JPS59156995A - Liquid-phase epitaxial device - Google Patents

Abstract

PURPOSE:To form an epitaxial film at a high yield by spraying a gas to remove the molten liquid adhered on the surface of a wafer pulled up from an epitaxial molten liquid. CONSTITUTION:A holder 15 wherein Plural wafers 14 are fixed so as to incline in a definite direction is vertically movable. The wafers 14 are immersed in a molten liquid 13, and after the epitaxial films are formed on the surfaces, the holder 15 is pulled up above a crucible 12. When the residue 17 of molten liquid adhered on the surface of each wafer 14 is collected sufficiently at the lower part of the inclined wafer 14, an inert gas or air 19 is sprayed from each nozzle 18 of a gas-blowing pipe 16. Said residue 17 is collected at the inclined lower part of the wafer 14 by the gas 19 blown out from each nozzle 18 which is confronted with the upper end of each inclined wafer 14 and whose tip is inclined downwards in conformity with the inclination of the wafer, and removed by dropping along the holder 15 or blowing off.

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to a liquid phase epitaxial apparatus, and particularly to a structure for removing residual melt adhering to a wafer pulled up from the melt.

(b) Background of the technology An apparatus for forming a liquid phase epitaxial film for semiconductor devices, etc., for example, an apparatus for growing a Garnenoto film on a GGG substrate in the production of magnetic bubble memory elements, uses dipping, in which a wafer is lowered and immersed in a melt in a container. (dipping
) method, the melt is placed in one side of the horizontally long container, and the wafer 7 is placed in the other side.
There is a tipp-ing method in which the melt is brought into contact with the wafer by inserting a wafer into the wafer and tilting the container.Currently, the former method is generally used.

(e) Prior Art and Problems FIG. 1 is a schematic side sectional view showing the main part of a conventional liquid-phase Evita kinial apparatus that uses the denoving method.

In FIG. 1, 1 is a core tube made of alumina or the like, 2 is a crucible (melt container) inserted into the core tube 1, 3 is a melt containing epitaxial film components containing flux, 4 is a wafer, and 5 is a wafer holder. In such an apparatus, the holder 5 to which a plurality of wafers 4 (three in the figure) are fixed is capable of vertical movement and rotational movement (spin), and the wafers 4 are immersed in the melt 3. After the epitaxial film was formed on the surface, the afterflame 6 of the melt 3 deposited on the surface of the wafer 4 was removed by the centrifugal force of the rotation.

However, in order to make the ueno holder resistant and insoluble to high-temperature melt, it
The rotational movement of the holder is approximately several hundred revolutions per minute due to the fact that the wafer is made of aluminum alloy, and it is difficult to align the center of gravity of the holder to which the wafer is fixed with the center of rotation of the holder. Therefore, it is difficult to completely remove the afterflame from the wafer, which hinders the reduction in defects in the epitaxial film.

(d) Purpose of the Invention The purpose of the present invention is to eliminate the above-mentioned problems and form an epitaxial film with a high yield.

(e) Structure of the Invention The above object is to provide an inert gas to the upper side of the container containing the liquid-phase epitaxial melt in the reactor core tube to remove melt afterflame adhering to the surface of the wafer pulled up from the melt. Alternatively, this can be achieved by providing an air jet nozzle.

(f) Examples of the invention Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic side sectional view showing the main part of a dipping type liquid phase epitaxial device according to an embodiment of the present invention;
The figure is a cross-sectional view of the main part.

In Fig. 2, 11 is a core tube made of alumina, etc.;
2 is a crucible (melt container) inserted into the core tube 11;
13 is a melt of epitaxial film components containing flux;
14 is a wafer, 15 is a wafer holder, and 16 is an air pipe. In such a device, multiple sheets (three sheets shown)
The holder 15 fixed to which the wafer 14 is tilted in a certain direction can be moved up and down, and after the wafer 14 is immersed in the melt 13 and an epitaxial film is formed on its surface, the holder 15 is fixed as shown in the figure. It is pulled up above the crucible 12. Then, when the melt afterflame 17 adhering to the surface of each wafer 14 gathers appropriately on the lower side of the inclined wafer 14, an inert gas (for example, N
2 gas) or air 19 is ejected. Then, gas 1 is blown out from each nozzle 18 that faces the high end of each wafer 14 and whose tip is inclined downward in accordance with the inclination.
9 collects the melt afterflame 17 at the lower part of the slope of the wafer 14;
It is removed by dripping or blowing away along the holder 15.

However, the gas outlet of the nozzle 18 is connected to the opposing wafer 1.
A flat shape that efficiently sprays the gas 19 on the entire surface of 4,
Or, as shown in FIG. 3, the air supply pipe 16 may be configured to have a round shape so that it can rotate in the direction indicated by the arrow within an appropriate angular range.

(, 9) As described in detail, according to the present invention, gas is injected without rotating the wafer when removing the melt afterflame attached to the wafer, which is different from conventional spin removal. It is possible to add a strong removal force, and it has a great effect in greatly reducing defects caused by melt afterflame adhering to and solidifying the epitaxial film.

[Brief explanation of the drawing]

Fig. 1 is a schematic side sectional view showing the conventional structure of the main part of a dipping type liquid phase epitaxial electrical manufacturing device, and Fig. 2 is a schematic side view showing the main part of a dipping type liquid phase copitaxial device according to an embodiment of the MC invention. The side sectional view, FIG. 3, is a sectional view of the main part of the outfit shown in FIG. 2. Oite in the figure, 1. IIU core tube, 2, 12 ij
if' f+g+ (melt container), 3.13f is melting,
4 and 14 are Ueno pipes, 16 is an air pipe, 18 is an I-nozzle pipe, and 19 is a spray gas.

Claims (2)

[Claims] (1) An inert gas or air jet nozzle is installed above the container containing the liquid-phase epitaxial melt in the reactor core tube to remove residual melt adhering to the surface of the wafer pulled up from the melt. A liquid phase epitaxial device characterized by: (2) A patented taxial device characterized in that the nozzle is configured to oscillate in the left and right directions by an appropriate angle.