KR100827033B1 - Method of manufacturing defect-free single crystal and single crystal manufactured by using the same - Google Patents

Abstract

A method of manufacturing a defect-free single crystal and the single crystal are provided to increase a process margin in a rise speed of the single crystal by growing the single crystal at a changed rise speed by changing a temperature gradation on a solid-liquid interface. A silicon single crystal ingot(IG) is grown in a chamber(10). Silicon melting solution(SM) is filled in the chamber. A crucible(20) is implemented in the chamber. An outer periphery of the crucible is supported by a crucible supporter(25), which is made of graphite. The crucible supporter is fixed on a rotation axis(30). The rotation axis is rotated by a driver, such that the crucible is elevated while rotating and a solid-liquid interface is maintained at a constant height. A cylindrical heater(40) surrounds the crucible supporter with a predetermined distance between them. The heater is surrounded by a heat insulation container(45).

Description

Method of manufacturing defect-free single crystal and single crystal manufactured by using the same

The following drawings attached to this specification are illustrative of preferred embodiments of the present invention, and together with the detailed description of the invention to serve to further understand the technical spirit of the present invention, the present invention is a matter described in such drawings It should not be construed as limited to.

1 is a graph showing the concentration of point defects during growth of single crystal by Czochralski method as a function of V / G (V is the crystal pulling rate, G is the temperature gradient of the solid-liquid interface).

2 is a block diagram of a single crystal pulling apparatus according to a preferred embodiment of the present invention.

FIG. 3 is a graph showing the defect crystal pulling speed as a function of rotation factor SR / CR (SR: single crystal rotation speed, CR: crucible rotation speed) according to a preferred embodiment of the present invention.

FIG. 4 is a graph showing the defect crystal pulling rate as a function of flow rate and pressure factor g _flow / P (g _flow is _flow rate of inert gas, P is pressure of single crystal growth chamber) according to a preferred embodiment of the present invention.

<Main reference number in drawing>

10: chamber 20: crucible

30: rotating shaft 40: heater

45: thermos 50: heat shield

60: heat shield SM: silicon melt

IG: monocrystalline ingot

The present invention relates to a method for producing a single crystal, and more particularly, to a method for producing a high quality defect free single crystal using the Czochralski method.

Examples of the single crystal used for the substrate of the semiconductor device include silicon single crystal and the like, and are mainly manufactured by the Czochralski method. When the silicon single crystal is grown by the Czochralski method, when the crystal pulling rate V is relatively high, it is a gland such as FPD (Flow Pattern Defect) or COP (Crystal Originated Particle) due to the void-based defects of the public type. A defect of-is present at a high density. For reference, the region in which such void cause defects exist is called a V (Vacancy) region. In addition, if the crystal pulling speed is lower than the speed causing the defect due to the void, the OSF (Oxidation Induced Stacking Fault) region occurs in a ring shape around the crystal with the decrease of the pulling speed. When lowered, the OSF ring contracts and disappears to the center of the single crystal. When the crystal pulling rate is further lowered, LSEPD (Large Secco Etch Pit Defect), LFPD (Large Flow Pattern Defect), etc., which are defects due to dislocation loops in which inter-grating silicon is collected, are present at low density. For reference, the region in which the defect due to the dislocation loop is present is called an I (Interstitial) region.

Outside the OSF ring between the V region and the I region, a defect-free region exists without defects such as FPD or COP due to voids or defects such as LSEPD and LFPD due to dislocation loops. This area is called P (Pure) area. This P region is classified into a Pv region (a region with many voids) adjacent to the outer side of the OSF ring and a Pi region (region with a large amount of silicon between lattice) adjacent to the I region. In the Pv region, the amount of oxygen precipitation is large when the thermal oxidation treatment is performed, and in the Pi region there is little amount of oxygen precipitation.

The above-described gross-in defect is called V / G (mm ² / ° C.), which is a ratio of the crystal pulling rate V (mm / min) when growing a single crystal and the temperature gradient G (° C./mm) near the solid-liquid interface. It is known that the introduction amount is determined by a parameter (see, for example, VVVoronkov, Journal of Crystal Growth, 59 (1982), 625 to 643). That is, when single crystal growth is carried out while controlling V / G to a predetermined value constantly, it is possible to produce a single crystal having a desired defect region or a desired defect region.

1 is a graph illustrating defect concentrations flowing into a single crystal according to V / G. In the figure, the abscissa is V / G, and the ordinate is the concentration of void type defects (V) or inter-lattice defects (I). Referring to the drawings, when V / G becomes larger than V / G _crit , the concentration of the open type defects in the single crystal to be increased increases, and when the concentration of the open type defects exceeds the critical concentration C _v ^* , the open type defects are caused by the void. Aggregates with gron-in defects to form the V region. On the other hand, if the concentration of the open type defects is less than the critical concentration of C _v ^* , the open type defects are present in an unaggregated state to form a Pv region without the gron-in point defects. On the other hand, although not explicitly shown in the figure, the OSF region is present when the single crystal is grown under V / G conditions corresponding to the void type defect concentration slightly lower than C _v ^* .

Contrary to the above, when V / G is smaller than V / G _crit , the concentration of inter-grating defects increases in the single crystal to be pulled up, and when the concentration of inter-lattice defects becomes more than C _I ^* , the inter-lattice defects aggregate to cause a potential loop. A gron-in defect occurs. On the other hand, if the concentration of inter-lattice defects is less than the critical concentration, C _I ^* , the inter-lattice defects are present in an unaggregated state to form a Pi region having no gron-in defects.

Therefore, growing single crystals under conditions where V / G is greater than V / G corresponding to the critical concentration C _I ^* and less than V / G corresponding to the critical concentration C _v ^{* results} in high quality defect-free single crystal growth without gron-in defects. It becomes possible. Here, the range of V / G that can raise the defect-free single crystal will be referred to as 'defective margin'. As an example, Japanese Patent Laid-Open No. 11-147786 discloses that when a silicon single crystal is grown, a defect due to voids and a defect in potential loops exist when the V / G value is controlled to 0.112 to 0.142 mm ² / ° C. at the crystal center. It can be used to grow silicon single crystals that do not.

The temperature gradient G near the solid-liquid interface at V / G, which determines the type and concentration of point defects introduced into the single crystal during the single crystal pulling, is mainly a structure for transferring and controlling radiant heat including a heater Radiation radiation transfer mechanism and other residual melt amount. However, changing the hot zone during single crystal pulling is not preferable because it hinders process stability. Therefore, it is common to manufacture high quality single crystals without gron-in defects by controlling the crystal pulling rate V rather than the temperature gradient G near the solid-liquid interface to control the V / G value to be within the flawless margin. G slightly increases or decreases with the convection and temperature distribution of the melt.

In the case of the silicon single crystal, the flawless margin width of the crystal pulling rate V should be normally 0.01 mm / min or more, and preferably 0.02 mm / min or more, assuming that there is no change in the temperature gradient G near the solid-liquid interface. Known. For reference, the width of the defect margin of the crystal pulling rate V may vary slightly depending on the diameter of the single crystal. Therefore, by using the high precision control system to adjust the crystal pulling rate V well within the above flawless margin width, high quality single crystal can be grown. Here, the high precision control system refers to an apparatus for precisely controlling the temperature of the melt or directly controlling the power of the heater so that the silicon single crystal ingot can be grown at a predetermined target pulling rate. However, even with the use of a high precision control system, the crystal pulling rate V is actually intact and often exceeds the margin range.

Specifically, in order to grow a defect-free single crystal, the temperature gradient of the solid-liquid interface and the heat distribution profile of the heater for each length of the single crystal ingot must be precisely controlled to enable high quality defect-free single crystal growth without changing the diameter of the single crystal ingot. However, convection and temperature distribution of semiconductor melt have nonlinear characteristics, so precise control of subcooling for solidification near solid interface is difficult. Therefore, the degree of subcooling for solidification near the solid-liquid interface often increases or decreases beyond the control target value by various temperature settings or process variables. In this case, a diameter change of the single crystal is caused. Conventionally, the diameter of the single crystal ingot is constantly adjusted to the control target value by appropriately changing the single crystal pulling speed by an ADC (Auto Diameter Control) based on PID control in response to the diameter change of the single crystal. I'm using a method of keeping it. That is, when the diameter of the single crystal ingot increases than the control target value, the growth rate of the single crystal increases, and when the diameter of the single crystal ingot decreases than the control target value, the growth rate of the single crystal is decreased (see Korean Patent Publication No. 2003-20474). However, as described above, since the flawless margin width of the single crystal pulling speed V is quite small, the single crystal pulling speed V is out of the flawless margin width in the process of changing the single crystal pulling speed for controlling the diameter of the single crystal ingot so that it can be grown on the single crystal. Problems that cause phosphorus defects may occur.

Therefore, in the technical field to which the present invention belongs, in the process of controlling the single crystal pulling rate V according to the diameter change of the single crystal, which is inevitably involved in single crystal growth, and furthermore, even if the single crystal pulling speed changes according to the change of process conditions, V / G There is an urgent need for measures to prevent marginal margins.

The present invention was devised to solve the above-described problems of the prior art, and the process of controlling the single crystal pulling rate according to the change of the diameter of the single crystal by expanding the process margin of the defect-free crystal pulling rate, which enables defect-free single crystal growth during semiconductor single crystal growth. Furthermore, it is an object of the present invention to provide a high quality defect-free single crystal manufacturing method which prevents the V / G from leaving the range of defect free margin even if the single crystal pulling rate is changed according to the process conditions of single crystal growth.

Another object of the present invention is to realize substantial defect free margin without large structural changes of the single crystal pulling apparatus by indirectly controlling other process factors affecting the temperature gradient G of the solid-liquid interface without directly changing the hot zone during single crystal growth. To provide a high quality defect-free single crystal manufacturing method that can increase the width of the process to increase the defect processing margin for the crystal pulling rate.

Another object of the present invention is to provide a high quality defect-free single crystal manufactured in a state where the defect free process margin of single crystal pulling rate is increased.

In order to achieve the above technical problem, the defect-free single crystal manufacturing method according to the present invention, in the single crystal manufacturing method of growing a single crystal ingot by gradually pulling the single crystal seed to the semiconductor melt contained in the crucible and then gradually raised to the top, If the ratio V / G, which is the ratio of the pulling speed V and the temperature gradient G of the solid-liquid interface, is set within a flawless margin, and the single-crystal pulling rate is changed, the temperature gradient G of the solid-liquid interface is in the same direction as the change direction of the single-crystal pulling rate V. It is characterized by maintaining the V / G within the defect margin by controlling the process factors causing the change.

Preferably, the V / G before and after the change of the crystal pulling rate V is kept the same within the defect free margin.

According to one aspect of the invention, the process factor is the ratio (SR / CR) of single crystal rotation speed (SR) and crucible rotation speed (CR).

In this case, for example, if the crystal pulling speed is increased during the growth of the defect at the defect free crystal pulling rate lower than the maximum defect pulling rate, the SR / CR may be increased to increase the temperature gradient G of the liquid-liquid interface. have.

As another example, if the crystal pulling speed is increased during the growth of the defect at the defect free pulling rate lower than the maximum defect pulling rate, SR / CR may be reduced to increase the temperature gradient G of the liquid-liquid interface.

As another example, if the crystal pulling rate decreases during the growth of the defect at the defect free pulling rate lower than the maximum defect pulling rate, SR / CR may be reduced to reduce the temperature gradient G at the liquid-liquid interface.

As another example, if the crystal pulling rate decreases during the growth of the defect at the defect free pulling rate lower than the maximum defect pulling rate, the SR / CR may be increased to reduce the temperature gradient G at the liquid-liquid interface. .

According to another aspect of the invention, the process factor is the ratio (g _flow / P) of the _flow rate (g _flow ) of the inert gas supplied to the top of the melt along the outer circumferential surface of the single crystal ingot and the pressure (P) of the single crystal growth chamber. . In this case, if the crystal pulling rate is increased during the defect-free single crystal growth at a predetermined defect crystal pulling rate, g _flow / P may be increased to increase the temperature gradient G of the solid-liquid interface. In addition, when the crystal pulling rate is decreased during the growth of the defect-free single crystal at a predetermined defect crystal pulling rate, g _flow / P may be reduced to reduce the temperature gradient G of the solid-liquid interface.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the present specification and claims should not be construed as being limited to the common or dictionary meanings, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of the present invention, various equivalents that may be substituted for them at the time of the present application It should be understood that there may be water and variations.

Meanwhile, although the preferred embodiment of the present invention shows a case where single crystal silicon is grown by the Czochralski method as an example, the technical idea of the present invention is not limited by the type of material constituting the single crystal. It is self-evident to those of ordinary knowledge in Esau.

Fig. 2 is an apparatus block diagram showing the configuration of a single crystal pulling apparatus by the Czochralski method used in the method for producing a single crystal according to a preferred embodiment of the present invention.

As shown in FIG. 2, the single crystal pulling apparatus according to the present invention includes a chamber 10 in which a silicon single crystal ingot IG is grown. The quartz crucible 20 enclosed by the crucible support 25 made of graphite contains a silicon melt SM in the chamber 10. At this time, the crucible support 25 is fixedly installed on the rotary shaft 30, the rotary shaft 30 is rotated by a driving means (not shown) to raise while rotating the quartz crucible 20, the solid-liquid interface is Keep the same height. The crucible support 25 is surrounded by a cylindrical heater 40 at predetermined intervals, and the heater 40 is surrounded by a thermos 45.

That is, the heater 40 is installed on the side of the crucible 25 to melt a high-purity polysilicon mass loaded in the quartz crucible 20 to form a silicon melt SM, and the thermostat 45 is formed by the heater 40. Heat dissipation is prevented from spreading toward the wall of the chamber 10 to improve thermal efficiency.

In addition, a heat shield 50 is disposed between the silicon single crystal ingot IG and the crucible 20 to block the heat radiated from the ingot. In this case, the heat shield 50 may be attached to the closest portion with the ingot IG to install a cylindrical heat shield 60 to further block heat flow to conserve heat.

In addition, an upper portion of the chamber 10 is provided with an pulling means (not shown) for winding up and pulling the cable, and the lower portion of the cable is brought into contact with the silicon melt SM in the quartz crucible 20 and pulled up to form a single crystal. A seed crystal for growing the ingot IG is provided. The pulling means rotates while pulling up the cable during the growth of the single crystal ingot IG, wherein the silicon single crystal ingot IG is rotated about the same axis as the rotation axis 30 of the crucible 20. Rotate in the opposite direction to lift it up.

In the upper portion of the chamber 10, an inert gas such as argon (Ar), neon (Ne), and nitrogen (N) is supplied to the grown single crystal ingot (IG) and the silicon melt (SM). Discharge through the bottom of the chamber (10).

In the present invention, when growing a silicon single crystal using the single crystal pulling apparatus having the above-described configuration, V / G is set within a range of a defect free margin. When the pulling rate V is changed by the change of process conditions or ADC (Auto Diameter Control), V / G is maintained within the margin of integrity by controlling the process factor so that G is changed in the same direction as the change direction of V. To help.

Where V is the crystal pulling rate and G is the temperature gradient at the solid-liquid interface. As described with reference to FIG. 1, the defect margin refers to a section of V / G (see the shaded portion) in which public type defects or inter-lattice defects introduced during the single crystal growth process are not aggregated and may exist only in the form of defects. it means. In addition, the fact that G changes in the same direction as the change direction of V means that G increases as V increases, and G decreases when V decreases.

According to the present invention, growth of the defect-free single crystals is possible even under the changed V conditions, and the G process changes with the change of V so that V / G can be maintained within the defect-free margin range. This has the effect of being enlarged.

According to the present invention, the ratio (SR / CR) of the single crystal rotation speed (SR) and the crucible rotation speed (CR) or the single crystal ingot without changing the structure of the hot zone to change G according to the change of the crystal pulling speed V is shown. The ratio (g _flow / P) between the _flow rate g of the inert gas supplied to the upper portion of the silicon melt SM and the pressure P of the chamber is controlled along the outer circumferential surface of the IG. However, the present invention is not limited thereto. For example, a change in the melt gap, which is the distance between the heat shield and the melt surface, may be used.

3 is a graph showing the relationship between the ratio [SR / CR] of the single crystal rotation speed SR and the crucible rotation speed CR and the defect free crystal pulling speed V ^* according to the preferred embodiment of the present invention, and FIG. According to a preferred embodiment of the invention is a graph showing the relationship between the ratio (g _flow / P) between the _flow rate (g _flow ) of the inert gas and the pressure (P) of the chamber and the defect-free single crystal pulling rate V ^* .

In Figures 3 and 4, each point on each graph line represents the crystal pulling rate at which defectless single crystals can be pulled up given the X-axis process factor. In addition, the rectangular box A represents a preferable range of single crystal pulling rate in a given single crystal growing atmosphere. At crystal pulling speeds outside the rectangular box range, the productivity of single crystal production is reduced, or process abnormalities occur, thereby making it difficult to produce a practically flawless single crystal.

First, referring to FIG. 3, a method for manufacturing a defect-free single crystal according to the present invention by controlling the rotation factor will be described. A single crystal with a defect free pulling speed of V ₁ ^* at a rotational speed ratio (SR / CR) ₁ of a single crystal and a crucible is described. It is assumed that the crystal pulling rate is increased to V ₂ ^* by the ADC according to the change of the process conditions or the diameter of the single crystal ingot during the pulling up (first embodiment). At this time, when only the crystal pulling speed is increased to V ₂ ^* without changing G, if the rising degree is large, V / G may be out of margin. However, in the present invention, even if the crystal pulling speed increases, the crystal pulling speed is changed by increasing the rotation factor SR / CR, which is one of the process factors causing the rise of G, from (SR / CR) ₁ to (SR / CR) ₂ . Ensure that the previous (V / G) ₁ and the (V / G) ₂ after the crystal pulling rate are changed remain substantially the same. This allows the growth of flawless single crystal ingots even at the changed crystal pulling rate V ₂ ^* . Here, there are several ways to increase SR / CR from (SR / CR) ₁ to (SR / CR) ₂ , for example, to keep the crucible rotational speed the same and to increase the speed of single crystal or to rotate the single crystal. There is a method of keeping the speed the same and reducing the rotation speed of the crucible. However, the present invention is not limited thereto. By controlling the rotation factor as described above, it is possible to raise the defect-free single crystal even at the changed crystal pulling speed V ₂ ^* , and by controlling the process factor causing the change of G according to the change of the crystal pulling speed V, Flawless process margins increase. In other words, if there is no change in G, it is possible to raise the defect-free single crystal even at the rate of crystal raising, which was difficult for growth of the defect-free single crystal.

As another example, the crystal pulling rate is increased by the ADC according to the change of process conditions or the diameter of the single crystal ingot while the single crystal is being pulled up at a rotational ratio ratio (SR / CR) ₃ of single crystal and crucible at V ₁ ^* . Assume that is raised to V ₂ ^* (second embodiment). In this case, the present invention increases the crystal pulling speed by reducing the rotation factor SR / CR, which is one of the process factors causing the increase of G even if the crystal pulling speed increases, from (SR / CR) ₃ to (SR / CR) ₄ . Ensure that (V / G) ₁ before the change and (V / G) ₂ after the crystal pulling rate are changed remain the same. This allows the growth of flawless single crystal ingots even at the changed crystal pulling rate V ₂ ^* . Here, there are several ways to reduce SR / CR from (SR / CR) ₃ to (SR / CR) ₄ , for example, to keep the crucible's rotational speed the same and reduce the rotational speed of the single crystal, or There is a method of increasing the rotation speed of the crucible while maintaining the rotation speed of the same. However, the present invention is not limited thereto. In addition, the process factor causing the change of G is controlled according to the change of the crystal pulling speed V, thereby increasing the defect-free process margin of the crystal pulling speed V. In other words, if there is no change in G, it is possible to raise the defect-free single crystal even at the rate of crystal raising, which was difficult for growth of the defect-free single crystal.

As another example, a single crystal is being pulled up at a rotational speed ratio (SR / CR) ₂ between single crystal and crucible at V ₂ ^* while the single crystal is being pulled up by the ADC according to the change of process conditions or the diameter of the single crystal ingot. Assume that the speed has dropped to V ₁ ^* (third embodiment). In this case, the crystal pulling speed is changed by reducing the rotation factor SR / CR, which is one of the process factors that cause the drop of G, from (SR / CR) ₂ to (SR / CR) ₁ in response to the lowering of the pulling rate. Ensure that (V / G) ₂ before the change and (V / G) ₁ after the crystal pulling rate are changed remain substantially the same. This allows the growth of flawless single crystal ingots even at the changed crystal pulling rate V ₁ ^* . In this case, in order to reduce the SR / CR from (SR / CR) ₂ to (SR / CR) ₁ , a method opposite to that of the first embodiment may be used. By controlling the rotation factor as described above, it is possible to pull up the defect-free single crystal even at the changed crystal pulling speed V ₁ ^* . In addition, since the process factors causing the change of G are controlled together with the change of the crystal pulling speed V, the defect free process margin of the crystal pulling speed V is increased. In other words, if there is no change in G, it is possible to raise the defect-free single crystal even at the rate of crystal raising, which was difficult for growth of the defect-free single crystal.

As another example, the crystal pulling rate is increased by the ADC according to the change of the process conditions or the diameter of the single crystal ingot while the single crystal is being pulled up at the rotational speed ratio SR / CR ₄ of single crystal and crucible at V ₂ ^* . Assume that it is lowered to V ₁ ^* (fourth embodiment). In this case, the crystal pulling speed is changed by increasing the rotation factor SR / CR from (SR / CR) ₄ to (SR / CR) ₃ , which is one of the process factors causing the drop of G in response to the lowering of the pulling rate. Ensure that (V / G) ₂ before the change and (V / G) ₁ after the crystal pulling rate are changed remain substantially the same. This allows the growth of flawless single crystal ingots even at the changed crystal pulling rate V ₁ ^* . In this case, in order to increase the SR / CR from (SR / CR) ₄ to (SR / CR) ₃ , a method opposite to the second embodiment may be used. In addition, since the process factors causing the change of G are controlled together with the change of the crystal pulling speed V, the defect free process margin of the crystal pulling speed V is increased. In other words, if there is no change in G, it is possible to raise the defect-free single crystal even at the rate of crystal raising, which was difficult for growth of the defect-free single crystal.

Next, referring to FIG. 4, the method for preparing a defect-free single crystal according to the present invention by controlling the flow rate and the pressure factor will be described. The ratio between the flow rate of the inert gas and the chamber pressure (g _flow / P) ₁ at V ₁ ^* It is assumed that the crystal pulling rate is increased to V ₂ ^* by the ADC in accordance with the change of the process conditions or the diameter of the single crystal ingot while the single crystal is being pulled up at the defect free pulling speed of the fifth crystal (Example 5). At this time, when only the crystal pulling speed is increased to V ₂ ^* without changing G, if the rising degree is large, V / G may be out of margin. However, in the present invention, the ratio of the flow rate of the inert gas and the chamber pressure, g _flow / P, which is one of the process factors causing the increase of G even if the crystal pulling rate is increased, is _changed from (Ar _flow / P) ₁ to (g _flow / P) ₂ In this case, the (V / G) ₁ before the crystal pulling speed is changed and the (V / G) ₂ after the crystal pulling speed are changed are kept substantially the same. This allows the growth of flawless single crystal ingots even at the changed crystal pulling rate V ₂ ^* . There are several ways to increase g _flow / P from (g _flow / P) ₁ to (g _flow / P) ₂ , for example by keeping the pressure in the chamber the same and increasing the flow rate of the inert gas, There is a method of maintaining the flow rate of the inert gas in the same manner and reducing the pressure in the chamber. However, the present invention is not limited thereto. By controlling the flow rate and the chamber pressure factor of the inert gas as described above, it is possible to raise the defect-free single crystal even at the changed crystal pulling rate V ₂ ^* , and by controlling the process factor causing the change of G according to the change of the crystal pulling rate V. The defect-free process margin of crystal pulling rate V increases. In other words, if there is no change in G, it is possible to raise the defect-free single crystal even at the rate of crystal raising, which was difficult for growth of the defect-free single crystal.

In another example, a single crystal was being pulled up at a ratio (g _flow / P) ₁ of the inert gas flow rate to a V ₁ ^* flawless pulling rate, and the ADC was changed according to process conditions or diameter change of the single crystal ingot. It is assumed that the crystal pulling speed is reduced to V ₃ ^* by the sixth embodiment. At this time, when only the pulling rate is reduced to V ₃ ^* without changing G, if the decrease is large, V / G may be out of margin. However, in the present invention, the ratio of the flow rate of the inert gas and the chamber pressure, g _flow / P, which is one of the process factors causing the decrease of G even if the crystal pulling rate decreases, is reduced from (g _flow / P) ₁ to (g _flow / P) ₃ By reducing it to (V / G) ₁ before the crystal pulling speed is changed and (V / G) ₃ after the crystal pulling speed is changed to be substantially the same. This allows the growth of flawless single crystal ingots even at the changed crystal pulling rate V ₃ ^* . Herein, in order to reduce g _flow / P from (g _flow / P) ₁ to (g _flow / P) ₃ , a method opposite to the fifth embodiment may be used. As described above, by controlling the flow rate and the chamber pressure factor of the inert gas, it is possible to raise the defect-free single crystal even at the changed crystal pulling rate V ₃ ^* , and by controlling the process factor causing the change of G according to the change of the crystal pulling rate V. The defect-free process margin of crystal pulling rate V increases. In other words, if there is no change in G, it is possible to raise the defect-free single crystal even at the rate of crystal raising, which was difficult for growth of the defect-free single crystal.

On the other hand, the above-described embodiment controls the process factor causing the change of G according to the change of the crystal pulling speed V to maintain the V / G before and after the crystal pulling speed is changed to maintain the defect free process margin of the crystal pulling speed. Extended. However, the V / G after the change of the crystal pulling speed is not the same as before and after the change of the crystal pulling speed. The V / G after the change of the crystal pulling speed is intact. It is apparent to those skilled in the art to which the present invention pertains.

In the above embodiment, the specific numerical range of the defect margin and the range of the desirable defect crystal pulling rate, etc. are determined according to the type of single crystal grown and the quality of the product required by the customer, and the process factors according to the variation of the crystal pulling rate. It is obvious that the specific variation of can be calculated through an iterative test run.

In addition, the essence of the present invention is the hot zone structure so that the temperature gradient of the solid-liquid interface fluctuates in the same direction according to the variation of the crystal pulling speed as shown in FIGS. It is apparent to those skilled in the art to control the process factors that do not cause a change in the defect growth rate of the crystal growth rate to increase the process margin.

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 the claims to be described.

 According to the present invention, in the production of single crystal by the Czochralski method, in response to the change of crystal pulling rate V, by controlling a process factor that causes a change in temperature gradient G of the solid-liquid interface, the pulling of the defect-free single crystal is reduced even at the changed crystal pulling rate. There is an advantage to enable this and to extend the process margin of defect-free single crystal pulling rates. In addition, when the process margin of the crystal pulling rate is extended, it is possible to further increase the crystal pulling speed while maintaining the V / G within the defect margin range, thereby increasing the monocrystal manufacturing speed, thereby contributing to productivity improvement. In addition, since the structure of the hot zone does not need to be changed, the effect of reducing the cost of single crystal production can be described.

Claims (11)

In the single crystal manufacturing method of growing a single crystal ingot by contacting the single crystal seed in the crucible of the semiconductor melt and gradually pulled upward When pulling up the single crystal, V / G, which is the ratio of the single crystal pulling speed V and the temperature gradient G of the solid-liquid interface, is set within the defect margin When the single crystal pulling speed is changed, a process factor that causes a change in the temperature gradient G of the solid-liquid interface in the same direction as the change direction of the single crystal pulling speed V is controlled to maintain V / G within a flawless margin. Defect single crystal manufacturing method. The method of claim 1, A method for producing a defect-free single crystal, characterized in that the V / G before and after the change of the crystal pulling rate V is kept the same within the defect margin. The method of claim 1, The process factor is a ratio (SR / CR) of single crystal rotation speed (SR) and crucible rotation speed (CR). The method of claim 3, If the crystal pulling speed is increased during the growth of the defect at the zero crystal pulling rate lower than the maximum defect pulling rate, the SR is increased to increase the temperature gradient G of the solid interface. Single crystal production method. The method of claim 3, If the crystal pulling speed is increased during the growth of the defect at the zero crystal pulling rate lower than the maximum crystal pulling rate, the SR / CR is decreased to increase the temperature gradient G of the liquid interface. Single crystal production method. The method of claim 3, If the crystal pulling speed decreases during the growth process, the SR / CR is reduced to reduce the temperature gradient G of the solid-state interface. Single crystal production method. The method of claim 3, If the crystal pulling speed decreases during the growth process, the SR / CR is increased to reduce the temperature gradient G at the liquid-liquid interface. Single crystal production method. The method of claim 1, The process factor is a defect-free single crystal, characterized in that the ratio (g _flow / P) of the _flow rate (g _flow ) of the inert gas supplied to the upper portion of the melt along the outer peripheral surface of the single crystal ingot (P) of the single crystal growth chamber. Manufacturing method. The method of claim 8, A method for producing a defect-free single crystal, characterized in that if the crystal pulling speed increases during the progress of defect-free single crystal growth at a predetermined defect crystal pulling speed, the temperature gradient G of the solid-liquid interface is increased by increasing g _flow / P. The method of claim 8, A method for producing a defect-free single crystal, characterized in that, if the crystal pulling rate decreases during the progress of defect-free single crystal growth at a predetermined defect crystal pulling rate, g _flow / P is reduced. A single crystal produced by the method according to any one of claims 1 to 10.

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