JP2001284338A - Device for manufacturing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor manufacturing device, capable of simply performing film forming and cleaning and of improving safety and availability. SOLUTION: The semiconductor manufacturing device has reaction chambers 15, 25, a reaction gas supply means 17 for supplying a reaction gas to the respective reaction chambers, cleaning gas supply means 27 for supplying a cleaning gas to the respective reaction chambers to perform cleaning by etching, exhaust lines 18, 28 for exhausting the respective reaction chambers of air, traps disposed in the respective exhaust lines and for trapping substances in the cleaning gas, and a cleaning gas exhaust line 34 for exhausting the cleaning gas which is branched from the exhaust line at the upstream side of the traps and communicates with the same exhaust unit 35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor manufacturing apparatus, and more particularly to a semiconductor manufacturing apparatus for manufacturing a semiconductor element by forming a thin film on a substrate surface by chemical vapor deposition (CVD) or performing a process such as etching. It is about.

[0002]

2. Description of the Related Art High-density integrated circuits are manufactured by forming a thin film on the surface of a silicon wafer and subjecting the thin film to diffusion of impurities, etching, and the like.

[0003] As an apparatus for forming a thin film on a wafer, a reaction gas is supplied under heating under reduced pressure, and a chemical vapor deposition (CV) method is used.
There is a CVD apparatus that forms a thin film on the substrate surface according to D).

A CVD apparatus has an airtight reaction chamber. After a wafer is carried into the reaction chamber, the reaction chamber is evacuated, heated to 400 to 900 ° C., and supplied with a reaction gas. The supplied reaction gas causes a chemical reaction by heating, and a thin film is formed on the wafer surface.

During the wafer processing, the reaction chamber is evacuated to maintain a predetermined reduced pressure in the reaction chamber. The exhaust gas to be exhausted contains a reaction product, a reaction by-product, a reaction gas that has not been consumed, and the like.

As a reaction gas used in the thin film forming step of the CVD apparatus, for example, pentaethoxy tantalum (T
a (OC2H5) 5) is used. The pentaethoxy tantalum is a liquid at normal temperature, and a water-cooled trap is provided in the middle of the pipe so that the pentaethoxy tantalum in the exhaust gas liquefies during the exhaust and does not clog the piping and the exhaust pump. Unreacted gas is liquefied and collected and removed from the exhaust gas.

When a film is formed on a wafer, the reaction product adheres not only to the wafer but also to the wall surface of the reaction chamber and the wafer mounting table. The reaction product gradually adheres to the wall surface of the reaction chamber and the wafer mounting table each time the film forming process is repeatedly performed, and when the reaction product reaches a certain thickness, the reaction product separates and floats in the reaction chamber as particles. When particles adhere to the wafer and contaminate the wafer, defects such as disconnection of semiconductor elements occur, so that the reaction chamber is cleaned at predetermined intervals.

For cleaning, wet cleaning,
Although there is dry cleaning, dry cleaning that does not require troublesome work such as disassembly of a reaction chamber is employed. In dry cleaning, a cleaning gas (cleaning gas) is introduced, plasma is generated, or heating is performed to activate the cleaning gas, react with a deposited film, and remove by etching.

Referring to FIG. 5, a conventional semiconductor manufacturing apparatus equipped with a water-cooled trap will be described.

A reaction gas supply device 3 and a cleaning gas supply device 4 are connected to the hermetic reaction chamber 1 via a switching valve 2, and the reaction chamber 1 and the reaction gas supply device 3 are switched by switching the switching valve 2. Alternatively, the communication between the reaction chamber 1 and the cleaning gas supply device 4 is switched. An exhaust line 5 is connected to the reaction chamber 1, and a water-cooling trap 6, an exhaust pump 7, and a switching valve 8 are sequentially provided from the upstream side (the reaction chamber 1 side) in the exhaust line 5. A combustible gas abatement device 9 to the exhaust line 5 via
The combustion supporting gas removing device 10 is connected.

Hereinafter, the case of processing a wafer will be described.

A wafer is carried into the reaction chamber 1, the reaction chamber 1 is hermetically sealed, the pressure is reduced to a predetermined processing pressure (10 Pa to 5000 Pa) by the exhaust pump 7, and the reaction chamber 1 is heated by a heater (not shown). Processing temperature (400 ° C ~
In a state of being heated to 900 ° C.), the reaction chamber 1 and the reaction gas supply device 3 are communicated by the switching valve 2, and the reaction gas is supplied. The reaction gas is activated by heating, and a film is formed on the wafer by a chemical reaction. When the processing is completed, the reaction chamber 1 is opened, and the processed wafer is unloaded.

During the film forming process, the switching valve 8 communicates the exhaust line 5 with the combustible gas abatement device 9, and the exhaust pump 7 sucks and exhausts the reaction chamber 1 and maintains the process pressure. I do. The sucked gas after the reaction is exhausted to the combustible gas abatement device 9 through the water-cooled trap 6.

As the reaction gas, for example, pentaethoxy tantalum is used. As described above, pentaethoxy tantalum is liquid at room temperature, and is removed by the water-cooled trap 6 so that dew condensation does not occur on the downstream side.

In the water-cooled trap 6, a water-cooled cooler is provided in the flow path, and the exhaust gas is cooled to a temperature below the dew point.
It liquefies and removes pentaethoxy tantalum in the exhaust gas.

After operating the device for a predetermined time, the switching valve 2
And the cleaning gas supply device 4 and the reaction chamber 1 are switched.
And communicate with. The switching valve 8 is switched so that the combustion supporting gas elimination device 10 communicates with the exhaust line 5, and the cleaning gas is supplied from the cleaning gas supply device 4 while sucking and exhausting by the exhaust pump 7.

When the reaction gas is pentaethoxy tantalum, ClF 3 is supplied as a cleaning gas. The reaction chamber 1 is heated to remove the reaction products attached to the wall surface of the reaction chamber 1 and the wafer mounting table by etching,
The reaction chamber 1 is cleaned.

Exhaust gas after etching is sucked by the exhaust pump 7 and exhausted to the combustion supporting gas eliminator 10 through the water cooling trap 6.

[0019]

In the above-described conventional semiconductor manufacturing apparatus, the exhaust gas is exhausted through the water-cooled trap 6 in any of the film forming process and the cleaning process. Pentaethoxytantalum collected by cooling during the film forming process remains on the water-cooled trap 6, and the pentaethoxytantalum reacts with ClF3 in the exhaust gas during the cleaning process. Reaction of pentaethoxy tantalum (Ta (OC2H5) 5) with ClF3
2 OF is produced, and this Ta 2 OF is a dangerous substance with strong acidity, and also causes clogging and corrosion of the pump.

Since Ta2OF is a dangerous substance,
Opening of pipes for maintenance work, water cooling trap 6
Maintenance work becomes very difficult.

For this reason, in preparation for performing the cleaning process, the deposits on the water-cooled trap 6 are removed, or the water-cooled trap 6 itself is replaced.

Therefore, the cleaning process is a complicated and time-consuming operation, which increases maintenance costs and lowers the operating rate of the semiconductor manufacturing apparatus.

In view of such circumstances, the present invention can easily perform a film forming process and a cleaning process, and has high safety.
It is another object of the present invention to provide a semiconductor manufacturing apparatus capable of improving the operation rate.

[0024]

SUMMARY OF THE INVENTION The present invention comprises a plurality of reaction chambers for processing a substrate, a reaction gas supply means for supplying a reaction gas to each reaction chamber, and a plurality of reaction chambers for cleaning by etching. In a semiconductor manufacturing apparatus having a cleaning gas supply means for supplying a cleaning gas to a semiconductor device, an exhaust line for exhausting each reaction chamber, and a trap provided in each exhaust line for trapping substances in the exhaust gas, A cleaning gas exhaust line that exhausts gas is provided so as to branch off from the exhaust line on the upstream side of the trap, and the cleaning gas exhaust line relates to a semiconductor manufacturing apparatus that communicates with the same exhaust device. Since the cleaning gas exhaust line is separated, the residual gas remaining in the exhaust line and traps Reaction of Ningugasu is avoided, the occurrence of harmful substances is prevented, workability upon maintenance,
Safety is improved.

[0025]

Embodiments of the present invention will be described below with reference to the drawings.

The first embodiment shown in FIG. 1 shows a semiconductor manufacturing apparatus having a plurality of reaction chambers 15 and 25.

A reaction gas supply device 17 is connected to the first reaction chamber 15 via a reaction gas switching valve 16, and the reaction gas supply device 17 is connected to a second reaction chamber 25 via the reaction gas switching valve 16. Have been. A first combustible gas abatement device 22 is connected to the first reaction chamber 15 via an exhaust line 18, and the first switching valve 1 is connected to the exhaust line 18 from an upstream side.
9, a first water-cooled trap 20, and a first exhaust pump 21 are provided. The first reaction chamber 15 of the exhaust line 18
The section between the first water-cooled trap 20 and the first water-cooled trap 20 is heated so that the reaction gas does not condense due to condensation.

A cleaning gas supply device 27 is connected to the second reaction chamber 25 via a cleaning gas switching valve 26. The cleaning gas supply device 27 is connected to the first reaction chamber 15 via the cleaning gas switching valve 26. It is connected. A second combustible gas abatement device 32 is connected to the second reaction chamber 25 via an exhaust line 28, and a second switching valve 29, a second water-cooled trap 30, a second An exhaust pump 31 is provided. Also in the exhaust line 28, the section between the second reaction chamber 25 and the second water-cooled trap 30 is heated so that the reaction gas does not condense due to condensation.

A cleaning gas exhaust line 34 is connected to the first switching valve 19 and the second switching valve 29. The branched upstream end of the cleaning gas exhaust line 34 is connected to the first switching valve 19 and the second switching valve 29, and a third exhaust pump 35 and a combustion supporting gas removing device 36 are provided downstream from the branch point. The third exhaust pump 35, the supporting gas elimination device 36, and the like constitute an exhaust device.

Hereinafter, the first reaction chamber 15 and the second reaction chamber 2 will be described.
The case where the substrate processing is performed in parallel at step 5 will be described.

The reaction gas switching valve 16 is opened, the cleaning gas switching valve 26 is closed, and the reaction gas supply device 17 is communicated with the first reaction chamber 15 and the second reaction chamber 25. The first switching valve 19 communicates the first reaction chamber 15 with the first water-cooled trap 20, and the second switching valve 2
9 connects the second reaction chamber 25 with the second water-cooled trap 30.

The wafer is loaded into the first reaction chamber 15 and
The first reaction chamber 15 is hermetically sealed and reduced to a predetermined processing pressure by the first exhaust pump 21.
5 is heated to a processing temperature by a heater (not shown), and a reaction gas is supplied from the reaction gas supply device 17. A film is formed on the wafer by a chemical reaction of the reaction gas activated by heating.

During the film forming process, the first exhaust pump 21 sucks and exhausts the first reaction chamber 15, and the exhausted gas after the reaction passes through the first water-cooled trap 20 to the first combustible gas abatement apparatus. It is exhausted to 22. Pentaethoxytantalum in the exhaust gas is collected and removed by the first water-cooled trap 20.

Similarly, in the second reaction chamber 25, a film is formed on the wafer by the reaction gas supplied from the reaction gas supply device 17.

When the processing is completed in the first reaction chamber 15, the processed wafer is unloaded from the first reaction chamber 15. Similarly, a processed wafer is unloaded from the second reaction chamber 25. Note that different processing is also performed in the first reaction chamber 15 and the second reaction chamber 25, and the unloading timing is not always the same.

After a lapse of a predetermined operating time, the first and second reaction chambers 15 and 25 are cleaned.
Although the cleaning process may be performed simultaneously with the first reaction chamber 15 and the second reaction chamber 25, the case where the cleaning process is individually performed on the first reaction chamber 15 will be described below.

The reaction gas switching valve 16 is closed, and the cleaning gas switching valve 26 is opened. The first switching valve 19 is switched, the exhaust line 18 and the cleaning gas exhaust line 34 are communicated, the second switching valve 29 is switched, and the cleaning gas exhaust line 34 and the exhaust line 28 are disconnected. I do.

The first reaction chamber 15 is heated, and a cleaning gas is supplied from the cleaning gas supply device 27 to the first reaction chamber 15. The film of the reaction product deposited in the first reaction chamber 15 is removed by etching with the cleaning gas. At the same time, the exhaust gas is suctioned and exhausted by the third exhaust pump 35, and the exhaust gas is exhausted after the harmful substances are removed by the combustion supporting gas elimination device 36.

In the cleaning process, the exhaust gas does not pass through the first water-cooled trap 20, so that the reaction gas is pentaethoxy tantalum (Ta (OC2H5) 5).
Even when the cleaning gas is ClF3, Ta2 OF which is a dangerous substance is not generated, and the piping can be opened and the second water-cooled trap 20 can be cleaned without danger. Further, as a preparatory work for performing the cleaning process, the second water-cooled trap 20 is used.
It is not necessary to clean or replace the device, and the cleaning process can be performed simply by switching the valve, so that the time for stopping the apparatus can be significantly reduced. Also, the first exhaust pump 2
First, the third exhaust pump 35 is not corroded or clogged, and maintenance is facilitated. Further, since the first switching valve 19 is provided in a heated portion of the exhaust line 18, the pentaethoxy tantalum or the like does not adhere to the first switching valve 19 and becomes clogged.

Further, the cleaning gas supply device 27 is connected to the second reaction chamber 25 by the cleaning gas switching valve 26.
And the second switching valve 29 is switched, the exhaust line 28 and the cleaning gas exhaust line 34 are communicated, and the first switching valve 19 is switched.
When the cleaning gas exhaust line 34 and the cleaning gas exhaust line 34 are not communicated with each other, the same cleaning processing as in the case of the first reaction chamber 15 can be performed.

As can be seen from the above configuration, the cleaning gas exhaust line 34 for performing the cleaning process is provided in common for the first reaction chamber 15 and the second reaction chamber 25. The cleaning gas exhaust line can be simplified. That is, the number of exhaust devices including an exhaust pump for exhausting the cleaning gas and the supporting gas elimination device can be reduced, and it is not necessary to provide an exhaust device for cleaning for each of a plurality of reaction chambers. Can be reduced.

FIG. 2 shows a second embodiment in which the present invention is applied to a single first reaction chamber 15.

In the second embodiment, the cleaning gas switching valve 26, the second reaction chamber 25,
The second switching valve 29, the second water cooling trap 30, the second exhaust pump 31, and the second combustible gas abatement device 32 are omitted. Also, the cleaning gas exhaust line 34
Instead, a cleaning exhaust line 37 is connected to the exhaust line 18 via a first switching valve 19, and the cleaning exhaust line 37 is provided with a third exhaust pump 35 and a combustion supporting gas abatement device 36.

After the film forming process has been performed and a predetermined operation time has elapsed, the first reaction chamber 15 is subjected to a cleaning process.

The first switching valve 19 is switched to connect the exhaust line 18 with the combustion supporting gas elimination device 36. The cleaning gas supply device 27 is switched by switching the reaction gas switching valve 16.
And the first reaction chamber 15. The first reaction chamber 15
Is heated, and a cleaning gas is supplied from the cleaning gas supply device 27. The film of the reaction product deposited in the first reaction chamber 15 is removed by etching with the cleaning gas. At the same time, the exhaust gas is suctioned and exhausted by the third exhaust pump 35, and the exhaust gas is exhausted after the harmful substances are removed by the combustion supporting gas elimination device 36. In order to prevent mixing of the cleaning gas and the reaction gas, it is preferable from the viewpoint of safety that the reaction gas switching valve 16 is not switched before the switching of the first switching valve 19. If the inside of the first reaction chamber 15 is not sufficiently exhausted (for example, exhausted at a pressure of 5 Pa or less for about 5 minutes) before the switching of the first switching valve 19, the first switching valve 19 is not switched. It is more preferable for safety.

Also in the above-described cleaning process, since the exhaust gas of the cleaning process does not pass through the first water-cooled trap 20, the reaction gas is pentaethoxy tantalum (Ta).
Even when the cleaning gas is ClF3 in (OC2H5) 5), Ta2OF, which is a dangerous substance, is not generated, and the piping can be opened and the second water-cooled trap 20 can be cleaned without danger. In addition, since there is no need to clean or replace the first water-cooled trap 20 as a preparatory work for performing the cleaning process, the cleaning process can be performed simply by switching the valve, so that the time for stopping the apparatus can be significantly reduced.

In the above embodiment, the case where the reaction gas is pentaethoxy tantalum (Ta (OC2H5) 5) and the cleaning gas is ClF3 has been described. However, the same applies when the cleaning gas is NF3 or HF as the cleaning gas. Needless to say, the present invention can be implemented.

In the above embodiment, the case where the number of the reaction chambers is two and the case where the number of the reaction chambers is one have been described.

The embodiment shown in FIGS. 3 and 4 shows a case where a normal stop valve (open / close valve) is used instead of the switching valve.

FIG. 3 corresponds to the first embodiment shown in FIG. 1, in which the reaction gas supply line 38 is branched to communicate with the first reaction chamber 15 and the second reaction chamber 25, On-off valves 40 and 41 are provided further downstream, and the cleaning gas supply line 39 is branched to communicate with the first reaction chamber 15 and the second reaction chamber 25. On-off valves 42 and 41 are provided downstream from the branch point. , 43 are provided.

The cleaning gas exhaust line 34 branches and communicates with the exhaust line 18 and the exhaust line 28, respectively. An on-off valve 44 is provided on the exhaust line 18 downstream of the communication point of the cleaning gas exhaust line 34, and an on-off valve 46 is provided on the exhaust line 28 downstream of the communication point of the cleaning gas exhaust line 34, An on-off valve 45 is provided downstream of the branch point of the cleaning gas exhaust line 34.

The other configuration is the same as that of the first embodiment, and the description is omitted.

In the above construction, the on-off valve 40 is opened,
The on-off valve 41 is closed and the reaction gas supply device 17
The on-off valve 40 is closed and the on-off valve 41 is communicated with the reaction chamber 15.
Is closed, the cleaning gas supply device 27 communicates with the second reaction chamber 25.

Thus, the function of the reaction gas switching valve 16 in the first embodiment is achieved by the cooperation of the on-off valves 40 and 41.

Similarly, the on-off valves 42 and 43 have the same function as the cleaning gas switching valve 26.

By opening any one of the on-off valves 44, 45 and 46, a line having an on-off valve opened communicates with the first reaction chamber 15 and the second reaction chamber 25. That is, by the cooperation of the on-off valves 44, 45, 46, the first
The switching valve 19 and the second switching valve 29 have the same function.

The operation of this embodiment is the same as that of the first embodiment, and will not be described.

FIG. 4 corresponds to the second embodiment shown in FIG. 2. The reactive gas supply device 17 is connected to the first reaction chamber 15 by a reactive gas supply line 38, and the cleaning gas supply device The cleaning gas supply line 39 communicates with the first reaction chamber 15, the reaction gas supply line 38 is provided with an on-off valve 40, and the cleaning gas supply line 39 is provided with an on-off valve 43. By selectively opening and closing the on-off valves 40 and 43, the second
It has the same function as the reaction gas switching valve 16 of the embodiment.

The cleaning gas exhaust line 34 branches from the exhaust line 18, and an opening / closing valve 44 is provided downstream of the branch point of the exhaust line 18, and an opening / closing valve 45 is provided downstream of the branch point of the cleaning gas exhaust line 37. Is provided. By selectively opening and closing the on-off valves 44 and 45, a function equivalent to that of the first switching valve 19 of the second embodiment is achieved.

Note that the other configuration and operation of the apparatus are the same as those of the second embodiment, so that the description will be omitted.

The present invention also provides a plurality of reaction chambers for processing a substrate, reaction gas supply means for supplying a reaction gas to each reaction chamber, and a cleaning gas for cleaning by etching. A cleaning gas supply means for supplying a gas, an exhaust line for exhausting the respective reaction chambers, and a trap provided in the exhaust line, and a cleaning gas exhaust line for exhausting the cleaning gas is provided separately from the exhaust line. The cleaning gas exhaust line communicates with the exhaust line on the upstream side of the trap and communicates with the same exhaust device, so that the reaction gas liquefied at normal pressure is reliably collected and the reaction gas remaining in the trap is removed. The contact between the gas and the cleaning gas is prevented, and the generation of dangerous substances due to the reaction between the two gases is prevented.

[0062]

As described above, according to the present invention, there are provided a plurality of reaction chambers for processing a substrate, a reaction gas supply means for supplying a reaction gas to each reaction chamber, and a plurality of cleaning chambers for performing cleaning by etching. In a semiconductor manufacturing apparatus, there is provided a cleaning gas supply means for supplying a cleaning gas to a reaction chamber, an exhaust line for exhausting each reaction chamber, and a trap provided in each exhaust line for trapping substances in the exhaust gas. A cleaning gas exhaust line for exhausting the cleaning gas is provided so as to branch off from the exhaust line on the upstream side of the trap, and the cleaning gas exhaust line communicates with the same exhaust device. The reaction between cleaning gas and the remaining reactant gas is avoided, preventing the generation of harmful substances and improving workability during maintenance. More secure, is prevented corrosion of the exhaust system due to toxic substances, the life of the exhaust system is lengthened, maintenance costs and equipment costs are excellent effects such that reduction.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of the present invention.

FIG. 3 is a schematic configuration diagram showing a modification of the first embodiment.

FIG. 4 is a schematic configuration diagram showing a modification of the second embodiment.

FIG. 5 is a schematic configuration diagram showing a conventional example.

[Explanation of symbols]

 Reference Signs List 15 first reaction chamber 16 reaction gas switching valve 17 reaction gas supply device 18 exhaust line 19 first switching valve 20 first water-cooled trap 22 first combustible gas abatement device 25 second reaction chamber 26 cleaning gas switching valve 27 cleaning gas supply Device 28 Exhaust line 29 Second switching valve 30 Second water-cooled trap 32 Second combustible gas abatement device 34 Cleaning gas exhaust line 35 Third exhaust pump 36 Supporting gas abatement device

Claims (1)

[Claims] 1. A plurality of reaction chambers for processing a substrate, a reaction gas supply means for supplying a reaction gas to each reaction chamber, and a cleaning gas for supplying a cleaning gas to each reaction chamber for performing cleaning by etching. A cleaning gas exhaust line for exhausting a cleaning gas in a semiconductor manufacturing apparatus having a supply unit, an exhaust line for exhausting each reaction chamber, and a trap provided in each exhaust line for trapping substances in the exhaust gas Is provided so as to branch off from the exhaust line upstream of the trap, and the cleaning gas exhaust line communicates with the same exhaust device.