JP2582582B2 - Silicon single crystal pulling equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Object of the Invention [Industrial Application Field] The present invention relates to a silicon single crystal pulling apparatus, and in particular, by supplying a high-temperature inert gas to a heat treatment furnace.
The power consumption in the heat treatment furnace is reduced, the time required for melting the silicon material is shortened, and at the same time, a low-temperature inert gas is supplied to the pull-up passage of the silicon single crystal to pull the silicon single crystal. The present invention relates to a silicon single crystal pulling apparatus which is cooled immediately after the above to suppress the growth of crystal defect nuclei.

[Prior Art] Conventionally, as this type of silicon single crystal pulling apparatus, one that supplies an inert gas at room temperature to a heat treatment furnace in a reduced pressure state via a pulling chamber has been proposed.

[Problems to be Solved] However, in the conventional silicon single crystal pulling apparatus, since the inert gas removes heat from the silicon material melted in the heat treatment furnace, the power consumption of the heater for heating the silicon material is reduced. There are disadvantages that increase and that a long time is required for melting the silicon material, and that there is a disadvantage that growth of crystal defect nuclei in a pulled silicon single crystal cannot be suppressed.

In order to eliminate these drawbacks, the present invention raises the temperature of the inert gas supplied to the heat treatment furnace in advance, thereby reducing power consumption in the heating heater and shortening the time required for melting the silicon material. Is achieved, and the inert gas supplied to the silicon single crystal pulling passage is cooled in advance, whereby the silicon single crystal is cooled immediately after the pulling, thereby suppressing the growth of crystal defect nuclei. It is intended to provide a silicon single crystal pulling apparatus.

(2) Configuration of the Invention [Means for Solving the Problems] The means for solving the problems provided by the present invention is as follows: "A heating heater is provided around a crucible device in a heat treatment furnace, and silicon is used in the crucible device. In a silicon single crystal pulling apparatus formed by melting a material and pulling a silicon single crystal, a high-temperature inert gas is supplied to the heat treatment furnace, and a low-temperature inert gas is passed through the silicon single crystal pulling passage. And a silicon single crystal pulling apparatus.

[Operation] The silicon single crystal pulling apparatus according to the present invention has an operation of supplying a high-temperature inert gas to a heat treatment furnace and an operation of supplying a low-temperature inert gas to a silicon single crystal pulling passage. As a result, it has the effect of reducing the power consumption of the heater for heating and the effect of shortening the time required for melting the silicon material, and at the same time, the effect of suppressing the growth of nuclei of crystal defects in the silicon single crystal. Eggplant

EXAMPLES Next, the present invention will be specifically described with reference to the accompanying drawings.

FIG. 1 is a sectional view showing one embodiment of a silicon single crystal pulling apparatus of the present invention.

FIG. 2 is an explanatory view of the operation, in which the horizontal axis indicates the length of the silicon single crystal in the pulling direction, that is, the crystal growth direction, with the origin as the origin, and the vertical axis indicates the concentration of crystal defects. ing.

First, the configuration of an embodiment of the silicon single crystal pulling apparatus of the present invention will be described in detail.

10 is a silicon single crystal pulling apparatus of the present invention, heat treatment furnace 20
The heater 30 for heating is arranged inside the. Heat treatment furnace
20 has a pull-up hole 22 connected to a pull-up chamber 21 at the upper bottom.
Is formed, and an exhaust pipe 23 communicated with a vacuum pump (not shown) as an exhaust means is provided at a lower bottom portion. The heating heater 30 has a cylindrical shape and is connected to an appropriate power supply (not shown), and the inside thereof is extended toward a rotary elevating device (not shown) below and outside the heat treatment furnace 20. A crucible device 50 fixed to one end of the connected rotary shaft 51 is arranged. The crucible device 50 includes a carbon crucible 52 fixed to a rotary shaft 51 and a carbon crucible.
A quartz crucible 54 disposed within 52 and containing a silicon material 53 is included. With respect to the silicon material 53 housed and melted in the quartz crucible 54, a pulling wire member 55 having a seed crystal (not shown) attached to the tip thereof through a pulling hole 22 of the heat treatment furnace 20. From the lifting chamber 21.

Reference numeral 60 denotes an inert gas supply device, one end of which is a lifting chamber 21.
After being extended along the inner peripheral surface of the heating chamber 30 , it is opened in the vicinity of the heating heater 30 , and the other end is extended from the upper end of the lifting chamber 21 to the outside of the lifting chamber 21, and then, via a temperature control device 61. Gas supply pipe 63 communicated with an inert gas source 62
Is included. The inert gas supply device 60 also includes another inert gas supply pipe 65 extending from the inert gas source 62 to the upper end of the lifting chamber 21 via another temperature control device 64. Prior to reaching the lifting chamber 21, a hoisting device 66 is provided in the inert gas supply pipe 65 so that the extension distance into the lifting chamber 21 can be adjusted. Therefore, it is preferable that the inert gas supply pipe 65 be formed of a flexible material in a portion below the hoisting device 66. Reference numeral 67 denotes an annular inert gas ejection member having a plurality of ejection ports 67a formed in the inner peripheral surface thereof, which is disposed at the tip of the inert gas supply pipe 65, and is vertically inserted into the lifting chamber 21. It is movable along a guide member 68 provided. 69 is an inert gas supply device 60
A temperature control device included in the heat treatment furnace 20 according to the temperature detected by a temperature sensor 70 disposed in the heat treatment furnace 20 (especially preferably above the heating heater 30 and near the pulling-up passage of the silicon single crystal 56). , And outputs a temperature control signal to the temperature control devices 61 and 64.

Further, the operation of one embodiment of the silicon single crystal pulling apparatus of the present invention will be described in detail.

After the silicon material 53 is accommodated in the quartz crucible 54 of the crucible device 50 outside the heat treatment furnace 20 , the crucible device 50 is inserted into the inside of the heat treatment furnace 20 from below by a rotary elevating device (not shown). After that, exhaust means (not shown)
The heat treatment furnace 20 is evacuated in the direction of arrow A through the exhaust pipe 23 until the pressure reaches 10 to 25 Torr, and the inert gas is supplied from the inert gas supply device 60 through the pulling chamber 21 and the pulling hole 22 (for example, (Argon gas) while rotating shaft
An appropriate voltage is applied to the heater 30 from the appropriate power source (not shown) while the crucible device 50 is rotated by the rotary elevating device via 51. Along with this, a heater for heating
30 heats and melts the silicon material 53 contained in the quartz crucible 54 of the crucible device 50 .

At this time, when the inert gas is transferred from the inert gas source 62 to the upper end of the lifting chamber 21 via the inert gas supply pipes 63 and 65, the temperature is adjusted to a desired temperature by the temperature controllers 61 and 64. ing. That is, in response to an appropriate temperature control signal generated by the temperature control device 69 in accordance with the temperature detected by the temperature sensor 70, the temperature control devices 61 and 64 pass through the inert gas supply pipes 63 and 65, and the heating heater The temperature of the inert gas supplied to the vicinity of 30 and the pull-up passage of the silicon single crystal 56 is set to an appropriate temperature (for example, 150 ° C. and normal temperature, respectively) so that the temperature in the vicinity of the heater 30 becomes constant.

Thereby, the heat melting of the silicon material 53 is efficiently advanced, and when the silicon material 53 is sufficiently melted,
A pull-up wire member 55 is hung from the pull-up chamber 21 through the pull-up hole 22 of the heat treatment furnace 20 , and the seed crystal attached at the tip is immersed in the silicon material 53, and then pulled slowly. increase. Along with this, a silicon single crystal 56 is grown and formed,
It is pulled up to the pulling chamber 21 through the pulling hole 22.

An inert gas jetting member 67 is on standby near the pull-up passage of the silicon single crystal 56, and jets an inert gas at an appropriate temperature toward the peripheral surface of the silicon single crystal 56 as the silicon single crystal 56 is pulled. . As soon as the silicon single crystal 56 is pulled up from the crucible device 50 , it is cooled by the low-temperature inert gas ejected by the inert gas ejecting member 67, thereby preventing nuclei of crystal defects from growing. The standby position of the inert gas ejection member 67 may be appropriately set by the hoisting device 66 corresponding to the time from the pulling of the silicon single crystal 56 to the cooling.

In the silicon single crystal pulling apparatus 10 of the present invention, the heat treatment furnace 20
Since the temperature of the inert gas (eg, argon gas) supplied to the heating heater 30 or the crucible device 50 is raised to a desired temperature, the power consumption in the heating heater 30 can be reduced, and silicon Since the inert gas (eg, argon gas) supplied to the pull-up passage of the single crystal 56 has been lowered to a desired temperature, the silicon single crystal 56 is cooled after being pulled up, and crystal defect nuclei are grown. Can be prevented.

In order to further understand the operation of the silicon single crystal pulling apparatus 10 of the present invention, specific numerical values will be described.

(Embodiment) In the silicon single crystal pulling apparatus 10 of the present invention shown in FIG. 1, the inside of the heating furnace 20 is depressurized through the exhaust pipe 23, and the inert gas supply apparatus 60 supplies the inert gas supply pipe 63. When a voltage of 46 volts was applied to the heater 30 and a current of 1640 amps was applied to the heater 30 while supplying argon gas at 150 ° C. to the heater 30 at 15 Torr through the quartz crucible 54, 30 kg of the polysilicon or silicon material 53 contained in the sample could be melted in 2.5 hours.

After the silicon material 53 is melted, the inert gas supply pipe
The supply of argon gas through 63 is continued, and the rotation speed of rotary shaft 51 is appropriately selected while injecting argon gas at room temperature from inert gas ejection member 67 at 15 Torr through inert gas supply pipe 65. Then, the seed crystal was pulled up by the pulling wire member 55 to grow a silicon single crystal 56 having a diameter of 5 inches (12.7 cm).

At this time, the power consumed by the heating heater 30 was 75 kWh, and the number of crystal defect nuclei generated and grown in the silicon single crystal 56 was as shown in FIG.

(Comparative Example) The temperature of the argon gas supplied from the inert gas supply device 60 into the heat treatment furnace 20 is set to 25 ° C., and the supply of the low-temperature inert gas to the silicon single crystal pull-up passage is stopped. The example was repeated except for.

The time required from when the voltage was started to be applied to the heater 30 to when the polysilicon, that is, the silicon material 53 was melted, was 4 hours.

The power consumed by the heating heater 30 was 90 kWh, and the number of crystal defect nuclei generated and grown in the silicon single crystal was as shown in FIG.

According to the present invention, in particular, the heater 30
As a result, the power consumption and the melting time of the silicon material 53 can be reduced, and the number of crystal defect nuclei in the silicon single crystal can be reduced.

Although the crucible device 50 is rotated by the rotating shaft 51, the present invention is not limited to this,
If desired, the rotary shaft 51 may be removed.

(3) Effects of the Invention As is apparent from the above description, the silicon single crystal pulling apparatus according to the present invention has a heating heater disposed around a crucible apparatus in a heat treatment furnace, and melts the silicon material with the crucible apparatus. A silicon single crystal pulling apparatus which pulls up a silicon single crystal by supplying a high-temperature inert gas to the heat treatment furnace, and supplies a low-temperature inert gas to a pull-up passage of the silicon single crystal. (I) has the effect of reducing the heat taken from the molten silicon material, and (ii) has the effect of reducing the power consumption of the heating heater, and (iii) has the effect of reducing the power consumed by the heating heater. This has the effect of shortening the time required for melting the material, and has the effect of (iv) suppressing the growth of nuclei of crystal defects in the silicon single crystal.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is an explanatory view of the operation. 10 Silicon single crystal pulling device 20 Heat treatment furnace 21 Pulling chamber 22 Pulling hole 23 Exhaust pipe 30 Heating heater 50 Crucible device 51 Rotating shaft 52 Carbon crucible 53 Silicon material 54 Quartz crucible 55 Pulling wire member 56 Silicon single crystal 60 Inert gas supply device 61, 64 Temperature control device 62 Inert gas source 63 , 65… inert gas supply pipe 66… hoisting device 67… inert gas ejection member 68… guide member 69… temperature control device 70… temperature sensor

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-53-8374 (JP, A) JP-A-52-61180 (JP, A) JP-A-49-15366 (JP, A) JP-A-60-180 77115 (JP, A)

Claims (1)

(57) [Claims] 1. A silicon single crystal pulling apparatus in which a heating heater is provided around a crucible device in a heat treatment furnace and a silicon material is melted by the crucible device to pull up a silicon single crystal. A silicon single crystal pulling apparatus, wherein an inert gas is supplied to the heat treatment furnace, and a low-temperature inert gas is supplied to a pulling passage of the silicon single crystal.