KR100830047B1 - Semiconductor single crystal production method, apparatus and semiconductor single crystal ingot capable of controlling oxygen concentration by convection distribution control - Google Patents

Abstract

The present invention discloses a method for producing a semiconductor single crystal, an apparatus and a semiconductor single crystal ingot capable of controlling oxygen concentration by convection distribution control. The semiconductor single crystal manufacturing method according to the present invention controls the oxygen concentration flowing into the single crystal by changing the relative position of the ZGP (Zero Gauss Plane) based on the semiconductor melt by using an asymmetric magnetic field during the single crystal growth by the Czochralski method. Alternatively, the present invention uses a horizontal type magnetic field to control the oxygen concentration flowing into the single crystal by changing the relative position of the Gauss Maximum Plane (GMP) relative to the semiconductor melt.

According to the present invention, it is possible to diversify the single crystal product because no measures such as changing the hot zones or changing the process parameters are possible, to produce wafers having various oxygen concentration conditions from one single crystal, and to control the oxygen concentration. Even in possible process conditions, it is possible to manufacture high quality single crystals without crystal defects due to voids or dislocation loops, thereby maximizing prime yield.

Description

Method for manufacturing semiconductor single crystal capable of controlling oxygen concentration based on convection distribution control, Apparatus using the same and Semiconductor single crystal ingot}

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 block diagram of a semiconductor single crystal manufacturing apparatus according to a first embodiment of the present invention.

2 is a block diagram of a semiconductor single crystal manufacturing apparatus according to a second embodiment of the present invention.

3A is a layout view of a coil included in a magnetic field applying unit for applying a magnetic field of a horizontal type.

3B is another layout view of the coil included in the magnetic field applying unit for applying the magnetic field of the horizontal type.

4 is a diagram showing a simulation of the convective distribution of the silicon melt when a Cusp type asymmetric magnetic field is applied when the 8-inch silicon single crystal is manufactured by the Czochralski method.

FIG. 5 is a view showing a simulation of convective distribution of a silicon melt when a horizontal magnetic field is applied in the production of a 12 inch silicon single crystal by the Czochralski method.

6 shows the position of the ZGP when R values of the asymmetric magnetic fields are 2.3 (Example 1) and 1.36 (Example 2) when growing a 8-inch silicon single crystal by applying a cusp-type asymmetric magnetic field according to the present invention. It is a figure which shows the convection distribution of a silicon melt together.

7 is a graph showing an oxygen concentration profile along the length direction of the silicon single crystal ingot prepared according to Example 1 and Example 2, respectively.

8 shows GMP of 210 mm (Example 3), 135 mm (Example 4) and 35 mm (Example 5) from the surface of the silicon melt when growing a 12 inch silicon single crystal by applying a horizontal type magnetic field according to the present invention. It is a figure which shows the case where it is located below, respectively.

9 is a graph showing an oxygen concentration profile along the length direction of each of the silicon single crystal ingots prepared according to Examples 3 to 5. FIG.

<Main reference number in drawing>

10: quartz crucible 20: crucible support

30: crucible rotating means 40: heating means

50: insulation means M1, M2: coil

G _upper : Upper magnetic field G _lower : Lower magnetic field

100: auxiliary magnet C: silicon single crystal

SM: Silicone Melt ZGP: Zero Gauss Plane

GMP: Gauss Maximum Plane A, B: Convection Cells

E: convection cell interface X: single crystal axis of rotation

The present invention relates to a method for producing a single crystal by the Czochralski method, more specifically, to a level of quality requirements such as Oi / ORG uniform in the radial direction according to the reduction of the design rule according to Moore's Law. It relates to a high quality single crystal production method capable of controlling the oxygen concentration to be satisfied.

At present, in the production of silicon single crystal using the Czochralski method, a quartz crucible has been essentially used to contain the melted silicon melt by a heater. However, the quartz crucible dissolves in the melt together with the reaction with the silicon melt to be transferred to SiOx form and eventually is incorporated into the single crystal through the solid-liquid interface. SiOx incorporated into a single crystal acts as a gettering site for metal impurities during semiconductor processing by enhancing wafer strength and forming micro internal defects (BMD), and on the other hand, by causing various crystal defects and segregation. Eventually, it becomes a factor that adversely affects the yield of semiconductor devices. Therefore, when growing silicon single crystal using Czochralski method, it is necessary to appropriately control the oxygen concentration flowing into the crystal through the solid-liquid interface.

Conventionally, the method of changing the design of the hot zone (H / Z) in the crystal growth apparatus has been mainly used to control the oxygen concentration in the single crystal. For example, the melting speed of the quartz crucible is controlled by adjusting the length of the heater, the power or the relative position of the heater and the quartz crucible, or by changing the structure of the heat shield installed around the outer circumferential surface of the single crystal to adjust the distribution of radiant heat supplied to the silicon melt. The method was used. As another example, by controlling the ratio of the single crystal rotation speed and the quartz crucible rotation speed to control the movement path of SiOx by convection or the flow rate of argon gas supplied to the upper part of the silicon melt along the outer circumferential surface of the silicon crystal on the surface of the silicon melt A method of controlling the oxygen concentration in the single crystal by controlling the parameters of the single crystal growth process such as effectively discharging the evaporated SiOx gas has been used.

However, the method of controlling the oxygen concentration of the single crystal by changing the design of the hot zone is not only a hassle to design the hot zone individually according to the various oxygen concentration quality levels of the wafer required by the customer, but also to replace the hot zone. Therefore, there is a problem that it takes a lot of time and the test operation cost of the single crystal growth apparatus is increased due to the replacement of the hot zone, and nevertheless, since the prime length of the single crystal that can be commercialized is short, there are not many wafers that can be produced per single crystal ingot. There is this. In addition, the method of controlling the oxygen concentration of the single crystal by controlling the process parameters has some effect on the control of the oxygen concentration of the single crystal, but there is no growth defect in the grown-in crystal due to the void or dislocation loop. Crystal growth conditions for producing high quality single crystals have limitations that adversely affect them.

The present invention was devised to solve the above-mentioned problems of the prior art, and includes a heater and an insulating structure inside a single crystal manufacturing apparatus in the control of oxygen concentration, which is one of the main quality items during single crystal growth by the Czochralski method. A method and apparatus for manufacturing a semiconductor single crystal capable of controlling a desired level of oxygen concentration by controlling the convection form of a melt contained in a quartz crucible without changing the structure of a hot zone made of components or changing process parameters. Its purpose is to provide a semiconductor single crystal ingot.

In the semiconductor single crystal manufacturing method according to an aspect of the present invention for achieving the above technical problem, the seed crystal is immersed in the semiconductor melt contained in the quartz crucible, and the seed crystal is slowly rotated upward while rotating the seed crystal to grow the semiconductor single crystal through the solid-liquid interface. In the method for manufacturing a semiconductor single crystal by using the Czochralski method, a crucible of an asymmetric magnetic field of Cusp type having different magnetic field strengths at the top and the bottom is based on ZGP (Zero Gauss Plane) where the vertical component of the magnetic field is 0. While applied, it is characterized by controlling the concentration of oxygen introduced into the single crystal by adjusting the relative position of the ZGP and the melt.

According to one aspect of the present invention, there is provided a semiconductor single crystal manufacturing apparatus comprising: a quartz crucible containing a semiconductor melt; A crucible support coupled to the outer circumferential surface of the crucible to support the shape of the crucible in a high temperature environment; Heating means installed to surround sidewalls of the crucible zone to provide radiant heat to the semiconductor melt contained in the crucible; It is provided that the heating means, the crucible holder and the quartz crucible is accommodated, and is installed around the heating means so that the inner side wall of the hollow and the outer circumferential surface of the heating means face each other and the radiant heat emitted from the heating means is lost to the outside. Thermal insulation means for preventing; Magnetic field applying means installed around the quartz crucible to apply a Cusp-type asymmetric magnetic field having different magnetic field strengths at the top and the bottom of the ZGP having a vertical component of zero to the quartz crucible; Single crystal ingot pulling means for pulling the seed crystals upward while contacting the seed crystals on the surface of the semiconductor melt contained in the quartz crucible; And crucible rotating means for gradually elevating the crucible support so that the position of the solid-liquid interface is maintained at a constant level while rotating the crucible support in a constant direction, and the relative position of the quartz crucible and the magnetic field applying means and asymmetry of the asymmetric magnetic field. By controlling the degree or a combination thereof, the position of ZGP based on the semiconductor melt is changed to control the oxygen concentration flowing into the single crystal.

According to the present invention, increasing the position of the ZGP based on the semiconductor melt reduces the oxygen concentration flowing into the single crystal, and decreasing the position of the ZGP based on the semiconductor melt increases the oxygen concentration flowing into the single crystal.

Preferably, the magnetic field applying means includes an upper coil and a lower coil spaced apart from the outer circumferential surface of the thermal insulation means by a predetermined distance. In this case, an asymmetric magnetic field is formed by adjusting the number of windings of the upper coil and the lower coil, the magnitude of the applied current, the area of the coil, or a combination thereof.

Optionally, at least one intermediate coil may be further interposed between the upper coil and the lower coil. In this case, after combining two or more coils in the coil assembly in which the upper coil, the lower coil and the intermediate coil are assembled, an asymmetric magnetic field is adjusted by adjusting the number of turns of each coil, the magnitude of the applied current, the area of the coil, or a combination thereof. To form.

Optionally, it may further include an auxiliary magnet installed below or above the quartz crucible. Auxiliary magnets intensify, weaken, or cause an asymmetric magnetic field.

In the semiconductor single crystal manufacturing method according to another aspect of the present invention for achieving the above technical problem, the seed crystal is immersed in the semiconductor melt contained in the quartz crucible and then gradually raised to the top while rotating the seed crystal to grow the semiconductor single crystal through a solid-liquid interface In the method of manufacturing a semiconductor single crystal by using the Czochralski method, a magnetic field of a horizontal type having a horizontal magnetic field direction near the maximum magnetic field strength (GMP) is applied to the crucible, and the relative position of the GMP and the melt is controlled. By controlling the concentration of oxygen introduced into the single crystal.

According to another aspect of the present invention, there is provided a semiconductor single crystal manufacturing apparatus comprising: a quartz crucible containing a semiconductor melt; A crucible support coupled to the outer circumferential surface of the crucible to support the shape of the crucible in a high temperature environment; Heating means installed to surround sidewalls of the crucible support to provide radiant heat to the semiconductor melt contained in the crucible; It is provided that the heating means, the crucible holder and the quartz crucible is accommodated, and is installed around the heating means so that the inner side wall of the hollow and the outer circumferential surface of the heating means face each other and the radiant heat emitted from the heating means is lost to the outside. Thermal insulation means for preventing; Magnetic field applying means installed around the quartz crucible to apply a horizontal type magnetic field having a horizontal magnetic field direction near the GMP with the maximum magnetic field strength to the quartz crucible; Single crystal ingot pulling means for pulling the seed crystals upward while contacting the seed crystals on the surface of the semiconductor melt contained in the quartz crucible; And crucible rotating means for gradually elevating the crucible support so that the position of the solid-liquid interface is maintained at a constant level while rotating the crucible support in a constant direction. The relative position of the quartz crucible and the magnetic field applying means, The intensity, direction or distribution, or a combination thereof is controlled to change the position of the GMP based on the semiconductor melt to control the oxygen concentration flowing into the single crystal.

According to the present invention, increasing the position of GMP based on the semiconductor melt increases the oxygen concentration flowing into the single crystal, and decreasing the position of the GMP based on the semiconductor melt decreases the oxygen concentration flowing into the single crystal.

Preferably, the magnetic field applying means forms a horizontal type magnetic field by n coil pairs, including 2n coils (an integer greater than or equal to 1), and each of the n coil pairs has a quartz crucible therebetween. The coil faces are arranged to face each other.

Preferably, the 2n coils are arranged in the form of regular polygons with a quartz crucible interposed therebetween.

Alternatively, the magnetic field applying means may be made of a saddle type coil wrapped around the quartz crucible.

The above technical problem is also achieved by a single crystal ingot manufactured by the semiconductor single crystal production method according to the present invention. The semiconductor single crystal ingot made in accordance with the present invention is a high quality single crystal ingot having a controlled oxygen concentration profile along the longitudinal direction of the single crystal ingot and without crystal defects due to voids or dislocation loops.

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.

On the other hand, the embodiment of the present invention described below describes the growth of silicon single crystal using the Czochralski method as an example, but the technical idea of the present invention should not be construed as being limited to silicon single crystal growth. Therefore, the technical idea according to the present invention is the single crystal growth of all the small elements such as Si, Ge, GaAs, InP, LN (LiNbO ₃ ), LT (LiTaO ₃ ), YAG (yttrium aluminum garnet), LBO (LiB ₃ O ₅ ) And CLBO (CsLiB ₆ O ₁₀ ), which can be applied to the growth of all compound semiconductor single crystals.

1 is a schematic configuration diagram of a semiconductor single crystal manufacturing apparatus according to the first embodiment used for the practice of the silicon single crystal manufacturing method according to the present invention.

Referring to FIG. 1, a semiconductor single crystal manufacturing apparatus according to a first embodiment of the present invention includes a quartz crucible 10 in which a silicon melt SM in which polycrystalline silicon and a dopant are melted at a high temperature is accommodated; A crucible support 20 surrounding the outer circumferential surface of the quartz crucible 10 and supporting the quartz crucible 10 in a predetermined form in a high temperature environment; A crucible rotating means (30) installed at the bottom of the crucible support (20) to gradually raise the quartz crucible (10) to rotate the quartz crucible (10) together with the support (20) to maintain a constant height of the solid-liquid interface; Heating means 40 for heating the quartz crucible 10 spaced a predetermined distance from the side wall of the crucible support 20; Heat insulation means (50) installed on the outside of the heating means (40) to prevent heat generated from the heating means (40) from flowing out; Single crystal pulling means (60) for pulling the single crystal (C) from the silicon melt (SM) accommodated in the quartz crucible (10) by using a seed crystal rotating in a constant direction; Heat shield means (70) for reflecting heat emitted from the single crystal (C) spaced a predetermined distance from the outer circumferential surface of the single crystal (C) pulled by the single crystal pulling means (60); And inert gas supply means (not shown) for supplying an inert gas (eg, Ar gas) to the upper surface of the silicon melt SM along the outer circumferential surface of the single crystal (C). Since these components are typical components of the semiconductor single crystal manufacturing apparatus using the Czochralski method well known in the art, detailed description of each component will be omitted.

In addition to the above-described components, the semiconductor single crystal manufacturing apparatus according to the first embodiment of the present invention further includes magnetic field applying means (M1, M2: hereinafter referred to as M) for applying a magnetic field to the quartz crucible 10. do. Preferably, the magnetic field applying means (M) applies an asymmetric magnetic field (G _upper , G _lower : collectively referred to as G) to the high temperature silicon melt SM contained in the quartz crucible 10.

Preferably, the asymmetric magnetic field G is a magnetic field having a higher G _lower intensity than a G _upper intensity based on ZGP (Zero Gauss Plane 90) where the vertical component of the magnetic field is zero. to be. That is, R = G _lower / G _upper is a magnetic field greater than one. Under these asymmetric magnetic field conditions, the ZGP 90 has a parabolic shape that is convex toward the top. The distribution of the magnetic fields formed at the top and bottom of the ZGP is asymmetrical.

Alternatively, the asymmetric magnetic field G may be a magnetic field in which the _upper magnetic field G _upper intensity is greater than the _lower magnetic field G _lower intensity. That is, the asymmetric magnetic field G may be a magnetic field in which R = G _lower / G _upper is less than one. In this asymmetric magnetic field condition, although not shown in the figures, the ZGP 90 has a parabolic shape that is convex toward the bottom.

Preferably, the magnetic field applying means M applies a cusp type asymmetric magnetic field G to the quartz crucible 10. In this case, the magnetic field applying means (M) comprises an annular upper coil (M1) and lower coil (M2) installed spaced apart from the outer peripheral surface of the heat insulating means (50) by a predetermined distance. Preferably, the upper coil M1 and the lower coil M2 are installed substantially coaxially with the quartz crucible 10. The upper coil M1 and the lower coil M2 may be general electromagnet coils or superconducting coils. However, the present invention is not limited by the type of coil.

In order to form the asymmetric magnetic field G, the number of turns of the upper coil M1 and the lower coil M2, the magnitude of the current applied to each coil, the diameter of each coil, or an optional combination thereof may be appropriately adjusted. . For example, the number of windings and the diameter of the upper coil M1 and the lower coil M2 are equal to each other, and currents having different magnitudes are applied to the upper coil M1 and the lower coil M2. That is, a larger current is applied to the lower coil M2 than the upper coil M1 or vice versa. Alternatively, the size of the current applied to the upper coil M1 and the lower coil M2 and the diameter of the coil may be the same, and the number of turns of each coil may be adjusted to form an asymmetric magnetic field G. As another alternative, the asymmetric magnetic field G may be formed by simultaneously adjusting the current applied to the coil and the number of turns of the coil while keeping the diameter of the coil the same. As another alternative, the asymmetric magnetic field G may be formed by equalizing the current applied to the coil and the number of turns, and changing the diameters of the upper coil M1 and the lower coil M2. As another alternative, the auxiliary magnet 100 may be installed around the rotary mount 35 above the crucible rotating means 30 to form an asymmetric magnetic field. In this case, the asymmetric magnetic field G is formed by the magnetic field generated by the auxiliary magnet 100 even though the magnetic fields generated through the upper coil M1 and the lower coil M2 have the same magnitude. Of course, if the upper coil M1 and the lower coil M2 can form the asymmetric magnetic field G, the asymmetric magnetic field G may be strengthened or weakened by the use of the auxiliary magnet 100. The auxiliary magnet 100 may be a permanent magnet or may be an electromagnet. The position at which the auxiliary magnet 100 is mounted is not limited to the periphery of the rotary mount 35. Therefore, the circumference of the quartz crucible 10, the circumference of the crucible support 20 may be installed at various positions. In forming the asymmetric magnetic field G in various ways as described above, the distribution of the asymmetric magnetic field G can be moved upward or downward by adjusting the position of the magnetic field applying means M. When the distribution of the asymmetric magnetic field G is shifted, the ZGP 90 is also moved. Of course, since the quartz crucible 10 gradually rises upward in order to maintain a constant height of the solid-liquid interface during the growth of the single crystal C, an asymmetric magnetic field applied to the silicon melt SM even by the movement of the quartz crucible 10. (G) The relative position of the distribution may change.

Although not shown in the drawings, a coil assembly may be configured by further installing at least one intermediate coil between the upper coil M1 and the lower coil M2. In this case, in the process of growing the silicon single crystal C, two coils may be selected from the coil assembly to form an asymmetric magnetic field G. For example, if three coils are installed, asymmetric magnetic field (G) is formed by selecting two coils at the bottom of the single crystal (C) growth, and asymmetrical by selecting two coils at the top of the single crystal (C) growth. The magnetic field G can be formed. In this case, the two selected coils may form an asymmetric magnetic field G by appropriately adjusting the diameter of the coil, the magnitude of the current applied to the coil, the number of windings of the coil, or an optional combination thereof. Obviously, the auxiliary magnet 100 may be utilized to form the asymmetric magnetic field G. This content has already been described above. When the coil assembly is configured, there is an advantage that the distribution of the asymmetric magnetic field G in the silicon melt SM may be maintained even when the crucible support 20 rises as the single crystal C grows.

The present invention adjusts the ZGP position of the asymmetric magnetic field (G) in the process of growing the silicon single crystal (C) through the solid-liquid interface using the single crystal manufacturing apparatus according to the first embodiment described above to determine the oxygen concentration flowing into the silicon single crystal. To control.

FIG. 4 is formed in a silicon melt when a cusp-type asymmetric magnetic field is applied to a quartz crucible when growing an 8-inch silicon single crystal using the semiconductor single crystal manufacturing apparatus shown in FIG. 1. The melt convection distribution is simulated using a commercial program.

Referring to the drawings, the convection distribution of the melt formed in the silicon melt SM is the convection cell A and the quartz crucible D, which are represented by the rotation of the single crystal C with respect to the imaginary boundary E indicated by the dotted line. It is largely divided into convection cell (B) which is shown by the rotation.

However, if the position of ZGP is changed by changing the R value of the asymmetric magnetic field, the boundary surfaces of the convective cells (A, B) move directionally, and the concentration of oxygen incorporated into the single crystal (C) depends on where the boundary surfaces move. Different.

For example, if the R value of the asymmetric magnetic field G increases (in this case, ZGP rises) under the condition that the strength of the lower magnetic field is greater than that of the upper magnetic field, the convection cell produced by the rotation of the quartz crucible D Since (B) becomes relatively larger than the convection cell A produced by the rotation of the single crystal C, the boundary surface E of the convection cells A and B is moved in the direction of the rotation axis X of the single crystal C. . In addition, the velocity of the convective cell B decreases due to the increase in the strength of the lower magnetic field, thereby suppressing the pumping effect in which the melt containing a large amount of SiOx rises to the solid-liquid interface side, thereby being incorporated into the single crystal C. Oxygen concentration may be reduced. On the other hand, if the value of the lower magnetic field is greater than the strength of the upper magnetic field, decreasing the R value of the asymmetric magnetic field causes the interface of the convection cells A and B to be pushed toward the sidewall of the quartz crucible D. In this case, the speed of the convection cell B becomes relatively large, and the effect of suppressing the pumping effect in which the melt containing a large amount of SiOx rises to the solid-liquid interface side is reduced, thereby increasing the oxygen concentration incorporated into the single crystal (C). Done. On the other hand, the effect of moving the interface E of the convection cells A and B also occurs when the position of the magnetic field applying means is moved up / down based on the quartz crucible D. For example, if the position of the magnetic field applying means is moved upward, the boundary surface E of the convection cells A and B moves in the direction of the rotation axis of the single crystal C, and if the position of the magnetic field applying means is moved downward, the convection cell A , B) moves to the side wall of the quartz crucible D.

On the other hand, the cause of the movement of the boundary surfaces of the convection cells A and B is closely related to the movement of the ZGP of the asymmetric magnetic field. Therefore, the method of moving the boundary surface in applying the asymmetric magnetic field to the quartz crucible using the cusp magnetic field has been described above. The present invention is not limited to the bar, and any method may be employed as long as it causes the movement of the ZGP.

2 is a schematic configuration diagram of a semiconductor single crystal manufacturing apparatus according to a second embodiment used for carrying out the method for manufacturing a silicon single crystal according to the present invention.

Referring to the drawings, the semiconductor single crystal manufacturing apparatus according to the second embodiment of the present invention has a configuration substantially the same as that of the semiconductor single crystal manufacturing apparatus shown in FIG. 1 except for the magnetic field applying means (M). Therefore, only the magnetic field applying means (M1, M2: hereinafter referred to as M) will be described in detail here.

The magnetic field applying means M applies a horizontal magnetic field G to the quartz crucible 10 containing the silicon melt SM. The horizontal type magnetic field (G) has the greatest strength of the magnetic field GMP (Gauss Maximum Plane: 110) is substantially horizontal magnetic field direction in the vicinity of an upper magnetic field on the basis of the GMP (G _upper) and a lower magnetic field (G _lower) the Gaussian (Gaussian) means a magnetic field with a distribution.

According to an aspect of the present invention, the magnetic field applying means (M) so that at least two coils face each other with the quartz crucible 10 therebetween to apply a horizontal type magnetic field (G) to the quartz crucible 10. Is placed. For convenience of description, the coil on the left is called the left coil M1 and the coil on the right is called the right coil M2. At this time, the left coil M1 and the right coil M2 are disposed in parallel with the sidewall of the quartz crucible 10. In the horizontal type magnetic field G generated by the left coil M1 and the right coil M2, GMP, which is the plane with the greatest intensity of the magnetic field, is located near the line connecting the center of the coil surface, and is based on GMP. As the upper magnetic field (G _upper ) and the lower magnetic field (G _lower ) move away from GMP, the intensity decreases.

Preferably, the magnetic field applying means (M) is a front coil (front and rear respectively disposed in front and rear, respectively, with a quartz crucible (10) between the left coil (M1) and the right coil (M2) as shown in FIG. M3) and the rear coil M4 is further included. More preferably, the magnetic field applying means M includes 2n coils arranged in a regular n-square (n is a positive integer greater than 2) around the quartz crucible 10.

Each coil constituting the magnetic field applying means (M) is preferably composed of a superconducting coil. However, the present invention is not limited only to the superconducting coil. When the horizontal type magnetic field G is applied to the quartz crucible 10 by the magnetic field applying means M having the above-described configuration, the number of windings of each coil and the magnitude and direction of the applied current are changed to It is obvious that the distribution (direction, intensity, etc.) can be modified in various forms.

According to another aspect of the present invention, the magnetic field applying means (M) may be a saddle-shaped coil (M5) surrounding the periphery of the quartz crucible 10, as shown in Figure 3b. Even in this case, the saddle coil M5 is preferably configured of a superconducting coil. However, the present invention is not limited only to the superconducting coil.

On the other hand, in addition to the saddle coil M5, the magnetic field applying means M for forming the horizontal magnetic field G can be modified in various ways. Therefore, it is understood that the technical idea of the present invention is not in the specific configuration of the magnetic field applying means M, but in the technical idea itself that the magnetic field applying means M applies the horizontal type magnetic field G to the quartz crucible 10. Should.

The GMP formed by the magnetic field applying means M may be changed relative to the quartz crucible 10. Relative positioning of the GMP may be performed by vertical movement of the magnetic field applying means (M), and as the silicon melt (SM) is consumed by the single crystal (C) growth, the quartz crucible ( 10) may be made in the process of lifting up, or by a combination of both. However, the present invention is not limited thereto and may change the location of GMP by various other methods.

The present invention controls the oxygen concentration flowing into the silicon single crystal using a horizontal type magnetic field in the process of growing the silicon single crystal through the solid-liquid interface using the semiconductor single crystal manufacturing apparatus according to the second embodiment described above.

FIG. 5 illustrates a computer program for melt convection distribution formed in a silicon melt when a horizontal magnetic field is applied to a quartz crucible when a 12-inch silicon single crystal is grown using a semiconductor single crystal manufacturing apparatus according to a second embodiment of the present invention. The simulation results are shown.

 Referring to the drawing, as the horizontal type magnetic field is applied to the silicon melt SM, unlike the application of the cusp type asymmetric magnetic field, the rotation of the single crystal C is based on the imaginary boundary E indicated by the dotted line. The convection cell A produced by the convection cell B produced | generated by rotation of the quartz crucible D is divided into upper and lower sides. Specifically, the convection cell A due to the rotation of the single crystal C appears on the upper portion of the silicon melt SM, and the convection cell B due to the rotation of the quartz crucible D is below the silicon melt SM. Appears in the part. Therefore, in this convection distribution of the melt, in order for oxygen to be incorporated into the single crystal (C) through the solid-liquid interface, the silicon melt (SM) containing a large amount of SiOx through the interface (E) has a convection cell from the upper convection cell (B). You must go to (A).

However, when the GMP position of the horizontal type magnetic field is changed by changing the relative positions of the magnetic field applying means M and the silicon melt SM, the boundary surfaces E of the convection cells A and B move in a directional manner. The concentration of oxygen incorporated into the single crystal (C) varies depending on where E) moves.

For example, when the GMP of the horizontal type magnetic field moves upward, the interface E of the upper convection cell A and the lower convection cell B moves upward. In this case, since the distance that the silicon melt (SM) containing a large amount of SiOx moves to the solid-liquid interface through the convection is shortened, the concentration of oxygen flowing into the single crystal (C) increases. On the contrary, when the GMP of the horizontal type magnetic field moves downward, the interface E of the upper convection cell A and the lower convection cell B moves downward. This not only reduces the melt convection rate under the quartz crucible (D) and the dissolution rate of the quartz crucible (D), but also increases the distance that the silicon melt (SM) containing a large amount of SiOx moves to the solid-liquid interface through convection. Therefore, the concentration of oxygen mixed into the single crystal (C) is reduced.

Experimental Example

The present inventors experimented that it is possible to control the concentration of oxygen introduced into the single crystal by controlling the relative position between ZGP of the cusp type asymmetric magnetic field and the GMP of the horizontal type magnetic field and the silicon melt when the silicon single crystal is grown by the Czochralski method. It was confirmed through.

First, polycrystalline silicon was charged into a 24 inch diameter quartz crucible, and then 8 inch silicon single crystal was grown to a length of 1200 mm (based on the ingot body). The rotation speed of the single crystal is 13-20 rpm, preferably 16-18 rpm, the rotation speed of the quartz crucible is 0.1-1 rpm, the pulling speed of the single crystal is 0.6mm / min or more, the flow rate of argon is 30-100lpm, and the process pressure is 20- 100torr was set. Cusp type asymmetric magnetic field was applied to the quartz crucible during single crystal growth. In Example 1, R of the asymmetric magnetic field was adjusted to 2.3, and in Example 2, R of the asymmetric magnetic field was adjusted to 1.36. At this time, the position of the ZGP of the asymmetric magnetic field is as shown in FIG. Referring to the figure, it can be seen that in the case of Embodiment 1, since the R value is larger, the ZGP is located higher.

FIG. 7 is a graph showing a change pattern by measuring the oxygen concentration of each length of the silicon single crystal ingot grown according to Examples 1 and 2. FIG. Referring to the drawings, it can be seen that in the case of Example 1 having a large R value of the asymmetric magnetic field, the oxygen concentration is lower than that of Example 2 over the entire body of the single crystal ingot. This is because when the R value of the asymmetric magnetic field increases and the ZGP rises, the pumping effect of the silicon melt containing a large amount of SiOx flowing from the lower part of the quartz crucible to the solid-liquid interface is suppressed by moving the boundary surface of the convective cell in the direction of the axis of rotation of the single crystal. to be. From these results, it can be seen that controlling the relative position of ZGP and silicon melt when applying a cust-type asymmetric magnetic field can control the oxygen concentration incorporated into the single crystal in the desired direction to have a controlled oxygen concentration profile along the longitudinal direction of the single crystal. Able to know.

Next, after charging polycrystalline silicon into a 32-inch diameter quartz crucible, a 12-inch silicon single crystal was grown to a length of 1900 mm (based on the ingot body). The rotation speed of single crystal is 5 ~ 14rpm, preferably 8 ~ 12rpm, the rotation speed of quartz crucible is 0.1 ~ 1rpm, the pulling speed of single crystal is more than 0.4mm / min, the flow rate of argon is 100 ~ 200lpm, the process pressure is 30 ~ 100torr was set. At this time, a horizontal type magnetic field of 2000 G or more, preferably 2000 to 45000 G, was applied to the quartz crucible. In the case of Example 3, the position of the GMP is 210 mm below the upper surface of the silicone melt, in the case of Example 4, the position of the GMP is 135 mm below the upper surface of the silicone melt, and in the case of Example 5, the position of the GMP is It was placed 35 mm below the top surface of the silicone melt. 8 shows the GMP position of the horizontal type magnetic field applied in Examples 3 to 5 in more detail.

FIG. 9 is a graph showing a change pattern by measuring the oxygen concentration of each length of the silicon single crystal ingot grown according to Examples 3 to 5. FIG. Referring to the drawings, the lower the GMP of the horizontal type magnetic field lowers the oxygen concentration of the single crystal, the higher the GMP of the horizontal type magnetic field, the higher the oxygen concentration of the single crystal. That is, in Example 3, the oxygen concentration of the single crystal was the lowest, and in Example 5, the oxygen concentration of the single crystal was the highest. These results show that by adjusting the relative position of GMP and silicon melt when applying a horizontal magnetic field, it is possible to have a controlled oxygen concentration profile along the longitudinal direction of the single crystal by controlling the oxygen concentration incorporated into the single crystal in the desired direction. Can be.

In order to apply the above-described method for manufacturing a semiconductor single crystal according to the present invention in an actual process, it is necessary to quantify the relative positional relationship between the silicon melt and the magnetic field and the intensity of the magnetic field according to the oxygen concentration quality requirements through an iterative test-run process. have. Such a quantification process can be easily performed by those skilled in the art having the technical idea of the present invention, and once the quantification of the process conditions related to the magnetic field is completed, the semiconductor single crystal ingot whose oxygen concentration profile is controlled according to various oxygen concentration quality requirements Can be manufactured. In addition, if the oxygen concentration flowing into the single crystal is controlled according to the present invention, the temperature gradient at the solid-liquid interface is not largely influenced, while the oxygen concentration profile is controlled along the length direction of the single crystal, while crystal defects due to voids or dislocation loops are maintained within the defect margin. High quality single crystal ingots are possible.

On the other hand, in the above-described examples and experimental examples, a cusp-type magnetic field is applied when the 8-inch silicon single crystal is manufactured, and a horizontal magnetic field is applied when the 12-inch silicon single crystal is manufactured. However, the technical idea of the present invention is to control the oxygen concentration flowing into the single crystal by controlling the convective distribution of the silicon melt by controlling the position of ZGP by applying a cusp type magnetic field or by changing the position of GMP by applying a magnetic field of a horizontal type. Thus, it is apparent to those skilled in the art that the scope of the invention is not limited by the specific diameter of the single crystal to which the magnetic field is applied.

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.

According to the present invention, it is possible to diversify the single crystal product because no measures such as replacement of hot zones or change of process parameters, which have been conventionally applied for various levels of oxygen concentration control, are unnecessary.

According to another aspect of the present invention, it is possible to control the oxygen concentration for a specific length or position, including the overall oxygen concentration level control of a single crystal ingot, to produce a wafer having various oxygen concentration conditions from a single crystal.

According to another aspect of the present invention, there is little influence on the temperature gradient of the solid-liquid interface that requires strict control for defect-free single crystal growth in the oxygen concentration control process by applying a magnetic field. Therefore, it is possible to manufacture high quality single crystals without crystal defects due to voids or dislocation loops, thereby maximizing prime yield even in process conditions in which oxygen concentration can be controlled.

Claims (31)

In the method of manufacturing a semiconductor single crystal using the Czochralski method in which a seed crystal is immersed in a semiconductor melt contained in a quartz crucible, the seed crystal is rotated and pulled upward to grow a semiconductor single crystal through a solid-liquid interface. Apply a Cusp-type asymmetric magnetic field with different magnetic field strengths at the top and bottom, based on Zero Gauss Plane (ZGP) with zero vertical component, and adjust the relative position of ZGP and melt into single crystal. A method for producing a semiconductor single crystal, characterized by controlling the concentration of oxygen introduced. The method of claim 1, A method for manufacturing a semiconductor single crystal, characterized in that to increase the ZGP on the basis of the semiconductor melt to reduce the concentration of oxygen flowing into the single crystal. The method of claim 1, A method for manufacturing a semiconductor single crystal, characterized in that to increase the concentration of oxygen introduced into the single crystal by lowering the ZGP based on the semiconductor melt. The method of claim 1, Wherein the asymmetric magnetic field is an asymmetric magnetic field in which the upper magnetic field is larger than the lower magnetic field based on ZGP or an asymmetric magnetic field in which the lower magnetic field is larger than the upper magnetic field based on ZGP. The method of claim 1, The asymmetric magnetic field is formed by the upper and lower coils annularly installed around the crucible, And forming an asymmetric magnetic field by adjusting the number of windings of the upper coil and the lower coil, the magnitude of the applied current, the area of the coil, or a combination thereof. The method of claim 5, A coil assembly is formed by interposing an intermediate coil between the upper coil and the lower coil, And combining the two coils included in the coil assembly to form an asymmetric magnetic field by adjusting the number of turns of each coil, the magnitude of the applied current, the area of the coil, or a combination thereof. The method according to claim 5 or 6, A method for manufacturing a semiconductor single crystal, characterized in that to install an auxiliary magnet in the lower or upper portion of the quartz crucible to strengthen, weaken or cause an asymmetric magnetic field. delete delete delete delete In the method of manufacturing a semiconductor single crystal using the Czochralski method in which a seed crystal is immersed in a semiconductor melt contained in a quartz crucible, the seed crystal is rotated and pulled upward to grow a semiconductor single crystal through a solid-liquid interface. N pairs of coils are formed by 2n coils (an integer greater than or equal to 1) to apply a horizontal magnetic field with a horizontal magnetic field near the GMP (Gauss Maximum Plane) with the maximum magnetic field strength to the crucible. The method of claim 1, wherein the coil faces of the coil pairs are disposed to face each other with the quartz crucible interposed therebetween, and the concentration of oxygen introduced into the single crystal is controlled by adjusting the relative positions of the GMP and the melt. The method of claim 12, 2n coils are arranged in a regular polygonal shape with a quartz crucible interposed therebetween. In the method of manufacturing a semiconductor single crystal using the Czochralski method in which a seed crystal is immersed in a semiconductor melt contained in a quartz crucible, the seed crystal is rotated and pulled upward to grow a semiconductor single crystal through a solid-liquid interface. By applying a saddle type coil surrounding the quartz crucible, a horizontal type magnetic field near the GMP (Gauss Maximum Plane) where the magnetic field strength is maximum is applied to the crucible, but the relative position of the GMP and the melt is And controlling the concentration of oxygen introduced into the single crystal by adjusting the concentration of oxygen. The method according to any one of claims 12 to 14, A method for manufacturing a semiconductor single crystal, characterized in that the direction of the horizontal type magnetic field, the intensity or the distribution of GMP is adjusted by adjusting the number of windings of the coil, the magnitude of the applied current, the coil area, or a combination thereof. A quartz crucible containing a semiconductor melt; A crucible support coupled to the outer circumferential surface of the crucible to support the shape of the crucible; Heating means installed to surround sidewalls of the crucible support to provide radiant heat to the semiconductor melt contained in the crucible; It is provided that the heating means, the crucible holder and the quartz crucible is accommodated, and is installed around the heating means so that the inner side wall of the hollow and the outer circumferential surface of the heating means face each other and the radiant heat emitted from the heating means is lost to the outside. Thermal insulation means for preventing; Magnetic field applying means installed around the quartz crucible to apply a Cusp-type asymmetric magnetic field having different magnetic field strengths at the top and the bottom of the ZGP having a vertical component of zero to the quartz crucible; Single crystal ingot pulling means for pulling the seed crystals upward while contacting the seed crystals on the surface of the semiconductor melt contained in the quartz crucible; And And crucible rotating means for raising the crucible support such that the position of the solid-liquid interface is maintained at a constant level while rotating the crucible support in a constant direction. And controlling the relative concentration of the quartz crucible and the magnetic field applying means, the degree of asymmetry of the asymmetric magnetic field, or a combination thereof to change the position of ZGP based on the semiconductor melt to control the oxygen concentration flowing into the single crystal. Manufacturing device. The method of claim 16, And increasing the position of the ZGP on the basis of the semiconductor melt to reduce the oxygen concentration flowing into the single crystal. The method of claim 16, A device for manufacturing a semiconductor single crystal, characterized in that to increase the oxygen concentration flowing into the single crystal by lowering the position of the ZGP based on the semiconductor melt. The method of claim 16, The magnetic field applying means is provided with a semiconductor single crystal manufacturing apparatus, characterized in that spaced apart from the outer peripheral surface of the heat insulating means. The method of claim 16, The magnetic field applying means includes an upper coil and a lower coil annularly installed around the quartz crucible, And forming an asymmetric magnetic field by adjusting the number of windings of the upper coil and the lower coil, the magnitude of the applied current, the area of the coil, or a combination thereof. The method of claim 20, Further comprising an intermediate coil interposed between the upper coil and the lower coil, After combining two coils in the coil assembly in which the upper coil, the lower coil and the intermediate coil are assembled, an asymmetric magnetic field is formed by adjusting the number of windings of each coil, the magnitude of the applied current, the area of the coil, or a combination thereof. A semiconductor single crystal manufacturing apparatus. The method of claim 20 or 21, Further comprising an auxiliary magnet installed on the lower or upper portion of the quartz crucible, The auxiliary magnet is a semiconductor single crystal manufacturing apparatus, characterized in that for strengthening, weakening or causing an asymmetric magnetic field. A quartz crucible containing a semiconductor melt; A crucible support coupled to the outer circumferential surface of the crucible to support the shape of the crucible; Heating means installed to surround sidewalls of the crucible support to provide radiant heat to the semiconductor melt contained in the crucible; It is provided that the heating means, the crucible holder and the quartz crucible is accommodated, and is installed around the heating means so that the inner side wall of the hollow and the outer circumferential surface of the heating means face each other and the radiant heat emitted from the heating means is lost to the outside. Thermal insulation means for preventing; A pair of n coils each including 2n coils (an integer greater than or equal to 1) and arranged to face each other with the quartz crucible interposed therebetween is a horizontal type magnetic field whose horizontal magnetic field direction is as close to GMP as possible. Magnetic field applying means formed in the quartz crucible; Single crystal ingot pulling means for pulling the seed crystals upward while contacting the seed crystals on the surface of the semiconductor melt contained in the quartz crucible; And And crucible rotating means for raising the crucible support such that the position of the solid-liquid interface is maintained at a constant level while rotating the crucible support in a constant direction. Controlling the oxygen concentration flowing into the single crystal by controlling the relative position of the quartz crucible and the magnetic field applying means, the intensity, direction or distribution of the horizontal type magnetic field, or a combination thereof to change the position of the GMP based on the semiconductor melt. The semiconductor single crystal manufacturing apparatus characterized by the above-mentioned. The method of claim 23, wherein A device for manufacturing a semiconductor single crystal, characterized in that to increase the oxygen concentration flowing into the single crystal by raising the position of GMP based on the semiconductor melt. The method of claim 23, wherein A device for manufacturing a semiconductor single crystal, characterized in that to reduce the oxygen concentration flowing into the single crystal by lowering the position of GMP based on the semiconductor melt. delete The method of claim 23, wherein And the 2n coils are arranged in a regular polygonal shape with a quartz crucible interposed therebetween. delete The method of claim 27, The coil is a semiconductor single crystal manufacturing apparatus, characterized in that the superconducting coil. delete delete

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