JP4252142B2 - Gas processing device and purge mechanism of raw material supply system used therefor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas processing apparatus that vaporizes a liquid source and supplies it into a chamber to perform processing such as CVD film formation, and a purge mechanism of a source supply system used therefor.
[0002]
[Prior art]
In the manufacture of LSI, wiring is formed on a semiconductor wafer such as silicon. Al and Cu are used as such LSI wiring, and these are conventionally formed mainly by sputtering. Is formed.
[0003]
However, with the progress of miniaturization of wiring, it is becoming difficult to obtain wiring with a required miniaturization level by sputtering. For this reason, it is required to form wirings using a CVD (Chemical Vapor Deposition) method that can cope with miniaturization.
[0004]
When forming a Cu wiring by CVD, for example, an organometallic compound such as Cu (hfac) TMVS or Cu (hfac) ATMS is used as a film forming raw material, but these are liquid at room temperature and below the decomposition temperature. Since the vapor pressure is relatively low, these are vaporized by a vaporizer and introduced into the chamber.
[0005]
When stopping the supply of the reaction gas, the open / close valve provided on the upstream side of the vaporizer in the raw material supply pipe is closed, and the gap between the open / close valve and the vaporizer is purged with a purge gas.
[0006]
[Problems to be solved by the invention]
In this case, it is required to have high purge efficiency of the liquid body material.
[0007]
The present invention was made in view of such circumstances, it aims to provide a gas processing apparatus having a purge mechanism and such purging mechanism of the material feed system can increase the path over di efficiency And
[0008]
[Means for Solving the Problems]
In order to solve the above problems, according to a first aspect of the present invention, a processing unit for performing a predetermined gas process on an object to be processed, and a raw material supply for sending a liquid raw material toward the processing unit source and, the raw material pipe provided between the material supply source and the processing unit, and a vaporizer for supplying a gas into the processing unit to vaporize the liquid raw material in the course supply of the liquid material, the vaporizer An opening / closing valve provided on the upstream side pipe for opening and closing the raw material pipe, and a portion of the raw material pipe between the vaporizer and the opening / closing valve when the opening / closing valve is closed, A purge gas pipe for supplying a purge gas for purging the liquid raw material and a purge gas valve for opening and closing the purge gas pipe ,
The open / close valve and the purge gas valve are provided adjacent to each other, and a pipe from the open / close valve to the vaporizer and a pipe from the purge gas valve to the vaporizer are shared. Is provided.
[0009]
According to a second aspect of the present invention, the liquid material delivered through the material pipe from the liquid material supply source, after vaporized by the vaporizer is provided in the raw material supply system to be introduced into the processing unit, the liquid source A purge mechanism for purging
An open / close valve provided on the upstream side of the vaporizer of the raw material pipe, for opening and closing the raw material pipe; and between the vaporizer and the open / close valve of the raw material pipe when the open / close valve is closed The part includes a purge gas pipe for supplying a purge gas for purging the liquid raw material of the part, and a purge gas valve for opening and closing the purge gas pipe ,
The open / close valve and the purge gas valve are provided adjacent to each other, and a pipe from the open / close valve to the vaporizer and a pipe from the purge gas valve to the vaporizer are shared. Purge mechanism is provided.
[0015]
In the present invention, the opening / closing valve and the purge gas valve are provided adjacent to each other, and the piping from the opening / closing valve to the vaporizer and the piping from the purge gas valve to the vaporizer are shared, When the open / close valve is closed and the raw material piping between the open / close valve and the vaporizer is purged, the purge gas can be supplied to the most part, and high purge efficiency can be obtained.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a sectional view showing a CVD film forming apparatus according to an embodiment of the present invention. This film forming apparatus forms a Cu film by CVD, and includes a chamber 1 constituting a processing unit, a liquid raw material supply source 2 for supplying a liquid raw material containing Cu, and a liquid raw material supply source 2 to the chamber 1. A raw material pipe 3 for supplying the raw material and a vaporizer 4 for supplying the liquid raw material from the liquid raw material supply source 2 via the raw material pipe 3 and vaporizing the liquid raw material are provided.
[0019]
The chamber 1 has a substantially cylindrical shape and is configured to be evacuated. A susceptor 11 for horizontally supporting a semiconductor wafer W as an object to be processed is supported by a cylindrical support member 12 therein. Arranged in a state. Further, a heater 14 is embedded in the susceptor 11, and the heater 14 is heated by a power source 15 to heat the semiconductor wafer W as an object to be processed to a predetermined temperature. A controller 16 is connected to the power supply 15, whereby the output of the heater 14 is controlled in accordance with a signal from a temperature sensor (not shown).
[0020]
An exhaust port 17 is formed in the bottom wall 1 b of the chamber 1, and an exhaust system 18 is connected to the exhaust port 17. The inside of the chamber 1 can be depressurized to a predetermined vacuum level by the exhaust system 18.
[0021]
A shower head 20 is attached to the top wall 1 a of the chamber 1. The vaporizer 4 is disposed on the upper wall 21 of the shower head 20, and the reaction gas as the raw material that is sent from the liquid raw material supply source 2 and vaporized by the vaporizer 4 is formed in the shower head 20. Introduced in. The shower head 20 has a space 22 inside, and a plurality of gas discharge holes 24 in the lower wall 23. Accordingly, the reaction gas introduced into the internal space 22 of the shower head 20 through the raw material piping 3 is discharged toward the semiconductor wafer W from the gas discharge holes 24. A carrier gas introduction pipe 38 for introducing a carrier gas and an exhaust pipe 40 for exhausting the carrier gas are provided on the side wall of the vaporizer 4, and a valve 39 is provided at a connection portion of the exhaust pipe 40. The exhaust pipe 40 is connected to the exhaust system 18. A vaporizer heater 41 is provided around the vaporizer 4.
[0022]
The liquid raw material supply source 2 stores a liquid raw material containing Cu, for example, Cu (hfac) TMVS or Cu (hfac) ATMS, which is an organic copper compound, and the liquid raw material is supplied to the chamber through the raw material piping 3 by an appropriate means. Send to 1
[0023]
Since these organic copper compounds are liquid at room temperature and have a relatively low vapor pressure below the decomposition temperature, these raw materials are vaporized by the vaporizer 4. At this time, for example, when the raw material is Cu (hfac) TMVS or Cu (hfac) ATMS, it is heated to about 60 ° C. and vaporized to generate a reaction gas.
[0024]
On the upstream side of the vaporizer 4 of the raw material pipe 3, a liquid mass flow controller 31 and an opening / closing valve 32 for opening and closing the raw material pipe 3 are provided in this order from the upstream side. The opening / closing valve 32 is opened when the raw material is supplied, and is closed when the raw material is stopped.
[0025]
A heat insulating wall 34 is disposed between the opening / closing valve 32 and the vaporizer 4 in order to thermally shut off the opening / closing valve 32 and the vaporizer 4. As the heat insulating wall 34, various materials usually used for heat insulation can be selected. A cooling medium jacket 33 is provided around the piping from the opening / closing valve 32 to the heat insulating wall 34. By passing a cooling medium such as cooling water through the cooling medium jacket 33, the portion is controlled to a predetermined temperature. The A valve 37 is also provided between the vaporizer 4 and the chamber 1.
[0026]
A purge gas pipe 35 is connected in the vicinity of the open / close valve 32 of the raw material pipe 3, and a purge gas valve 36 for opening and closing the purge gas pipe 34 is provided adjacent to the open / close valve 32 at the junction between the purge gas pipe 35 and the raw material pipe 3. It has been.
[0027]
A specific structure of the portion is shown in FIG. As shown in this figure, the purge gas pipe 35 is connected to the raw material pipe 3 at a position in close proximity to the opening / closing valve 32 via a purge gas valve 36 . And, specifically, as in (b), however, the purge gas pipe 35, the opening and closing valve 32 is closed, when the purge gas valve 36 is opened, the purge gas flows into the opening and closing valve 32 immediately below the material pipe 3 As shown in FIG. When supplying the liquid material, as shown in (a), the opening / closing valve 32 is opened and the purge gas valve 36 is closed. As shown in FIG. 2, the portion from the open / close valve 32 to the vaporizer 4 of the raw material pipe 3 also functions as a pipe for supplying purge gas from the purge gas valve 36 to the vaporizer 4. As the purge gas, for example, He gas or H ₂ gas is used.
[0028]
In the film forming apparatus configured as described above, first, the semiconductor wafer W is loaded into the chamber 1 and placed on the susceptor 11. Then, while reducing the pressure by the exhaust system 18, the reaction gas generated as described later is introduced into the chamber 1 from the many gas discharge holes 24 of the shower head 20 together with a carrier gas such as He.
[0029]
At this time, since the semiconductor wafer W is heated to a temperature higher than the decomposition temperature of the reaction gas by the heater 14 embedded in the susceptor 11, the reaction gas is decomposed on the surface of the semiconductor wafer W, and Cu is deposited on the semiconductor wafer W. A film is formed.
[0030]
In order to generate the above-described reaction gas, first, a liquid source, for example, Cu (hfac) TMVS or Cu (hfac) ATMS is supplied from the liquid source supply source 2 through the pipe 3 to the vaporizer 4. Next, the liquid raw material is heated and vaporized in the vaporizer 4 to obtain a reaction gas.
[0031]
While the film forming process is continued in this way, the liquid material is continuously supplied from the liquid material supply source 2 to the vaporizer 4 through the pipe. At that time, the open / close valve 32 remains open.
[0032]
At the time when the film forming process is completed, the open / close valve 32 is closed to stop the supply of the liquid material to the vaporizer 4. At this time, if the length of the raw material pipe 3 between the vaporizer 4 and the open / close valve 32 is long, a large amount of raw material remains in the tube, and the purge efficiency is inevitably lowered. Then, since the heat insulation wall 34 which thermally interrupts these is provided between the vaporizer 4 and the open / close valve 32, the influence of the heat from the vaporizer 4 on the open / close valve 32 is suppressed, and the vaporizer 4 The open / close valve 32 can be brought close to each other, and the raw material remaining in the raw material pipe 3 can be reduced. Further, since the vaporizer 4 and the open / close valve 32 are close to each other in this way, the raw material between them can be purged with high efficiency.
[0033]
In this case, the purge gas pipe 35 is connected to the downstream side of the open / close valve 32 via a purge gas valve 36 at a position close to the open / close valve 32, and the open / close valve 32 and the purge gas valve 36 are provided adjacent to each other. Since the purge gas pipe 35 is provided so that the purge gas flows into the portion immediately below the opening / closing valve 32 of the raw material piping 3 when the purge gas valve 36 is opened when the valve 32 is closed , the vaporization is performed from the opening / closing valve 32 of the raw material piping 3. The portion up to the vaporizer 4 also functions as a pipe for supplying purge gas from the purge gas valve 36 to the vaporizer 4. For this reason, the remaining raw material can be purged with the purge gas over almost the entire region between the opening / closing valve 32 and the vaporizer 4 of the raw material pipe 3, and the portion can be purged with extremely high efficiency. .
[0034]
Further, a cooling medium jacket 33 is provided around the piping from the opening / closing valve 32 to the heat insulating wall 34, and the cooling medium is caused to flow therethrough so that the portion is controlled to a predetermined temperature. Can be more effectively eliminated.
[0035]
In addition, this invention is not limited to the said embodiment, A various deformation | transformation is possible. For example, in the above embodiment, Cu (hfac) TMVS or Cu (hfac) ATMS is used as the Cu raw material, but the present invention is not limited to this.
[0036]
Moreover, although the case where this invention was applied to the CVD film-forming of Cu was shown, the film-forming object is not necessarily limited to Cu, and can be applied as long as a liquid material such as Al is vaporized and used for CVD. In addition, as long as the process is performed using a gas generated by vaporizing the liquid raw material, the process is not limited to CVD but may be other processes.
[0037]
Furthermore, although the heat insulation wall was used as a heat insulation means, it is not restricted to this, What is necessary is just to be able to insulate effectively, for example, forming a low temperature air curtain. The temperature control means is not limited to one using a cooling medium jacket, and can be applied. However, if the heat insulation by the heat insulation means is sufficient, the temperature control means may not be provided.
[0039]
【The invention's effect】
As described above, according to the present invention, the opening / closing valve and the purge gas valve are provided adjacent to each other, and the piping from the opening / closing valve to the vaporizer and the piping from the purge gas valve to the vaporizer are Since they are shared, when purging the raw material piping between the open / close valve and the vaporizer by closing the open / close valve, the purge gas can be supplied to the majority, and high purge efficiency can be obtained.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing a CVD film forming apparatus according to an embodiment of the present invention.
FIG. 2 is a view showing a purge mechanism in the raw material piping of the apparatus shown in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Chamber 2 ... Liquid raw material supply source 3 ... Raw material piping 4 ... Vaporizer 11 ... Susceptor 20 ... Shower head 32 ... Open / close valve 33 ... Water cooling jacket (temperature control means)
34 …… Insulation wall (insulation means)
35 …… Purge gas piping 36 …… Purge gas valve W …… Semiconductor wafer

Claims (2)

A processing unit for performing predetermined gas processing on the workpiece, and the raw material supply source for sending towards the liquid source to the processing unit, provided between the material supply source and the processing unit material A pipe, a vaporizer that vaporizes the liquid raw material during supply of the liquid raw material, and supplies a gas to the processing unit; an open / close valve provided on a pipe upstream of the vaporizer for opening and closing the raw material pipe; When the open / close valve is closed, a purge gas pipe for supplying a purge gas for purging the liquid raw material in the portion of the raw material pipe between the vaporizer and the open / close valve and a purge gas pipe are opened and closed. A purge gas valve ,
The open / close valve and the purge gas valve are provided adjacent to each other, and a pipe from the open / close valve to the vaporizer and a pipe from the purge gas valve to the vaporizer are shared. . The liquid material delivered through the material pipe from the liquid material supply source, after vaporized by the vaporizer is provided in the raw material supply system to be introduced to the processing unit, a purging mechanism for purging the liquid material,
An open / close valve provided on the upstream side of the vaporizer of the raw material pipe, for opening and closing the raw material pipe; and between the vaporizer and the open / close valve of the raw material pipe when the open / close valve is closed The part includes a purge gas pipe for supplying a purge gas for purging the liquid raw material of the part, and a purge gas valve for opening and closing the purge gas pipe ,
The open / close valve and the purge gas valve are provided adjacent to each other, and a pipe from the open / close valve to the vaporizer and a pipe from the purge gas valve to the vaporizer are shared. Purge mechanism.

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