JPH02212389A - Pulling-up device for semiconductor single crystal - Google Patents

Abstract

PURPOSE:To directly control the temp. of melt of a semiconductor and to simpli fy the constitution of the device by constituting this device of such a structure that a heating body is directly provided to the outer surface of a crucible for housing semiconductor material and melting it. CONSTITUTION:An unrotary table supporting shaft 12 is provided in an envelope 15 equipped with a heat insulating material in the inner surface. A crucible 10 is arranged on a table 13 provided on the top end of this supporting shaft 12. A shaft 14 for pulling-up single crystal is fitted with seed crystal 107 to the lower end and unrotated and vertically moved. This shaft 14 is arranged to the upper part of the crucible 10. High-m.p. metal is coated on the outer surface of the crucible 10 and a patterned heating body 11 is provided. For example, this heating body 11 consists of both a heating body part 21 of the outer circumferential side and a heating body part 31 of the bottom face. Pt and W, etc., are properly utilized as the high-m.p. metal and the heating body 11 can be formed by fitting a mask having a pattern shape to the circumferen tial side of the crucible and coating the high-m.p. metal by a vacuum depositing method and thereafter removing the mask. In this device, the need for a temp. equalizing wall and rotation of the shaft 14 are eliminated.

Description

Detailed Description of the Invention [Objective of the Invention] (Industrial Field of Application) The present invention relates to a semiconductor single crystal pulling apparatus, and particularly relates to a semiconductor single crystal pulling apparatus, and particularly relates to the Czochralski method (hereinafter abbreviated as the Cz method) or the liquid capsule method ( Liquid
Encapusulated Czochralski
The present invention relates to improvements in heating means in the hot zone of a semiconductor single crystal pulling apparatus using the LEC method (hereinafter abbreviated as the LEC method).

(Prior Art) A main part of a conventional structure of a GaAs single crystal pulling apparatus using the Cz method, LEC method, etc. is shown in a sectional view in FIG. The hot zone shown in this figure is housed in an envelope (not shown) with a heat insulating material inside, and a predetermined atmosphere is created inside the envelope.
Single crystal is pulled as described below. The GaAs single crystal pulling apparatus shown in FIG. 4 includes a bottomed cylindrical crucible 101 made of heat-treated silicon nitride that accommodates and melts a semiconductor material, and a crucible 101 made of carbon that coaxially surrounds the crucible 101. and a heating body 102 facing the side and a part of the bottom, a table support shaft 103 piped through an opening 102a at the center of the bottom of the heating body 1G2, and a table support shaft 103 provided at the upper end of the table support shaft 103. The crucible 101 is placed coaxially with the table support shaft 108 on the table 104 , the isothermal wall 105 is attached to surround the crucible 101 , and the table support shaft 10 is placed on the table 104 .
It is composed of a rotational drive mechanism 108 that rotationally drives 3. Note that the table support shaft 103 is given a rotation of about 5 rpm, for example.

A seed crystal body 107 is placed above the crucible 101.
A single-crystal pulling shaft 108 is installed at the lower end and rotates coaxially and at a constant speed with the ruribo 101, and a single-crystal semiconductor is manufactured by pulling the single-crystal pulling shaft 108 at a predetermined speed.

(Problems to be Solved by the Invention) In the conventional structure of a device for pulling a GaAs single crystal using the LEC method, the heat generated by the heating body is transmitted to the temperature-uniforming wall mainly by radiation and also by conduction and convection, and then to the crucible. For this purpose, the temperature of the heating element is approximately 15% higher than the melting point of the semiconductor material required in the crucible, for example for GaP.
Heating to temperatures much higher than 00°C is required, placing undue restrictions on the configuration of the heating element. Currently, due to the upward slope, carbon materials are essentially limited. In addition, indirect heating makes it difficult to control the temperature of the crucible and, by extension, the temperature of the melt.

The present invention has been made to solve the above-mentioned problems in the conventional technology, and improves the heating method in a GaAs single crystal pulling apparatus using the LEC method.

[Structure of the invention]

(Means for Solving the Problems) A semiconductor single crystal pulling device according to the present invention is a semiconductor single crystal pulling device that pulls a semiconductor single crystal by placing a semiconductor material in a crucible and melting it. It is characterized by having been provided.

(Function) Since the semiconductor single crystal pulling apparatus of the present invention has a structure in which a heating body is attached to the outer surface of the crucible, the temperature of the crucible and the semiconductor melt can be directly controlled. Thereby, the semiconductor single crystal can be pulled at a predetermined temperature without overheating the heating element in the apparatus.

(Example) Hereinafter, an example of the semiconductor single crystal pulling apparatus according to the present invention will be described with reference to the drawings.

FIG. 1 shows the hot zone portion of this embodiment, and the envelope 15 provided with a heat insulating material on the inner surface is omitted by broken lines.

As shown in FIG. 1, the crucible 10 is placed on a table 13 provided at the upper end of a non-rotating table support shaft 12. Further, above the melt lO, a single crystal pulling shaft 14 is arranged which has a seed crystal body 107 attached to its lower end and moves up and down vertically without rotating.

FIG. 2 shows a side view of a crucible used in one embodiment.

This crucible lO is provided with a patterned heating element 11 having a refractory metal attached to its outer surface. As an example, this heating body 11 includes a circumferential side heating body 21 on the outer circumferential side;
It consists of a bottom heating body part 31 on the bottom surface, and platinum, tungsten, etc. are suitable as the high melting point metal for the bottom heating body part 31, and for its formation,
This is achieved by attaching a patterned mask to the peripheral side of the crucible, depositing a high melting point metal layer with a thickness of several tens of micrometers, for example, by vacuum evaporation, and then removing the mask. Also,
The bottom heating body 31 prevents or compensates for cooling from the bottom of the crucible, and an example of its pattern shape is shown in FIG. 3(a).
) or (b) shows a bottom view of the crucible.

Electrode 21a for energizing each of the heating body parts 21.31
, 31a are formed so that the electrode formation area at the end of the pattern is formed in the shape of the electrode lead-out member and has a thickness that can withstand pressure contact by the electrode lead-out member of the chain portion.

Note that if the material of the crucible is conductive at high temperature, an insulating layer, for example aluminum nitride AIN, is applied before forming the heating element 11.
This is achieved by forming a layer and performing heating element evaporation on the layer.

By configuring a semiconductor single crystal pulling device using a crucible with an inclined structure, there is no need for a constant temperature wall, which was essential in conventional similar devices, and there is no need to rotate the crucible and single crystal pulling shaft. The device configuration can be simplified.

〔Effect of the invention〕

Since the semiconductor single crystal pulling apparatus of the present invention has a structure in which a heating body is attached to the outer surface of the crucible, the temperature of the crucible and the semiconductor melt can be directly controlled. Thereby, the semiconductor single crystal can be pulled at a predetermined temperature and with a free heat distribution without overheating the heating element in the apparatus. Therefore, a rotation mechanism for temperature equalization is also not required. Furthermore, conventional members such as an independent heating element and a temperature-uniforming wall are no longer necessary, and the structure is simplified and costs can be reduced.

Note that the GaAs single crystal pulling apparatus exemplified in the above embodiment is not limited to pulling a GaAs single crystal;
It can be widely applied to general semiconductor single crystal pulling equipment including St.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a hot zone part of a semiconductor single crystal pulling apparatus according to an embodiment of the present invention, FIG. 2 is a side view of a crucible in a semiconductor single crystal pulling apparatus according to an embodiment of the present invention, and FIG. (a) and (b) are both bottom views of a crucible according to an embodiment of the present invention, and FIG. 4 is a sectional view of a hot zone portion of a conventional semiconductor single crystal pulling apparatus. DESCRIPTION OF SYMBOLS 10... Crucible 11... Heating body 21... Surrounding side heating body part 31... Bottom heating body part 21a, 31a... Electrode 12... Table support shaft 13... Table 15...・Envelope

Claims (1)

[Claims] A semiconductor single crystal pulling apparatus for pulling a semiconductor single crystal by placing a semiconductor material in a crucible and melting it, characterized in that a heating element is provided directly on the outer surface of the crucible.