JP2648871B2 - Heat treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a heat treatment apparatus.

(Prior Art) Conventionally, a heat treatment apparatus has been used in a thermal diffusion step and a film forming step in a semiconductor device manufacturing process.

As this heat treatment apparatus, for example, a horizontal heat treatment apparatus has a Si tube around a reaction tube (hereinafter referred to as a process tube) serving as a processing chamber.
A heat equalizing tube made of a member such as C is provided, and further, a heating mechanism is attached concentrically to the heat equalizing tube on the outer periphery thereof. Within the process tube, a longitudinal direction of the process tube is provided. A large number of objects to be processed, for example, semiconductor wafers, which are accommodated at a constant arrangement pitch, are subjected to a heat treatment at a predetermined temperature with a reaction gas corresponding to the processing content.

By the way, in such a heat treatment apparatus, an apparatus in which a heater wire is wound is used as a heating mechanism, and the inside of the process tube is heated to a predetermined processing temperature by heating the soaking tube by the heating mechanism. Temperature control is performed as follows.

In such a heat treatment apparatus, for example, 800-1100
When the treatment is performed at a temperature of ° C., there is a possibility that the heater element itself of the heating mechanism hangs down due to thermal intestine or softening, and a so-called sagging phenomenon of the heater element which comes into contact with the heat equalizing tube. If the heater element and the soaking tube come into contact in this way, the heating mechanism and the soaking tube may be damaged, or the transformer may be damaged due to a large current leak. A contact detector is provided for detecting the contact state between the heating mechanism and the soaking tube by measuring the insulation resistance between the tube and the soaking tube.

In this measurement, the power supply of the heating mechanism was shut off, and the contact state was determined by measuring the insulation resistance between the inspection electrode attached to the heat equalizing tube and the heater wire terminal provided on the heater wire.

(Problems to be Solved by the Invention) In the contact detector of the conventional heat treatment apparatus described above, the insulation resistance cannot be inspected during processing, that is, while the heating mechanism is energized. When this occurs, there is a problem that this cannot be detected immediately, and the damage to the device increases.

In addition, when an object to be processed is oxidized and diffused, an insulating film such as an oxide film may be formed on the surface of the inspection electrode attached to the heat equalizing tube. In some cases, a contact failure may occur, and such a contact failure may cause a detection error.

The present invention has been made in order to solve the above-described problems, and has as its object to provide a heat treatment apparatus that quickly and accurately detects a contact state between a heating mechanism and a soaking tube.

[Structure of the Invention] (Means for solving the problem) A heat treatment apparatus of the present invention includes: a reaction vessel in which an object to be treated is provided;
In a heat treatment apparatus including a heating mechanism provided on an outer periphery of the heat equalizing tube, a plurality of inspection electrodes provided at an end of the heat equalizing tube, and a predetermined voltage between the inspection electrodes and the heating mechanism. And a circuit for detecting a contact state between the heat equalizing tube and the heating mechanism from a current flowing through the inspection electrode.

(Operation) According to the present invention, a plurality of inspection electrodes are attached to a heat equalizing tube, and an electric change between each of the inspection electrodes and the heating mechanism is detected. By detecting the leakage current of, the contact state between the heating mechanism and the heat equalizing tube, and by detecting the contact state between each test electrode and the heat equalizing tube based on the resistance value between each test electrode,
This makes it possible to quickly and accurately detect the contact state between the heating mechanism and the soaking tube.

(Example) Hereinafter, an example in which the apparatus of the present invention is applied to a horizontal heat treatment apparatus will be described with reference to the drawings.

For example, a heat equalizing tube 2 made of a member such as SiC is provided around the outer periphery of a process tube 1 made of quartz glass, and further, for example, a Kanthal wire (product) A heater mechanism 4 around which a heater element wire 3 (manufactured by Kantargadelius Co., Ltd.) is wound is attached to the heat equalizing tube 2 while maintaining a predetermined gap, for example, 10 mm.

In the process tube 1, a large number of objects to be processed, for example, semiconductor wafers 5, are accommodated at a constant arrangement pitch in the longitudinal direction of the process tube 1. A reaction gas corresponding to the processing is introduced into the process tube, and the processing is performed by setting the inside of the process tube 1 to a predetermined temperature via the soaking tube 2 by the heater mechanism 4.

The processing temperature is controlled by varying the heater application voltage from the heater power supply 6 with a transformer 7. In the case of high-temperature processing, the temperature atmosphere in the process tube 1 is set to 800 to 1
Bring to 100 ° C.

Incidentally, annular test electrodes 8 and 9 for detecting insulation resistance between the heat equalizing tube 2 and the heater mechanism 4 are attached to one end of the heat equalizing tube 2 at two locations. Is connected to a contact detector 10 for detecting a contact state between the heat equalizing tube 2 and the heater wire 3.

Further, a DC low voltage Vcc is applied between each of the inspection electrodes 8 and 9 and the heater wire terminal 11 as a reference power supply for detection.

Hereinafter, the operation of the contact detector 10 will be described.
Note that the contact detector is operated by the detector power supply 12.

When the heater wire 3 sags due to high heat, the gap between the heat equalizing tube 2 and the heater wire 3 is narrowed, and the insulation resistance of the gap is reduced. At this time, since the DC inspection voltage Vcc is applied between the heater wire terminal 11 and each of the inspection electrodes 8 and 9, a leakage current Is flows through the heat equalizing tube 2 as the insulation resistance decreases.

This leakage current Is passes through the test electrodes 8 and 9 and is
It flows to 10 where it is amplified and compared with a predetermined reference value.

At this time, if the leakage current detection value is larger than the reference value,
It is determined that there is an abnormality in the contact state, and an abnormality signal is output, and the heater power is cut off by the abnormality signal.

Incidentally, the contact detector 10 also detects the resistance value between the two inspection electrodes 8 and 9 attached to the heat equalizing tube 2,
Due to the change in the resistance value, it is possible to perform a self-diagnosis of a contact failure due to adhesion of an oxide film or a defective mounting of the test electrode portions 8 and 9 and prevent a measurement error due to a poor contact between the test electrodes 8 and 9 and the heat equalizing tube 2. it can.

As shown in FIG. 2, the shape of the inspection electrodes 8 and 9 may be, for example, a 20 mm wide annular belt made of stainless steel or the like, which may be screwed to the heat equalizing tube 2 at intervals of 5 cm, for example. Alternatively, as shown in FIG. 3, an electrode mounting pedestal 12 may be protruded from the end of the heat equalizing tube 2, and holes may be formed in the pedestal 12 to mount the inspection electrodes 8 and 9.

Thus, the detection DC power supply independent of the heater power supply 6
Vcc is applied between the heater wire 3 and each of the inspection electrodes 8 and 9, and at this time, a contact state between the heat equalizer tube 2 and the heater wire 3 is detected by a leakage current Is flowing through the heat equalizer tube 2.
The contact state can be detected regardless of the operation state of the heater mechanism 4. Also, by mounting a plurality of test electrodes and monitoring the resistance value between these electrodes, the contact state between each test electrode 8, 9 and the heat equalizing tube 2 can be self-diagnosed, and the reliability of the measurement is greatly improved. improves.

As described above, according to this embodiment, accurate detection can always be performed regardless of the operation state of the heating mechanism, and the contact state between the inspection electrode and the soaking tube can be self-diagnosed. To improve.

[Effects of the Invention] As described above, according to the present invention, there is an effect that the contact between the heating mechanism and the soaking tube can be quickly detected.

[Brief description of the drawings]

FIG. 1 is a view showing the configuration of an embodiment in which the apparatus of the present invention is applied to a horizontal heat treatment apparatus, FIG. 2 is a view showing an example of attachment of the test electrode of FIG. 1, and FIG. 3 is a view of the test electrode of FIG. It is a figure showing other examples of attachment. 1 Process tube 2 Heat equalizing tube 3 Heater wire 4 Heater mechanism 5 Semiconductor wafer 6
Heater power supply, 8, 9 ... inspection electrode, 10 ... contact detector,
11 ... heater wire terminal.

Claims (1)

(57) [Claims] A reaction vessel in which an object to be processed is provided;
In a heat treatment apparatus provided with a heat equalizing tube provided on the outer periphery of the reaction vessel and a heating mechanism provided on the outer periphery of the heat equalizing tube, a plurality of inspection electrodes provided at an end of the heat equalizing tube; Heat treatment comprising: means for applying a predetermined voltage between an electrode and the heating mechanism; and a circuit for detecting a contact state between the heat equalizing tube and the heating mechanism from a current flowing through the inspection electrode. apparatus.