JPH0222535B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Technical Field of the Invention The present invention relates to the structure of a vertical heating furnace, and more particularly to a wafer basket holding system that takes into account earthquake resistance and safety in handling wafers.

(b) Background of the technology In recent years, the size of semiconductor substrates in particular has progressed, and with the trend towards highly dust-free and automation, the horizontal furnaces that have been used conventionally have a quartz container and a quartz wafer mounted Vertical heating furnaces have been adopted because of the drawback that quartz particles are generated due to sliding of the basket, which causes a decrease in wafer yield. Although it has many advantages such as being easy and requiring less space, in the case of a vertical furnace, the wafers that are heated inside the container are loaded in batches into a wafer basket. After a plurality of pieces are loaded into a basket holder, they are inserted into a container and heated in a heating furnace.

Therefore, the basket holder has an opening for inserting the wafer basket, and has the drawback that wafers loaded in the wafer basket may fall from this opening due to external vibrations or improper handling. Improvements are requested.

(c) Prior art and problems When forming an oxide film on a semiconductor substrate or doping and diffusing impurities into a semiconductor substrate,
This is done by heating these semiconductor substrates to a high temperature in an appropriate atmospheric gas, and the heating furnace in this case is usually used at a temperature of about 1000°C.

Fig. 1 is a schematic cross-sectional view of a conventional vertical heating furnace. There are also supply holes 3 and discharge holes 4 for atmospheric gas, which are heated by a heating element 5 disposed around the container.

The basket holder 6, which is heated inside the container, is made of quartz and is operated up and down by an operating cable 7.
The heat-treated basket holder is taken out to the outside by a take-out rod 8 having a partially sealed lid.

A plurality of wafer baskets 9 are mounted in multiple stages inside the basket holder 6 and are heated at the same time, but normally a wafer basket holds 25 wafers.
It is often stored in batches of approximately one sheet and used in combination with chemical treatment or cleaning treatment.

In this case, since one half of the cylindrical shape of the basket holder is open, there is a risk that the wafers may fall from the wafer basket mounted on this part, and a countermeasure against this is required.

(d) Purpose of the Invention In view of the above-mentioned conventional drawbacks, an object of the present invention is to provide a stopper for a wafer basket to prevent wafers from falling from a wafer basket inserted into a basket holder used in a heating furnace. do.

(e) Structure of the Invention The object of the present invention is to provide a container formed by vertically arranging elongated tubes, a lid provided at both ends of the container, a heating section for heating the container, and a container to be treated. A vertical heating furnace having a basket holder for inserting a wafer basket holding wafers into the container, the basket holder having a plurality of semi-cylindrical columns arranged vertically, and a space between the columns. The wafer basket is provided with a plurality of supports including stoppers arranged in a semi-cylindrical shape to prevent wafers from falling, and the wafer basket is provided with a plurality of supports arranged at intervals in the axial direction of the supports. The wafer basket is configured such that wafers can be inserted thereinto, and the wafer basket is installed on the basket holder, and the wafer basket is configured with a plurality of supports including a wafer drop prevention stopper, and the basket holder is configured. This problem can be solved by using a vertical heating furnace characterized in that a plurality of support columns are arranged in a substantially cylindrical shape surrounding the wafer.

(f) Embodiments of the Invention In general, the inner diameter of the container in the heating furnace is set to the minimum necessary inner diameter compared to the dimensions of the object to be heated, in order to achieve high heating efficiency and uniformity of temperature in the heating furnace. In particular, in the case of a basket holder, the gap is a few millimeters to a few millimeters at most, so for example, the basket holder may vibrate even slightly, or the position of the wafer basket may change due to the handling surface. If this is not appropriate, accidents may occur such as wafers hitting the wall of the container or falling from the wafer basket.

For this reason, the wafer basket inserted into the basket holder must be provided with a stopper to prevent the wafers from falling.

FIG. 2 is a perspective view of the wafer basket of the present invention, and there is a semicircular basket-shaped basket holder 11, and this basket holder has a wafer basket 13 on which wafers 12 are loaded in multiple stages. There are wafer basket stands 14 and 15 so that only one wafer basket can be loaded (FIG. 2 shows the case where there are two wafer basket stands). In order to install the wafer basket 13 on the wafer basket holder 14, a basket forklift 17 is used to insert the wafer basket 13 into the lift cylindrical part 18, carry it in, and then mount it on the wafer basket holder 14. be.

The wafer fall prevention stopper 19 provided on the wafer basket 13 according to the present invention prevents the wafers from falling from the wafer basket even after the wafer basket is mounted on the basket holder. For this reason, the wafers do not fall or shift from the wafer basket, and the wafers are not damaged even if there is a defect in the handling surface or there is some external vibration.

(g) Effects of the Invention As explained in detail above, the use of the basket holder of the present invention has the great effect of preventing wafers from falling.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a conventional heating furnace, and FIG. 2 is a perspective view of a basket holder of the present invention. In the figure, 11 is a basket holder, 12 is a wafer, 13 is a wafer basket, 14 and 15 are wafer basket stands, 16 is a wafer basket, 17 is a forklift for the basket, 18 is a lift cylindrical part, 19 is a wafer fall prevention stopper,
20 is a support.

Claims (1)

[Scope of Claims] 1. A container formed by vertically arranging elongated tubes, a lid provided at both ends of the container, a heating section for heating the container, and holding a wafer to be processed. This is a vertical heating furnace having a basket holder for inserting a wafer basket into the container, and the basket holder 11 includes a plurality of semi-cylindrical columns 20 arranged vertically, and a plurality of columns between the columns 20. The wafer basket 13 is provided with a plurality of supports including wafer drop prevention stoppers 19 arranged in a semi-cylindrical shape, and the wafer basket 13 is provided with a plurality of supports including wafer fall prevention stoppers 19 arranged in a semi-cylindrical shape. The wafer basket 13 is configured to allow insertion of wafers 12 at intervals in the axial direction, and the wafer basket 13 is installed on the basket mounts 14 and 15, and the wafer fall prevention stopper 19 constituting the wafer basket 13 is removed. A vertical heating furnace characterized in that a plurality of supports including a plurality of supports and a plurality of supports 20 forming the basket holder 11 are arranged in a substantially cylindrical shape surrounding a wafer 12.