JPS6245020A - Method for sealing quartz tube for semiconductor heating - Google Patents

Abstract

PURPOSE:To prevent the breakage of a quartz tube as well as to enable to mount or dismount the quartz tube mechanically by a method wherein a tapered part having the specific tilt angle is provided in the vicinity of the quartz tube and the end part of a cylindrical quartz cover, both of them are smoothed by performing a grinding work, and they are fitted together. CONSTITUTION:The heating furnace to be used in the manufacturing process of a semiconductor wafer and the like is formed in a tubular body by burying a heat source such as a heater and the like in a heat-insulating material, and it is provided with a quartz tube 1 that can be inserted into or taken out of it. The quartz tube of 20phi-300phi is used, and an SiC tube may be arranged between it and the tubular body according to the circumferences to enhance a soaking effect. On the other hand, a cover 2 consisting of cylindrical quartz is prepared, tapered parts 3 and 3 having the tilt angle of 1/6-1/2 are provided between the end of the quartz tube and the point located 50mm from the end of the tube, and said tapered part is finished smoothly by performing a grinding work. When said quartz tube and the quartz cover 2 are fitted together, they are integrally formed with the cover 2 positioned outside. A hole 4, wherein a control stick and the jig carrying the semiconductor wafer can be inserted, is provided on the cover 2.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a quartz tube used in a heating furnace essential to the manufacturing process of semiconductor devices, and a method for fitting a quartz lid thereto.

[Technical background of the invention]

Recently, the scale of production of semiconductor products has been increasing, and there is a need to establish highly productive manufacturing lines.
As a link to this, the size of semiconductor wafers is trending toward larger diameters.

As semiconductor wafers become larger in diameter.

Manual handling becomes difficult, and automation of wafer transport and equipment setting is inevitably required.

On the other hand, recent semiconductor devices, as typified by VLSI, have made remarkable progress in improving performance and increasing integration, and as a result, manufacturing processes have become more complex and diverse, and the cleanliness of the manufacturing line has an impact on yield. The impact is significant, and automation is also of great significance in terms of keeping the human body, which is the source of dust, away from the environment.

By the way, in a heating furnace such as a diffusion furnace which is indispensable in the manufacturing process of semiconductor wafers, etc., a heat insulating tube body in which a heating source such as a heater is embedded is provided, and a quartz tube is arranged so as to be insertable and extractable therein. Because it is necessary to prevent contamination of semiconductor wafers, which are objects to be heated, from impurities, quartz and SiC, which are substances with similar chemical composition and properties to the stabilizing substance, are selected as the tube material surrounding the semiconductor wafer. There is. On the other hand, this quartz tube etc. has a heat treatment temperature of 1000℃ for the semiconductor wafer placed on it.
Since a high degree of heat resistance is required, materials with excellent heat resistance are used.

Therefore, the lid body that closes the end of the quartz tube, which is placed so that it can be inserted into and taken out from the heat-insulating tube body in which the heating source is buried, is also made of cylindrical quartz, and the two bodies are integrated by a taper of the same angle formed near the end. It depends on the way the parts fit together. Note that this tapered portion is formed smoothly by applying a rubbing process.

By the way, the degree to which the cleanliness of the manufacturing line has an increasing effect on the yield of semiconductor devices has recently been developed, and in addition to the so-called soft lander that has been developed and is entering the stage of practical use.
There is also a trend toward improved cleaning of the quartz tubes and lids used in heating furnaces. That is, a quartz tube and a lid fitted thereto are placed in a clean room, and for cleaning, the quartz tube integrated with the lid is taken out from the opening of the heating furnace located outside the clean room and placed inside the clean room. The idea is to prevent pollution sources from scattering into the air.

[Problems with Background Art] The angle of the tapered portion formed at the end of the quartz tube and the cylindrical lid portion is approximately 1/10, and the length thereof is approximately 50 mm.

However, when fitting the two together, if the lid with a large opening is pushed too hard, it becomes difficult to remove the lid, and the only way to do this is to apply a light impact to the lid to loosen it and then remove it, or break it.

Furthermore, if the integrated quartz tube and lid undergo high-temperature heating and cooling cycles over a long period of time, it becomes increasingly difficult to remove them. Therefore, the force for fitting is usually adjusted by the operator based on intuition, and is naturally not constant. Naturally, when performing a series of these operations mechanically, a fairly strong force is required, so the quartz tube is frequently damaged.

[Purpose of the invention]

The present invention provides a method for sealing a quartz tube for semiconductor heating, which eliminates the above-mentioned difficulties.

[Summary of the invention]

In order to achieve the above object, in the present invention, a tapered part with an inclination angle of 1/2 to 1/6 is provided near the end of the quartz tube and the cylindrical quartz lid part, and a sliding process is performed to make the two fit together smoothly. We adopted a method that matches each other.

Note that if the inclination angle is less than 1/6, it will be difficult to remove the quartz tube, and if it exceeds 1/2, it will be impossible to insert the semiconductor wafer to be heated, so the above numerical value is limited. When fitting these two together, the cylindrical quartz lid was placed on the outside so that the force necessary to separate them could be applied.

[Embodiments of the invention]

The present invention will be explained in detail with reference to the drawings.

A heating furnace used in the manufacturing process of semiconductor wafers, etc. is a tubular body (not shown) with a heating source such as a heater buried in a heat insulating material.
, and the quartz tube (1) is installed here so that it can be inserted and removed. For this installation, there are two methods: partitioning the tubular body into multiple stages in the direction perpendicular to the axis, and arranging multiple quartz tubes in each stage, and installing multiple quartz tubes coaxially with the tubular body. be.

This quartz tube has a diameter of 20 φ to 300 φ, and a SiC tube may be placed between the tube and the tubular body to increase the heat uniformity effect. On the other hand, a lid part (2) made of cylindrical quartz is prepared,
A tapered part (3) with an inclination angle of 1/6 to 1/2 is provided between about 50 mm from the end of the quartz tube (1), and this part is smoothed by rubbing. When fitting these two together, they are integrated with the lid (2) on the outside. Of course, this fitting may be performed after the quartz tube (1) is set in the tubular body. The lid (2) is provided with a hole (4) into which a jig on which a semiconductor wafer is placed and an operating rod can be inserted.

〔Effect of the invention〕

As described above, in the method of the present invention, since the quartz tube and the cylindrical quartz lid can be easily attached and detached, it is possible to prevent damage to the quartz tube and also to enable mechanical attachment and detachment.

This is because, in this fitting or sealing method, both parts are made of the same material, quartz, and the inward direction of the quartz tube is weakened, allowing stable attachment and detachment. Therefore, the cylindrical quartz lid part is mechanically balanced.

Its detachment is possible by moving in a direction parallel to its axis, and can be achieved with a constant mechanical force, making it possible to automate it and also to keep away the human body, which is a source of dust. Therefore, it can contribute to improving the yield of semiconductor wafers.

[Brief explanation of drawings]

The drawings are cross-sectional views showing a part of the process of carrying out the method of the present invention.

Claims (1)

[Claims] A quartz tube for semiconductor heating that is inserted into an insulating tube in which a heating source is placed has a tapered part near the end thereof, and a quartz cover part that has a terminal part that fits into the tapered part, and is a taper that has been subjected to a sliding process. A method for sealing a quartz tube for semiconductor heating, characterized in that the angle is formed to be 1/6 to 1/2 to facilitate attachment and detachment.