KR20020045765A - Growing apparatus of a single crystal ingot - Google Patents

Abstract

PURPOSE: An apparatus for manufacturing a single crystal ingot is provided which reduces defects inside a crystal as improving productivity by improving a cooling speed of the crystal, thereby increasing a vertical temperature gradient. CONSTITUTION: In an apparatus for manufacturing a single crystal ingot comprising a quartz crucible(53) containing a silicon melt(55) so as to grow the single crystal ingot, a crucible support(57) supporting the quartz crucible(53), a heater(61) heating the quartz crucible(53), a thermal insulation sleeve(63) preventing heat of the heater(61) from being emitted to the outside, a pulling device pulling the single crystal ingot as growing the single crystal ingot from the silicon melt, a heat shield(75) encircling the single crystal ingot so that heat of the heater(61) is not transferred, and a cooler(77) cooling the upper part of the single crystal ingot, the apparatus is characterized in that the cooler(77) has two or more inlets(79) and outlets which are alternated each other, and a plurality of first walls and second walls which are extended so that the upper part is connected to the lower part inside the first walls, and the upper part is not connected to the lower part inside the second walls, and wherein the plurality of first and second walls are alternately formed so that a watercourse is formed between the inlets and outlets.

Description

Growing apparatus of a single crystal ingot

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for producing single crystal ingots, which grows liquid silicon into rod-shaped single crystals, and in particular, improves productivity by improving the cooling rate of crystals and increasing vertical temperature gradients. An apparatus for producing a single crystal ingot capable of reducing defects inside a crystal.

Wafers, such as silicon, used as a material for producing electronic components, such as semiconductors, are made by slicing a silicon single crystal ingot to a thin thickness. The silicon single crystal ingot is prepared by melting polycrystalline silicon in a liquid phase and then growing it by Czochralski method (hereinafter referred to as CZ method).

In crystal growth of a silicon single crystal by the CZ method, defect characteristics in the single crystal largely depend on the pulling rate and cooling conditions of the crystal. Therefore, many efforts have been made to control the type and distribution of growth defects by adjusting the thermal environment near the growth interface.

As the silicon melt is solid crystallized, point defects of vacancy-type and interstitial-type are mixed above the equilibrium concentrations, and these point defects aggregate during cooling, resulting in growth defects. To develop. Such growth defects include Crystal Originated Partical (COP), Large Dislocation Pit (LDP), or Oxidation-induced Stacking Fault (OSF). According to Voronkov's The mechanism of swirl defects formation in silicon "(Journal of crystal growth. Vol. 59 (1982), P. 625.,), the formation of these defects is closely related to the V / G ratio. Where V is the growth rate of the ingot and G is the vertical temperature gradient in the crystal near the growth interface. The void defect COP occurs mainly in the center of the single crystal ingot, the vacancy-rich region. However, the generated COP grows in size when the vertical temperature gradient is small, and therefore, a technique for increasing the vertical temperature gradient to improve the growth rate while reducing the size of the COP defects during crystal growth has been developed.

1 is a schematic cross-sectional view of an apparatus for manufacturing a single crystal ingot according to the prior art, FIG. 2 is a plan view of the water cooler shown in FIG. 1, and FIG. 3 is a side view of the water cooler shown in FIG. 2. The apparatus for manufacturing ingots is provided with a quartz crucible 13 containing a silicon melt 15 in a chamber 11 and a crucible support 17 made of graphite or the like for supporting the quartz crucible 13. The crucible support 17 is installed on a rotating shaft 19 that is rotated by a driving means (not shown) when the single crystal ingot 29 is grown to move up and down while rotating the quartz crucible 13. The crucible support 17 is surrounded by a cylindrical heater 21 spaced apart, which is surrounded by a thermos (23).

In the upper part of the chamber 11, the pulling means (not shown) which winds and pulls the cable 33 is provided, and this pulling means is rotated. A seed crystal 31 is provided in the lower portion of the cable 33 to grow the single crystal ingot 29 while contacting and pulling up the silicon melt 15 in the quartz crucible 13.

A heat shield 35 that surrounds the single crystal ingot 29 is provided between the single crystal ingot 29 and the crucible 13. The heat shield 35 is fixed on the thermos 23 and the lower part has a triangular cross section and is formed to protrude toward the single crystal ingot 29 so as to be spaced apart from the silicon melt 15 in the quartz crucible 13. In order to increase the cooling rate of the single crystal ingot 29, the single crystal ingot 29 is surrounded by a cylindrical stainless steel or a good thermal conductivity spaced apart from the surface of the silicon melt 15. A cooler 37 made of metal is installed. 2 and 3, the cooler 37 has an inlet 39 and an outlet 41 formed at an upper portion thereof and extends so as not to be connected from the upper portion to the lower portion thereof to form a hole. 45) and a plurality of second walls 47 extending so as not to be connected from the bottom to the top to form a hole are alternately formed. Moreover, the protrusion part 43 is formed in the surface which opposes the single crystal ingot 29 of the cooler 37. As shown in FIG.

The chamber 11 is argon (Ar) or neon (Ne) used as an atmosphere gas for the silicon melt 15 inside the single crystal ingot 29 and the crucible 13 which are grown by flowing between the cylindrical water coolers 37 at the top. A supply pipe (not shown) for supplying an inert gas such as) from the outside is provided. And an exhaust pipe 27 for discharging the inert gas used to the outside of the chamber 11 to the outside is provided.

In the apparatus for producing a single crystal ingot of the above-described configuration, after dipping the silicon melt 15 in the quartz crucible 13 with the seed crystal 31, the quartz crucible 13 and the seed crystal 31 are rotated in opposite directions. While raising, the single crystal ingot 29 is grown.

At this time, the heat shield 35 prevents the loss of radiant heat of the silicon melt 15 and the heat released through the side of the quartz crucible 13. In addition, the heat shield 35 should be spaced apart from the surface of the silicon melt 15 by a certain distance to maintain a constant temperature of the growth interface. Therefore, the quartz crucible 13 is moved upward by the rotating shaft 19 so that the silicon melt 15 is consumed due to the growth of the single crystal ingot 29 and the surface thereof is lowered, so that the heat shield 35 and the silicon melt 15 To keep the surface at a constant interval. The upper portion of the single crystal ingot 29 is cooled by the cooler 37 while supplying an inert gas such as nitrogen (N), argon (Ar), or neon (Ne) to the chamber 11 through a supply pipe (not shown). Cool. The cooler 37 has a uniform temperature since the first and second walls 45 and 47 are used as water channels so that the coolant injected through the inlet 39 flows evenly throughout, and the single crystal ingot 29 Since the protrusion 43 is formed on the surface opposite to) and the surface area is increased, the cooling efficiency is increased to increase the vertical temperature gradient of the single crystal ingot 29.

However, in the apparatus for manufacturing a single crystal ingot according to the prior art, since the cooler has only one inlet and one outlet, each of the cooling water flows in through the inlet and discharges through the outlet, and the contact area with the cooling water is small, In addition, since the cooler is formed of stainless steel having a low melting point or the like and is to be spaced apart from the silicon melt by a distance, cooling efficiency is lowered. Therefore, the vertical temperature gradient is reduced at the growth interface of the single crystal ingot, so that the size of the void, the COP, which is a void defect, is increased, and the growth rate is lowered.

Accordingly, it is an object of the present invention to provide an apparatus for producing a single crystal ingot which can reduce the size of COP, which is a void defect during growth of the single crystal ingot.

Another object of the present invention is to provide an apparatus for producing a single crystal ingot which can improve the growth rate of the single crystal ingot.

One embodiment of the present invention for achieving the above object is a quartz crucible containing a silicon melt to grow a single crystal ingot, a crucible support for supporting the quartz crucible, a heater for heating the quartz crucible, and the heat of the heater A heat insulating tube that prevents the outflow to the outside, an pulling device that raises and grows a single crystal ingot from the silicon melt, a heat shield surrounding the single crystal ingot so that the heat of the heater is not transferred, and the upper portion of the single crystal ingot is cooled. In the single crystal ingot manufacturing apparatus comprising a cooler for,

The cooler has two or more inlets and outlets each alternating, and has a plurality of first and second walls connected to the upper and lower portions, respectively, and extending from the lower and upper portions, respectively. The wall and the second wall are formed alternately and are configured to form a channel between the inlet and outlet.

Another embodiment of the present invention for achieving the above object is a quartz crucible containing a silicon melt to grow a single crystal ingot, a crucible support for supporting the quartz crucible, a heater for heating the quartz crucible, and the heat of the heater A heat insulating tube that prevents the outflow to the outside, an pulling device that raises and grows a single crystal ingot from the silicon melt, a heat shield surrounding the single crystal ingot so that the heat of the heater is not transferred, and the upper portion of the single crystal ingot is cooled. In the single crystal ingot manufacturing apparatus comprising a cooler for,

The cooler has two or more inlets and outlets each alternating, and has a plurality of first and second walls connected to the upper and lower portions, respectively, and extending from the lower and upper portions, respectively. The wall and the second wall is formed alternately to form a channel between the inlet and outlet, and further comprises a liner formed in contact with the inner surface of the cooler.

Another embodiment of the present invention for achieving the above objects is a quartz crucible containing a silicon melt to grow a single crystal ingot, a crucible support for supporting the quartz crucible, a heater for heating the quartz crucible, and A heat insulating tube that prevents heat from leaking to the outside, an pulling device that raises and grows a single crystal ingot from the silicon melt, a heat shield surrounding the single crystal ingot so that heat of the heater is not transmitted, and a top of the single crystal ingot is cooled. A single crystal ingot manufacturing apparatus comprising a cooler for cooling, said cooler having two or more inlets and outlets each alternatingly, and having a plurality of first extending therein, respectively connected to the upper and lower portions and not connected to the lower and upper portions. A wall and a second wall, wherein the plurality of first and second walls are alternating And a liner formed to form a channel between the inlet and the outlet, the liner formed in contact with the inner surface of the cooler, and a heat sink attached to the cooler and the lower edge of the liner. Preferably, the heat shield is made of graphite coated or bonded with molybdenum (Mo), tungsten (W), carbon (C) or SiC, and the bottom inside is filled with carbon felt.

Preferably, the coolers are formed such that the inlets and outlets each having two or more are arranged alternately and spaced apart at equal intervals and the inner surface is uneven.

Preferably, the liner is formed of graphite having an uneven surface facing the single crystal ingot, graphite coated with SiC on the surface, or carbon fiber. Preferably, the liner is formed by roundly processing a plate-like material at both ends. Are spaced apart without overlap and are formed of one, or a plurality of two or more.

Preferably, the heat sink is detachably attached to a screw joint and is formed of graphite, graphite coated with SiC on the surface, or carbon fiber.

Preferably, the heat sink has a length of 0 to 90 degrees towards the single crystal ingot with respect to the cooler and the length that is not in contact with the silicon melt.

1 is a schematic cross-sectional view of an apparatus for producing a single crystal ingot according to the prior art.

2 is a plan view of the water cooler shown in FIG.

3 is a side view of the water cooler shown in FIG.

4 is a schematic cross-sectional view of an apparatus for producing a single crystal ingot according to the present invention.

5 is a plan view of the water cooler shown in FIG.

FIG. 6 is a side view of the water cooler shown in FIG. 4. FIG.

FIG. 7 is a cross-sectional view of FIG. 5 taken along line A-A. FIG.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

4 is a schematic cross-sectional view of an apparatus for producing a single crystal ingot according to the present invention.

The apparatus for manufacturing a single crystal ingot according to the present invention is provided with a quartz crucible 53 containing a silicon melt 55 in a chamber 51, and a crucible support 57 made of graphite or the like for supporting the quartz crucible 53. . The crucible support 57 is installed on a rotating shaft 69 which is rotated by a driving means (not shown) to grow the single crystal ingot 69 and extends upward while rotating the quartz crucible 53. The crucible support 57 is surrounded by a cylindrical heater 61 spaced apart, which is surrounded by a thermos 63. In the growth of the single crystal ingot 69 on the top of the chamber 51, A pulling means (not shown) for winding up and pulling 73 is provided, and the single crystal ingot 69 is brought into contact with the silicon melt 55 in the quartz crucible 53 at the bottom of the cable 73 to be pulled up. Seed crystal (71) is formed to grow. In the above, the pulling means not only winds and pulls the cable 73 when the single crystal ingot 69 grows, but also rotates the single crystal ingot 69 in the opposite direction to the quartz crucible 53.

A heat shield 75 that surrounds the single crystal ingot 69 is provided between the single crystal ingot 69 and the crucible 53. The heat shield 75 is formed so that the upper part is fixed on the thermostat 63, and the lower part has a triangular cross section and protrudes toward the single crystal ingot 69. In the heat shield 75, the outer surface is made of molybdenum (Mo), tungsten (W), carbon (C) or SiC coated or bonded graphite, the inside of the protruding portion of the lower carbon felt (carbon felt) It is formed of a material having excellent heat insulating properties. The protruding portion of the lower portion of the heat shield 75 maintains a constant distance from the surface of the silicon melt 55 so that radiant heat is transferred to the upper portion of the single crystal ingot 69 while keeping the temperature around the lower portion of the single crystal ingot 69 constant. prevent. As the single crystal ingot 69 is grown, the silicon melt 55 in the crucible 53 is consumed and the surface is lowered. As the rotary shaft 59 rotates, the crucible 53 is moved to the surface of the silicon melt 55. This lowering is moved upward so that the gap between the silicon melt 55 and the protruding portion of the bottom of the heat shield 75 is kept constant.

Nitrogen (N) and argon (Ar) used as an atmosphere gas in the single crystal ingot 69 and the silicon melt 55 inside the crucible 53 which are grown by flowing between the cylindrical water coolers 77 on the upper part of the chamber 51. ) Or a supply pipe (not shown) for supplying an inert gas such as neon (Ne) from the outside. And an exhaust pipe 67 for discharging the inert gas used in the lower part of the chamber 11 to the outside is provided.

The upper surface of the chamber 51 is made of a cylindrical stainless steel or a metal having good thermal conductivity to enclose the single crystal ingot 69 to cool the single crystal ingot 69, thereby greatly increasing the vertical temperature gradient at the growth interface. The cooler 77 is installed. The cooler 77 is provided with two or more inlets 79 for injecting cooling water and two or more outlets (not shown) for discharging the heated water to the outside by the cooling action.

In addition, a liner 87 is formed in close contact with the inner surface of the cylindrical cooler 77. The liner 87 is made of graphite having good thermal radiation characteristics, graphite coated with SiC on the surface, carbon fiber, or the like to quickly absorb radiant heat of the single crystal ingot 69 to increase the cooling efficiency of the cooler 77. The liner 87 roundly processes the plate material and is inserted in close contact with the inner surface of the cooler 77. The liner 87 is spaced apart from each other without overlapping the liner 87 to be in close contact with the inner surface of the cooler 77 by the elastic restoring force. In addition, the liner 87 may be formed of one or more than two. The liner 87 is attached to the cooler 77 and the lower edge of the liner 87 and is maximally accessed without contacting the silicon melt 55. An elongated cylindrical heat sink 89 is formed. The heat sink 89 is made of graphite having good thermal radiation characteristics such as the liner 87, graphite coated with SiC on the surface, or carbon fiber to absorb radiant heat from the lower portion of the single crystal ingot 69 to be cooled. Since the efficiency is increased, the vertical temperature gradient of the growth interface of the single crystal ingot 69 is increased. Therefore, during growth of the single crystal ingot 69, COP, which is a void defect, is not grown, thereby preventing the size from increasing and increasing the growth rate.

5 and 6 are a plan view and a side view of the water cooler 77 shown in FIG. 4, and FIG. 7 is a cross-sectional view taken along the line A-A of FIG. 5.

The water cooler 77 has a plurality of first walls 83 formed with inlets 79 and outlets 81 each having two or more at the top thereof, and extending so as not to be connected from the top to the bottom to form holes therein. A plurality of second walls 85 are formed that extend from the bottom to the top to form holes. The first and second walls 83 and 85 formed in plural numbers, respectively, are alternately formed and used as a water channel to evenly flow the cooling water injected through the two or more inlets 79.

In addition, the water coolers 77 are also arranged to be spaced apart at equal intervals while alternately inlet 79 and outlet 81 having two or more, each having an uneven surface as shown in FIG. . Since the coolers 77 are arranged while the inlets 79 and the outlets 81 having two or more are alternately arranged, the coolant is rapidly circulated, and since the inner surface has irregularities, the contact area with the coolant is increased. Not only is it increased, but the coolant produces a vortex. Therefore, the cooling efficiency of the cooler 87 is increased by the rapid circulation of the coolant and the increase in the contact area with the vortex and the coolant.

In addition, the liner 87 formed to be in contact with the inner surface of the cooler 37 has a concave-convex surface facing the single crystal ingot 69, so that the heat absorber of the single crystal ingot 69 is quickly absorbed to cool the cooler 77. To increase the cooling efficiency.

As shown in FIG. 7, the heat sink 89 is attached to the lower edges of the cooler 77 and the liner 87 so as to be detachable, for example, by screwing. The heat sink 69 has a length that does not come into contact with the silicon melt 55 and has an inclination of 0 to 90 degrees with respect to the single crystal ingot 69 with respect to the cooler 77. Therefore, the cooler 77 adjusts the absorption of radiant heat according to the length and controls the flow of the inert gas injected according to the inclination angle to the lower portion of the single crystal ingot 69 so that the cooling rate of the crystal and the supercooling of the crystal interface and the flow into the crystal As described above, according to the present invention, the cooler has two or more inlets and outlets, respectively, so that the circulation of the coolant is not only fast, but also the inner surface has irregularities, so that the coolant is in contact with the vortex while causing the vortex. Increased, the liner formed in close contact with the cooler inner surface quickly absorbs the radiant heat of the single crystal ingot, and the heat sink is close to the silicon melt surface, thereby increasing the cooling efficiency, thereby greatly increasing the vertical temperature gradient of the growth interface of the single crystal ingot. do.

Therefore, in the present invention, since the single crystal ingot has a large vertical temperature gradient of the growth interface, the size of the COP, which is a void defect, can be reduced, as well as the growth rate can be improved.

Claims (37)

A quartz crucible containing a silicon melt to grow a single crystal ingot, a crucible support for supporting the quartz crucible, a heater for heating the quartz crucible, a thermos to prevent heat from flowing out of the heater, and the silicon An apparatus for producing a single crystal ingot comprising: an pulling apparatus for pulling up a single crystal ingot while growing from a melt; a heat shield surrounding the single crystal ingot so that heat of the heater is not transmitted; and a cooler for cooling the upper portion of the single crystal ingot. The cooler has two or more inlets and outlets each alternating, and has a plurality of first and second walls connected to the upper and lower portions, respectively, and extending from the lower and upper portions, respectively. And a second wall formed alternately to form a channel between the inlet and outlet. The apparatus of claim 1, wherein the heat shield is formed of graphite coated or bonded with molybdenum (Mo), tungsten (W), carbon (C), or SiC. The apparatus of claim 1, wherein the heat shield is filled with carbon felt at a lower portion thereof. The single crystal ingot manufacturing apparatus of claim 1, wherein the inlets and outlets each having two or more are alternately arranged to be spaced apart at equal intervals. The apparatus of claim 1, wherein the cooler is formed such that an inner surface thereof is uneven. The apparatus of claim 1, further comprising a liner formed in contact with the inner surface of the cooler. The apparatus of claim 6, wherein the liner is formed such that a surface of the liner facing the single crystal ingot is uneven. The apparatus of claim 1, wherein the liner is formed of graphite, graphite coated with SiC on the surface, or carbon fiber. The apparatus of claim 6, wherein the liner is formed by processing a plate-like material in a circular manner so that both ends thereof are spaced apart without overlapping. The single crystal ingot manufacturing apparatus of claim 6, wherein the liner is formed of one or a plurality of two or more. The apparatus of claim 6, further comprising a heat sink attached to a lower edge of the cooler and the liner. The apparatus of claim 11, wherein the heat sink is detachably attached. The apparatus of claim 12, wherein the heat sink is attached by screwing. The apparatus of claim 11, wherein the heat sink is formed of graphite, graphite coated with SiC on the surface, or carbon fiber. The apparatus of claim 11, wherein the heat sink has a length that is close to the silicon melt without being in contact with the silicon melt. The apparatus of claim 11, wherein the heat sink has an inclination of 0 ° to 90 ° toward the single crystal ingot with respect to the cooler. A quartz crucible containing a silicon melt to grow a single crystal ingot, a crucible support for supporting the quartz crucible, a heater for heating the quartz crucible, a thermos to prevent heat from flowing out of the heater, and the silicon An apparatus for producing a single crystal ingot, comprising: an pulling apparatus for pulling up a single crystal ingot while growing from a melt, a heat shield surrounding the single crystal ingot so that heat of the heater is not transmitted, and a cooler for cooling the upper portion of the single crystal ingot. The cooler has two or more inlets and outlets each alternating, and has a plurality of first and second walls therein, respectively connected to the top and the bottom and extending from the bottom and the top, the plurality of first walls. And a second wall are formed alternately to form a channel between the inlet and outlet Has the property, the single crystal ingot production device further comprises a liner formed in contact with the inner surface of the cooler. 18. The apparatus of claim 17, wherein the coolers are arranged to be spaced at equal intervals while alternating inlets and outlets each having two or more. The apparatus of claim 17, wherein the cooler is formed such that an inner surface thereof is uneven. 18. The apparatus of claim 17, wherein the liner is formed such that the surface of the liner facing the single crystal ingot is uneven. The apparatus of claim 17, wherein the liner is made of graphite, graphite coated with SiC on the surface, or carbon fiber. 18. The apparatus of claim 17, wherein the liner is formed by processing the plate material in a round shape so that both ends thereof are spaced apart without overlapping. 19. The apparatus of claim 18, wherein the liner is formed of one, or two or more. 19. The apparatus of claim 18, further comprising a heat sink attached to the cooler and the lower edge of the liner. 25. The apparatus of claim 24, wherein the heat sink is detachably attached. 26. The apparatus of claim 25, wherein the heat sink is attached by screw engagement. The apparatus of claim 24, wherein the heat sink is formed of graphite, graphite coated with SiC on the surface, or carbon fiber. 25. The apparatus of claim 24, wherein the heat sink has a length that is proximate without contact with the silicon melt. The apparatus of claim 24, wherein the heat sink has an inclination of 0 ° to 90 ° toward the single crystal ingot with respect to the cooler. A quartz crucible containing a silicon melt to grow a single crystal ingot, a crucible support for supporting the quartz crucible, a heater for heating the quartz crucible, a thermos to prevent heat from flowing out of the heater, and the silicon An apparatus for producing a single crystal ingot comprising: an pulling apparatus for pulling up a single crystal ingot while growing from a melt; a heat shield surrounding the single crystal ingot so that heat of the heater is not transmitted; and a cooler for cooling the upper portion of the single crystal ingot. The cooler has two or more inlets and outlets each alternating, and has a plurality of first and second walls connected to the upper and lower portions, respectively, and extending from the lower and upper portions, respectively. A wall and a second wall are formed alternately to form a channel between the inlet and the outlet, a liner formed in contact with the inner surface of the cooler, and a heat sink attached to the cooler and the lower edge of the liner. Single crystal ingot manufacturing apparatus further comprising a sink). 31. The apparatus of claim 30, wherein the coolers are arranged to be spaced apart at equal intervals while the inlets and outlets each having two or more are alternately formed, and the inner surfaces thereof are uneven. 31. The apparatus of claim 30, wherein the liner is formed such that a surface of the liner facing the single crystal ingot is uneven. 31. The apparatus of claim 30, wherein the liner is formed of plate-shaped graphite, graphite coated with SiC on its surface, or carbon fiber roundly processed so that both ends thereof are spaced apart without overlapping. 31. The apparatus of claim 30, wherein the liner is formed of one or a plurality of two or more. 31. The apparatus of claim 30, wherein the heat sink is detachably attached by screwing. 31. The apparatus of claim 30, wherein the heat sink is formed of graphite, graphite coated with SiC on the surface, or carbon fiber. 31. The apparatus of claim 30, wherein the heat sink has a length that is in contact with the silicon melt without contact and has an inclination of 0 to 90 degrees toward the single crystal ingot with respect to the cooler.