using a continuous charge method.

FIG. 16 is an explanatory diagram showing vibration propagating to a melt when a droplet is dropped due to melting of a raw material crystal rod.

FIG. 17 is an explanatory diagram when the lower end of the supply pipe separates from the melt surface, (a) is a state in which the melt is attached to the lower end of the supply pipe and lifted, and (b) is the lower end of the supply pipe. It is explanatory drawing which shows the state of the melt surface at the time of leaving | separating from a melt.

FIG. 18 is an explanatory diagram showing a state of liquid surface vibration that occurs when the melt surface descends in the supply pipe having the lower portion eroded.

[Explanation of symbols]

1, 2, 3, 6, 7, 8, 9, 10, 12, 25 ... Supply pipe, 6a, 7a, 8a, 8b ... Bottom plate, 6b, 7b, 8
c, 8d ... Hole, 4 ... Crucible, 5 ... Melt, 11, 13 ... Float, 20 ... Raw material replenishing mechanism, 22 ... Polycrystalline silicon (raw material crystal rod), 23 ... Raw material melting heater, 24 ... Protective cylinder, 26 … Main heater, 28… single crystal silicon.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tadashi Hata 2612 Shinomiya, Hiratsuka City, Kanagawa Prefecture, Komatsu Electronic Gold Co., Ltd. (72) Hiroshi Niikura 2612 Shinomiya, Hiratsuka City, Kanagawa Prefecture, Komatsu Electronic Gold Corporation

Claims (11)

[Claims] 1. A crucible for filling a raw material of a semiconductor single crystal, a main heater installed around the crucible for melting the raw material in the crucible, and a single crystal by immersing a seed crystal in a melt in the crucible. Has a lifting mechanism for lifting
In a semiconductor single crystal manufacturing apparatus provided with a raw material supply mechanism above a peripheral portion of a crucible for melting a raw material crystal rod by a raw material melting heater and supplying droplets thereof into the crucible, a cylindrical protection surrounding the raw material melting heater. An apparatus for producing a semiconductor single crystal, characterized in that a lower cross section of a supply pipe attached to a lower end of a cylinder has a shape surrounded by a non-circular curve. 2. The supply pipe having a lower cross section surrounded by a non-circular curve is rotated so that the major axis direction of the lower cross section is parallel to the rotation direction of the crucible and with the crucible. 2. The semiconductor single crystal production apparatus according to claim 1, wherein the supply pipe is arranged in a direction in which the resistance of the supply pipe to the melt is minimized. 3. A crucible for filling a raw material of a semiconductor single crystal, a main heater installed around the crucible for melting the raw material in the crucible, and a seed crystal immersed in a melt in the crucible to form a single crystal. Has a lifting mechanism for lifting
In a semiconductor single crystal manufacturing apparatus provided with a raw material supply mechanism above a peripheral portion of a crucible for melting a raw material crystal rod by a raw material melting heater and supplying droplets thereof into the crucible, a cylindrical protection surrounding the raw material melting heater. An apparatus for producing a semiconductor single crystal, wherein a supply pipe attached to a lower end of a cylinder has a bottom plate closing the supply pipe at its lower end, and at least one hole is provided in the bottom plate. 4. A supply pipe in which the lower end is cut obliquely with respect to the axis of the supply pipe and the lower end is closed by a bottom plate,
4. The semiconductor single crystal manufacturing apparatus according to claim 3, wherein at least one hole is provided in the bottom plate. 5. A bottom plate for closing the supply pipe is provided in upper and lower two layers at the lower end of the supply pipe, and at least one hole having a different opening position is provided in each bottom plate. Semiconductor single crystal manufacturing equipment. 6. The semiconductor according to claim 3, wherein the hole provided in the bottom plate that closes the supply pipe is provided at a position deviated from the axial center of the supply pipe. Single crystal manufacturing equipment. 7. A crucible for filling a raw material of a semiconductor single crystal, a main heater installed around the crucible for melting the raw material in the crucible, and a single crystal by immersing a seed crystal in a melt in the crucible. Has a lifting mechanism for lifting
In a semiconductor single crystal manufacturing apparatus provided with a raw material supply mechanism above a peripheral portion of a crucible for melting a raw material crystal rod by a raw material melting heater and supplying droplets thereof into the crucible, a cylindrical protection surrounding the raw material melting heater. A semiconductor single crystal manufacturing apparatus, wherein a lower surface of a supply pipe attached to a lower end of a cylinder is obliquely cut so as not to be orthogonal to an axis of the supply pipe. 8. The semiconductor single crystal manufacturing apparatus according to claim 7, wherein the difference in length between the long axial portion and the short axial portion of the supply pipe is 5 mm or more. 9. The supply pipe, in which the lower surface of the supply pipe is cut obliquely with respect to the axis, is attached to the protective cylinder such that a portion of the supply pipe having a short axial length is close to the inner wall of the crucible. The semiconductor single crystal manufacturing apparatus according to claim 7, wherein 10. A crucible for filling a raw material of a semiconductor single crystal, a main heater installed around the crucible for melting the raw material in the crucible, and a single crystal by immersing a seed crystal in a melt in the crucible. Has a lifting mechanism for lifting
In a semiconductor single crystal manufacturing apparatus provided with a raw material supply mechanism above a peripheral portion of a crucible for melting a raw material crystal rod by a raw material melting heater and supplying droplets thereof into the crucible, a cylindrical protection surrounding the raw material melting heater. An apparatus for producing a semiconductor single crystal, characterized in that an annular float is provided around a supply pipe attached to the lower end of a cylinder so as to surround the supply pipe with a slight gap therebetween. 11. A supply pipe attached to the lower end of the protective cylinder and an annular float surrounding the supply pipe are made of quartz or quartz whose surface is coated with silicon carbide, or silicon carbide or silicon nitride. Claim 1, claim 3, claim 4, claim 5, characterized in that there is
The semiconductor single crystal manufacturing apparatus according to claim 7 or 10.