CN214361839U - Quartz pin and monocrystalline silicon growth device - Google Patents

Abstract

The utility model provides a quartz pin, quartz pin includes the pole body, the pole body divide into first portion and second portion along the axial, first portion is less than along axial length the second portion is along axial length, just first portion with the axial nonparallel of second portion, the free end of second portion expands and forms projection portion, deviating from of projection portion the surface of second portion is the cambered surface. The first part is used for fixing the quartz pin at the bottom end of the reflector, the projection part can form a projection on the liquid level of the silicon melt, one surface of the projection part, back to the second part, is an arc surface, and the arc surface can better reflect light rays to the liquid level of the silicon melt. The projection can be clearer, an imaging unit can acquire the image of the projection and the projection part, and the distance between the projection and the projection part can be acquired. Correspondingly, the utility model also provides a monocrystalline silicon growth device.

Description

Quartz pin and monocrystalline silicon growth device

Technical Field

The utility model relates to a semiconductor manufacturing technology field, concretely relates to quartzy round pin and monocrystalline silicon growth device.

Background

The Czochralski method is mainly adopted for the growth of the semiconductor monocrystalline silicon. In this method, polycrystalline silicon is charged into a quartz crucible, the polycrystalline silicon is heated and melted to form a silicon melt, then the silicon melt is slightly cooled to give a certain supercooling degree, a silicon single crystal (seed crystal) of a specific crystal orientation is brought into contact with the silicon melt, and when crystallization occurs at the interface of the silicon melt and the seed crystal, the seed crystal is rotated while being pulled up, whereby a single crystal silicon ingot is grown. The diameter of the single crystal silicon ingot can be controlled by controlling and adjusting the temperature of the silicon melt and the seed crystal lifting rate.

Polycrystalline silicon is loaded into a quartz crucible, the polycrystalline silicon is heated by a heater arranged on the periphery of the quartz crucible, and after the polycrystalline silicon forms a silicon melt, the temperature of the silicon melt, particularly the temperature of the interface between the silicon melt and a seed crystal, namely the liquid level of the silicon melt, is controlled by controlling the heater. A reflector is arranged above the liquid level and can reflect heat radiated by the liquid level so as to obtain a specific temperature gradient to ensure the quality of the monocrystalline silicon ingot. The position of the heater and the reflector is fixed during crystal growth, and in order to better control the temperature at the interface of the silicon melt and the seed crystal, the relative positions of the interface of the silicon melt and the seed crystal, the heater and the bottom of the reflector are consistent, namely the distance between the heater and the liquid level of the silicon melt in the quartz crucible is kept constant. Therefore, the liquid level of the silicon melt needs to be measured in real time, the liquid level of the silicon melt and the bottom of the reflector also need to be kept at a certain distance, the liquid level of the melt is reduced along with the growth of the single crystal in the crystal growth process, and the height of the crucible is adjusted at the same time, so that the distance between the reflector and the liquid level of the silicon melt in the quartz crucible should be kept constant.

The quartz pin is a tool for measuring the liquid level of silicon melt suspended at the bottom of a reflector and suspended above the liquid level of the melt, and currently, the measurement of the liquid level of the silicon melt is difficult due to the structural limitation of the quartz pin, so that a quartz pin with a better structure is needed in the industry.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a quartz pin and monocrystalline silicon growth device, the relative position of the liquid level of measurement silicon melt that can be convenient and reflector.

In order to achieve the above object, the present invention provides a quartz pin, including:

the shaft body is divided into a first part and a second part along the axial direction, the length of the first part along the axial direction is smaller than that of the second part along the axial direction, the first part is not parallel to the second part along the axial direction, the free end of the second part expands to form a projection part, and the surface of the projection part, which is far away from the second part, is an arc surface.

Optionally, the first portion, the second portion and the projection portion are of an integral structure.

Optionally, the arc surface is a spherical surface.

Optionally, the projection portion is hemispherical.

Optionally, the projection portion is spherical.

Optionally, an axial included angle between the first portion and the second portion is 60 degrees to 90 degrees.

Optionally, the first portion and the second portion are both cylindrical or polygonal.

Correspondingly, the utility model also provides a monocrystalline silicon growth device, include:

a furnace cavity;

a crucible located within the furnace cavity for containing a silicon melt;

a reflector positioned above the crucible;

the quartz pin is arranged at the bottom of the reflector and is positioned above the silicon melt;

and the imaging unit is positioned outside the furnace cavity body and is used for shooting the projection part of the quartz pin and the projection of the projection part on the liquid level of the silicon melt.

Optionally, the single crystal silicon growth apparatus further comprises a heater located at the outer periphery of the crucible for heating the silicon melt.

Optionally, the furnace cavity has an observation window, and the imaging unit is disposed at the observation window.

The utility model discloses an among the quartz pin, the first part is used for being fixed in the bottom of reflector with the quartz pin, the one end of second part with the first part links to each other, the other end of second part is provided with a projection portion, projection portion can be formed with the projection at the liquid level of silicon melt, and the reflector all keeps fixedly with the relative position of furnace cavity with the heater. Thus, the distance between the projection and the projection portion can be indicative of the relative position of the liquid level of the silicon melt and the reflector. The utility model discloses in, the projection dorsad the one side of second part is the cambered surface, and the cambered surface can make with the better reflection of light to the liquid level of silicon melt the projection is more clear, is favorable to the imaging element acquires the projection with image between the projection, and then acquire the projection with distance between the projection. Therefore, the relative position of the liquid level of the silicon melt and the reflector can be more conveniently obtained.

Correspondingly, the utility model also provides a monocrystalline silicon growth device.

Drawings

FIG. 1 is a schematic view of a single crystal silicon growth apparatus according to a first embodiment of the present invention;

FIG. 2 is a schematic view of a quartz pin according to a first embodiment of the present invention;

fig. 3 is a schematic view of a quartz pin according to a second embodiment of the present invention;

fig. 4 is a schematic view of a quartz pin according to a third embodiment of the present invention;

fig. 5 is a schematic view of a quartz pin according to a fourth embodiment of the present invention;

wherein the reference numbers are as follows:

100-quartz pins; 110-a first portion; 120-a second portion; 130-a projection unit; 131-a projection plane;

200-a heat shield assembly; 210-a support ring; 220-a reflector;

300-a furnace cavity; 310-a crucible; 311-quartz crucible; 312-graphite crucible; 320-a base; 330-a heater; 340-a support bar;

400-an imaging unit;

500-a pulling assembly; 510-pulling a wire; 520-a seed chuck;

m-a silicon melt; m-seed crystal.

Detailed Description

The following description of the embodiments of the present invention will be described in more detail with reference to the drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in simplified form and are not to precise scale, and are provided for convenience and clarity in order to facilitate the description of the embodiments of the present invention.

As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense including "and/or" unless the content clearly dictates otherwise, and the terms "mounted" and "connected" are to be construed broadly, e.g., as meaning a fixed connection, a removable connection, or an integral connection. They may be mechanically or electrically connected, either directly or indirectly through intervening media, or may be interconnected within or in an interactive relationship with each other. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art. The same or similar reference numbers in the drawings identify the same or similar elements.

Example one

Fig. 1 is a schematic view of a single-crystal silicon growth apparatus in an embodiment. As shown in fig. 1, the single crystal silicon growth apparatus includes at least: a furnace chamber 300, a crucible 310, a reflector 220, a heater 330, and an imaging unit 400. Wherein the crucible 310 is located in the furnace chamber 300, and is used for containing a silicon melt M obtained by heating and melting polycrystalline silicon. Specifically, the crucible 310 has a hollow hemispherical shape. The crucible 310 includes a graphite crucible 312 and a quartz crucible 311 located inside the graphite crucible 312. The crucible 310 is mounted on a susceptor 320, the susceptor 320 being mounted on a turntable (not shown) for rotating the susceptor 320 and the crucible 310 about a central longitudinal axis. The susceptor 320 is also capable of being raised and lowered to enable the crucible 310 to be raised and lowered within the furnace chamber 300.

A heater 330 is located at the outer periphery of the crucible 310 for heating the silicon melt M. Specifically, in this embodiment, the heater 330 is connected to the bottom of the furnace chamber 300 through a support rod 340, and the relative position between the heater 330 and the furnace chamber 300 is fixed. The heater 330 is disposed around the outer circumference of the crucible 310 for heating the crucible 310 to melt the polycrystalline silicon in the crucible 310. Heater 330 is controlled by an external temperature control system (not shown) so that the temperature of silicon melt M is precisely controlled throughout the crystal pulling process. In one embodiment of this embodiment, the heater 330 is a graphite heater.

The single crystal silicon growing apparatus further comprises a pulling assembly 500, wherein the pulling assembly 500 is provided with a pulling wire 510, the tail part of the pulling wire 510 is provided with a seed crystal chuck 520, and the seed crystal chuck 520 is used for fixing a seed crystal m for growing the single crystal silicon ingot. In growing a single crystal silicon ingot, pull assembly 500 places seed crystal M down into contact with the surface of silicon melt M through pull wire 510. Once the seed crystal m starts to melt, the pulling assembly 500 slowly raises the seed crystal m upward to grow a single crystal ingot. The speed of the pulling assembly 500 for rotating the seed crystal m and the speed of the pulling assembly 500 for lifting the seed crystal m are controlled by an external motion control system, and the principle and operation of the pulling assembly 500 are well known to those skilled in the art and will not be described in detail herein.

The single crystal silicon growing apparatus further comprises a heat shield assembly 200, the heat shield assembly 200 comprises a support ring 210 and a reflector 220, the support ring 210 is connected with the furnace cavity 300 for supporting the reflector 220, and the reflector 220 is positioned above the crucible 310 and is kept fixed relative to the furnace cavity 300. Specifically, reflector 220 is mounted above silicon melt M and has a central opening (annular cylinder) sized and shaped such that when a single crystal silicon ingot is pulled upwardly from silicon melt M, reflector 220 surrounds the single crystal silicon ingot. The reflector 220, also referred to as a guide cylinder, is used to guide the flow of the shielding gas in the furnace chamber 300, and it should be noted that the shielding gas is argon. Typically, the reflector 220 has an inner reflector 220, an outer reflector 220, and a thermal insulation layer between the inner reflector 220 and the outer reflector 220. The structure and principle of the reflector 220 are well known to those skilled in the art, and will not be described herein in detail.

When growing a single-crystal silicon ingot, it is necessary to control the temperature of silicon melt M, in particular the temperature at the interface between silicon melt M and seed crystal M, i.e. the temperature of the liquid level of silicon melt M, as seed crystal M (or the growing single-crystal silicon ingot) is removed from the surface of silicon melt M. The temperature of the liquid surface of silicon melt M can be controlled by adjusting the relative position of heater 330 and silicon melt M. Further, the relative position of heater 330 and silicon melt M is adjusted by raising and lowering crucible 310. It should be understood that when controlling the temperature of silicon melt M, in addition to adjusting the relative position of the liquid level of silicon melt M and heater 330, control or additional control may be performed by adjusting the power of heater 330.

It should be appreciated that the relative position of the reflector 220 to the oven cavity 300 is fixed, as is the relative position of the heater 330 to said oven cavity 300. Thus, the relative position of the reflector 220 to the liquid level of the silicon melt M can be indicative of the relative position of the heater 330 to the silicon melt M. As such, the relative position between heater 330 and silicon melt M is characterized in the industry by measuring the distance between reflector 220 and the liquid level of silicon melt M. Specifically, the quartz pin 100 is disposed at the bottom of the reflector 220 and above the silicon melt M. The distance between the reflector 220 and the liquid level of the silicon melt M is measured by the quartz pin 100.

Fig. 2 is a schematic view of the quartz pin 100 in this example. As shown in fig. 2, the quartz glass comprises a shaft, the shaft is axially divided into a first portion 110 and a second portion 120, the length of the first portion 110 in the axial direction is smaller than that of the second portion 120, the first portion 110 is not parallel to the second portion 120 in the axial direction, the free end of the second portion 120 is expanded to form a projection 130, the projection 130 is quadrangular, and the projection 130 forms a projection on the liquid surface of the silicon melt M (or is understood as a reverse image of the projection 130 in the liquid surface of the silicon melt M).

Further, the first portion 110, the second portion 120 and the projection 130 are integrally formed, so that the quartz pin 100 has an outer shape similar to the shape of the arabic numeral 7.

Further, the axial included angle between the first portion 110 and the second portion 120 is 60 degrees to 90 degrees. It is advantageous that the quartz pin 100 is fixed to the bottom of the reflector 220.

Further, the first portion 110 and the second portion 120 are both cylindrical or polygonal.

The silicon single crystal growth apparatus has an imaging unit 400 for photographing the projection portion 130 of the quartz pin 100 and the projection of the projection portion 130 on the liquid surface of the silicon melt M. From the projection 130 and the projected image of the projection 130 on the liquid surface of the silicon melt M, the imaging unit 400 can obtain the distance between the projection and the projection 130, that is, the distance between the projection 130 and the liquid surface of the silicon melt M. As can be seen from the above, the relative position between the reflector 220 and the furnace chamber 300 is kept fixed, and the relative position between the heater 330 and the furnace chamber 300 is kept fixed, so that the positions of the heater 330 and the projection 130 of the quartz pin 100 are also relatively fixed. When the distance between the liquid surface of silicon melt M and projection unit 130 changes, it means that the relative position between the liquid surface of silicon melt M and reflector 220 and heater 330 also changes.

Further, an imaging unit 400 is located outside the furnace chamber 300, and is configured to capture a projection of the projection portion 130 of the quartz pin 100 and a projection of the projection portion 130 on the liquid surface of the silicon melt M. If the distance between the liquid level of silicon melt M and projection 130 changes, base 320 of the silicon single crystal growing apparatus is raised and lowered to adjust the height of crucible 310, so that the crucible 310 maintains the liquid level of silicon melt M at a constant height, and the relative position between the liquid level of silicon melt M and reflector 220 is kept fixed.

Further, the furnace chamber 300 has an observation window, and the imaging unit 400 is disposed at the observation window. The imaging unit 400 is a CCD camera and a signal processor, and the imaging principle of the CCD camera and the principle of the signal processor obtaining the distance between the projection and the projection unit 130 according to the image are well known to those skilled in the art, and will not be described herein in detail.

Example two

The same parts of the quartz pin 100 provided in this embodiment as those in the first embodiment will not be described again, and only different points will be described below.

Fig. 3 is a schematic view of the quartz pin 100 in an embodiment. As shown in fig. 3, the quartz pin 100 includes a shaft, the shaft is divided into a first part 110 and a second part 120 along an axial direction, a length of the first part 110 along the axial direction is smaller than a length of the second part 120 along the axial direction, the first part 110 is not parallel to the second part 120 along the axial direction, a free end of the second part 120 is expanded to form a projection 130, and the present embodiment is different from the first embodiment in that: the surface of the projection 130 facing away from the second portion 120 is a curved surface.

It should be noted that the surface of the projection 130 facing away from the second portion 120 is a projection surface 131, and the projection surface 131 is a cambered surface. It is advantageous to reflect the light projected to the projection portion 130 to the liquid surface of the silicon melt M. In this way, the projection of the projection portion 130 on the liquid level of the silicon melt M is clearer, which is beneficial for the imaging unit 400 to acquire the projected image. Thereby more conveniently obtaining the relative position of the liquid level of the silicon melt M and the reflector 220.

EXAMPLE III

The same portions of the quartz pin 100 provided in this embodiment as those in the first and second embodiments will not be described here, and only different points will be described below.

It should be noted that, the projection surface 131 of the quartz pin 100 having the projection portion 130 in the shape of a quadrangular prism is a plane, and if the light reflected by the plane is projected into the imaging unit 400 to the maximum extent, a certain included angle between the projection surface 131 and the imaging unit 400 is required, and if the included angle changes, the light reflected by the imaging unit 400 is sharply reduced, and the projected image obtained by the imaging unit 400 is unclear. This is common in the pulling process, and in addition, the edge region of the projection part 130 has a weak light reflection capability, which makes it difficult for the imaging unit 400 to capture the projection of the region, and therefore, the quartz pin 100 with the projection part 130 in the quadrangular prism shape has an imaging dead angle.

Fig. 4 is a schematic view of the quartz pin 100 in an embodiment. As shown in fig. 4, a surface of the projecting part 130 facing away from the second portion 120 is a spherical surface. The sphere has a wider range of light diffusion after reflection, and therefore, even if the positions of the imaging unit 400 and the projection unit 130 are changed, the imaging unit 400 is not affected to acquire the light reflected by the projection surface 131. In addition, since the projection plane 131 is a spherical surface, there is no edge on the projection plane 131, and thus the projection plane 131 can reflect light rays by 360 degrees, and there is no imaging dead angle, and the imaging unit 400 can clearly capture the projection of the projection unit 130 in a wider range of angles.

Optionally, in this example, the projection 130 is a hemisphere.

Example four

The same portions of the quartz pin 100 provided in this embodiment as those in the first, second, and third embodiments will not be described here, and only different points will be described below.

Fig. 5 is a schematic view of the quartz pin 100 in an embodiment. As shown in fig. 5, the projection 130 of the quartz pin 100 is spherical.

Specifically, the imaging unit 400 is configured to capture images of the projection portion 130 of the quartz pin 100 and projections of the projection portion 130 on the liquid surface of the silicon melt M. When the imaging unit 400 acquires the image of the projection part 130, the spherical projection part 130, the light reflected by the upper hemispherical surface of the spherical projection part 130, can be captured by the imaging unit 400 more conveniently, the lower hemispherical surface of the spherical projection part is the projection surface 131, and the light reflected by the projection surface 131 can form a clearer projection on the surface of the silicon melt M, so the spherical projection part 130 is beneficial for the imaging unit 400 to acquire the projection part 130 of the quartz pin 100 and the projection of the projection part 130 on the liquid level of the silicon melt M.

In summary, the embodiment of the present invention provides a quartz pin, which includes a pin body, the pin body is axially divided into a first portion and a second portion, the axial length of the first portion is less than the axial length of the second portion, the first portion is not parallel to the axial direction of the second portion, the free end of the second portion expands to form a projection, and the surface of the projection departing from the second portion is an arc surface. The utility model discloses an among the quartz pin, the first portion be used for being fixed in the bottom of reflector with the quartz pin, the one end of second portion with the first portion links to each other, the other end of second portion is provided with a projection portion, projection portion can the reflected light be formed with the projection with the liquid level at silicon melt, and the reflector all keeps fixedly with the relative position of furnace cavity with the heater. Therefore, the distance between the projection and the projection portion can represent the relative position of the liquid level of the silicon melt and the heater. The projection part back to the one side of second part is the cambered surface, and the cambered surface can be with better reflection of light to the liquid level of silicon melt, can make the projection is more clear, is favorable to the imaging element obtain the projection with image between the projection part, and then obtain the projection with distance between the projection part. Therefore, the relative position of the liquid level of the silicon melt and the reflector and the heater can be obtained more conveniently. Correspondingly, the utility model also provides a monocrystalline silicon growth device.

The above description is only for the preferred embodiment of the present invention, and does not limit the present invention. Any technical personnel who belongs to the technical field, in the scope that does not deviate from the technical scheme of the utility model, to the technical scheme and the technical content that the utility model discloses expose do the change such as the equivalent replacement of any form or modification, all belong to the content that does not break away from the technical scheme of the utility model, still belong to within the scope of protection of the utility model.

Claims (10)

1. A quartz pin, comprising: the shaft body is divided into a first part and a second part along the axial direction, the length of the first part along the axial direction is smaller than that of the second part along the axial direction, the first part is not parallel to the second part along the axial direction, the free end of the second part expands to form a projection part, and the surface of the projection part, which is far away from the second part, is an arc surface.

2. The quartz pin of claim 1, wherein said first portion, said second portion and said projection are of unitary construction.

3. The quartz pin of claim 2, wherein the arcuate surface is spherical.

4. The quartz pin of claim 3, wherein said projection is hemispherical.

5. The quartz pin of claim 2, wherein said projection is spherical.

6. The quartz pin of claim 1, wherein the first portion is axially angled from 60 degrees to 90 degrees from the second portion.

7. The quartz pin of claim 1, wherein the first portion and the second portion are both cylindrical or polygonal.

8. A single crystal silicon growth apparatus, comprising:

a furnace cavity;

a crucible located within the furnace cavity for containing a silicon melt;

a reflector positioned above the crucible;

the quartz pin of any of claims 1-7, disposed at a bottom of the reflector and above the silicon melt;

and the imaging unit is positioned outside the furnace cavity body and is used for shooting the projection part of the quartz pin and the projection of the projection part on the liquid level of the silicon melt.

9. The single crystal silicon growth apparatus of claim 8, further comprising a heater located at an outer periphery of the crucible for heating the silicon melt.

10. The single crystal silicon growth apparatus of claim 8, wherein the furnace chamber has a viewing window, the imaging unit being disposed at the viewing window.

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