JPH1022229A - Heat treatment device for substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide equipment for shorenting treatment time per substrate by eliminating useless waiting time until the oxygen concentration of gas containing low-concentration oxygen can be measured by an oxygen concentration measuring means after a substrate is carried into a furnace and a throat is closed by a lid member. SOLUTION: Inside a furnace 10, a piping 44 for nitrogen gas supply of which the conduit is connected to a nitrogen gas supply source is connected to a piping 40 for sampling for sucking gas near a throat 12, and switched by a stop valve 54 so as to supply nitrogen gas into the piping for sampling when the throat is opened and to lead gas inside the furnace through the piping for sampling to an oxygen concentration meter 30, by cutting off the communication between the nitrogen gas supply source and the piping for sampling when the throat is closed by a lid member 16.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a substrate heat treatment apparatus for heat treating various substrates such as semiconductor wafers one by one by heating means such as light irradiation, such as a lamp annealing apparatus.

[0002]

2. Description of the Related Art A heat treatment apparatus for heating a substrate, for example, a semiconductor wafer by light irradiation or the like, is shown in FIGS.
Has a configuration as shown in each of the schematic side sectional views. Each of the apparatuses shown in FIGS. 2 to 4 is a light irradiation type heat treatment apparatus, and has a furnace port block 14 in which a furnace port 12 for loading and unloading a substrate W is formed on the front side. 10 is provided. The furnace wall of the furnace body 10 is formed of, for example, quartz glass having infrared transmittance. The furnace port 12 of the furnace body 10 is closed by a lid 16 so as to be openable and closable. A susceptor 18 for supporting the substrate W in a horizontal position is integrally fixed to the inner surface side of the lid 16.
As the lid 16 reciprocates in the horizontal direction, the substrate W supported by the susceptor 18 is carried into and out of the furnace body 10. And the lid 16 is the furnace 1
By moving to the 0 side and abutting the furnace port block 14, the furnace port 12 is closed, and the substrate W supported by the susceptor 18 is arranged at a predetermined position in the furnace body 10. .

[0003] In the vertical direction of the furnace body 10, the furnace body 1
Light source 20 for light irradiation comprising a lamp group such as a halogen lamp, a xenon lamp, etc.
Are arranged. A reflector (reflector) 22 is arranged behind each light source 20 and on both sides and a rear portion of the furnace body 10 so as to surround the furnace body 10. The inner surface of each reflector 22 is mirror-polished or the like so that light can be reflected efficiently. The light irradiation light source 20 is
May be arranged only on the upper side.

[0004] The furnace body 10 has a gas introduction passage 24 formed at the rear side thereof, and the gas introduction passage 24 is connected to a supply source of a processing gas such as nitrogen. On the other hand, the furnace body 10
A gas exhaust path 26 is formed in the furnace port block 14 on the front side of the gas exhaust pipe 26, and a gas exhaust pipe 27 is connected to the gas exhaust path 26. Further, O-rings 28 are attached to the furnace opening block 14 in order to keep the inside of the furnace body 10 airtight.

[0005] In the light irradiation type heat treatment apparatus having the above-described structure, the furnace body 10 with the furnace port 12 side opened is opened.
A processing gas such as nitrogen is introduced into the furnace body 10 through the gas introduction path 24, and the substrate W supported by the susceptor 18 is inserted into the furnace body 10 while the processing gas flows out through the furnace port 12 of the furnace body 10. I do. When the furnace port 12 is closed by the lid 16, the furnace body 10 passes through the gas introduction passage 24.
The processing gas is introduced into the inside, the inside of the furnace body 10 is purged,
The gas is exhausted through the gas exhaust passage 26 of the furnace opening block 14. Then, electric power is supplied to the upper and lower light irradiation light sources 20 so that the substrate W is heated to a desired temperature programmed in advance by a temperature detection device and a temperature controller (not shown), and the substrate W is irradiated with light. . When the heat treatment is completed, the substrate W is cooled to a desired temperature in the furnace body 10, and thereafter, the lid 16 moves to open the furnace port 12 and to dispose the substrate W supported by the susceptor 18.
Is carried out of the furnace body 10.

In the heat treatment apparatus, it is necessary to maintain the internal atmosphere of the furnace body 10 at a high purity with a processing gas such as nitrogen during the heat treatment of the substrate W. The heat treatment of the substrate W is performed by loading the substrate W into the furnace body 10. After that, it is started after confirming that the inside of the furnace body 10 has been almost completely replaced with the processing gas. Therefore, in order to monitor whether or not the inside of the furnace body 10 is filled with the high-purity processing gas, the gas in the furnace body 10 or the gas exhausted from the furnace body 10 is sampled, and the oxygen concentration of the gas is sampled. Measuring has been done.

Conventionally, to measure the oxygen concentration of a gas, as shown in FIG. 2, a gas suction pipe 32 is inserted into a furnace body 10 and a sampling pipe 34 having one end connected to the gas suction pipe 32. The gas in the furnace body 10 is introduced into the oximeter 30 using a gas concentration measuring device having the other end connected to the oximeter 30 to measure the oxygen concentration of the gas in the furnace body 10. I was As shown in FIG. 3, a gas suction pipe 36 is attached to the lid 16 which reciprocates in the horizontal direction to open and close the furnace port 12 of the furnace body 10, and
When a gas concentration measuring device having a configuration in which one end of a sampling pipe 38 whose one end is connected to 6 and the other end of the sampling pipe 38 is connected to an oxygen concentration meter 30 is used and the furnace port 12 of the furnace Suction pipe 36 and sampling pipe 38
Gas in the furnace body 10 is introduced into the oxygen concentration meter 30 through
The oxygen concentration of the gas in the furnace body 10 was measured. Alternatively, as shown in FIG. 4, one end of a sampling pipe 40 is inserted into a gas exhaust pipe 27 connected to a gas exhaust path 26 formed in the furnace port block 14 of the furnace body 10 to perform sampling. Using a gas concentration measuring device having a configuration in which the other end of the piping 40 is connected to the oxygen concentration meter 30,
The gas exhausted from the furnace body 10 is introduced into the oxygen concentration meter 30 to measure the oxygen concentration of the gas flowing through the gas exhaust pipe 27.

[0008]

In the conventional gas concentration measuring device shown in FIG. 2, a substrate W is supported by a susceptor 18 integrally fixed to a lid 16 and the substrate W is inserted into the furnace body 10. It is necessary to sample the gas near the furnace port 12 so that it is possible to detect whether or not outside air has entered the furnace body 10 when the furnace body 10 is opened. It is located close to Therefore, when the furnace port 12 of the furnace body 10 is opened or when the substrate W is inserted into the furnace body 10, gas (atmosphere) containing a high concentration of oxygen is temporarily sucked into the gas suction pipe 32 through the suction port. Thus, the gas suction pipe 32, the sampling pipe 34, and the sensor part of the oximeter 30 may be exposed to a gas having a high oxygen concentration. Then, once the sampling pipe 34 and the sensor section of the oxygen concentration meter 30 are exposed to a gas having a high oxygen concentration, oxygen molecules adhere to the inner wall surface of the sampling pipe 34 and the sensor section of the oxygen concentration meter. It takes a long time before the oxygen concentration of a gas containing a low concentration of oxygen such as tens of ppm to several ppm or less can be measured.

In the conventional gas concentration measuring apparatus shown in FIG. 3, the lid 16 is separated from the furnace port 12 of the furnace body 10 as shown in FIG. Is located in the gas suction pipe 36, a gas (atmosphere) containing high-concentration oxygen is sucked into the gas suction pipe 36, and the sampling pipe 38 and the sensor unit of the oximeter 30 are exposed to the high-oxygen-concentration gas. become. For this reason, as described above, it takes a long time before the oxygen concentration of a gas containing oxygen having a low concentration of several tens ppm to several ppm or less, which is the target of measurement, can be measured. Further, in the conventional gas concentration measuring device shown in FIG.
When the furnace port 12 of the furnace body 10 is opened away from the furnace port 12, a part of the atmosphere is drawn into the gas exhaust path 26 of the furnace port block 14 through the furnace port 12, A gas having a high oxygen concentration flows through the pipe 27.
Since the oximeter 30 is constantly operating, the sampling pipe 40 and the sensor of the oximeter 30 are exposed to a gas having a high oxygen concentration. For this reason, as described above, it takes a long time before the oxygen concentration of the gas containing oxygen having a low concentration of several tens ppm to several ppm or less can be measured.

[0010] In the conventional gas concentration measuring apparatus, as described above, after the furnace port 12 of the furnace body 10 is closed by the lid 16, it takes a long time to measure a low oxygen concentration which is a target in the measurement. Since it takes a long time, the determination timing when starting the heat treatment of the substrate W after the loading of the substrate W into the furnace body 10 is delayed. As a result, there is a problem that the processing time per substrate becomes longer and the throughput is reduced.

The present invention has been made in view of the above circumstances, and after a substrate is carried into a furnace, a furnace port is closed by a lid, and a low concentration target to be measured by oxygen concentration measuring means. Eliminates or shortens the wasteful waiting time until it becomes possible to measure the oxygen concentration of the gas containing oxygen, and increases the processing time per substrate due to a delay in determining when to start the heat treatment of the substrate. It is an object of the present invention to provide a heat treatment apparatus for a substrate, which can prevent the occurrence of the heat treatment and improve the throughput.

[0012]

The invention according to claim 1 is
A furnace body having a furnace port for carrying in and out the substrate and housing the substrates in a single wafer, and heat treatment of the substrate housed in the furnace body, in particular, the furnace port is hermetically closed and the substrate is introduced into the furnace body. A lid for opening the furnace port when loading and unloading the substrate from the furnace, a sampling pipe for sucking gas in the furnace near the furnace port, and a sampling pipe connected to the sampling pipe for sampling. An oxygen concentration measuring means for measuring an oxygen concentration of a gas introduced through a pipe for gas supply, wherein an inert gas supply pipe connected to an inert gas supply source is connected to the sampling pipe. While providing a switching means for switching the flow path, the inert gas supply source and the sampling pipe through the inert gas supply pipe when the furnace port of the furnace body is open The inert gas is supplied into the sampling pipe by communicating with the pipe, and when the furnace port of the furnace body is closed by the lid, the communication between the inert gas supply source and the sampling pipe is cut off to cut the sampling pipe. The apparatus is characterized in that the apparatus is switched so as to introduce gas into the oxygen concentration measuring means.

[0013] In the substrate heat treatment apparatus having the above-described structure, when the lid is separated from the furnace port of the furnace body and the furnace port is opened, the inert gas is supplied from the inert gas supply source to the inert gas supply source. It is supplied to the sampling pipe through the pipe. Therefore, a gas having a high oxygen concentration (such as the atmosphere) is not sucked into the sampling pipe, and the sampling pipe and the sensor portion of the oxygen concentration measuring means are not exposed to a gas containing a high concentration of oxygen. . On the other hand, when the furnace opening of the furnace body is closed by the lid, the flow path is switched by the switching means so that the communication between the inert gas supply source and the sampling pipe is cut off, and the gas in the furnace body is sampled. The gas is drawn into the piping for use, and the suctioned gas is introduced into the oxygen concentration measuring means through the sampling pipe. Then, the oxygen concentration of the gas in the furnace is measured by the oxygen concentration measuring means, and when it is confirmed that the measured oxygen concentration is a low concentration equal to or less than a certain value, the inside of the furnace body is a high-purity processing gas. Is determined, the heat treatment of the substrate is started. At this time, as described above, even when the furnace port of the furnace body is opened, the sampling pipe and the sensor part of the oxygen concentration measuring means are not exposed to the gas containing high concentration of oxygen, so that the low concentration gas for the purpose of measurement is immediately obtained. It becomes possible to measure the oxygen concentration of the gas containing oxygen.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best embodiment of the present invention will be described below with reference to FIG.

FIG. 1 is a schematic side sectional view showing an example in which the present invention is applied to a conventional light irradiation type heat treatment apparatus having the structure shown in FIG. The basic configuration itself of this heat treatment apparatus is shown in FIG.
4 to FIG. 4, the same reference numerals as those used in FIG. 2 to FIG.
The description is omitted. Further, one end of a sampling pipe 40 is inserted into a gas exhaust pipe 27 connected to a gas exhaust path 26 formed in the furnace port block 14, and the other end of the sampling pipe 40 is connected to the oxygen concentration meter 30. The configuration of the connected gas concentration measuring device is the same as that of the device shown in FIG.

In this heat treatment apparatus, a nitrogen gas supply pipe 44 connected to a supply source (utility) 42 of an inert gas, for example, nitrogen gas, is connected to a sampling pipe 40 of the gas concentration measurement apparatus. I have. The nitrogen gas supply pipe 44 is provided with a filter 46, a regulator 48, a pressure gauge 50, and a flow control valve 52, and a stop valve 54. And
Controlling the opening and closing of the stop valve 54 to supply nitrogen gas from the nitrogen gas supply source 42 into the sampling pipe 40 through the nitrogen gas supply pipe 44;
It is configured such that the communication between the nitrogen gas supply source 42 and the sampling pipe 40 is interrupted and the operation of stopping the supply of the nitrogen gas from the nitrogen gas supply source 42 into the sampling pipe 40 can be switched. .

The operation of the heat treatment apparatus shown in FIG. 1 will now be described. As shown in FIG.
2 and the furnace port 12 is open, the stop valve 54 is opened and the nitrogen gas supply source 42 is opened.
Then, nitrogen gas is supplied into the sampling pipe 40 through the nitrogen gas supply pipe 44. At this time, the furnace body 10
A processing gas such as nitrogen gas is introduced into the inside through a gas introduction path 24, and the processing gas is exhausted from the inside of the furnace body 10 through a gas exhaust path 26 of the furnace port block 14 and a gas exhaust pipe 27. I have. A part of the nitrogen gas supplied to the sampling pipe 40 flows into the oxygen concentration meter 30, and another part flows out of the flow path of the gas exhaust pipe 27.
The flow rate of the nitrogen gas supplied from the nitrogen gas supply source 42 into the sampling pipe 40 is equal to or slightly (0 to 30%) higher than the sample gas flow rate required for measurement in the oximeter 30. I do. As described above, since the inside of the sampling pipe 40 is purged with the nitrogen gas, the gas exhaust path 26
Even if a part of the atmosphere is drawn into the furnace through the furnace port and a gas containing high-concentration oxygen flows in the gas exhaust pipe 27, the gas flows from the gas exhaust pipe 27 into the sampling pipe 40. Is prevented.

Next, the lid 16 is moved, and the susceptor 18 is moved.
Is inserted into the furnace body 10 and the lid 16 is supported.
When it is confirmed that the furnace port 12 is closed by being pressed against the furnace port block 14, the stop valve 54 is closed and the supply of nitrogen gas from the nitrogen gas supply source 42 into the sampling pipe 40 is stopped. Is done. The gas flowing from the furnace body 10 into the gas exhaust pipe 27 through the gas exhaust path 26 of the furnace port block 14 and flowing through the gas exhaust pipe 27 is sucked into the sampling pipe 40, It is introduced into the oximeter 30 through 40,
The oxygen concentration is measured. At this time, the sampling pipe 40 and the sensor part of the oxygen concentration meter 30 are connected to the furnace port 1 of the furnace body 10.
Since the sample 2 was not exposed to the gas having a high oxygen concentration even when it was opened, it is possible to immediately measure the oxygen concentration of a gas containing a low concentration of oxygen. Then, when the oxygen concentration measured by the oxygen concentration meter 30 becomes equal to or less than a certain value, the heat treatment of the substrate W is started.

After the heat treatment of the substrate W is completed, the substrate W
When the temperature is cooled to a desired temperature within 0, the lid 16 moves to open the furnace port 12, and at the same time, the stop valve 54 is opened. Then, nitrogen gas is supplied from the nitrogen gas supply source 42 into the sampling pipe 40 through the nitrogen gas supply pipe 44,
The inside and the sensor part of the oximeter 30 are purged.

The above-described embodiment is an example in which the present invention is applied to a heat treatment apparatus provided with a conventional gas concentration measuring device having the configuration shown in FIG. 4, but the present invention is applied to FIGS. 2 and 3. The present invention can also be applied to the heat treatment apparatuses provided with the conventional gas concentration measuring apparatuses shown in the figures, and in these applications, the sampling pipes 34 and 38 connecting the gas suction pipes 32 and 36 and the oxygen concentration meter 30 are used. The inert gas supply pipe is connected and connected.

[0021]

Next, when the furnace port 12 is closed by the lid 16 from the state where the furnace port 12 of the furnace body 10 is opened using the heat treatment apparatus having the structure shown in FIG. An experimental example in which the time from when the oxygen concentration of the gas introduced into the oxygen concentration meter 30 through the sampling pipe 40 reaches the predetermined low concentration and the result thereof will be described.

In this experiment, nitrogen gas was introduced into the furnace body 10 through the gas introduction path 24, and the amount of the introduced gas was set to 40 l / min when the furnace port 12 was opened.
At the time of occlusion was 10 l / min. Further, the amount of exhaust gas exhausted from the furnace body 10 through the gas exhaust pipe 27 is reduced through the gas introduction passage 24 while the furnace port 12 is closed.
When 30 l / min of nitrogen gas was introduced into the furnace body 10
The exhaust volume was set such that the inside of the chamber became atmospheric pressure. When the furnace port 12 is opened, the flow rate of the nitrogen gas supplied from the nitrogen gas supply source 42 into the sampling pipe 40 is set to 1.2 l /
Minutes. When the furnace port 12 was closed, the supply of the nitrogen gas to the sampling pipe 40 was stopped. The amount of gas introduced into the oxygen concentration meter 30 was 0.8 l / min. When the furnace port 12 of the furnace body 10 is closed, the oxygen concentration of the gas measured by the oximeter 30 becomes 50 pp.
The time to reach m, 30 ppm and 20 ppm was measured, respectively. For comparison, a similar experiment was performed using a conventional heat treatment apparatus having the configuration shown in FIG. Table 1 shows the results.

[0023]

[Table 1]

As can be seen from the results shown in Table 1, when the apparatus according to the present invention is used, the oxygen content of the gas introduced into the oximeter 30 through the sampling pipe 40 is smaller than when the conventional apparatus is used. The time required for the concentration to reach a low concentration is reduced. It can also be seen that the lower the oxygen concentration of the gas, the greater the difference in arrival time between when the apparatus according to the present invention is used and when the conventional apparatus is used.

[0025]

When the substrate heat treatment apparatus according to the first aspect of the present invention is used, the substrate is carried into the furnace, the furnace port is closed with the lid, and the object is measured by the oxygen concentration measuring means. The wasteful waiting time until the oxygen concentration of a gas containing a very low concentration of oxygen can be measured is eliminated or shortened, so that the processing time per substrate is shortened and the throughput is improved. Becomes

[Brief description of the drawings]

FIG. 1 is a side sectional view showing an example of an embodiment of the present invention and showing a schematic configuration of a substrate heat treatment apparatus.

FIG. 2 is a schematic side sectional view showing an example of a configuration of a conventional substrate heat treatment apparatus.

FIG. 3 is a schematic side sectional view showing another example of the configuration.

FIG. 4 is a schematic side sectional view showing still another configuration example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Furnace body 12 Furnace opening 14 Furnace opening block 16 Lid 18 Susceptor 20 Light irradiation light source 22 Reflector 24 Gas introduction path 26 Gas exhaust path 27 Gas exhaust pipe 30 Oxygen concentration meter 40 Sampling pipe 42 Nitrogen gas supply source 44 Nitrogen Gas supply piping 54 Stop valve

Claims (1)

[Claims] 1. A furnace having a furnace port for loading and unloading substrates, and a furnace body for accommodating substrates in a single wafer, and heat treatment of the substrates housed in the furnace body, particularly, the furnace port is hermetically closed. A lid for opening the furnace port when the substrate is loaded into and out of the furnace, and a sampling pipe for sucking gas near the furnace port inside the furnace, A substrate heat treatment apparatus comprising: a flow path connected to the pipe; and an oxygen concentration measuring means for measuring an oxygen concentration of the gas introduced through the sampling pipe. And connecting the inert gas supply pipe to the sampling pipe through the inert gas supply pipe when the furnace port of the furnace body is open. Sa An inert gas is supplied into the piping for pulling, and when the furnace port of the furnace body is closed by the lid, the communication between the inert gas supply source and the piping for sampling is cut off and the oxygen is passed through the piping for sampling. A heat treatment apparatus for a substrate, comprising switching means for switching so as to introduce gas into the concentration measuring means.