JPS63285185A - Apparatus for pulling up silicon single crystal - Google Patents

Abstract

PURPOSE:To obtain an apparatus for pulling up Si single crystal and effective in suppressing the intrusion of CO gas and CO2 gas generated from a heater into molten Si material in a crucible, by placing a shielding part made to carbon between a crucible in a pulling up furnace and a heater placed around the crucible. CONSTITUTION:An Si material 53 is charged into a quartz crucible 54 of a crucible device 50 outside of a pulling up furnace 20 and the device 50 containing the Si material is put into the furnace 20. The space in the furnace 20 is evacuated 22 to 10-20Torr, the device 50 is rotated while supplying (B) an inert gas such as Ar gas through a pulling-up hole 21 and the Si material 53 is melted by heating with a heater 30. A suspended pulling-up wire 55 is introduced into the furnace through the pulling-up hole 21 and the seed crystal attached to the lower end of the wire is dipped into the Si material 53 and slowly pulled up to effect the growth of an Si single crystal 56. Even if CO gas or CO2 gas is generated from the heater 30, the intrusion of the gas into the material 53 in the device 50 can be prevented by a carbon-made shielding part 60 placed between the heater 30 and the device 50. Accordingly a high- quality Si single crystal can be produced by this apparatus.

Description

Detailed Description of the Invention (1) Purpose of the Invention [Field of Industrial Application] The present invention relates to a silicon single crystal melting device, and in particular to disposing a carbon shielding member between a heating heater and a crucible device. This suppresses the carbon oxide gas and carbon dioxide gas generated from the heating heater from being mixed into the molten silicon material in the crucible device, and ultimately reduces the concentration of carbon in the silicon single crystal. This invention relates to a silicon single crystal pulling device that suppresses the existence rate of latent crystal defects that grow into minute crystal defects in the subsequent heat treatment process over the entire length in the pulling direction, that is, the J & length direction. .

[Prior art] Conventionally, a crystal pulling device in silicon for uniformizing the # element or carbon concentration that forms the nucleus of this type of microdefects has been developed by adjusting the temperature gradient in the drawing furnace or rotating the crucible device. By using at least one of the methods, the concentration of oxygen in the silicon single crystal is adjusted to be uniform over the entire length in the pulling direction, that is, the r & length directions, and the potential abundance rate of crystal defects that grow into minute crystal defects during the subsequent heat treatment can be reduced. It has been proposed to adjust the temperature uniformly over the entire length in the pulling direction, that is, the growth direction.

[Problems to be solved] However, although oxygen can be made uniform to some extent in conventional silicon single crystal pulling equipment, the segregation coefficient of carbon is less than 1, so the molten silicon material in the crucible equipment There is a drawback that the overall concentration of carbon monoxide and J-carbon oxide mixed in the silicon increases over time, and as a result, the concentration of carbon gradually increases as the silicon single crystal grows. In particular, the carbon concentration at the terminal portion increased, making it unsuitable for practical use.

Therefore, in order to eliminate these drawbacks, the present invention disposes a carbon shielding member between the crucible device and the heating heater that generates the largest amount of carbon monoxide gas or carbon dioxide gas among the constituent members. , suppresses carbon monoxide gas and carbon dioxide gas from directly flying into the molten silicon material in the crucible device from the heating heater, and further reduces the amount of carbon monoxide and carbon dioxide in the molten silicon material in the crucible device. The contamination concentration is suppressed, and as a result, the concentration of carbon in the silicon single crystal is suppressed over the entire length in the pulling direction, that is, the growth direction. It is an object of the present invention to provide a silicon single crystal pulling device that suppresses the growth of silicon single crystals in one direction, that is, over the entire length in the growth direction.

(2) Structure of the invention [Means for solving problems] The solution to the problem provided by the present invention is as follows.

In a silicon single crystal pulling device in which a heating heater is arranged around a crucible device in a two-furnace, a carbon shielding member is arranged between the heating heater and the crucible device. 2 devices featuring silicon crystals.

[Function] Silicon single crystal drawn L according to the present invention! The device has a carbon shielding member placed between the heating heater and the crucible device, in other words, carbon monoxide gas and carbon dioxide gas generated from the heating heater are protected against the molten silicon material in the crucible device. It has the effect of suppressing contamination by
Furthermore, the concentration of carbon in the silicon single crystal is suppressed over the entire length in the pulling direction, that is, the growth direction, and the abundance rate of latent nuclei that grow into minute crystal defects in the subsequent heat treatment process is suppressed over the entire length in the pulling direction, that is, the growth direction. act.

[Example] Next, the present invention will be explained in detail with reference to the accompanying drawings.
JI.

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

FIG. 2 is an explanatory diagram of the same operation, in which the length of the silicon single crystal in the pulling direction, that is, the growth direction, is scaled with the tip as the origin on the horizontal axis, and the carbon concentration in the silicon single crystal is plotted on the vertical axis. It is scaled.

First, the structure of an embodiment of the silicon single crystal device of the present invention will be described in detail.

This is a device in the silicon single crystal of unexploited IJ1, and a heater ear for heating is arranged inside the YuJ-furnace. pull 1
A drawing hole 21 is formed at the bottom of L and is connected to a vacuum pump (not shown) as an evacuation means. An exhaust hole 22 is formed.A heat insulating member concavity is provided between the heating heater 4 and the pull-up 1.The heat insulating member is a heat insulating cylinder located on the outer periphery of the heating heater η. The heat retaining ring 42 is located on the L side and is similar to a heating heater.The heater ear is cylindrical and is connected to an appropriate power source (not shown). Inside it, there is a rotating lift 22 (1:
A crucible device is fixed to one end of a rotating shaft 51 (not shown). The crucible device includes a carbon crucible (which may be a SiC coated crucible) 52 fixed to a rotating shaft 51 and a quartz crucible 54 disposed within the carbon rubra 2 and containing a silicon material 53. There is. A silicon material 53 such as polysilicon, which is melted and housed in a quartz crucible 54, is pulled up from a pull-up chamber using a pull-out wire member 55 with a seed crystal (not shown) attached to the tip. It hangs down through the draw hole 21 of.

between the heater base for heating and the crucible assembly 2250.

A carbon shield material made of a highly insulating and thermally conductive material (for example, a silicon carbide material) is provided, and its E end is brought into contact with the heat retaining ring 42 . Therefore, even if carbon monoxide gas and carbon dioxide gas are generated while heating the silicon material 53 of the crucible assembly fi50 from the heating heater base made of carbon material, the carbon oxide gas and carbon dioxide gas will be removed from the crucible. It is possible to prevent the particles from flying directly to the molten silicon material 53 in the container and the chamber, and furthermore, it is possible to prevent them from being mixed into the molten silicon material 53.

Furthermore, the operation of one embodiment of the apparatus for undeveloped IJ1 silicon single crystal will be explained in detail.

After storing the silicon material 53 in the quartz crucible 54 of the crucible device outside the two drawing furnaces, the crucible device 2 is placed inside the drawing furnace by a rotating lifting device (not shown).

Thereafter, the exhaust is evacuated from the exhaust hole 22 in the direction of arrow A by an exhaust stage R (not shown) until the pressure reaches 10 to 2 Torr, and the inert gas source is removed through the pulling chamber and the pulling hole 2I. While supplying an active gas such as argon gas in the direction of arrow B.

While the crucible device is rotated by the rotating shaft 51, an appropriate voltage is applied to the heating heater base from an appropriate power source (not shown). Along with this, the heating heater base heats and melts the silicon material 53 housed in the quartz crucible 54 of the crucible device. At this time, since the heat insulating members are arranged around the heater base, heating and melting of the silicon material 53 can proceed efficiently.

When the silicon material 53 is sufficiently melted, the pulling wire member 55 is removed from the pulling chamber through the hole 21.
of! It is lowered and immersed in the molten silicon material 53 in the crucible Hso, which is a seed crystal attached to the tip thereof, and then slowly pulled toward the pulling chamber. Along with this, a silicon single crystal 56 is grown and formed.

At this time, in the present invention, since the carbon shielding member is disposed between the heating heater base and the crucible device,
Even if carbon monoxide gas and carbon dioxide gas are generated from the heating heater base, it is possible to prevent the crucible from directly flying into and mixing with the molten silicon material 53 in the chamber. The concentration of carbon can be suppressed over the entire length in the pulling direction, that is, the growth direction, and the existence rate of latent nuclei that J & lengthen to minute crystal defects in the subsequent heat treatment process can be suppressed over the entire length in the pulling direction, that is, the growth direction.

In order to better understand the operation of the silicon crystal pulling apparatus of the present invention described above, specific numerical values will be given and explained.

Silicon single crystal pulling apparatus i! of the present invention shown in FIG. 1
At 1G, with only 15 kg of polysilicon as the silicon material 53 housed in the quartz crucible 54, the inside of the IJji 20 was kept at 15)--, and while supplying argon gas, it was heated to the heater base for heating. A voltage of 48 volts was applied and a current of 1800 bears was applied.

At this time, the rotational speed of the rotating shaft 51 was appropriately selected to grow a silicon single crystal 56 with a diameter of 125mm and an orientation of (1,0,0).
The concentration of carbon contained in 6 was as shown by the solid line in FIG.

As a comparative example, the concentration of RA (contained in a silicon single crystal grown using a conventional silicon single crystal pulling apparatus without a carbon shielding member) is shown by a broken line. According to this comparative example, the carbon concentration is suppressed particularly at the terminal end of the silicon single crystal, and the carbon concentration is kept almost constant from the tip to the terminal end of the silicon single crystal.

In addition, in the above, the heat insulation member, i! ! The present invention is not limited to this, and it may be removed depending on the location.

Furthermore, the unreleased IJ1 is not limited to being rotated by the rotating shaft 51 or may be configured to remove the rotating shaft 51 if desired.

(3) Effects of the Invention As is clear from the description, the present invention provides a silicon single crystal device comprising a heating heater arranged around a crucible device in a drawing furnace. A carbon shielding member is placed between the crucible and the crucible device.

(i) Carbon monoxide gas and carbon dioxide gas generated from the heating heater are suppressed from flying directly to the molten silicon material in the crucible device, and as a result, they are prevented from contaminating the molten silicon material. As a result, (ii) the carbon concentration in the silicon width crystal can be sufficiently suppressed even at the end of growth, and the concentration can be maintained almost constant from the tip to the end. has.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an embodiment of the present invention, and FIG. 2 is an explanatory diagram of the same operation. 10・・・・・・・・・・・・・・・Transfer the device to the silicon crystal crystal・・・・・・・・・・・・・・・Two furnaces 2 ■・・・・・・・・・・・・・・・Draw hole 22・・・・
・・・・・・・・・Exhaust hole ear・・・・・・・・・・・・
・・・・・・Heating heater 赳・・・・・・・・・・・・
...Thermal insulation member 41...Thermal insulation cylinder body 42...Thermal insulation ring body 50
・・・・・・・・・・・・・・・ Crucible device 5I...
......Rotating shaft 52...
・・・・・・・・・Carbon crucible 53・・・・・・・・・
・・・・・・Silicon material 54・・・・・・・・・・・・
・・Quartz crucible 55・・・・・・・・・・・・・M member for pulling 60・・・・・・・・・・・・・Carbon shielding member Patent applicant Toshiba Ceramics Co., Ltd. Company Representative Patent Attorney Takao Kudo Figure 1

Claims (1)

[Claims] A silicon single crystal pulling device comprising a heating heater arranged around a crucible device in a pulling furnace, characterized in that a carbon shielding member is arranged between the heating heater and the crucible device. Silicon single crystal pulling equipment.