KR20100085640A - Apparatus and method for manufacturing silicon crystal improved cooling efficiency of remaining silicon melt - Google Patents

Abstract

PURPOSE: An apparatus and method for manufacturing silicon crystal, having an improved cooling efficiency of remaining silicon melt are provided to improve the productivity of silicon single crystal by reducing a cooling time for solution in a quartz crucible. CONSTITUTION: An inert gas supplying unit(90) supplies an insertion gas to the surface of a silicon solution according to the outer side of a single crystal ingot. A spry nozzle(95) receives the insertion gas from the inert gas supplying unit and directly sprays the insertion gas on a silicon solution. A controller(200) controls the spray nozzle to discharge the insertion gas on the silicon solution to cool down remaining solution.

Description

Apparatus and Method for manufacturing silicon crystal Improved cooling efficiency of remaining silicon melt

The present invention relates to a silicon single crystal production apparatus and a manufacturing method, and more particularly, to manufacture a silicon single crystal with improved cooling efficiency of the residual melt that can improve the cooling rate of the residual melt after the production of the silicon single crystal using Czochralski method It relates to an apparatus and a manufacturing method.

Generally, silicon single crystal ingots are manufactured by the Czochralski (hereinafter referred to as CZ) method. In the method of growing a silicon single crystal ingot by the CZ method, polycrystalline silicon and a dopant are laminated on a quartz crucible and the polycrystalline silicon and the impurity are melted using heat radiated by a heater installed around the sidewall of the quartz crucible. Necking to form a silicon melt, dipping the seed, the growth source of the silicon single crystal ingot, to the surface of the silicon melt, and pulling up while minimizing the diameter of the growing crystal growing along the seed ), And a shouldering process to extend the growth crystal to the desired crystal diameter. In the body growth process, the seed is slowly raised to grow the silicon single crystal ingot to the desired length, and the tailing ( In the tailing process, the quartz crucible is rapidly rotated to gradually reduce the diameter of the silicon single crystal ingot to separate the melt and the ingot. This completes the growth of the silicon single crystal ingot.

Since the melt remaining in the silicon single crystal ingot and the quartz crucible at the early stage of the completion of single crystal growth is in a high temperature state, opening the growth chamber in this state reacts with the outside air to cause oxidation of the silicon single crystal ingot and the residual melt, which adversely affects the product. Will be affected. Therefore, after the melt is cooled by cooling the melt for a predetermined time, the silicon single crystal ingot and the quartz crucible are separated from the growth chamber.

Conventionally, it takes about 15 hours to perform the cooling process of the melt remaining in the quartz crucible. Accordingly, there is a problem that the productivity of the silicon single crystal manufacturing apparatus is lowered. Moreover, with the large diameter of ingots (wafers), the capacity of the quartz crucible is gradually increasing, and the apparatus has become larger. Therefore, the amount of polycrystalline silicon injected into one growth process increases, and the amount of melt remaining after the growth is increased. For example, the amount of silicon used for the growth of a 300 mm ingot is about 400 kg, and the amount of residual melt after the tailing process is about 40 kg. The amount of silicon used for the growth of the 450 mm ingot is about 600 kg or more, and the amount of residual melt is about 70 kg. The greater the amount of this residual melt, the longer it takes to cool the residual melt. Therefore, in the technical field to which the present invention belongs, there is an urgent need for a method for reducing the cooling time of residual melt after completion of growth in order to improve the productivity of the silicon single crystal.

The present invention has been made to solve the above problems, the residual melt that can improve the productivity of the silicon single crystal by reducing the cooling time of the melt remaining in the quartz crucible after completing the production of the silicon single crystal by the CZ method It is an object of the present invention to provide an apparatus and a method for producing a silicon single crystal with improved cooling efficiency.

In order to achieve the above technical problem, a silicon single crystal manufacturing apparatus having improved cooling efficiency of a residual melt includes a chamber in which silicon single crystal ingots are grown, a quartz crucible installed inside the chamber and accommodating a silicon melt, and a quartz crucible. A silicon single crystal manufacturing apparatus using the Czochralski method comprising a crucible rotating means for rotating, a heater installed around a quartz crucible sidewall, and single crystal pulling means for pulling a silicon single crystal ingot from a silicon melt contained in a quartz crucible by a seed, wherein Inert gas supply means for supplying an inert gas to the upper surface of the silicon melt along the outer circumferential surface of the silicon single crystal ingot; An injection nozzle which receives an inert gas from the inert gas supply means and directly injects an inert gas to the upper surface of the silicon melt; And a controller configured to control the injection nozzle to cool the residual melt while directly injecting an inert gas to the upper surface of the residual melt when the growth of the silicon single crystal ingot is completed.

In the present invention, it further comprises a water cooling tube installed to surround the silicon single crystal ingot grown from the quartz crucible to cool the silicon single crystal ingot, wherein the injection nozzle is installed in the water cooling tube.

Preferably, the injection nozzle is provided in an annular arrangement at a plurality of locations along the circumference of the water cooling tube.

Preferably, when the growth of the silicon single crystal ingot is completed, the control unit controls the single crystal pulling means to move the silicon single crystal ingot to the top of the water cooling tube, while controlling the crucible rotating means to rotate the quartz crucible containing the residual melt The cooling of the residual melt proceeds.

Preferably, the control unit moves the silicon single crystal ingot 100mm to 300mm above the water cooling tube.

Preferably, the controller rotates the quartz crucible at 30 rpm to 40 rpm.

Preferably, the heat shield means for blocking the heat released from the silicon single crystal ingot and forming a melt gap with the surface of the silicon melt; And heat shield driving means for moving the heat shield means up and down, wherein the controller controls the heat shield driving means when the growth of the silicon single crystal ingot is completed, thereby positioning the position of the heat shield means on the upper surface of the residual melt. The maximum distance from the

In order to achieve the above technical problem, a method for manufacturing a silicon single crystal having improved cooling efficiency of a residual melt according to the present invention includes dipping a seed in a silicon melt contained in a quartz crucible, pulling the seed upward while rotating the seed, and growing a silicon single crystal ingot. In the silicon single crystal manufacturing method using the Czochralski method which cools the ingot by passing the growth ingot through a cold pipe, when the growth of the silicon single crystal ingot is completed, the residual melt is directly injected to the upper surface of the residual melt while injecting an inert gas. It characterized in that the cooling of the.

According to the present invention, the cooling time of the residual melt can be shortened by improving the process conditions for cooling the residual melt of the quartz crucible after completing the production of the silicon single crystal using the CZ method. Thereby, productivity can be improved by shortening the manufacturing time of a silicon single crystal.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, words used in this specification and claims are not to be construed as limiting in their usual or dictionary sense, but rather to properly define the concept of terms in order to best describe the inventor's own invention in the best way possible. It should be interpreted as meaning and concept corresponding to the technical idea of the present invention based on the principle that it can. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

1 is a cross-sectional view showing a schematic configuration of a silicon single crystal manufacturing apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the silicon single crystal manufacturing apparatus according to the present invention includes a chamber 10, a space in which silicon single crystal ingots are grown, and a silicon melt M melted at a high temperature and installed inside the chamber 10. The crucible 20 to be wrapped, the crucible housing 30 surrounding the outer circumferential surface of the quartz crucible 20 and supporting the quartz crucible 20 in a predetermined form, is installed at the bottom of the crucible housing 30 and the housing 30 together with the housing 30 Crucible rotating means 40 for raising or lowering the quartz crucible 20 while rotating the quartz crucible 20, and a heater 50 for heating the quartz crucible 20 spaced apart from a sidewall of the crucible housing 30 by a predetermined distance. Is installed on the outside of the heater 50, the heat insulating means 60 to prevent the heat generated from the heater 50 to flow out to the quartz crucible 20 by using a seed (seed) seed crystals Accepted Silicone Melt (M) The water cooling tube in which the cooling water is circulated to cool the single crystal pulling means 70 and the single crystal pulling ingot IG pulled up by the single crystal pulling means 70 while rotating the silicon single crystal ingot IG in a predetermined direction. (80), inert gas supply means (90) connected with an inert gas supply conduit (91) to supply an inert gas (eg, Ar gas) to the upper surface of the silicon melt (M) along the outer circumferential surface of the ingot (IG), The above-described components throughout the manufacturing of the silicon single crystal and the heat shield means 100 for shielding the external emission of heat emitted to the ingot IG for forming the temperature gradient of the solid-liquid interface and forming a melt gap with the silicon melt M It includes a control unit 200 for controlling.

Since the above-described components are typical components of the silicon single crystal manufacturing apparatus using the CZ method, which is well known in the art, detailed description of each component will be omitted.

In the exemplary embodiment of the present invention, the silicon melt M is formed by stacking polysilicon and dopant and melting using heat applied from the heater 50. However, since the present invention is not limited to the type of the melt M, the type and composition of the melt M vary depending on the type of the semiconductor single crystal grown by the CZ method.

In the silicon single crystal manufacturing apparatus according to the present invention, after the growth of the silicon single crystal ingot (IG) by controlling the above-described components in the control unit 200, the cooling of the melt (M) remaining in the quartz crucible 20 effectively It is characterized by

The silicon single crystal manufacturing apparatus according to the present invention further includes an injection nozzle 95 for receiving an inert gas from the inert gas supply means 90 and directly injecting the inert gas to the upper surface of the silicon melt M.

The injection nozzles 95 are provided in an annular arrangement at a plurality of locations along the circumference of the water cooling tube 80. At this time, the injection nozzle 95 is formed to be inclined at an angle to allow the inert gas to be injected to the surface side of the silicon melt (M). However, the present invention is not limited to the manner in which the injection nozzle 95 is installed, and any method may be employed as long as the inert gas injected from the injection nozzle 95 can be directly injected onto the surface of the silicon melt M. This is possible. An inert gas supply conduit 91 is connected to the injection nozzle 95, and the inert gas supply means 90 supplies an inert gas to the inert gas supply conduit 91.

More specifically, when the growth of the silicon single crystal ingot IG is completed, the injection nozzle 95 directly injects an inert gas to the upper surface of the residual melt M under the control of the controller 200. It is preferable that such direct injection of the inert gas is made only in the cooling process of the residual melt M. Then, the flow rate of the inert gas flowing into the residual melt (M) surface is further increased to effectively cool the residual melt (M).

When the growth of the silicon single crystal ingot IG is completed, the control unit 200 controls the single crystal pulling means 70 to effectively cool the residual melt so that the position of the silicon single crystal ingot IG is lower than that of the water cooling tube 80. Move to a higher position. Preferably, when the movement of the silicon single crystal ingot (IG) is completed, the interval between the bottom of the ingot (IG) and the top of the water cooling tube 80 is 100m to 300mm. When the silicon single crystal ingot IG moves upward of the water cooling tube 80, thermal interaction between the silicon single crystal ingot IG and the residual melt M can be minimized, and the inert gas supplied from the single crystal pulling means 70 side. It can make movement of the smooth.

When the growth of the silicon single crystal ingot IG is completed, the control unit 200 rotates the quartz crucible 20 in which the residual melt M is accommodated by controlling the crucible rotating means 40 for effective cooling of the residual melt. . Preferably, the quartz crucible 20 is rotated at a speed of 30rpm to 40rpm. When the quartz crucible 20 rotates within the speed range, the upper surface area of the residual melt M is increased by the centrifugal force, thereby increasing the heat dissipation surface, thereby improving cooling efficiency of the residual melt M.

The controller 200 may adjust the height of the heat shield 100 when the growth of the silicon single crystal ingot IG is completed in order to further improve the cooling efficiency of the residual melt M. FIG. This is because the heat shield means 100 acts as a factor of inhibiting the cooling of the residual melt M in the process of cooling the residual melt M. Specifically, the controller 200 controls the heat shield driving means 110 to move the heat shield means 100 upward so as to space the heat shield means 100 from the upper surface of the residual melt M to the maximum. . Then, a gap is formed between the heat shield means 100 and the quartz crucible 20 so that the inert gas can be smoothly discharged. Therefore, the inert gas injected onto the residual melt M surface absorbs radiant heat from the residual melt M surface and then smoothly discharges to the outside through a gap formed between the heat shield means 100 and the quartz crucible 20. As a result, the cooling rate of the residual melt M can be further improved. Although not shown in the drawing, the heat shield driving means 110 is a mechanical mechanism that enables the vertical movement of the heat shield means 100 and the guider and the heat shield means 100 for guiding the linear movement of the heat shield means 100. It includes a motor for driving).

Next, a process of manufacturing a silicon single crystal ingot using the silicon single crystal manufacturing apparatus according to an embodiment of the present invention will be described in brief.

First, polycrystalline silicon and impurities are stacked in a quartz crucible 20 to meet the specifications of the silicon single crystal ingot to be manufactured. Then, the heater 50 is operated to melt polycrystalline silicon and impurities to form a silicon melt M. When the silicon melt M is formed, the crucible 20 is rotated in a predetermined direction by using the crucible rotating means 40. Then, when the convection of the silicon melt M is stabilized after a predetermined time, the single crystal pulling means 70 is controlled to drip the seed into the silicon melt M, and the seed is raised upward while slowly rotating, thereby increasing the silicon single crystal ingot. (IG) grows. In the initial stage of growth, the pulling rate of the seed is adjusted to form a shoulder of the ingot IG until a desired diameter is obtained. When the shoulder formation is completed, the body of the silicon single crystal ingot IG is grown. When the growth of the body portion is completed, the pulling speed is gradually increased to gradually reduce the diameter of the ingot IG while leaving the lower end of the ingot IG from the silicon melt M to complete the growth of the silicon single crystal ingot IG.

When the growth of the silicon single crystal ingot is completed, the controller 200 controls the single crystal pulling means 70 to move the silicon single crystal ingot IG above the water cooling tube 80. In addition, the controller 200 controls the heat shield driving means 110 to position the heat shield means 100 at a maximum distance from the upper surface of the residual melt M. In this state, the control unit 200 controls the crucible rotating means 40 to rotate the quartz crucible 20 in which the residual melt M is accommodated. Then, the controller 200 controls the inert gas supply means 90 to supply the inert gas to the upper surface of the residual melt M along the outer circumferential surface of the silicon single crystal ingot IG and to control the injection nozzle 95. To inject the inert gas directly to the surface of the residual melt (M).

When the residual melt M is cooled under the above conditions, not only the thermal effect of the silicon single crystal ingot IG is minimized but also the surface area of the residual melt M is increased, so that the radiant heat release rate is increased and the heat shield means 100 The gap between the) and the quartz crucible 20 can be smoothly discharged so that the external discharge of the inert gas absorbing the radiant heat from the surface of the residual melt M is quickly performed. As a result, it is possible to improve the cooling efficiency of the residual melt compared to the prior art, thereby improving the productivity of the silicon single crystal.

< Experimental Example >

Hereinafter will be described experimental examples to confirm the effect of the present invention. The following experimental examples are described for the purpose of helping the understanding of the present invention, and the present invention should not be construed as being limited to terms or experimental conditions described in the experimental examples.

Comparative example

After 400 kg of polycrystalline silicon was charged into a quartz crucible and a single crystal ingot having a body diameter of 300 mm was grown, the residual melt was cooled under the conventional cooling conditions shown in FIG. At this time, the amount of the residual melt was about 40 kg. Since conventional cooling conditions were used, the positions of the silicon single crystal ingot and the heat shield means were not adjusted, and inert gas was also supplied to the quartz crucible side along the outer circumferential surface of the single crystal ingot.

Example

After 400 kg of polycrystalline silicon was charged into a quartz crucible and a single crystal ingot having a body diameter of 300 mm was grown, the remaining melt was cooled under the cooling conditions shown in FIG. 3. At this time, the amount of the residual melt was about 40 kg. In the embodiment, the silicon single crystal ingot was raised to increase the cooling efficiency of the residual melt so that the distance H between the lower end of the silicon single crystal ingot and the upper surface of the residual melt was 1680 mm, and the heat shield means and the top of the residual melt were The distance (H ') from the surface was spaced 400 mm. Then, the crucible rotating means was controlled to rotate the quartz crucible at a speed of 30 rpm, and an inert gas was directly injected to the surface of the residual melt using an injection nozzle provided in the water cooling tube.

After cooling the residual melt for about 2 hours according to Comparative Examples and Examples, the temperatures of P1 point (Comparative Example) and P2 point (Example) were measured, respectively. As a result, the temperature of the P1 point was 1200 degreeC and the temperature of the P2 point was 1000 degreeC. In addition, the time taken for the temperature of the residual melt to be reduced to 200 ° C. was 15 hours for the comparative example, the time for the example was 10 hours, and the example shortened the cooling time of the residual melt for 5 hours.

Through the above experimental results, it can be seen that by cooling the residual melt according to the present invention, the productivity of the silicon single crystal ingot can be improved by improving the cooling efficiency of the residual melt compared with the conventional method.

As described above, although the present invention has been described by way of limited embodiments and drawings, the present invention is not limited thereto and is intended by those skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of equivalents of the claims to be described.

The following drawings, which are attached to this specification, illustrate preferred embodiments of the present invention, and together with the detailed description of the present invention serve to further understand the technical idea of the present invention, the present invention includes the matters described in such drawings. It should not be construed as limited to.

1 is a cross-sectional view showing a schematic configuration of a silicon single crystal production apparatus according to the present invention.

2 and 3 are views for explaining the cooling conditions of the residual melt according to the comparative example and the embodiment.

DESCRIPTION OF THE REFERENCE NUMERALS OF THE DRAWINGS

M: silicone melt IG: silicon single crystal ingot

10 chamber 20 quartz crucible

30: crucible housing 40: crucible rotating means

50: heater 60: insulation means

70: single crystal pulling means 80: water cooling pipe

90: inert gas supply means 91: inert gas supply conduit

95 spray nozzle 100 heat shield means

110: heat shield driving means 200: control unit

Claims (13)

From the chamber in which the silicon single crystal ingot is grown, the quartz crucible installed inside the chamber to accommodate the silicon melt, the crucible rotating means to rotate the quartz crucible, the silicon melt contained in the quartz crucible by a heater and seed installed around the sidewall of the quartz crucible In the silicon single crystal production apparatus using the Czochralski method comprising a single crystal pulling means for pulling the silicon single crystal ingot, Inert gas supply means for supplying an inert gas to the upper surface of the silicon melt along the outer circumferential surface of the silicon single crystal ingot; An injection nozzle which receives an inert gas from the inert gas supply means and directly injects an inert gas to the upper surface of the silicon melt; And And a control unit for cooling the residual melt while directly injecting an inert gas to the upper surface of the residual melt by controlling the injection nozzle when the growth of the silicon single crystal ingot is completed. The method of claim 1, It further comprises a water cooling tube installed to surround the silicon single crystal ingot grown from the quartz crucible to cool the silicon single crystal ingot, The injection nozzle is a silicon single crystal manufacturing apparatus, characterized in that installed in the water cooling pipe. The method of claim 2, Said injection nozzle is provided in multiple places along the periphery of the said water cooling pipe, The silicon single crystal manufacturing apparatus characterized by the above-mentioned. The method of claim 2, The spray nozzles are silicon single crystal manufacturing apparatus, characterized in that installed in an annular arrangement along the circumference of the water cooling tube. The method of claim 2, When the growth of the silicon single crystal ingot is completed, the control unit controls the single crystal pulling means to move the silicon single crystal ingot above the water cooling tube, and controls the crucible rotating means to rotate the quartz crucible containing the residual melt to maintain the remaining melt. Silicon single crystal production apparatus characterized in that the cooling proceeds. The method of claim 5, The control unit is a silicon single crystal manufacturing apparatus, characterized in that for moving the silicon single crystal ingot up to 100mm to 300mm above the water cooling tube. The method of claim 5, The control unit is a silicon single crystal manufacturing apparatus, characterized in that for rotating the crucible at 30rpm to 40rpm. The method of claim 1, Heat shield means for blocking heat emitted from the silicon single crystal ingot and forming a melt gap with the surface of the silicon melt; And Further comprising a heat shield driving means for moving the heat shield means up and down, And the control unit controls the heat shield driving means when the growth of the silicon single crystal ingot is completed to position the position of the heat shield means at a maximum distance from the upper surface of the residual melt. Method of manufacturing silicon single crystal using Czochralski method to cool silicon ingot by dipping the seed into the silicon melt contained in the quartz crucible, growing the seed while rotating the seed, and growing the silicon single crystal ingot through the water cooling tube. To And when the growth of the silicon single crystal ingot is completed, cooling the residual melt while directly injecting an inert gas to the upper surface of the residual melt. 10. The method of claim 9, A silicon single crystal ingot is moved before injecting an inert gas into the upper portion of the water cooling tube, and the quartz crucible is rotated when cooling of the remaining melt proceeds. The method of claim 10, The silicon single crystal ingot is silicon single crystal manufacturing method characterized in that to move up to 100mm to 300mm above the water cooling tube. The method of claim 10, Rotational speed of the quartz crucible is a silicon single crystal manufacturing method, characterized in that 30rpm to 40rpm. 10. The method of claim 9, Shielding the external release of heat emitted from the ingot using a heat shield means when the silicon single crystal ingot is grown and forming a melt gap with the silicon melt surface for temperature gradient control of the solid-liquid interface, When the growth of the silicon single crystal ingot is completed, the method of manufacturing a silicon single crystal, characterized in that the position of the heat shield means is located at a maximum distance from the upper surface of the residual melt before proceeding to the cooling process of the residual melt.

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