JPH07106053A - Heater breakage detector - Google Patents

Abstract

PURPOSE:To prevent the pollution of a treatment bath caused by a washing solution polluted with metal by the breakage of a pipe by arranging a liquid detecting sensor, which detects the inflow of a liquid, in a space between an inner pipe and an outer pipe or in a piping which reduces pressure in the space. CONSTITUTION:Boil washing is conducted by directly putting a liquid heating part 2 in a treatment bath to heat a washing solution. Pressure in a space between double structure quartz pipes 4A and 4B is reduced with a pressure reducing pump 13 to optimum pressure at which a pipe is not broken through a pressure controller 12. If breakage or a pinhole is produced in the outside quartz pipe 4A and the washing solution flows in the space, a laser sensor 10, for example, detects the washing solution based on the variation of quantity of light in a trap box 9 through a Y-shaped tube 7. By linking the sensor 10 with the heating part 2 and the operation of the pump 13, the heating part 2 and the pump 13 are turned off to stop washing and the pollution in the treatment bath can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heater breakage detector, and is suitable for application to, for example, a heater breakage detector used for boil cleaning in pretreatment for diffusion.

[0002]

2. Description of the Related Art Conventionally, in processing a wafer in a semiconductor manufacturing process, a cleaning process is provided as a pre-diffusion process. The tank used in this cleaning process consists of several processing tanks, such as one that performs cleaning processing at room temperature with each processing tank, and one that heats the cleaning liquid in the processing tank to enhance the cleaning effect. is there.

Here, as a boiling cleaning method for cleaning at a high temperature, there is a method in which a liquid heating section is directly put into a processing tank and heated. In this method, in order to heat the cleaning liquid, a liquid heating section having a nichrome wire as a heater source is used inside the quartz tube, but there is a problem that detection is delayed even if the quartz tube is damaged or pinholes occur.

When such damage or pinhole occurs, the cleaning liquid flowing into the tube comes into contact with the nichrome wire, and the cleaning liquid in the tube contaminated by this contact flows out into the processing tank, so that the wafer is cleaned. Nevertheless, there was a problem that the inside of the processing tank was contaminated.

Therefore, as a method for detecting breakage, conventionally, the quartz tube of the liquid heating unit has a double structure, a nichrome wire is provided inside the quartz tube inside, and a breakage or pinhole occurs in the quartz tube outside. As a result, a sensor provided with a breakage detection sensor between the outer quartz tube and the inner quartz tube is used to detect the cleaning liquid flowing into the tube.

For example, a ground wire and a wire to which a positive voltage is applied are provided between the outer quartz tube and the inner quartz tube. When the cleaning liquid flows into the outer quartz tube due to breakage or pinholes, an electric current flows between the ground wire and the wire to which the positive voltage is applied using the cleaning liquid as a medium. By detecting this current, it is possible to quickly detect the occurrence of damage or pinhole.

[0007]

However, during the period from the detection of breakage or pinholes in the quartz tube outside the liquid heating section to the removal of the liquid heating section from the processing tank, the cleaning liquid remains in the quartz tube. However, there is a problem that the cleaning liquid contaminated by flowing into the metal wire of the damage detection sensor flows into the processing tank and contaminates the processing tank.

The present invention has been made in consideration of the above points, and is capable of quickly detecting even if a quartz tube outside the liquid heating portion is damaged or pinholes are generated, and the cleaning liquid flowing into the quartz tube and for damage detection are detected. It is an object of the present invention to propose a heater breakage detector capable of preventing the cleaning liquid, which is metal-contaminated by contact with the metal wire of the sensor, from contaminating the inside of the processing tank.

[0009]

In order to solve the above problems, in the present invention, a tank filled with a liquid, and an inner tube 4B and an outer tube 4A arranged in the tank and having both ends sealed respectively.
A double tube 4 having a double structure, a heating means 5 provided inside the inner tube 4B for heating the tank, and surrounded by an inner tube 4B and an outer tube 4A of the double tube 4. The pipe 7 taken out from the outer pipe 4A for decompressing the space, the space surrounded by the inner pipe 4B and the outer pipe 4A, and the decompression pump 13 exhausting from the pipe 7 are arranged between the pipe 7 and the outer pipe. Liquid detection sensor 1 for detecting the presence or absence of liquid flowing into the space due to breakage of 4A
Be prepared with 0 and.

Further, in the present invention, a tank filled with a liquid, a double tube 4 having a double structure, which is arranged in the tank and has inner and outer tubes 4B and 4A sealed at both ends, Tube 4
A pipe 5 taken out of the outer pipe 4A for decompressing the space surrounded by the inner pipe 4B and the outer pipe 4A of the double pipe 4 and the heating means 5 provided inside B. 7 and
The liquid detection sensor 10 is arranged in a space surrounded by the inner pipe 4B and the outer pipe 4A, and detects the presence or absence of inflow of liquid into the space due to breakage of the outer pipe 4A.

[0011]

[Function] A double tank 4 having a double structure composed of a liquid-filled tank, an inner tube 4B and an outer tube 4A, which are arranged in the tank and sealed at both ends, and provided inside the inner tube 4B. And the heating means 5 for heating the tank, and the inner tube 4B and the outer tube 4 of the double tube 4.
In addition to the pipe 7 taken out from the outer pipe 4A for decompressing the space surrounded by A, the space surrounded by the inner pipe 4B and the outer pipe 4A and the decompression pump exhausting from the pipe 7. 1
By disposing a liquid detection sensor 10 which is arranged between the inner pipe 4B and the outer pipe 4A and which is surrounded by the inner pipe 4B and the outer pipe 4A, and which detects the presence or absence of inflow of liquid into the space due to breakage of the outer pipe 4A. It is possible to prevent contamination in the tank.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows a heater breakage detecting device 1 as a whole. The heater breakage detection device 1 includes a liquid heating unit 2 that heats the cleaning liquid in the processing tank, and a detection unit 3 that detects a breakage of the liquid heating unit 2 and a pinhole.

The liquid heating section 2 is composed of a quartz tube 4 having a double structure. The quartz tube 4 is composed of an outer quartz tube 4A and an inner quartz tube 4B, and is bent to have a U shape and an L shape when viewed from the side. The nichrome wire 5 for heating the cleaning liquid does not come into contact with the cleaning liquid flowing into the inside of the quartz tube 4B due to the damage or the pinhole even if the outer quartz tube 4A is damaged or pinholes are generated. It is provided inside. Further, suction ports 6A and 6B for connecting to the detection unit 3 are provided near both ends of the outer quartz tube 4A, and a Y-shaped tube 7 is attached to the suction ports 6A and 6B for connecting to the detection unit 3. ing.

The quartz tube 4B is provided at both ends of the inner quartz tube 4B.
Caps 8A and 8 to maintain a vacuum inside
B is attached. Both ends between the quartz tubes 4A and 4B are welded.

On the other hand, the detector 3 is a trap box 9 for storing the cleaning liquid, and a laser sensor 1 for detecting the cleaning liquid.
0, a pressure gauge 11, a pressure regulator 12, and a decompression pump 13.

The trap box 9 is an outer quartz tube 4A.
The suction ports 6A and 6B of the outer quartz tube 4A for accumulating the cleaning liquid that has flowed into the quartz tube 4A due to damage to the tube or pinholes.
It is provided at the tip of the tube 7 attached to the. In addition, the trap box 9 has the trap box 9
A laser sensor that detects that the cleaning liquid has entered the inside by a change in the amount of light and a pressure adjuster 12 that adjusts the pressure are connected by pipes.

A pressure gauge 11 for measuring the pressure is provided in the middle of the pipe connecting the trap box 9 and the pressure regulator 12. The decompression pump 13 is a pressure regulator 1
The quartz tube 4 adjusted by 2 is connected to the pressure adjuster 12 through a pipe for depressurizing and sucking at a constant pressure that does not damage the quartz tube 4.

In the above construction, when the boil cleaning is performed, the cleaning liquid in the processing tank is heated by directly introducing the liquid heating unit 2 into the processing tank. Also quartz tubes 4A and 4B
The pressure is constantly reduced by the pressure reducing pump 13 between and.
At this time, the pressure adjuster 12 sets the optimum pressure so as not to damage the quartz tube 4 and adjusts the pressure reduction amount.

On the other hand, when the outer quartz tube 4A is damaged or pinholes are formed, the pressure between the quartz tubes 4A and 4B is constantly reduced by the decompression pump 13, so that the pressure difference causes the cleaning liquid in the treatment tank to be rapidly abruptly generated. Is sucked into the tube. At this time, the cleaning liquid flowing between the quartz tubes 4A and 4B flows into the trap box 9 through the Y-shaped tube 7 to change the light amount, and the laser sensor 10 detects this change.

When the laser sensor 10 detects a change in the amount of light, the operations of the laser sensor 10, the liquid heating unit 2 and the pressure reducing pump 13 are interlocked so that the nichrome wire 5 of the liquid heating unit 2 and the pressure reducing pump 13 are both operated. Turn off and stop boil cleaning.

According to the above structure, the decompression pump 13 constantly depressurizes the space between the quartz tubes 4A and 4B, so that when the outer quartz tube 4A is damaged or pinholes are formed, the quartz tube 4 is temporarily removed. By taking it out and detecting it, the inside of the processing tank can be prevented from being contaminated.

Although the laser sensor 10 is used as the breakage detecting sensor in the above-mentioned embodiment, the present invention is not limited to this, and it is possible to detect that the cleaning liquid has entered the trap box like a capacitance sensor, for example. Any sensor will do.

Further, in the above embodiment, the liquid heating section 2
Although the nichrome wire 5 is used as the heater source of the above, the present invention is not limited to this, and other than the nichrome wire may be used as long as it serves as a heater source of the liquid heating unit.

Further, in the above-mentioned embodiment, the laser sensor 10 for detecting the damage is provided outside the double-structured quartz tube 4, but the present invention is not limited to this, and the laser sensor 10 outside the double-structure is provided. Even if a sensor for detecting damage is provided between the quartz tube and the inner quartz tube, the same effect can be obtained by constantly reducing the pressure between the outer quartz tube and the inner quartz tube by the decompression pump. .

For example, the pressure between the outer quartz tube and the inner quartz tube is constantly reduced by a decompression pump, and a ground wire and a wire to which a positive voltage is applied are provided between the outer quartz tube and the inner quartz tube. Should be provided. When the outer quartz tube is damaged or pinholes occur, the cleaning liquid in the processing tank is drawn into the tube due to the pressure difference due to the decompression pump and does not flow out into the processing tank.
By contacting the ground wire and the wire to which a positive voltage is applied, current flows and damages and pinholes can be detected.

Although the heater breakage detector used for cleaning the boil in the diffusion pretreatment has been described in the above embodiment, the present invention is not limited to this and is also applied to the heater breakage detector used for wafer etching. obtain.

[0028]

As described above, according to the present invention, by constantly reducing the pressure between the inner and outer quartz pipes by the decompression pump, it is possible to detect the chemical liquid flowing into the quartz pipe and the breakage due to the damage or the pinhole. It is possible to easily realize a heater breakage detector capable of preventing the chemical solution contaminated with metal from contaminating the inside of the processing tank due to the contact with the metal wire of the usage sensor.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a heater breakage detection device according to an embodiment of the present invention.

[Explanation of symbols]

1 ... Heater breakage detection device, 2 ... Liquid heating part, 3 ...
Detector 4, 4, 4A, 4B ... Quartz tube, 5 ... Pyromax, 6A, 6B ... Suction port, 7 ... Tube, 8A,
8B: Cap, 9 ... Trap box, 10 ...
Laser sensor, 11 ... pressure gauge, 12 ... pressure regulator,
13 ... Decompression pump.

Claims (4)

[Claims] 1. A double-structured double tube composed of a liquid-filled tank, an inner tube and an outer tube, both ends of which are arranged inside the tank, and which is provided inside the inner tube. A heating means for heating the tank, a pipe taken out from the outer pipe for decompressing a space surrounded by the inner pipe and the outer pipe of the double pipe, and the inner pipe And a liquid detection sensor disposed between a space surrounded by the outer pipe and a decompression pump exhausting from the pipe, and detecting the presence or absence of liquid flowing into the space due to breakage of the outer pipe. A heater breakage detector characterized by comprising: 2. A double tube having a double structure consisting of a liquid-filled tank, an inner tube and an outer tube which are arranged in the tank and whose both ends are sealed, and which are provided inside the inner tube. A heating means for heating the tank, a pipe taken out from the outer pipe for decompressing a space surrounded by the inner pipe and the outer pipe of the double pipe, and the inner pipe A heater breakage detection device, which is arranged in a space surrounded by the outer pipe and a liquid detection sensor for detecting the presence or absence of liquid flowing into the space due to breakage of the outer pipe. vessel. 3. The heater breakage detector according to claim 1 or 2, wherein the liquid contained in the tank is a cleaning liquid. 4. The heater breakage detector according to claim 1, wherein the liquid contained in the bath is an etching liquid.