JPH03250625A - Heat treating furnace for manufacturing semiconductor device and cantilever - Google Patents

Abstract

PURPOSE:To convey a semiconductor substrate without winding the atmosphere into a heat treating furnace by providing a ventilation hole at a cantilever, and obtaining the flow of gas even if the cantilever is inserted into the furnace to form a gas curtain. CONSTITUTION:A reaction tube 1 is heated by a heater 10 in an oxidation furnace, N2 gas 4 is supplied into the tube 1, N2 gas is injected from an injector 2 to form a gas curtain. A semiconductor substrate 6 to be processed is held by a jig 7, the jig 7 is placed at the end 19b of a cantilever 19, conveyed into the tube 1, and mounted at a predetermined position. When the substrate is conveyed, the gas 4 injected from the injector 2 is passed through the hole 19a of the jig 19 and supplied rapidly to the ventilation hole 7a of the jig 7 to the upper part of the inlet of the tube 1 to maintain a gas curtain. Accordingly, the flow of the atmosphere 5 into the tube 1 is prevented, and predetermined oxidation can be performed without fail.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a heat treatment furnace for semiconductor device manufacturing that can heat-treat semiconductor substrates used in semiconductor device manufacturing without deteriorating their characteristics, and a semiconductor device in the furnace. This invention relates to a cantilever used for carrying in substrates.

<Prior Art> In recent years, semiconductor devices have become highly integrated and miniaturized, and the diameter of semiconductor substrates used in the manufacture of semiconductor devices has become increasingly large. Under these circumstances, the diameter of oxidation diffusion furnaces (heat treatment furnaces) used in the manufacture of semiconductor devices has also been increased, and the entrainment of air from the furnace mouth has become a problem. Inclusion of air into the furnace not only causes unnecessary oxidation and deterioration of the characteristics of the semiconductor substrate due to the effects of carbon, alkali metals, etc. contained in the air, but also causes damage when attempting to form a thin oxide film on the semiconductor substrate. This caused variations in film thickness.

The fifth method for preventing air from getting into the furnace is
As shown in the figure, a gas curtain is formed at the mouth of the furnace by introducing an inert gas such as nitrogen N2 gas into the furnace. That is, a gas injector 2 is provided near the inlet of a reaction tube 1 forming a furnace body, and in addition to N2 gas 3 that forms the atmosphere inside the reaction tube 1, N2 gas 4 is jetted and supplied from the gas injector 2, and the gas from the injector 2 is A gas curtain is formed at the entrance of the reaction tube 1 by the N2 gas 4 to prevent atmospheric air 5 from entering the reaction tube 1. In this method, the jig 7 that holds the semiconductor substrate 6 is provided with a large number of ventilation holes 7a through which the N2 gas 4 passes, so as not to inhibit the formation of the gas curtain.

<Problems to be Solved by the Invention> In the method of forming a gas curtain at the entrance of the reaction tube 1 as described above, conventionally, as shown in FIG. It was carried into the reaction tube 1 by placing it on a car.

However, the planer bar 9 is wide in order to carry the jig 7, and since the planer lever 9 itself is inserted into the reaction tube 1, the planer bar 9 obstructs the flow of the N2 gas 4 and the gas A hole is made in the curtain and the reaction tube 10
Atmosphere 5 flows in from the upper part of the inlet, causing various problems due to air entrainment as described above.

Note that it has been known for a long time that the jig 7 is inserted into the reaction tube 1 by pushing the rear end with a push-pull rod (not shown). Push-pull rod itself into the reaction tube 1
Since the jig 7 does not need to be inserted into the reaction tube 1, the jig 7 can be inserted into the reaction tube 1 without interfering with the formation of the gas curtain. However, in this insertion method, instead of placing the jig 7 on the cantilever and transporting it (soft landing of the jig), the jig 7 is inserted into the reaction tube 1, which is made of quartz for heat resistance. Since it is caused to slide, the quartz powder may be rolled up and attached to the semiconductor substrate 6. In other words, this insertion method cannot be adopted because it creates a new extremely serious problem that causes deterioration of the characteristics of the semiconductor substrate 6.

The present invention has been made in view of the above-mentioned conventional circumstances, and an object thereof is to provide a heat treatment furnace for semiconductor device manufacturing and a cantilever that does not inhibit the formation of a gas curtain when a jig is carried into the furnace using a cantilever. I'm going to do it.

<Means for Solving the Problems> A heat treatment furnace for semiconductor device manufacturing of the present invention that achieves the above object includes a reaction tube with one end open, a heating device for heating the reaction tube, and a semiconductor substrate held in the reaction tube. In a heat treatment furnace for manufacturing semiconductor devices, which is equipped with a cantilever that carries a jig and a gas supply device that forms a gas curtain at the inlet of a reaction tube, the gas supplied from the gas supply device is not passed through the cantilever. It is characterized by having ventilation holes.

Further, the cantilever of the present invention that achieves the above object is used in the manufacture of semiconductor devices, and is used for transporting a jig for holding a semiconductor substrate into a reaction tube having an open end. It is characterized by having ventilation holes.

<Function> According to the heat treatment furnace for manufacturing semiconductor devices of the present invention, the gas supplied from the gas supply device is caused to flow through the vent hole of the cantilever, and the gas flow is ensured even when the semiconductor substrate is carried in by the cantilever, thereby creating a gas curtain. This prevents atmospheric entrainment.

Further, according to the cantilever of the present invention, in a heat treatment furnace for semiconductor device manufacturing of a type in which air entrainment is prevented by a gas curtain, a gas flow is ensured through the vent hole to ensure the formation of the gas curtain.

<Example> The present invention will be specifically explained based on examples.

FIG. 1 shows an oxidation furnace for manufacturing semiconductor devices according to an embodiment of the invention, and FIG. 2 shows a cantilever according to an embodiment of the invention. Incidentally, the same parts as in the prior art are given the same reference numerals.

As shown in the figure, the oxidation furnace for manufacturing semiconductor devices of this example is
A reaction tube 1 made of a quartz tube with one end open, a heating device 10 made of an electric heating coil to heat the reaction tube 1, and a gas supply device (not shown) for supplying N2 gas 3 to form an atmosphere in the reaction v1. In order to form a gas curtain at the inlet of the reaction tube, a gas injector 2 is provided at the inlet of the reaction v1, and a gas supply device is also provided for injecting N2 gas 4 from the injector 2. ing. Furthermore, a cantilever 19 is provided as a means for carrying the jig 7 that holds the semiconductor substrate 6 into the reaction tube 1, and this cantilever 19 is provided with a vent hole 19a.

As shown in FIG. 2, the cantilever 19 has a wide plate-shaped tip 19b on which the jig 7 is placed, and three rectangular ventilation holes 19a are formed in the tip 19b. There is.

Processing in the oxidation furnace with the above configuration is performed using the heating device 10 and the reaction tube 1.
and supplying N2 gas 4 into the reaction tube 1,
This is performed with N2 gas being ejected from the injector 2 to form a gas curtain. The semiconductor substrate 6 to be processed is held by a jig 7, and the jig 7 is placed on the tip 19b of the cantilever 19, carried into the reaction tube 1, and set at a predetermined position.

At the time of loading the substrate, the N2 gas 4 supplied from the injector 2 is quickly supplied to the upper part of the inlet of the reaction tube 10 through the vent hole 19a of the cantilever 19 and the vent hole 7a of the jig 7 to maintain the gas curtain. do. Therefore, the air 5 is prevented from flowing into the reaction tube 1, and the intended oxidation treatment can be carried out without any problem.

FIGS. 3 and 4 show other embodiments of the planing bar according to the present invention.

The cantilever 29 shown in FIG. 3 has six triangular ventilation holes 29a at its tip 29b on which the jig 7 is placed. The cantilever 39 shown in FIG. 4 has a notch 39a formed at the tip 39b on which the jig 7 is placed, and a substantial ventilation hole through which the N2 scum 4 flows through the notch 39a.

In addition, the number of ventilation holes provided on the cantilever may be increased,
Although it is preferable to increase the ventilation area of the N2 gas 4 by enlarging the shape, it may be appropriately set to a value that does not cause any practical problems in relation to the strength of the cantilever and the like.

Further, the present invention can be applied not only to the above-mentioned oxidation furnace but also to various heat treatment furnaces such as a diffusion furnace.

<Effect> According to the present invention, since the cantilever is provided with a ventilation hole,
Even if the cantilever is inserted into the furnace, gas flow can be ensured and a gas curtain can be formed. Therefore, the semiconductor substrate can be carried into the heat treatment furnace for semiconductor device manufacturing without air being drawn in, and the semiconductor substrate can be heat-treated without deterioration of characteristics or variation in oxide film thickness.

In addition to the above, in the cantilever of the present invention, the weight can be reduced by providing ventilation holes, which improves the operability of the cantilever, or if the weight is the same, the jig mounting part of the cantilever can be made larger. Therefore, it is possible to improve the mounting stability.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a diffusion furnace for manufacturing semiconductor devices according to an embodiment of the present invention, FIG. 2 is a perspective view of a cantilever according to an embodiment of the present invention, and FIG. 3 is another embodiment of the present invention. FIG. 4 is a perspective view of a cantilever according to still another embodiment of the present invention, and FIG. 5 is a perspective view of a cantilever according to another embodiment of the present invention.
A cross-sectional view of a diffusion furnace for manufacturing semiconductor devices to explain the gas curtain; FIG. 6 is a cross-sectional view of a conventional diffusion furnace for manufacturing semiconductor devices;
FIG. 7 is a perspective view of a conventional cantilever. 1 is a reaction tube, 2 is a gas injector, 4 is N2 gas, 5 is the atmosphere, 6 is a semiconductor substrate, 7 is a jig, 19, 29, 39 are cantilevers 19a, 29a, and 39a are ventilation holes.

Claims (2)

[Claims] (1) A reaction tube with one end open, a heating device that heats the reaction tube, a cantilever that carries a jig for holding a semiconductor substrate into the reaction tube, and a gas that forms a gas curtain at the entrance of the reaction tube. 1. A heat treatment furnace for manufacturing semiconductor devices comprising a supply device, wherein the cantilever is provided with a vent hole through which gas supplied from the gas supply device passes. (2) A cantilever used in the manufacture of semiconductor devices, in which a jig for holding a semiconductor substrate is placed and carried into a reaction tube with an open end, is characterized in that a vent hole is provided at least in the part where the jig is placed. cantilever