JPH09143739A - Method for supplying treating gas and device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a treating gas supplying device capable of supplying a large amt. of high-viscosity liquid while controlling the flow rate with high accuracy. SOLUTION: This treating gas supplying device vaporizes the high-viscosity liquid having a viscosity at ordinary temp. of 4000 to 10000cp to form the treating gas and supplies this treating gas to a treating device 30. The device described above includes a liquid housing vessel 34 in which the liquid 32 is housed, a heating means 36 which heats the liquid 32 in order to lower the viscosity of the liquid housed in this liquid housing vessel, a supplying passage 38 which connects the liquid housing vessel 34 to the treating vessel 30, a force feeding means 40 which forcibly feeds the liquid lowered in the viscosity to this supplying passage and a vaporizing means 42 which is intervened in mid- way of the supplying passage and forms the treating gas by vaporizing the liquid. As a result, the viscosity of the liquid is lowered and the smooth flow is generated to allow flow rate control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and apparatus for supplying a processing gas to gasify a highly viscous liquid to, for example, a semiconductor manufacturing apparatus.

[0002]

2. Description of the Related Art In general, a semiconductor device tends to have a multilayer wiring structure in response to recent demands for higher density and higher integration. In this case, a lower device and an upper aluminum wiring are required. Embedding technology such as a contact hole as a connection portion with the via and a via hole as a connection portion between the lower aluminum wiring and the upper aluminum wiring has become important in order to make an electrical connection between them. It is preferable to use a cheap and highly conductive material such as aluminum for filling the contact holes and via holes, and it is highly directional in order to prevent the occurrence of voids due to the technical limitation of filling holes. CVD (Chemical Vapor Deposition) instead of sputtering
The film formation by the position) is desired.

To form an aluminum-CVD film,
Generally, DMAH which is an organic metal gas as a processing gas
(Dimethylaluminum hydride) is used, but this DMAH has a very high viscosity of about 8000 cp (centipoise) at room temperature and has a syrup-like form, and moreover, it reacts violently with moisture and oxygen in the air to ignite. It is a very difficult substance to handle.

As a method for gasifying a liquid material and supplying it as a processing gas, there are generally a bubbling method, a baking method and a direct vaporization method as shown in FIG. FIG. 8A shows a bubbling method, in which a carrier gas such as N ₂ gas whose flow rate is controlled by the mass flow controller 6 is supplied into the liquid material 2 stored in the liquid container 4 to cause bubbling, which is generated at this time. The DMAH gas is carried by a carrier gas and supplied to the processing apparatus. FIG. 8B shows a baking method, in which the liquid container 4 in which the liquid material 2 is stored and the mass flow controller 6 for controlling the flow rate of the processing gas are housed in the same oven 8 and heated to heat the liquid material. 2 is directly vaporized by heat, and the processing gas is pressure-fed by the vapor pressure at this time to be supplied to the processing apparatus.

FIG. 8C shows a direct vaporization method, in which a pressurized gas is supplied into a liquid container 4 in which the liquid material 2 is stored, and the pressure causes the liquid material in the container 4 to be pumped as a liquid. The flow rate of this supply is controlled by the liquid flow rate controller 10, and is fed into the vaporizer 12. Then, in the vaporizer 12, the carrier gas whose flow rate is controlled by the mass flow controller 6 is vaporized, and the generated processing gas is supplied to the processing apparatus.

[0006]

By the way, FIG. 8 (A)
In the bubbling method shown in (1), since the DMAH is in the form of a starch syrup due to its high viscosity as described above, only a flow rate of about 4 SCCM can be obtained even if bubbling is performed, which is not suitable for mass production. Moreover, in the case of the baking method shown in FIG.
The vapor pressure of DMAH is low even if heated to about 8 Torr
However, assuming that the process pressure is 2 Torr, the processing gas is supplied with a differential pressure of only 6 Torr, and in this case as well, it is not possible to obtain a sufficiently large flow rate as in bubbling, and mass productivity is high. Not suitable for
In this case, it is conceivable to raise the temperature of the oven 8 to raise the vapor pressure, but since DMAH decomposes at about 100 ° C. and aluminum is deposited, the temperature cannot be raised so much in consideration of safety. .

Further, in the case of the direct vaporization method shown in FIG. 8C, DMAH is 8000 cp at room temperature as described above.
Due to its high viscosity, it is in the form of a syrup, so the amount of pumping is very small and it is not suitable for mass production. As described above, in the conventional process gas supply method, there is no method for supplying DMAH in an amount sufficient for mass productivity, so that aluminum cannot be used to fill the via hole of the contact hole as described above. For example, a tungsten film that can be mass-produced by CVD film formation is used. FIG. 9 shows an example of a step of filling a contact hole. First, as shown in FIG. 9A, a first aluminum layer 16 formed by sputtering is formed on a substrate 14, and, for example, SiO 2 is formed thereon. _{2 The} insulating film 18 is formed, and the contact hole 20 is formed in a part of the insulating film 18.

First, when tungsten and aluminum come into direct contact with each other, the contact resistance increases due to the sucking effect generated between the two. To prevent this, a barrier metal 22 made of, for example, TiN is formed on the entire surface (FIG. 9B).
Are formed in advance, and the portions other than the barrier metal in the holes are removed by etching, and a tungsten film 24 is formed thereon by, for example, CVD to fill the holes (FIG. 9).
(C)). Next, except the tungsten embedded in the holes is removed by etching (FIG. 9D), and the second aluminum layer 26 is formed on the entire surface by sputtering.
As a result, the first aluminum layer 16 and the second aluminum layer 26
Are electrically connected via the barrier metal 22 of the contact hole and the tungsten film 24.

As described above, since it is impossible to supply a large amount of DMAH corresponding to the mass production of aluminum film forming CVD, it is necessary to form a barrier metal film, a tungsten film, or an etching film as described above for filling holes. A complicated DMA process must be incorporated, and in order to avoid this, mass production of Al-CVD film formation is possible.
At present, there is a strong demand for a supply device capable of supplying H 2. The present invention has been devised in view of the above problems and effectively solving them. An object of the present invention is to provide a processing gas supply method and apparatus capable of supplying a large amount of high-viscosity liquid while controlling the flow rate with high accuracy.

[0010]

In order to solve the above problems, the present invention has a viscosity at room temperature of 4000 cp-1.
A high-viscosity liquid having a viscosity of 0000 cp is vaporized to form a processing gas, and the processing gas supply apparatus supplies the processing gas to the processing apparatus. A heating means for heating the liquid to reduce the viscosity of the liquid; a supply passage connecting the liquid storage container and the processing device; and a pressure feed for pumping the liquid with the reduced viscosity to the supply passage. And a vaporization unit that is provided in the middle of the supply passage and vaporizes the liquid that is pumped to form a processing gas.

Since the present invention is constructed as described above, the viscosity of the highly viscous liquid of about 4000 to 10,000 cp at room temperature in the liquid storage container is lowered by heating to a proper temperature by the heating means. For example, it becomes about 2000 cp, which facilitates the flow. With the viscosity reduced in this way, the liquid is pressure-fed in the supply passage by the pressurized gas of the pressure-feeding means, and this liquid is vaporized by the vaporizing means, for example, by the carrier gas to become the processing gas, which is directly supplied to the processing device. Will be done. In this case, since the viscosity of the liquid is lowered, it is possible to flow a large amount at the time of pressure feeding. The liquid flow rate at this time can be easily controlled by providing a liquid flow rate control means in the supply passage. Further, by providing a micro pump means for sucking the liquid in the supply passage, it is possible to supply a larger amount of liquid, and it is possible to supply a large amount of liquid even when the viscosity is high to some extent.

Further, a first heater is provided in the supply passage from the container to the vaporizing means, and this portion is heated to an appropriate temperature to maintain the low viscosity state of the liquid flowing therein. It is possible to perform smooth supply. Further, by providing a second heater in the supply passage on the downstream side of the vaporizing means and heating it to the vaporization temperature or higher, the processing gas can be supplied to the processing apparatus without reliquefaction.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a method for supplying a processing gas and an apparatus therefor according to the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is an overall configuration diagram showing a processing gas supply device of the present invention, FIG. 2 is a schematic configuration diagram of a liquid flow rate control means, and FIG.
Is an operation explanatory view showing an operation of the flow rate control means shown in FIG. 2, FIG. 4 is a schematic sectional view showing the vaporization means, and FIG. 5 is a plan view of the vaporization means shown in FIG. As shown in the figure, the processing gas supply device 28 supplies the processing gas to a processing device 30 that performs a process such as film formation on the object W to be processed of a semiconductor wafer. Here, CV is used by using DMAH as a processing gas.
A case of forming an aluminum film by D will be described. This DMAH is 8000 at room temperature as described above.
It has a high viscosity of about cp and is in a syrup-like liquid state. Further, while it is highly reactive and reacts violently with water vapor and oxygen in the air, it is extremely difficult to handle at temperatures above about 100 ° C. due to thermal decomposition and precipitation of metallic aluminum.

The processing gas supply unit 28 includes a liquid container 34 for storing a liquid for forming a processing gas for film formation, here, a DMAH 32, and a heating means 36 for heating the DMAH 32 to reduce its viscosity. A supply passage 38 that connects the liquid storage container 34 and the processing device 30, a pressure feeding means 40 that feeds the reduced viscosity DMAH 32 to the supply passage 38 side, and a feed passage that is interposed midway in the feed passage 38. And the vaporizing means 42 for vaporizing the DMAH to form a processing gas.

Specifically, the liquid storage container 34 is made of, for example, a sealed container made of stainless steel and having a capacity of about 2 liters, and an electrolytic polishing process is applied to the inner wall of the liquid storage container 34 so that gas, moisture and the like are less likely to adhere thereto. There is. The storage container 34 is provided with a gas introduction pipe 46 having a lower end located above the liquid level and a container opening / closing valve 44 interposed therebetween.
A pressure feeding pipe 48 extending from the pressure feeding means 40 is connected through a joint 50 so that the gas for pressure feeding can be introduced into the container 34. In addition, in the storage container 34,
A liquid outlet pipe 54 having a lower end immersed in the liquid and a container opening / closing valve 52 interposed in the middle is provided, and the outlet side is connected to the supply passage 38 via a joint 56.

The heating means 36 includes joints 50 and 56.
The temperature sensor 58 is provided on the wall surface of the container 34, and the temperature controller 60 supplies the heating means 38 based on the detection value of the sensor 58. By controlling the electric power to be applied, the DMAH 32 is always controlled to have an appropriate temperature. In this case, the heating temperature is set to a temperature range that only lowers the viscosity of DMAH32 and does not cause thermal decomposition, for example, in the range of 40 to 80 ° C., and is maintained at 50 ° C. in this embodiment. Therefore, the viscosity of DMAH is reduced to about 2000 cp.

The pressure feeding means 40 comprises, for example, a He gas cylinder 62 filled with high-pressure He gas of 5 kg / cm ^{2 and} a pressure feeding pipe 48 connected to the He gas cylinder 62. In the middle of the pressure feeding pipe 48, first, second and 3 on-off valves 64A, 64B, 64C
5 kg / c of DMAH 32 in the container 34 by sequentially installing
It is designed to pump at a pressure of m ² . On the downstream side of the third opening / closing valve 64C, a trap pipe 68 having a trap opening / closing valve 66 interposed in the middle is provided so as to be branched, so that the pressure supply pipe 48 can be degassed as necessary. Has become.

The supply passage 38 is made of a stainless steel tube having a diameter of, for example, 1/4 inch, which is large enough to allow the flowing DMAH to flow without causing excessive pressure loss. From the upstream side to the downstream side, a first opening / closing valve 70A, a liquid flow rate control means 72 for controlling the flow rate of the flowing liquid, a second opening / closing valve 70B, the vaporizing means 42 and a third opening / closing valve 70C are sequentially provided. Therefore, DMAH flows as a liquid up to the vaporization means 42, is vaporized here, and then flows in a gas state.

The vaporizing means 42 has a carrier gas pipe 7
A hydrogen gas cylinder 76 for storing, for example, hydrogen gas as a carrier gas is connected via 4 to the gas pipe 7
4 is a first opening / closing valve 78 from the upstream side to the downstream side.
A, mass flow controller 80 and second opening / closing valve 78B
The hydrogen gas can be supplied as the vaporized gas and the carrier gas by sequentially interposing. In addition, the supply passage 38 upstream of the first on-off valve 70A, between the liquid flow rate control means 72 and the second on-off valve 70B, and between the vaporization means 42 and the third on-off valve 7.
From 0C, the trap tubes 82A and 82A,
B and 82C are provided in a branched manner, and trap opening / closing valves 84A, 84B, and 84C are provided in the respective trap tubes. In addition, each trap tube 68, 82A, 8
Although not shown, 2B and 82C are commonly connected,
A vacuum pump is installed on the way, and a vacuum is drawn during the trap. In addition, the second of the pressure feeding pipe 48
The first opening / closing valve 70 on the downstream side of the opening / closing valve 64B and the supply passage 38
The downstream side of A is a communication pipe 88 in which an opening / closing valve 86 is provided on the way.
Is communicated by In addition, the first opening / closing valve 64 of the pressure feeding pipe 48
A purge pipe 92 in which the downstream side of A and the downstream side of the second opening / closing valve 70B of the supply passage 38 are connected and an opening / closing valve 90 is provided in the middle thereof.
Is provided so that DMAH can be eliminated by He gas at the time of maintenance of the piping system.

Here, the liquid container 34 and the vaporizing means 42
And the first opening / closing valve 70A, the liquid flow rate control means 72, and the second opening / closing valve 7 which are provided in the passage between them.
0B, and the top pipe 82 including the open / close valve 86 of the communication pipe 88, the communication pipe 88 up to this point, and the trap open / close valve 84A.
A, including the trap opening / closing valve 84B, the lap pipe 82B, the opening / closing valve 90, and the purge pipe 92 up to this point are wound with a first heater 94 (shown by a broken line) made of, for example, a tape heater, and the flowing liquid. In order to maintain the low viscosity, the heating temperature is about 50 ° C., which is the same as that of the storage container 34.

Further, the vaporizing means 42 and the vaporizing means 42 and the processing device 3
A second heating heater 96 (shown by a broken line) made of, for example, a tape heater is also wound around the entire supply passage between 0 and 0 and the trap tube 82C including the third opening / closing valve 84C, and vaporized DMAH is regenerated. It is heated to a constant value within a temperature range that does not liquefy and does not undergo thermal decomposition, for example, a range of 60 to 80 ° C. Furthermore, on the entire downstream side of the carrier gas pipe 74,
For example, a third heater 98 such as a tape heater is wound and the same temperature as that of the vaporizing means 42, 60 to 80.
It is heated in the range of ° C to preheat the flowing carrier gas to promote the vaporization of DMAH.

The liquid flow rate control means 72, the vaporization means 42, and the mass flow controller 80 for controlling the flow rate of the carrier gas supplied thereto are controlled by a flow rate control unit 100 composed of, for example, a microcomputer, and the vaporization means 42 has a DMAH. The carrier gas is always supplied in an amount sufficient to vaporize the gas.

Here, the structures of the liquid flow rate control means 72 and the vaporization means 42 will be described. As shown in FIG. 2, the liquid flow rate control unit 72 is configured in substantially the same manner as a normal mass flow controller that detects a small amount of gas flow rate, but the normal mass flow controller heats the fluid to change the temperature according to the flow rate. On the other hand, in the case of DMAH, there is a risk of vaporization and thermal decomposition due to heating, so that it is possible to sense even if the temperature is high and the temperature change is detected according to the flow rate by cooling the fluid. The configuration is different from that of a normal mass flow controller in that the sensor tube is set to a tube diameter that can obtain a flow velocity of a certain degree and that does not impair the flow. That is, the sensor tube 1 connected to the supply passage 38 in FIG.
In 02, an electronic cooling element 104 such as a Peltier element is provided, and the bridge circuit 106 detects the flow rate as a potential difference. The detected value is amplified by the amplifier circuit 108, and the temperature is further corrected by the correction circuit 110, which constitutes the sensor 112.

The comparison control circuit 114 compares the set voltage instructed from the flow rate control unit 100 (see FIG. 1) with the sensor detection value, and the valve drive circuit 116 is, for example, a laminated type so that this deviation becomes zero. The actuator 118 composed of a piezoelectric element is driven to control the valve opening of the piezo valve 120. In this case, the sensor tube 1
The pipe diameter of 02 gives a flow rate that can be detected by the sensor with respect to the predetermined flow rate of the liquid, for example, about 0.5 CCM (100 SCCM) as described above, and has a viscosity of 200.
The size is set to a level that allows the flow of the liquid even if it is as high as 0 cp, for example, about 5 mm in this embodiment. If the pipe diameter is too thin, for example, about 1 mm, the pressure loss is too large to flow due to its viscosity, and if it is too thick, for example, about 10 mm, the flow velocity becomes too slow for the sensor to detect. .

FIG. 3 shows the relationship between the flow direction and the detected temperature. In the figure, the solid line shows the characteristics when the liquid is not flowing and the broken line shows the characteristics when the liquid is flowing. When the liquid flows, the temperature rise of ΔT is detected, but this rise is proportional to the flow rate, and the flow rate is obtained by electrically processing this temperature rise.

FIGS. 4 and 5 show the structure of the vaporization means 42. A liquid introduction port 124 is provided in the center of the valve body 122, and a carrier introduction port 126 and a gas discharge port 128 are provided on the opposite sides of the liquid introduction port 124 in the diameter direction. To provide.
Then, on the outer circumference of the liquid introduction port 124, another port 1
Ring-shaped vaporization groove 130 so as to connect 26 and 128
To form And, on the upper part of this valve body 122,
For example, a thin plate-shaped valve body 132 having a corrugation 134 that can be bent in the vertical direction is provided, and the valve is bent in the vertical direction by an actuator (not shown) to close the port or change the valve opening. .
Therefore, the liquid flowing out from the liquid introduction port 124 causes a pressure drop by flowing the controlled carrier gas, reaches the vaporization groove 130 while being vaporized by the Joule-Thomson effect, and can be transported as a processing gas together with the carrier. It has become. Also in this case, the carrier introduction port 126 and the pipe diameter of the pipe connected thereto are
Like the previous sensor tube 102, it is set to about 5 mm.

Now, returning to FIG. 1, the structure of the processing device 30 will be described. The processing apparatus 30 is a so-called single-wafer CVD process for processing semiconductor wafers W one by one.
The device is shown as an example. A mounting table 140 heated by, for example, a resistance heater 138 is provided in a processing container 136 made of, for example, aluminum of this apparatus, and the wafer W is held on the upper surface of the mounting table 140 by, for example, a mechanical clamp 141. Placed. An electrostatic chuck may be used instead of the mechanical clamp 141. On the top of the container 136 is a mounting table 140.
A shower head 142 is provided facing the
A supply passage 38 for supplying a processing gas is connected to the shower head 142, so that the processing gas is introduced into the processing container 136. Further, an exhaust port 144 connected to the illustrated vacuum pump is provided at the bottom of the container so that the inside of the container can be evacuated.

Next, the operation of the apparatus configured as described above will be described. First, an unprocessed semiconductor wafer W is loaded into the processing container 136, placed and held on the mounting table 140, the inside of the container 136 is evacuated to the base pressure, and the wafer W is processed by the resistance heater 138 at the process temperature. A predetermined value within the range, 180 ° C. to 250 ° C., for example, is maintained at 200 ° C. Then, while supplying a predetermined processing gas from the shower head 142 to the inside of the container 136, the inside of the container 136 has a process pressure range of 0.5 Torr to 100 Torr.
While maintaining a predetermined value within the range of, for example, about 2 Torr, a film forming process of, for example, aluminum is performed.

Here, in order to supply the processing gas to the processing container 136, the high-viscosity syrup-like DMAH 32 is used as the liquid material. However, the viscosity is too high and the DMAH 32 is supplied while controlling the flow rate. I can't. Therefore, in the present invention, the entire liquid storage container 34 for storing the DMAH 32 is covered with the oven 36 and DM
AH32 is heated to a predetermined temperature, for example 50 ° C, and the viscosity is adjusted to 8
The flow rate is lowered from about 000 cp to about 2000 cp to facilitate the flow. This heating temperature is in a temperature range that reduces the viscosity of the liquid material to some extent and does not vaporize or thermally decompose, that is, in the case of DMAH, about 40 ° C. to 60 ° C.
A range up to about 0 ° C is preferable.

The temperature of the storage container 34 is detected by the temperature sensor 58, and this is input as a feedback signal to the temperature control unit 60 so that it is always maintained at 50 ° C., for example. Here, the relationship between the temperature of DMAH and the viscosity will be described with reference to FIG. 6. At room temperature, for example, 25 ° C., the viscosity is as high as about 8000 cp, but it is 50 ° C.
When heated to a certain degree, the viscosity sharply drops to about 2000 cp. With the viscosity of the DMAH 32 reduced in this way, 5 kg from the He gas cylinder 62 of the pressure feeding means.
When a He gas having a pressure of / cm ² is introduced into the storage container 34 through the pressure feeding pipe 48, the viscosity of DMAH3 is lowered.
2 is smoothly pumped in the supply passage 38 by this gas pressure. The first, second and third on-off valves 64A, 64B and 64C provided on the pressure feed pipe 48 and the first, second and third on-off valves 70A and 7 provided on the supply passage 38 are provided.
It is needless to say that 0B and 70C are opened and the container opening / closing valves 44 and 52 are also opened. As the pressurized gas, other than He gas, other inert gas such as Ar gas and Xe gas can be used.

Liquid DMAH pumped in the supply passage 38
Is introduced into the vaporization means 42 while flowing while the flow rate is controlled by the liquid flow rate control means 72. The liquid DMAH introduced into the vaporizing means 42 is vaporized by the Joule-Thomson effect by the high-pressure hydrogen gas supplied from the hydrogen gas cylinder 76 through the carrier gas pipe 74 to the processing gas, and the processing gas generated here is generated. Accompanying the hydrogen gas, the gas flows further downstream in the supply passage 38 to reach the processing device 30, and is finally introduced into the processing container 136 from the shower head 142 as described above.

Here, the passage portion in which the flowing DMAH is in a liquid state, that is, the supply passage 38 and the liquid flow rate control means 72 on the upstream side of the vaporization means 42 are substantially separated from the storage container 34 by the first heater 94. Same temperature, eg 50 ° C
Since the liquid DMAH is heated and maintained at a low temperature, it is possible to prevent the viscosity of the liquid DMAH from being lowered during the supply to hinder the supply. Further, the vaporizing means 42 and the supply passage 38 on the downstream side thereof are heated by the second heater 96 in a temperature range higher than the vaporization temperature of DMAH and lower than the thermal decomposition temperature, for example, in the range of 60 ° C to 80 ° C. Therefore, the vaporized gas of the DMAH, that is, the processing gas does not reliquefy and is not thermally decomposed, and the DMAH can be smoothly supplied to the processing device 30 by flowing through the passage.

Further, a third heater 98 is provided in the carrier gas pipe 74 through which the carrier gas flows, and the vaporizing means 42 is provided.
The carrier gas introduced into the same temperature as the vaporization means 42,
For example, since it is preheated within the range of 60 ° C. to 80 ° C., the liquid DMAH can be vaporized quickly and smoothly. In addition to H ₂ gas, an inert gas such as Ar gas or He gas can be used as the carrier gas. As described above, under the highly accurate flow rate control, the conventional apparatus could supply only about 4 SCCM at most, but according to the present invention, it is necessary to mass-produce the aluminum film on one wafer W. It is possible to supply a large flow rate of DMAH, for example, about 100 SCCM (0.4 CCM in terms of liquid) while controlling it with high accuracy. Therefore, Al on a mass production basis
-CVD film formation becomes possible, and for example, a hole filling process as shown in FIG. 9 can be performed on a mass production basis by Al-CVD film formation.

Here, when replacing the liquid storage container 34, both container opening / closing valves 44 and 52 are closed and the first opening / closing valve 70A of the supply passage 38 is also closed to stop the supply of the liquid DMAH. Next, the third on-off valve 64C of the pressure feed pipe 48 is closed, and the trap on-off valve 66 of the trap pipe 68 is opened to release the gas pressure in this portion. Then, by opening the on-off valve 86 of the communication pipe 88 and opening the trap on-off valve 84A of the trap pipe 82A, the liquid DMAH remaining in the supply passage 38 at this portion is trapped by the pressure of He gas. Remove from tube 82A. If the liquid container 34 is replaced in this state, the DMAH will not come into contact with the air.

Next, when performing maintenance of the liquid flow rate control means 72, the second opening / closing valve 64B of the pressure feeding pipe 48 is opened, the third opening / closing valve 64C is closed, and the container opening / closing valve 52 and the trap opening / closing valve 84A. Is closed, and the opening / closing valve 86 of the communication pipe 88 is opened, the first opening / closing valve 70A of the supply passage 38 is opened, the second opening / closing valve 70B is closed, and in this state, the trap opening / closing valve 84B of the trap pipe 82B is closed. The liquid DMAH remaining in the liquid flow rate control means 72 can be removed from the trap tube 82B by the He gas pressure by opening. Furthermore, when performing maintenance on the vaporization means 42, the second and third opening / closing valves 70B and 70 of the supply passage 38 are provided.
When C is closed, the opening / closing valve 90 of the purge pipe 92 is opened, and the trap opening / closing valve 84C of the trap pipe 82C is opened in this state, the liquid D remaining in the vaporizing means 42 at the He gas pressure.
MAH can be excluded from the trap tube 82C.

In the above embodiment, 50 parts of liquid DMAH was used.
Although the viscosity was reduced to about 2000 cp by heating to ℃, the temperature is not limited to this temperature, and any temperature value may be used as long as it allows a flow rate above a certain level to be controlled under high precision control. Refer to DMAH 3
The viscosity may be lowered to about 6000 cp by heating to about 0 ° C. In addition to the pressure feeding means 40,
For example, the supply passage 38 on the upstream side of the liquid flow rate control means 72.
Further, as shown by the phantom line in FIG. 1, the micro pump means 146 which operates by the piezoelectric element may be provided to suck the liquid DMAH and assist the pressure feeding of the DMAH. According to this, more DM with the same viscosity
AH can be supplied, and if the supply amount is the same, smooth pressure supply / supply is possible even in a state where the viscosity is higher.

Further, in the above embodiment, the case where the oven is used as the heating means 36 for heating the storage container 34 has been described as an example, but the present invention is not limited to this and, for example, FIG.
As shown in (A), the resistance heater 14 is placed in the storage container 34.
8 is wound and heated, the temperature of the storage container 34 is detected by the temperature detection unit 150, the detected value is compared with a reference value by the comparator 152, and the temperature is adjusted so that this deviation becomes zero. The controller 154 may be configured to control the power to the heater 148. Alternatively, as shown in FIG. 7B, a heating pipe 156 for flowing a heat medium is wound around the storage container 34, and the heat medium heated and maintained at, for example, 50 ° C. is caused to flow from the thermostat 158 through the pipe 156. May be heated.

In the above embodiment, D is used as the organic metal material.
Although the case of using MAH has been described as an example, the present invention is not limited to this. For example, TMA (trimethylaluminum) may be used, or pentaethoxytantalum may be used when forming a Ta film. You may In addition, it is not limited to the case of forming a film on a semiconductor wafer,
Of course, it can be applied to the case of forming a film on another object to be processed such as an LCD substrate or a glass substrate.

[0039]

As described above, according to the method and apparatus for supplying a processing gas of the present invention, the following excellent operational effects can be exhibited. In the conventional device, high-viscosity liquid could only be supplied at about 4 SCCM at most, but by heating the high-viscosity liquid, the viscosity was lowered, and this was vaporized after pressure-feeding while controlling the flow rate with high accuracy, and then supplied as processing gas. Since this is done, it is possible to stably supply a large amount of, for example, about 100 SCCM under high-precision flow rate control. Therefore, the metal film can be formed by CVD at a deposition rate that allows mass production. Further, by providing the supply passage with the first heater for keeping the viscosity of the liquid low and the second heater for preventing reliquefaction,
Liquid and vaporized gas can flow smoothly and stably,
It is possible to more stably supply a large amount of processing gas whose flow rate is controlled with high accuracy. Furthermore, by providing the micropump means in the supply passage, it is possible to stably supply more processing gas.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing a processing gas supply device of the present invention.

FIG. 2 is a schematic configuration diagram of a liquid flow rate control unit.

FIG. 3 is an operation explanatory view showing an operation of the flow rate control means shown in FIG.

FIG. 4 is a schematic sectional view showing a vaporizing means.

5 is a plan view of the vaporizing means shown in FIG. 4. FIG.

FIG. 6 is a graph showing the relationship between temperature and viscosity of DMAH.

FIG. 7 is a diagram showing a modification of the heating means.

FIG. 8 is a schematic configuration diagram showing a conventional processing gas supply device.

FIG. 9 is an explanatory diagram for explaining a conventional hole embedding process.

[Explanation of symbols]

 28 Processing Gas Supply Device 30 Processing Device 32 DMAH (Liquid) 34 Liquid Storage Container 36 Heating Means 38 Supply Passage 40 Pressure Feeding Means 42 Vaporizing Means 48 Pressure Feeding Pipe 62 He Gas Cylinder 72 Liquid Flow Control Means 74 Carrier Gas Pipe 76 Hydrogen Gas Cylinder 94 1st Heater 96 second heater 102 sensor tube 136 processing container 140 mounting table 142 shower head 148 resistance heater 156 heating pipe 158 constant temperature layer W semiconductor wafer

Claims (7)

[Claims] 1. The viscosity at room temperature is 4000 cp to 10 cp.
In a method of supplying a processing gas, which comprises vaporizing a high-viscosity liquid of 000 cp to form a processing gas, and supplying the processing gas to a processing apparatus, the viscosity is lowered by heating the liquid, and the liquid whose viscosity is lowered A method for supplying a processing gas, characterized in that the processing gas is formed by pumping and vaporizing the processing gas to a vaporizing means, and the formed processing gas is supplied to the processing apparatus. 2. The viscosity at room temperature is 4000 cp-10.
In a processing gas supply device for forming a processing gas by vaporizing a high-viscosity liquid of 000 cp and supplying the processing gas to the processing device, a liquid storage container for storing the liquid, and a storage container for storing the liquid in the liquid storage container. A heating means for heating the liquid to reduce the viscosity of the liquid; a supply passage connecting the liquid storage container and the processing device; and a pressure feed for pumping the liquid with the reduced viscosity to the supply passage. An apparatus for supplying a processing gas, comprising: a means and a vaporizing means that is provided in the middle of the supply passage and vaporizes the liquid that is pumped to form a processing gas. 3. The processing gas according to claim 2, wherein the supply passage on the upstream side of the vaporization means is provided with a liquid flow rate control means for controlling the flow rate of the liquid flowing therein. Supply device. 4. The micro-pump means for sucking the liquid in order to assist the pressure feeding of the liquid is provided in the supply passage on the upstream side of the liquid flow rate control means. The processing gas supply device described. 5. A first heating heater for heating a liquid flowing to maintain a low viscosity state of the liquid is provided in the supply passage between the liquid storage container and the vaporizer. The processing gas supply device according to any one of claims 2 to 4. 6. A second heater provided in the supply passage between the vaporizing means and the processing device, for heating the processing gas flowing therein to maintain the vaporized state of the processing gas flowing therein. The processing gas supply device according to claim 2, wherein the processing gas supply device is provided. 7. The processing gas supply apparatus according to claim 2, wherein the high-viscosity liquid is dimethyl aluminum hydride.