JPS6051691A - Growing apparatus of single crystal semiconductor - Google Patents

Abstract

PURPOSE:To provide a titled apparatus free from fear of a magnetic field leakage and with small consumption of energy by winding a couple of coils to the inner surface side of an outer magnetic body constituting a chamber to generate a magnetic field, and constituting an inner magnetic body capable of being cooled. CONSTITUTION:A crucible 16 is supported by a supporting rod 14 freely rotatably in a chamber 11 in a titled apparatus. A seed crystal 20 which is hung down by a chain 19 is immersed in a molten semiconductor material 24 obtained by heating with a heater 17, and then pulled up to grow a single crystal semiconductor 25. Said chamber 11 is formed of a nonmagnetic stainless steel body 12 equipped with a cooling waterway 21 and a magnetic stainless steel body 13 surrounding the outside. In addition a couple of coils 22 and 23 are wound around the inner surface side of said magnetic body 13 at the position of the side surface of the crucible 16 facing each other, and a magnetic field is impressed to the molten semiconductor material 24. The chamber 11 proper is used as a yoke in this way, and the leakage of the magnetic field is eliminated. The consumption of energy can be reduced because the whole body of the chamber 11 is easily cooled.

Description

[Detailed description of the invention] [Technical field of invention] TECHNICAL FIELD The present invention relates to an improvement in an apparatus for growing a crystalline semiconductor.

[Technical background of the invention and its problems]

Fluorescent crystal semiconductors used for manufacturing semiconductor devices are mainly manufactured by the Czochralski method (C2 method). For example, when manufacturing single crystal silicon, this method
It is as follows. In other words, a quartz crucible is rotatably supported in a chamber, a silicon raw material is put into the quartz crucible and melted by a heater placed around the crucible, and a seed is suspended rotatably from above the molten silicon. Single-crystal silicon is grown by dipping the crystal and pulling up the seed crystal.

By the way, in this method, during the growth of single crystal silicon, forced convection and thermal convection occur in the molten silicon due to rotation, so the impurity concentration unevenness (striation) in the grown single crystal silicon becomes significant. The disadvantage is that it is difficult to freely control the concentration.

Therefore, a technique is known in which a magnetic field is applied to the molten semiconductor raw material in the H-acid of the nested crystal semiconductor (for example,
104791. Unexamined Japanese Patent Publication No. 56-104795, Unexamined Japanese Patent Publication No. 5
6-121339° JP-A-57-] 49894, etc.).

The schematic structure of these conventional single crystal semiconductor growth apparatuses is as shown in FIG. 1 or 2.

That is, the device shown in FIG. Two normal conducting magnets 31 * 32 are arranged at positions corresponding to both sides of the magnet 2 so that the poles of different polarities face each other. This device uses normal conducting magnets) J...? ! By Ruth? A single crystal semiconductor 6 is grown by immersing a seed crystal 5 in the molten semiconductor raw material 4 and pulling it up while applying a horizontal magnetic field (indicated by a broken line in the figure) to the molten semiconductor raw material 4 in the molten semiconductor raw material 2 .

The device shown in FIG. 2 is the same as the device shown in FIG.
In place of the individual normal conducting magnets J1*32, a ring-shaped normal conducting or superconducting magnet 7 is arranged around the outer periphery of the chamber 1. In this device, a normal conductor b is applied by applying a vertical magnetic field (indicated by a broken line in the figure) to the molten semiconductor raw material 4 in the Rud 2 using a superconducting magnet 7, and immerses a seed crystal in the molten semiconductor raw material 4. By pulling, a single crystal semiconductor 6 is grown.

These devices can suppress convection within the molten semiconductor raw material 4, thereby reducing the occurrence of striations in the grown single crystal semiconductor and making it easier to control the level of impurity concentration. There is.

However, conventional devices have the following problems.

(1) In the apparatus shown in FIG. 1, two normal conducting magnets are arranged on the left and right sides of the chamber, so the entire apparatus becomes extremely large. In addition, the cooling system for the chamber and the magnet are separate systems, which increases energy consumption. Also,
In the device shown in Figure 2, when a superconducting magnet is used and the refrigerant for cooling the first magnet is used as a closed circuit, the energy consumption is small, but when a normal conducting magnet is used, the energy consumption is small.
Like the device shown in the figure, energy consumption is large.

(11) Various sensors for executing computer control are installed in the breeding device. However, in both the apparatuses shown in Figures 1 and 2, the magnetic field acts even at a location far away from the molten semiconductor raw material, so such leakage magnetic fields can cause sensor malfunctions and phenomena such as image distortion of the TV sensor. For example, diameter control may become impossible. Therefore, there is a drawback that the sensor must be installed at a very distant location or a shield must be provided for each sensor.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and provides an apparatus for growing high-quality quartz crystalline semiconductors without adversely affecting various control sensors and with low energy consumption. = 4%.

[Summary of the invention]

In the single-crystal semiconductor growth apparatus of the present invention, the chamber is formed of a non-magnetic material and a magnetic material surrounding the outside thereof, and the magnetic material is arranged such that poles with different polarities are generated at mutually opposing positions on the Ludde side surface of the magnetic material. A pair of coils are wound around the inner surface of the body to apply a magnetic field to the molten semiconductor raw material, and a coolant is caused to flow within the non-magnetic body or between the non-magnetic body and the magnetic body.

According to such a device, since the chamber itself serves as a yoke, there is no fear of magnetic field leakage and there is no adverse effect on various sensors for control. In addition, by flowing a refrigerant inside the non-magnetic material or between the non-magnetic material and the magnetic material, the entire chamber can be cooled, and the temperature rise caused by the heater and coil can be prevented at the same time, resulting in low energy consumption. .

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 3 and 4.

Reference numeral 11 in FIG. 3 is a chamber with an open top and bottom, consisting of a non-magnetic stainless steel 12 with an inner diameter of 6]0+a and a magnetic stainless steel 13 with a thickness of 15 or more surrounding the non-magnetic stainless steel 12.

A support rod 14 is rotatably inserted into the lower opening of the chamber 11 to support a graphite protector 15, which has an internal diameter of 12 inches (304,8 m+
) of quartz rutz? 16 is protected. A heater 17 and a heat retaining tube 18 are sequentially arranged around the outer periphery of the protector 15. For example, a chain 19 is suspended from the upper opening of the chamber 11, and holds 20 seed crystals.

Further, a cooling water passage 2 is provided inside the non-magnetic stainless steel 12 constituting the chamber 11, so that cooling water flows therethrough. Furthermore, chamber 11
A pair of coils 22 and 23 are wound around the winding groove on the inner surface of the magnetic stainless steel 13 constituting the magnetic stainless steel 13 so that nuclei of different polarities are generated at positions opposite to the recesses on the side surface of the ruby 16. . A direct current of 20 A or more can be passed through these coils 22 and 23.

Growth of a single crystal semiconductor using the above apparatus is performed as follows. For example, a silicon raw material is put into the Rugge 16 without being separated, and is melted by the heater 17 in, for example, an argon gas atmosphere. As shown in FIG. 4, a horizontal magnetic field (indicated by strong arms in the figure) is applied to this molten silicon 24 by coils 22 and 23 as shown in FIG. 4, and cooling water is caused to flow into the non-magnetic stainless steel 12. In this state, the seed crystal 2o is immersed in the molten silicon 24, and the single crystal silicon 25 is grown by pulling up the seed crystal 20 while rotating the Luppi 16 and the seed crystal 20 in opposite directions.

According to the above device, the magnetic stainless steel 13 constituting the chamber 11 has the coils 22 and 23f.
The magnetic stainless steel 13 itself becomes a yoke, and its interior can be used as a closed circuit for the magnetic field.
There is no risk of magnetic field leakage to the outside. Therefore, there is no adverse effect f# on various sensors for control (for example, diameter control can be performed well. Also, the chamber 1
Since cooling water is flowing inside the non-magnetic stainless steel 12 constituting the chamber 1, the entire chamber 11 can be cooled. Therefore, it is possible to simultaneously prevent temperature rise due to the heater 17 and temperature rise due to the coils 22, 23, resulting in less energy consumption.

Moreover, by applying a magnetic field, convection in the molten silicon 24 can be suppressed and the quality of the single crystal silicon 25 can be improved.

In fact, using the above-mentioned apparatus, 20 yen of high purity silicon raw material was charged into the Luzde 16, and 1500 yu of high-purity silicon material was charged into the Luzde 16 using the normal dislocation-free short crystal growth method using the dash method using the coils 22 and 23.
While applying a Gaussian magnetic field, single-crystal silicon was grown with the goal of having a diameter of 103±1 cm, a specific resistivity of 1 to 3 Ω・cm + N type, and a crystal orientation of (100), and the results shown in Table 1 below were obtained. Obtained. Note that the reference examples in Table 1 below are based on the normal C2 method in which no magnetic field is applied.

From Table 1 above, it can be seen that the variations in specific resistivity and minute specific resistivity distribution are improved.

Further, when comparing the device dimensions, leakage magnetic field, and cooling cost with the conventional device (comparative example) shown in FIG. 1, the results shown in Table 2 below were obtained.

From Table 2 above, it can be seen that the single crystal semiconductor growth apparatus of the present invention is compact in size and far superior in terms of leakage magnetic field and cooling costs compared to conventional apparatuses.

In the above embodiment, the cooling water was flowed inside the non-magnetic stainless steel that constitutes the chamber, but the cooling water is not limited to this and may be flowed between the non-magnetic stainless steel and the magnetic stainless steel. Additionally, in addition to these, cooling water may also be allowed to flow inside the magnetic stainless steel to mainly prevent temperature increase due to the coil.

Furthermore, although the above description has been made regarding the case of growing single-crystal silicon, it goes without saying that the apparatus of the present invention can also be used to grow other single-crystal semiconductors such as GaAs.

〔Effect of the invention〕

As detailed above, according to the phoenix crystal semiconductor growth apparatus of the present invention, there is no adverse effect on various sensors for control.
This method has remarkable effects such as being able to grow high quality single crystal semiconductors with less energy consumption.

[Brief explanation of drawings]

Figures 1 and 2 are schematic diagrams of conventional single crystal semiconductor growth equipment, respectively, Figure 3 is a sectional view of a single crystal semiconductor growth equipment in an embodiment of the present invention, and Figure 4 is the state of the magnetic field in the equipment. FIG. 1 No... Chamber s12... Non-magnetic stainless steel, 13... Magnetic stainless steel, 14
...Support rod, 15...Homan body, 16...Rusude,
17... Heater, 18... Heat insulation cylinder, 19... Chain, 20... Seed crystal, 2... Cooling water channel, 22
, 23... Coil, 24... Molten silicon, 25
...Single crystal silicon. Applicant's agent Patent attorney Takehiko Suzue No. 21iii Figure 3

Claims (1)

[Claims] A device for growing a single crystal semiconductor by rotatably supporting a Rugge in a chamber, and pulling up a nuclide crystal by dipping a seed crystal rotatably suspended from above the Rugge into the molten semiconductor raw material in the crucible. In the method, the chamber is formed of a non-magnetic material and a magnetic material surrounding the outside thereof, A pair of coils are wound around the inner surface of the magnetic material so that poles with different polarities are generated at mutually opposing positions on the side surface, and a magnetic field is applied to the molten semiconductor raw material. A single crystal semiconductor growth device characterized by flowing a coolant between the body and the body.