JPH06211593A - Crucible for crystal growing device - Google Patents

Abstract

PURPOSE:To provide the crucible which maintains the angularly symmetrical flow of molten crystal raw material and prevents the vortex structure to be generated in a circumferential direction even in high-speed crucible rotation at the time of growing the crystal. CONSTITUTION:Plural sheets of plate members 2 projecting in a radial direction are mounted to the inside wall of the crucible 1 to segment the inside of the crucible and the melt convection is suppressed within these segmented parts, by which the movement in the circumferential direction is regulated. As a result, the melt convection is approximated to the angularly symmetrical flow and the generation of the vortex structure in the circumferential direction is prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crucible for a crystal growing apparatus used when growing a semiconductor crystal by using the Czochralski method or the liquid sealed Czochralski method.

[0002]

2. Description of the Related Art Conventionally, when growing a crystal of silicon (Si), gallium arsenide (GaAs) or the like by using the Czochralski method or the liquid-encapsulated Czochralski method, the crucible containing the crystal raw material is set to 0. Crystals are grown by rotating at 0.5-1 rpm. However, the temperature distribution in the crucible deviates from the rotation center axis due to the limit of machining accuracy for the heat insulating material that constitutes the crystal pulling device,
Therefore, as shown in the cross-sectional view of FIG. 2, the phenomenon that the left and right melt convections 3 are not symmetrical about the rotation axis occurs. In order to compensate for this deviation from the axial symmetry, the rotation of the crucible should be 10-2.
It was increased to 0 rpm and rotated at high speed to grow crystals.

[0003]

However, in the conventional crucible, as described above, when the rotation speed of the crucible is increased, a vortex structure in the circumferential direction is generated in the melt, and the doping material in the grown crystal or It is known that the distribution of impurities such as oxygen becomes non-uniform. Therefore, even when the crucible is rotated at such a high speed, a crucible having a structure capable of obtaining an axisymmetric flow is required.

An object of the present invention is to provide a crucible for crystal growth capable of realizing an axisymmetric flow of a melt even when the crucible rotates at a high speed.

[0005]

According to the present invention, in order to suppress and hold a melt flow in the circumferential direction during crucible rotation, a crystal provided with a plate-shaped convection-suppressing plate protruding in the radial direction on the inner wall of the crucible. It is a crucible for growing equipment.

[0006]

According to the present invention, the axisymmetric flow of the melt is stopped in each partition by partitioning the crucible into a plurality of locations by the convection inhibiting plates, and as a result, the vortex structure generated in the circumferential direction by the high speed rotation is eliminated. Has a suppressing effect.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a crucible capable of realizing an axisymmetric flow even at high speed rotation will be described below with reference to the drawings. FIG. 1 is a view showing an embodiment of the present invention, and is a plan view (a) and a side view (b) showing a structure of a crucible for making a silicon convection convection symmetrical.

As shown in FIG. 1, in this embodiment, four rectangular plate members 2 made of quartz having a length of one side approximately half the radius of the crucible 1 are provided in the radial direction from the inner wall of the crucible 1. The convection suppression plate is realized by protruding and welding.
The size and number of the quartz plates are not limited to the above-mentioned four rectangular shapes, and trapezoidal or triangular shapes can be used as long as they have a shape that prevents convection in the radial direction. When a silicon crystal was melted in the crucible of this example and melt convection was observed by X-ray fluoroscopy, it was possible to realize an axisymmetric flow even at a rotation speed of 15 rpm.

In the above embodiment, silicon (S
i) and germanium (Ge) crystal growth have been described as targets, but in crystal growth of compound semiconductors represented by gallium arsenide (GaAs) and indium phosphide (InP), pyrolitec boron nitride (p) is used. −
Since BN) is used as a crucible material, it can be realized by mounting a p-BN convection suppressing plate in the crucible by plasma welding.

[0010]

As described above, in the present invention, by providing the convection inhibiting plate in the crucible, it is possible to realize an axisymmetric flow even when the crucible is rotating at a high speed.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, in which FIG. 1 (a) is a plan view and FIG. 1 (b) is a side view.

FIG. 2 is a cross-sectional view showing melt convection in a crucible.

[Explanation of symbols]

 1 Crucible 2 Plate member 3 Melt liquid flow

Claims (2)

[Claims] 1. A crucible for a crystal growing device used in the Czochralski method or the liquid-encapsulated Czochralski method, comprising:
A crucible for a crystal growing apparatus, characterized in that a plurality of plate members protruding in a radial direction are attached to an inner wall of the crucible, and the plate serves as a convection suppressing plate that suppresses melt convection in a circumferential direction in a rotating crucible. 2. The crucible for a crystal growing apparatus according to claim 1, wherein the number of the plate members is four.