JPH0230692A - Apparatus for pulling up semiconductor single crystal - Google Patents

Abstract

PURPOSE:To enable free control of the rotational speed of a crucible by combining a rotatable crucible, a heater, a uniform-temperature wall and a semiconductor single crystal pull-up means in such a manner as to exert a specific action. CONSTITUTION:Two coaxial supporting shafts are extended through an opening 12a. A cylindrical uniform-temperature wall 14 made of carbon or calcined BN is attached to the top end of the outside hollow 1st supporting shaft 13 interposing a space between a heater 12. The uniform-temperature wall 14 is provided with an opening 14a inside of the connection part of the 1st supporting shaft 13 and the inside 2nd supporting shaft 23 is extended through the opening 14a. A table 15 is attached to the top of the 2nd supporting shaft 23 extending through the opening 14a. The table 15 is kept from contact with the uniform-temperature wall 14. A rotation driving mechanism 16 for the 1st supporting shaft is placed below the 1st supporting shaft 13 and a rotation driving mechanism 26 for the 2nd supporting shaft is placed below the 2nd supporting shaft 23 and each supporting shaft is rotated at an independently selected rotational speed.

Description

Detailed Description of the Invention [Objective of the Invention] (Field of Industrial Application) The present invention is directed to the Czochralski method (hereinafter abbreviated as Cz method) or the liquid capsule method (Li
Quid Encapsulated Czochr
alski method.

The present invention relates to a semiconductor single crystal pulling device using the LEC method (hereinafter abbreviated as LEC method).

(Prior Art) The structure of the hot zone of a GaAS single crystal pulling apparatus using the conventional Cz method or LEC method is shown in cross section in FIG. In FIG. 2, reference numeral 101 is a crucible for storing and melting semiconductor material, and is made of heat-treated boron nitride.

This crucible 101 is disposed at the center of a heater 102 made of carbon, with its side surfaces and a portion of its bottom facing each other. Further, the crucible 101 has the heater 102
There is a carbon or nitride groove (BN
), etc., and is housed in an assembly of a table 104 and a temperature-uniforming wall 105.

When a current is applied to the heater 102 to generate heat and the support shaft 103 is similarly driven to rotate by the rotary drive structure 106, the table 104, the temperature-uniforming wall 105. and crucible 10
Rotate 1 as one unit. The rotating shaft 103 is, for example, 5
Rotation on the order of ppm is given. In addition, the above crucible 10
Above the crucible 101 is a single crystal pulling shaft 108 which has a seed crystal body 107 attached to its lower end and rotates at the same speed as the crucible 101.
is arranged, and this single crystal pulling shaft 108 is pulled up at a predetermined speed to manufacture a single crystal semiconductor.

(Problem to be Solved by the Invention) In the structure of the hot zone in the conventional single crystal pulling apparatus described above, the rotational speed of the assembly is Although increasing the temperature is effective for temperature equalization, on the other hand, the force forcefully applied to the semiconductor melt in the crucible increases, causing problems with the properties of the single crystal, which may cause melt flow.

In view of the problems with the conventional apparatus described above, the present invention provides a Cz method that is improved so that the number of crucibles can be freely controlled.
Alternatively, it is an object of the present invention to provide a single crystal pulling device using the LEC method.

[Structure of the Invention] (Means for Solving the Problems) A semiconductor single crystal pulling apparatus of the present invention includes a rotatable crucible for melting and storing a semiconductor material, and a heater for separately surrounding and heating the crucible. , a constant temperature wall body provided between the heater and the crucible in a non-contact manner and rotated separately from the crucible; and a semiconductor single crystal pulling means for pulling the semiconductor single crystal from the crucible. It is equipped with the following.

(Function) With the above-described structure, the table and the temperature-uniforming wall can be rotated at a freely selected rotation speed, and sufficient temperature uniformity of the crucible can be obtained to eliminate unevenness in the heat generation distribution of the heater. Also,
The crucible can be rotated by selecting the most advantageous rotation speed for crystal growth, thereby achieving improved crystallinity.

(Example) An example of the present invention will be described below with reference to FIG. FIG. 1 shows a cross-sectional view of a hot zone of an apparatus for pulling a semiconductor single crystal according to an embodiment. A carbon crucible 11 is used to store and melt a semiconductor material, for example, a semiconductor (3a AS). This crucible 11 is placed in the center of the furnace and is surrounded by a heater 12 made of carbon. And, an example of Q installed inside crucible 11
a. Heat the AS to approximately its melting point of 1300°C.

This heater 12 is supplied with a heating current from the outside, and is formed into a cylindrical shape with plate-shaped resistors arranged in a meandering manner.

An opening 12a is provided at the center of the lower surface of the crucible 11, facing the side and bottom surfaces of the crucible 11 at a certain distance.

Two coaxial support shafts are provided penetrating through this opening 12a, and a hollow first support shaft 13 on the outside thereof is formed of carbon or fired N at its upper end without contacting the heater 12. A cylindrical temperature-uniforming wall body 14 is attached, and the temperature-uniforming wall body 14 is provided with an opening 14a on the inner side of the connecting portion with the first support shaft 13, through which the inner second support shaft 23 passes. ing. The second support shaft 2 passes through the opening 14a.
A table 15 is attached to the upper end of the table 15 without contacting the temperature-uniforming wall 14, and a crucible 11 is attached thereon without contacting the temperature-uniforming wall 14. Next, the first support shaft 13 is provided with a first support shaft rotation drive mechanism 16 at the bottom, and the second support shaft 23 is provided with a second support shaft rotation drive mechanism 26 at the bottom, respectively. The rotation speed can be freely selected and rotated. As an example, the rotation speed of the first support shaft 13 is 5 rpm, and the rotation speed of the second support shaft 23 is 2 Orpm, and the rotation speed is the same as that of the first support shaft 13 or the opposite direction. Good results were obtained with the drive.

[Effects of the Invention] According to the semiconductor single crystal pulling apparatus according to the present invention, there is no contact between the crucible and the heater, and
By providing a temperature-uniform wall that rotates at a sufficiently high rotational speed, non-uniform distribution of heat generation from the heater is eliminated, temperature uniformity in the circumferential direction is sufficiently improved, and high-quality single crystal pulling is achieved.

On the other hand, since the crucible is unrelated to the rotation of the isothermal wall, it has the advantage of being able to select and rotate the crucible at the most suitable rotation speed for crystal growth.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a hot zone in a semiconductor single crystal pulling apparatus according to an embodiment of the present invention, and FIG. 2 is a sectional view of a hot zone in a conventional semiconductor single crystal pulling apparatus. 11... Crucible 12... Heater 14... Unitemperature wall body 13... First support shaft 23... Second support shaft

Claims (1)

[Claims] a rotatable crucible for melting and containing semiconductor material;
a heater that surrounds and heats the crucible at a distance; a constant temperature wall that is provided between the heater and the crucible in a non-contact manner and is rotationally driven separately from the crucible;
A semiconductor single crystal pulling apparatus comprising: a semiconductor single crystal pulling means for pulling the semiconductor single crystal from the crucible.