JP2003031507A - Apparatus and method for vacuum processing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent reaction between gases in an exhaust pipe, when the gases reacting with each other when mix, are exhausted. SOLUTION: In this method, the filled gases in a raw material gas supplying apparatus, in which a combustible gas and a combustion support gas are filled, are successively supplied to a decompressible vacuum processing furnace for vacuum processing, and the method comprises the steps of exhausting (S302-S305) the combustible gas remaining in the raw material gas supply apparatus for a predetermined time, prior to supplying (S306) the combustible gas, and exhausting (S307-S310) the combustion support gas remaining in the raw material gas supply apparatus for a predetermined time, prior to supplying (S311) the combustion support gas.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus and method for introducing a raw material gas into a vacuum atmosphere to perform processing on a substrate. More specifically, the present invention relates to a vacuum processing apparatus and a vacuum processing method for forming a device by performing vacuum processing on a substrate with an etching apparatus, a CVD (Chemical Vapor Deposition) apparatus, or the like.

[0002]

2. Description of the Related Art In recent years, vacuum processing for processing a substrate in a vacuum system has been applied to various fields. Among them, sputtering, plasma etching, plasma CVD and the like have a wide range of applications and are practically used in various fields. I am offering.

As an example of a technique for producing a device by using a vacuum treatment, a technique for forming an electrophotographic image forming member by using plasma CVD is disclosed in JP-A-54-145539 (hereinafter referred to as Reference 1). Has been done. According to this publication, a photoconductive layer made of amorphous silicon or amorphous germanium containing nitrogen atoms or oxygen atoms is formed by plasma CVD using various gases in combination. Also, JP-A-57-105
Japanese Patent Publication No. 745 (hereinafter referred to as Document 2) discloses a technique using amorphous silicon containing nitrogen atoms and oxygen atoms as a barrier layer of a photoconductive member.

FIG. 11 shows a schematic structure of a vacuum processing apparatus by plasma CVD for forming a device by using the above technique. This vacuum processing apparatus includes a vacuum processing furnace 50.
And an external raw material gas supply device 100 for supplying a predetermined raw material gas thereto via a pipe 132.

The vacuum processing furnace 50 includes a base plate 18,
Cylindrical vacuum container 6 made of dielectric material, and lid 3
The exhaust pipe 15 is connected to the closed space formed by, and a vacuum pump (not shown) provided at the tip of the exhaust pipe 15 can hold the inside of the closed space in vacuum at a predetermined pressure. A plurality of cylindrical substrates 7 are arranged inside the vacuum container 6, and each substrate 7 is attached to a different rotating shaft 9 via the dummy 2. Each rotating shaft 9 is connected to a motor 12 via a gear 10, and by driving the motor 12, the attached base 7 can be rotated. Each of the bases 7 has a heater 5 enclosed therein, and can be heated to a desired temperature by the heater 5.

The base plate 18 includes a vacuum processing furnace 50.
The outermost shield 19 is installed so as to cover the sealed space. A plurality of electrodes 1 are arranged on the inner wall of the shield 19 so as to face each other with the vacuum container 6 interposed therebetween, and a branch plate 2 electrically connected to the electrodes 1 is provided.
5 are arranged. A part of the branch plate 25 is a connection terminal 29.
The connection terminal 29 is connected to the power source 20 via a matching box 21 provided on the outer wall of the shield 19. Each of the plurality of electrodes 1 is provided with a capacitor 30 for phase adjustment on the side of the base plate 18 for increasing the ease of matching and the stability of discharge.

The external source gas supply device 100 includes a plurality of cylinders 101 to 104 filled with a desired source gas, pressure regulators 105 to 108, valves 109 to 112, mass flow controllers 113 to 116, and valves 117 to 1.
It consists of 28. The raw material gas supplied from the cylinders 101 to 104 is reduced to an appropriate pressure by the pressure regulators 105 to 108, and the valves 109 to 112,
After being adjusted to a desired flow rate by the mass flow controllers 113 to 116, it reaches the pipe 132 through the valves 121 to 124, and passes through the pipe 132, and the vacuum processing furnace 50.
Is supplied to.

The raw material gas inflow side pipes of the mass flow controllers 113 to 116 are branched, and these branched pipes are the raw material gas inflow side pipes of the valves 117 to 120, respectively. The raw material gas outflow side pipes of the valves 117 to 120 are respectively branched, one branch pipe is connected to the raw material gas outflow side pipes of the mass flow controllers 113 to 116, and the other branch pipe is the raw material of the valves 125 to 128, respectively. It is a pipe on the gas inflow side. The pipes on the raw material gas outflow side of the valves 125 to 128 are connected to an exhaust pipe 133 which is an exhaust path of the raw material gas supply device 100, and the exhaust pipe 133 is the valve 12.
It is connected to the vacuum pump 130 via 9. In addition,
Here, the four cylinders 101 to 104 are filled with four.
Although the configuration has been shown in which the raw material gases of various types are supplied, the number of cylinders, gas supply and exhaust paths, and the type of gas used can be changed according to the purpose.

The raw material gas supplied from the above-mentioned raw material gas supply device 100 passes through a pipe 132, a branch pipe 22, and a plurality of nozzles 4 inserted in the vacuum container 6 of the vacuum processing furnace 50.
Is supplied to. Each nozzle 4 is provided with a plurality of orifices 32, and the supplied raw material gas is discharged into the vacuum container 6 from these orifices 32.

In the vacuum processing furnace 50, high frequency power is supplied from the power source 20 to the connection terminal 29 via the matching box 21. The high frequency power supplied to the connection terminal 29 is distributed to the branch plate 25 and the plurality of electrodes 1, whereby glow discharge is generated in the discharge space 23 and the raw material gas in the vacuum container 6 is decomposed. In this way, the vacuum process is performed on the base 7. At the time of this vacuum processing, the outermost shield 19 of the vacuum processing furnace 50 prevents leakage of high frequency power.

According to the vacuum processing apparatus described above, by appropriately selecting and using various raw material gases,
The desired vacuum treatment can be applied to the substrate.

[0012]

Among the wide variety of source gases, it is not desirable for them to be mixed with one another. For example, combustible gas and combustion-supporting gas.
In particular, it is known that among combustible gases, a gas having self-combustibility causes a reaction with each other, even under the conditions of normal temperature and normal pressure, when mixed with a combustion-supporting gas. Of the combustible gases used for vacuum processing, those that have self-combustibility include:
SiH ₄ (monosilane), Si ₂ H ₆ (disilane), Ge
Examples include H ₄ (germane), B ₂ H ₆ (diborane), PH ₃ (phosphine) and the like. As the combustion-supporting gas, O ₂ (oxygen),
NO (nitric oxide), NO ₂ (nitrogen dioxide), N ₂ O (nitrous oxide), Cl ₂ (chlorine), F ₂ (fluorine) and the like can be used. Further, there are other gas species that react with each other even if they are not classified as a combustion-supporting gas. For example, it is known that the above B ₂ H _{6 and the} like cause a reaction when mixed with ammonia (NH ₃ ).

In actual vacuum processing, there are many cases in which gases that react with each other when mixed as described above are used at the same time. For example, when a silicon oxide film is formed by plasma CVD, SiH ₄ or Si _{2 is used.}
H ₆ and O ₂ or NO for introducing oxygen atoms may be used at the same time. In the above-mentioned reference 1, SiH ₄ or Si ₂ H _{6 is used} as a gas for forming amorphous silicon,
GeH _{4 and the} like are disclosed as a gas for forming amorphous silicon germanium, and it is disclosed that O ₂ and NO are suitable as a gas for introducing oxygen atoms and nitrogen atoms into them. Further, Document 2 described above discloses an example in which SiH ₄ and O ₂ are mixed and used as a method for forming amorphous silicon containing oxygen atoms. As described above, for reasons of device characteristics, there are not a few examples in which gases that react with each other when mixed are mixed and used.

From the above, conventionally, when gases which react with each other when mixed are used at the same time, in order to prevent the gases from reacting with each other in the pipe, the mutual gases are kept below the reaction limit. Consideration was given such that the gases were mixed after controlling the partial pressure.

However, even under the partial pressure condition as described above, the inside of the source gas supply apparatus 100 shown in FIG. 11, for example, the valves 109 to 112 and the valves 121 to 12 are used.
In the case where the inside of the pipe between 4 is exhausted, the pressure in the exhaust pipe 133 may temporarily rise, though it is an extremely short time.

The step of evacuating the inside of the raw material gas supply device as described above is, for example, a so-called slow introduction step of introducing the raw material gas into the vacuum processing furnace while suppressing the pressure fluctuation, or the raw material after the vacuum processing of the substrate is completed. This is often performed in a purging process in which the source gas is replaced with an inert gas such as Ar or N ₂ in the gas supply device.

The problem of gas reaction due to pressure increase will be described below by taking the purging process as an example.

In the vacuum processing apparatus shown in FIG. 11,
After the vacuum treatment of the substrate is completed, the raw material gas supply device 100
A purging step of replacing the mass flow controllers 113 to 116 therein with an inert gas is executed. When purging the mass flow controllers 113 to 116, first open the valves 117 to 120 and 125 to 129 to open the vacuum pump 1.
The mass flow controllers 113 to 116 are exhausted by 30. Then, the valve 129 is closed and the cylinder 101
~ 104 filled with Ar (argon), N
An inert gas for purging such as 2 (nitrogen) is supplied and filled into the mass flow controllers 113 to 116. For example, when the inert gas for purging filled in the cylinder 104 is used, the purge gas is filled in the mass flow controller by opening the valves 112, 120 and 128.

In the above-mentioned purging step, when the gases which react with each other when mixed as described above, especially the raw material gases having self-combustibility, are simultaneously exhausted, a reaction due to the raw material gases occurs in the pipe of the exhaust path, and heat or reaction formation occurs. May produce large amounts of organisms. In such a case, the generated heat may loosen the joint of the exhaust pipe, damage the seal member, and cause problems such as gas leakage. In addition, the reaction product may cause clogging of the exhaust pipe or the vacuum pump. Further, when the reaction product flows into the vacuum pump, abnormal wear or the like occurs inside the vacuum pump, which causes a problem that the maintenance interval of the vacuum pump is significantly shortened. The problem that the maintenance interval of the vacuum pump is shortened also causes a reduction in the operating rate of the vacuum processing apparatus.

The object of the present invention is to overcome the above-mentioned problems,
Even when gases that react with each other when mixed are used at the same time, by preventing the reaction of such gases in the pipes in advance, it is possible to prevent the consumption of equipment such as pipes and vacuum pumps. It is to provide a processing apparatus and a vacuum processing method.

[0021]

In order to achieve the above object, the vacuum processing apparatus of the present invention is a raw material for supplying a raw material gas consisting of at least two kinds of gases which react with each other when mixed to a vacuum processing furnace capable of reducing the pressure. So that the gas supply means, an exhaust means for exhausting the raw material gas remaining in the raw material gas supply means, and the raw material gas are separately exhausted,
A control means for controlling the exhaust of the raw material gas by the exhaust means.

In the above case, the control means has a timer for counting the time required for exhausting the raw material gas by the exhaust means, and the control means exhausts the gases which react with each other when mixed and are exhausted separately by the exhaust means. Whether or not to switch the type may be determined by whether or not the time counted by the timer reaches a predetermined time.

Further, the control means has a pressure gauge which is attached to a predetermined position of an exhaust passage for exhausting the raw material gas remaining in the raw material gas supply means and measures the pressure in the exhaust passage. Then, whether to switch the type of gas to be exhausted when the gases that react with each other are separately exhausted by the exhaust means may be determined by whether or not the pressure value of the pressure gauge becomes equal to or less than a predetermined value. .

In the vacuum processing method of the present invention, a step of supplying at least two kinds of raw material gases that react with each other when mixed to a vacuum processing furnace capable of reducing the pressure from a raw material gas supply device, and before or after the supply of the raw material gas. A step of separately exhausting the raw material gas remaining in the raw material gas supply device for each raw material gas.

In the above case, when the gases that react with each other when mixed are separately exhausted, it may be possible to include a step of judging whether or not the gases to be exhausted can be switched depending on whether or not the exhaust has been performed for a predetermined time. In this case, the predetermined time is the time required for the pressure in the exhaust passage for exhausting the raw material gas remaining in the raw material gas supply device to become equal to or lower than the preset pressure value.

In addition, whether or not the gases to be exhausted can be switched when the gases that react with each other when mixed are separately exhausted is determined by the pressure in the exhaust passage for exhausting the raw material gas remaining in the raw material gas supply device. A step of determining whether or not the pressure value is equal to or lower than a preset pressure value may be included.

In the present invention as described above, the above-mentioned problems are solved by the following actions.

As described in the above-mentioned problems, when the raw material gases remaining in the raw material gas supply device are exhausted in the slow introduction step and the purging step, the gases that react with each other when mixed are exhausted at the same time. Reactions due to these source gases occur inside, and problems such as gas leakage, clogging of the exhaust pipe and vacuum pump, and abnormal wear inside the vacuum pump occur. According to the invention, the gases which react with each other when mixed are evacuated separately and not simultaneously. That is, in the present invention, the gases that react with each other when mixed are exhausted differentially. Therefore, a reaction due to the raw material gas such as the combustion-supporting gas and the combustible gas does not occur in the pipe of the exhaust path.

Further, when the gases which react with each other when mixed are exhausted separately, some mixing of these gases occurs when switching the exhausted gases. In the present invention, whether to switch the gas to be exhausted is basically determined by whether or not the pressure in the exhaust passage for exhausting the raw material gas remaining in the raw material gas supply device is equal to or lower than a preset pressure value. Since the determination is made, the gas switching is always performed under the control of pressure conditions that do not cause reactions with each other. Therefore, even if the gases are mixed when the gas to be exhausted is switched, the problem of the reaction of the raw material gas as described above does not occur due to the mixing.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION The vacuum processing apparatus of the present invention is equipped with a raw material gas supply apparatus for supplying a raw material gas consisting of at least two kinds of gases which react with each other when mixed, to a vacuum processing furnace capable of depressurizing. As a mechanism for exhausting the raw material gas remaining in the raw material gas supply device before or after the gas supply, a control mechanism is provided so that the gases that react with each other when mixed are not exhausted at the same time. This control mechanism is, for example, in the vacuum processing apparatus shown in FIG.
It is realized by controlling a plurality of valves 125, 126, 127, 128 so that they are not opened simultaneously by a mechanical or soft interlock. It is also realized by controlling so that the gases that react with each other when mixed are not exhausted at the same time by a predetermined operation sequence.

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

(First Embodiment) FIG. 2 shows a first embodiment of the present invention.
3 is a block diagram showing a schematic configuration of a control system of the vacuum processing apparatus of the embodiment of FIG. This control system controls the supply and exhaust of the raw material gas of the vacuum processing apparatus according to the first embodiment of the present invention, and in FIG. 2, an example applied to the vacuum processing apparatus shown in FIG. It is shown.

Referring to FIG. 2, the control system includes a valve 10
Electromagnetic valves 202 to 218 provided for every 9 to 129 and opening and closing the respective valves, and these electromagnetic valves 202 to 21
8 valve opening and closing and mass flow controller 1
The control device 201 controls the adjustment of the gas flow rate by 13 to 116. A signal for controlling the opening and closing of the valve is supplied from the control device 201 to the electromagnetic valves 202 to 218 to control the opening and closing of the valves 109 to 129,
Further, the control device 201 supplies a signal for controlling the flow rate of the raw material gas to the mass flow controllers 113 to 116, thereby controlling the flow rate of the raw material gas supplied from each of the cylinders 101 to 104.

The control device 201 controls the opening and closing of valves and the flow rate of the mass flow controller according to a predetermined flow rate pattern of the raw material gas and individual gas flow rate instructions. Thereby, the raw material gas can be supplied into the vacuum processing apparatus under a desired flow rate condition.

Further, the control device 201 controls the opening / closing of the valves so that the gases that react with each other when mixed are not exhausted at the same time. For example, when exhausting a certain type of gas and then switching to exhausting the types of gases that react with each other when mixed, the control device 201 performs the switching after elapse of a predetermined time. By such a switching operation, the partial pressure of the gas in the pipe 133 or the pump 130 becomes lower, and the reaction of the gas can be prevented more effectively.

The slow introduction procedure and the purge procedure in the control system of the vacuum processing apparatus of this embodiment will be described in detail below.

(1) Slow introduction step: FIG. 1 is for explaining the vacuum processing method of the present invention, and is a flow chart showing one procedure of the slow introduction step performed in the control system shown in FIG. Is. Here, in the configuration shown in FIG. 11, the cylinder 101 is filled with a combustible gas,
Assuming that the cylinder 102 is filled with the combustion-supporting gas, the exhaust gas switching operation of these gases will be specifically described.

When the slow introduction command is input to the control device 201 (step S301), the control device 201 determines whether or not the input slow introduction command of the flammable gas is included in the input slow introduction command. Judge (step S
302). When the slow combustible gas introduction command is included, the control device 201 controls the valves 125, 117, and 12.
9 is opened to start exhausting the combustible gas (step S3).
03), a timer (not shown) is started to count the exhaust time of the flammable gas. If the slow introduction instruction for flammable gas is not included in the slow introduction instruction,
The process moves to step S307 described later.

When a preset time elapses from the start of the exhaust of the combustible gas (step S304), the control device 201 closes the valves 125 and 117 and ends the exhaust of the combustible gas (step S305). When the exhaust of the flammable gas is completed, the control device 201 then temporarily sets the flow rate of the mass flow controller 113 to 0 ml / min (no
rmal), the valves 121 and 109 are opened to supply the combustible gas while controlling the flow rate of the mass flow controller 113 to the designated flow rate (step S306).

By the above operation, the flammable gas filled in the cylinder 101 is supplied into the vacuum processing apparatus.

When the introduction of the combustible gas is completed, the control device 201 then determines whether or not the slow introduction instruction of the combustion supporting gas is included in the slow introduction instruction input in step S301 (step S307). ). When the slow introduction instruction of the combustion-supporting gas is included, the control device 201
Opens the valves 126 and 118 to start exhausting the combustion supporting gas (step S308) and starts a timer (not shown) to count the exhaust time of the combustion supporting gas. When the slow introduction command does not include the slow introduction command for the combustion-supporting gas, step S312 described later.
Then, the process of introducing the slow is finished.

When a preset time has elapsed from the start of exhausting the combustion-supporting gas (step S309), the control unit 201 closes the valves 126 and 118 and ends the exhaust (step S310). When the exhaust of the combustion-supporting gas is completed, the controller 201 once sets the flow rate of the mass flow controller 114 to 0 ml / min (normal), and then opens the valves 122 and 110 to specify the flow rate of the mass flow controller 114. The combustion-supporting gas is supplied while controlling the flow rate (step S31).
1).

By the above operation, the combustion-supporting gas filled in the cylinder 102 is supplied into the vacuum processing apparatus. After the supply of the combustion-supporting gas, the slow introduction process is ended (step S312).

(2) Purge step: FIG. 3 is a flow chart for explaining the vacuum processing method of the present invention and showing one procedure of the purge step performed in the control system shown in FIG. . Here, in the configuration shown in FIG. 11, the cylinder 101 is filled with a combustible gas, and the cylinder 1
Assuming that 02 is filled with the combustion-supporting gas and the cylinder 104 is filled with the inert gas, the switching operation of the exhaust of these gases will be specifically described.

When a purge command is input to the control device 201 (step S401), the control device 201 determines whether or not the input purge command includes a combustible gas purge command (step S401). Step S402). When the combustible gas purge command is included, the control device 201 opens the valves 125, 117, and 129 to start exhausting the combustible gas (step S403), and
A timer (not shown) is started to count the exhaust time of the flammable gas. If the purge command does not include the combustible gas purge command, the process proceeds to step S409 described below.

When a preset time has elapsed from the start of the exhaust of the flammable gas (step S404), the control device 201 closes the valve 129 and ends the exhaust of the flammable gas (step S405). When the exhaust of the combustible gas is completed, the control device 201 controls the valves 112, 120, 12
8 is opened to start filling the mass flow controller 113 between the valve 109 and the valve 121 with the inert gas (step S406), and a timer (not shown) is started to count the filling time of the inert gas. To do.

When a preset time elapses from the start of filling the inert gas (step S404), the control device 201 causes the valves 128, 120, 112, 125, 1
17 is closed to complete the filling of the inert gas (step S
408). If necessary, the above steps S403 to S403
The processing of 408 may be repeated.

When the filling of the inert gas is completed, the control device 201 then determines whether or not the purge command input in step S401 includes the purge command of the combustion supporting gas (step S409). When the instruction to purge the combustion-supporting gas is included, the control device 201 determines that the valve 1
26, 118, 129 are opened to start exhausting the combustion-supporting gas (step S410), and a timer (not shown)
Start and count the exhaust time of the combustion-supporting gas.
If the purge command does not include the combustion-supporting gas purge command, the process proceeds to step S416, which will be described later, and the slow introduction process ends.

When a preset time elapses from the start of the exhaust of the combustion supporting gas (step S411), the control device 201 closes the valve 129 and ends the exhaust of the combustion supporting gas (step S412). When the exhaust of the combustion-supporting gas is completed, the control device 201 causes the valves 112, 120, 12
8 is started to start filling the mass flow controller 114 between the valve 110 and the valve 122 with the inert gas (step S413), and a timer (not shown) is started to count the filling time of the inert gas. To do.

When a preset time elapses from the start of filling with the inert gas (step S414), the control device 201 causes the valves 128, 120, 112, 126, 1 to operate.
18 is closed to complete the filling of the inert gas (step S
415). If necessary, the above steps S410 to S410
The process of 415 may be repeated.

The above is the procedure of the slow introducing step and the purging step in the control system of the vacuum processing apparatus of the present embodiment. In these slow introduction process and purge process,
In either case, the combustible gas and the combustion-supporting gas are controlled not to be exhausted at the same time, so that the reaction between the combustion-supporting gas and the combustion-supporting gas in the pipe 133 and the pump 130 can be effectively prevented. I can.

In the present embodiment, the time until the second type of gas that causes a reaction when mixed with the first type of gas is exhausted depends on the configuration of the apparatus and the capacity of the exhaust pump. Therefore, it is desirable to determine in consideration of the conditions that the gases that react with each other when mixed do not cause the reaction. For example, for such time, the relationship between the exhaust time and the pressure in the pipe 133 is measured in advance,
It is desirable to determine after determining the exhaust time at which the pressure becomes lower than the set pressure. In this case, since it is not necessary to provide a pressure gauge in the actual operation of the device, it is not necessary to incorporate the signal of the pressure gauge into the pressure gauge or the control system and the operation can be easily performed.

(Second Embodiment) A vacuum gauge is provided in the exhaust path of a vacuum processing apparatus as shown in FIG. 11, and when they are mixed, they react with each other depending on whether or not the pressure value of the vacuum gauge is below a set value. Even if the switching timing of the exhaust of the gas that causes the above is obtained, the same operation as that of the above-described first embodiment is achieved. Here, a vacuum processing apparatus equipped with such a vacuum gauge will be described.

FIG. 4 is a schematic diagram showing a schematic structure of a vacuum processing apparatus having a vacuum gauge in the exhaust pipe. This vacuum processing apparatus has the same configuration as that shown in FIG. 11 except that a pressure gauge 134 is provided. In FIG. 4, the same components are designated by the same reference numerals. The pressure gauge 134 is provided in the pipe connecting the valve 129 and the exhaust pump 130, and can measure the pressure of the exhaust passage in the raw material gas supply device 100.

FIG. 5 is a block diagram showing a schematic configuration of a control system of the vacuum processing apparatus according to the second embodiment of the present invention. FIG. 5 shows an example applied to the vacuum processing apparatus shown in FIG.

Referring to FIG. 5, the control system includes a pressure gauge 134 for measuring the pressure in the exhaust path and valves 109-109.
Electromagnetic valves 202 to 218 provided for each 129 and opening and closing the respective valves, and valve opening and closing by these electromagnetic valves 202 to 218 and the mass flow controller 113.
2 for controlling the adjustment of the flow rate of gas by
It consists of 01 and. A signal for controlling the opening / closing of the valve is supplied from the control device 201 to the solenoid valves 202 to 218 to control the opening / closing of the valves 109 to 129, and also to control the flow rate of the raw material gas from the control device 201. Is supplied to the mass flow controllers 113 to 116, the flow rates of the raw material gases supplied from the cylinders 101 to 104 are controlled.

The controller 201 controls the opening / closing of valves and the flow rate of the mass flow controller according to a predetermined flow rate pattern of the source gas and individual gas flow rate instructions. Thereby, the raw material gas can be supplied into the vacuum processing apparatus under a desired flow rate condition.

Further, the control device 201 controls the opening and closing of the valves so that the gases which react with each other when mixed are not exhausted at the same time, and the exhaust gas switching timing is set by the pressure value measured by the pressure gauge 134. Judgment is made based on whether the value is below the value. For example, the control device 20
1 is to wait for the pressure value measured by the pressure gauge 134 to be equal to or less than the set value when switching to the exhaust of the gas that reacts with each other when mixed with the exhausted gas after exhausting a certain type of gas. Do it. By such a switching operation, the partial pressure of the gas in the pipe 133 or the pump 130 becomes lower, and the reaction of the gas can be prevented more effectively.

The operation of switching the exhaust of gases of the types that react with each other when mixed will be specifically described below by taking the slow introduction step and the purge step as an example. (1) Slow introduction step: FIG. 6 is a flow chart for explaining the vacuum processing method of the present invention and showing one procedure of the slow introduction step performed in the control system shown in FIG. Here, assuming that the cylinder 101 is filled with the combustible gas and the cylinder 102 is filled with the combustion supporting gas in the configuration shown in FIG. 4, the switching operation of the exhaust of those gases will be specifically described. To do.

When a slow introduction command is input to the control device 201 (step S701), the control device 201 determines whether or not the input slow introduction command includes a slow combustible gas introduction command. Judge (step S
702). When the slow combustible gas introduction command is included, the control device 201 controls the valves 125, 117, and 12.
9 is opened to start exhausting the combustible gas (step S7).
03), it is determined whether or not the value of the pressure in the exhaust path measured by the pressure gauge 134 has become equal to or less than the set value (step S704). When the slow introduction command does not include the combustible gas slow introduction command, the process proceeds to step S707 described later.

When it is confirmed that the value of the pressure gauge 134 has become equal to or less than the set value, the control device 201 causes the valve 125, 1
17 is closed and the exhaust of the combustible gas is completed (step S
705). When the exhaust of the flammable gas is completed, the controller 201 once sets the flow rate of the mass flow controller 113 to 0 ml / min (normal), and then the valve 12
1 and 109 are opened to supply the combustible gas while controlling the flow rate of the mass flow controller 113 to the designated flow rate (step S706).

By the above operation, the flammable gas filled in the cylinder 101 is supplied into the vacuum processing apparatus.

When the introduction of the combustible gas is completed, the control device 201 then determines whether or not the slow introduction instruction of the combustion supporting gas is included in the slow introduction instruction input in step S701 (step S707). ). When the slow introduction instruction of the combustion-supporting gas is included, the control device 201
Opens valves 126 and 118 to start exhausting the combustion-supporting gas (step S708), and pressure gauge 1
It is determined whether or not the value of the pressure of the exhaust passage measured at 34 is equal to or less than the set value (step S709). When the slow introduction command does not include the slow introduction command for the combustion-supporting gas, the process proceeds to step S712, which will be described later, and the slow introduction process ends.

When it is confirmed that the value of the pressure gauge 134 has become equal to or less than the set value, the control device 201 causes the valves 126, 1
18 is closed and exhausting is completed (step S710). When the exhaust of the combustion-supporting gas is completed, the control device 201 is then activated.
Once set the flow rate of the mass flow controller 114 to 0 ml.
/ Min (normal), the valves 122 and 110 are opened to supply the combustion-supporting gas while controlling the flow rate of the mass flow controller 114 to the designated flow rate (step S711).

By the above operation, the combustion-supporting gas filled in the cylinder 102 is supplied into the vacuum processing apparatus. After the supply of the combustion-supporting gas, the slow introduction process is ended (step S712).

In the present embodiment, the pressure value at the time of switching to the exhaust of the second type of gas, in which the first type of gas is exhausted and then reacts with each other when mixed with it, the pressure value is the reaction limit of both gases to be mixed. You can set it below. However, the pressure at the reaction limit in that case changes depending on conditions such as the combination of gases used, the ratio of flow rates, and temperature.

Further, even under a pressure condition in which no reaction occurs, when the gases that react with each other when simply mixed are mixed, when the gases are flowing in the pipe, they are generated in the gas flow. Since the reaction may locally proceed due to the influence of turbulence or the like, it is difficult to uniquely determine the pressure value that becomes the exhaust gas switching timing. In such a case, it is desirable that the pressure value that becomes the exhaust gas switching timing be determined based on a value that is measured in advance in accordance with each device configuration and actual use conditions.

Further, in the present embodiment, the type of the pressure gauge installed in the pipe 133 may be any type as long as it can output a pressure signal to the control device. For example, Pirani gauge, ionization type vacuum gauge,
It is possible to use a vacuum gauge such as a capacitance manometer or a Bourdon tube. Among them, the capacitance manometer has a simple gas contact structure, and decomposition and deposition of the source gas due to heat inside the vacuum gauge occur. It is most suitable in terms of things such as not doing.

(2) Purging step: FIG. 7 is a flow chart for explaining the vacuum processing method of the present invention and showing one procedure of the purging step performed in the control system shown in FIG. . Here, in the configuration shown in FIG. 4, the cylinder 101 is filled with a combustible gas, and the cylinder 10
Assuming that 2 is filled with a combustion-supporting gas and the cylinder 104 is filled with an inert gas, the switching operation of the exhaust of these gases will be specifically described.

When a purge command is input to the control device 201 (step S801), the control device 201 determines whether the input purge command includes a combustible gas purge command (step S801). Step S802). When the combustible gas purge command is included, the control device 201 opens the valves 125, 117, and 129 to start exhausting the combustible gas (step S803), and
It is determined whether or not the value of the pressure in the exhaust path measured by the pressure gauge 134 is equal to or less than the set value (step S80)
4). When the purge command does not include the combustible gas purge command, the process proceeds to step S809 described below.

When it is confirmed that the pressure value of the pressure gauge 134 has become less than or equal to the set value, the control device 201 causes the valve 129 to operate.
To close the exhaust of flammable gas (step S80).
5). When the exhaust of the flammable gas ends, the control device 201
Opens valves 112, 120, 128 to open valve 10
Mass flow controller 113 between the valve 9 and the valve 121
The filling of the inert gas with the gas is started (step S806).
At the same time, it is determined whether or not the value of the pressure in the filling path measured by the pressure gauge 134 has become equal to or less than the set value (step S807).

When it is confirmed that the value of the pressure gauge 134 has become less than or equal to the set value, the control device 201 causes the valves 128, 1
20, 112, 125, 117 are closed to complete the filling of the inert gas (step S808). If necessary, the processes of steps S803 to S808 may be repeated.

When the filling of the inert gas is completed, the control device 201 then determines whether or not the purge command input in step S801 includes the purge command of the combustion-supporting gas (step S809). When the instruction to purge the combustion-supporting gas is included, the control device 201 determines that the valve 1
26, 118, 129 are opened to start exhausting the combustion-supporting gas (step S810), and it is determined whether or not the value of the pressure of the exhaust passage measured by the pressure gauge 134 is equal to or less than the set value. (Step S811). If the purge command does not include the combustion-supporting gas purge command, the process proceeds to step S816 described below, and the slow introduction process ends.

When it is confirmed that the value of the pressure gauge 134 has become less than or equal to the set value, the control device 201 closes the valve 129 and ends the exhaust of the combustion-supporting gas (step S81).
2). When the exhaust of the combustion-supporting gas ends, the control device 201
Opens valves 112, 120 and 128 to open valve 11
Mass flow controller 114 between 0 and valve 122
The filling of the inert gas with the gas is started (step S813).
At the same time, it is determined whether or not the value of the pressure in the filling path measured by the pressure gauge 134 has become equal to or less than the set value (step S814).

When it is confirmed that the pressure value of the pressure gauge 134 has become less than or equal to the set value, the control device 201 causes the valve 12 to operate.
8, 120, 112, 126, 118 are closed to complete the filling of the inert gas (step S815). The processes of steps S810 to S815 described above may be repeated if necessary.

The above is the procedure of the slow introduction step and the purge step in the control system of the vacuum processing apparatus of this embodiment. In these slow introduction process and purge process,
In either case, the combustible gas and the combustion-supporting gas are controlled not to be exhausted at the same time, so that the reaction between the combustion-supporting gas and the combustion-supporting gas in the pipe 133 and the pump 130 can be effectively prevented. I can.

In the present embodiment, a pressure gauge is provided in the pipe 133, and the timing at which the exhaust of gases that react with each other when mixed is switched is obtained according to the indicated value of the pressure gauge. It is possible to prevent the reaction of the raw material gas in. For example, even if the pump capacity decreases due to aging or failure, the type of gas exhausted is switched according to the actual pressure value, so the reaction of the raw material gas in the pipe can be effectively prevented. Can be done.

Further, when the timer or the like is used to evacuate for a certain period of time as in the above-described first embodiment, the pumping time is determined by considering the fluctuation of the pump capacity as described above. It is desirable to set a time longer than the actual exhaust time (with a margin) where the gases that react with each other when mixed will fall below the pressure at which they react, but as shown in this embodiment When switching the gas exhaust, the gas may be exhausted to a set pressure equal to or lower than the pressure at which the gas reacts, and thus the time required for exhaust may be shorter than that in the first embodiment.

In each of the above-described embodiments, the flammable gas is exhausted, and then the combustion-supporting gas is exhausted. However, the present invention is not limited to this, and when mixed, they react with each other. As long as the generated gas is not exhausted at the same time, there is no problem even if those processes are reversed.

Further, with respect to the types of gases which do not react with each other even when mixed, even if they are exhausted at the same time, the effect of the present invention is not affected at all. For example, in the above-described process (see the purging process in FIGS. 3 and 7), the combustible gas and the inert gas may be exhausted at the same time, or the combustion-supporting gas and the inert gas may be exhausted at the same time. Absent.

Furthermore, when a plurality of types of combustible gas and combustion-supporting gas are used as the source gases, respectively, the combustible gas may be any gas type that does not react with each other even when mixed. There is no problem in exhausting each other and combustion-supporting gases at the same time.

[0082]

EXAMPLES Examples of the present invention will be described in detail below, but the present invention is not limited thereto.

Example 1 In this example, the vacuum processing apparatus shown in FIG. 4 was used. As the source gas, the cylinder 101 was filled with SiH ₄ , and the cylinder 102 was filled with NO, and the slow introduction of these gases was performed according to the procedure shown in FIG. The exhaust time of each gas at the time of this slow introduction was set to 60 seconds. The supply pressure of each gas is 0.1.
The pressure was adjusted to 5 MPa by the pressure adjusters 105 and 106.

FIG. 8 shows changes in the pressure in the pipe 133 when the slow introduction is performed under the above conditions. In the example of FIG. 8, the vertical axis represents the pipe pressure (Pa) and the horizontal axis represents the exhaust time. For exhaust of flammable gas (SiH ₄ ), valve 1
25 and 117 are opened and exhaust of the combustible gas (SiH ₄ ) is started, the pressure in the pipe 133 is rapidly increased to about 9 kPa, and 60 seconds later, the pressure is about 0.06 Pa.
Went down. In the exhaust of combustion-supporting gas (NO),
When the valves 126 and 118 are opened to start exhausting the combustion supporting gas (NO), the pressure in the pipe 133 is about 8 k again.
After 60 seconds, the pressure rises to about 0.0
It fell to around 6Pa.

After completion of a series of slow introduction steps, the pipe 133
The inside of the pump and the inside of the pump were visually inspected, but no generation of reaction products was observed. Further, according to the experiments by the present inventors, in the device used in this example, SiH ₄ and NO
Even if the gas is mixed with S, if the partial pressure of one of the gases is kept below 0.1 Pa, S
It was also obtained that the reaction of iH ₄ and NO did not occur.

From the above, the gases that react with each other when mixed are differentially exhausted, and the exhaust time is set sufficiently to keep the pressure when switching the gas type to be exhausted below the exhaust limit. Thus, the reaction of the raw material gas can be effectively prevented.

(Comparative Example 1) In this comparative example, the line of the cylinder 101 and the line of the cylinder 102 are assumed by using the apparatus shown in FIG. Evacuated at the same time. In the actual experiment, in order to avoid the reaction of the raw material gas, the cylinder 10
Both 1 and 102 were filled with N2.

FIG. 9 shows changes in the pressure in the pipe 133 when the gas is exhausted under the above conditions. In the example of FIG. 9, the vertical axis represents the pipe pressure (Pa) and the horizontal axis represents the exhaust time. Immediately after the valves 125, 117 and 126, 118 were opened simultaneously and the two lines were evacuated, the pressure in the pipe rose to about 9.8 kPa. As can be seen from these results, when gases that actually react with each other when mixed are actually used and those gases are exhausted at the same time, there is a high possibility that the raw material gases will react because the gases are compressed especially in the pump. It can be said that

(Example 2) In this example, the vacuum processing apparatus shown in FIG. 11 was used. As a raw material gas, a cylinder 10
1 was filled with SiH ₄ , and the cylinder 102 was filled with N ₂ O, and the slow introduction of these gases was performed according to the procedure shown in FIG. The exhaust time of each gas at the time of this slow introduction was set to 30 seconds based on the result of Example 1. For this exhaust time of 30 seconds, the pressure value for switching the type of gas to be exhausted was set to 0.1 Pa, and in consideration of fluctuations in the capacity of the pump, the time required for actual exhaustion was extended to 25 seconds by 20%. It's time.

After a series of slow introductions, the inside of the pipe 133 and the inside of the pump 130 were visually inspected, but no generation of reaction products was observed.

As in this example, the exhaust time is determined and controlled based on the relationship between the exhaust time and the pressure measured in advance, so that the gases that react with each other when mixed can be added without adding new control. The reaction can be effectively prevented. Also, since the exhaust time can be set according to the actual device, it is possible to shorten the exhaust time without increasing the risk that the gases that react with each other when mixed will react.

Example 3 In this example, the device shown in FIG. 4 was used. As a source gas, the cylinder 101 has Si
H ₄ and the cylinder 102 were filled with N ₂ O, and the slow introduction of these gases was performed according to the procedure shown in FIG. The pressure value for switching from the exhaust of the combustible gas to the exhaust of the combustion-supporting gas was set to 0.1 Pa, as in the second embodiment.

FIG. 10 shows changes in the pressure in the pipe 133 when the slow introduction is performed under the above conditions. In the example of FIG. 10, the vertical axis represents the pipe pressure (Pa) and the horizontal axis represents the exhaust time. The exhaust of the combustible gas (SiH _4), at the time of starting the evacuation of combustible gas by opening the valve 125,117 (SiH _4), pressure in the pipe 133 is about 9kPa
Rapidly rises to 25P and the pressure is about 0.1P 25 seconds later.
It went down to a. When the pressure drops to about 0.1 Pa, the valves 126 and 118 are opened and the combustion-supporting gas (N
₂ O) was started to be exhausted. At the time when the exhaust of the combustion supporting gas (N ₂ O) was started, the pressure in the pipe 133 was about 8 kPa again.
25 seconds later, the pressure is about 0.1 Pa again.
Went down. After performing a series of slow introduction, piping 13
The inside of 3 and the inside of the pump 130 were visually inspected, but no generation of reaction products was observed.

As in this embodiment, the pressure gauge 1 is attached to the pipe 133.
It is possible to perform the exhaust in the minimum required exhaust time by providing the control unit 34 and incorporating the control for switching the exhaust gas type according to the indicated value. Further, according to the present embodiment, even if the exhaust capacity of the pump 130 changes, exhaust is performed until the set pressure is reached, so the pump 130
It is not necessary to extend the exhaust time considering the fluctuation of Therefore, it is possible to substantially reduce the exhaust time.

[0095]

As described above, according to the present invention,
When gases that react with each other when mixed are used at the same time, when exhausting those gases, it is possible to prevent the reaction of those gases in the exhaust pipe, so that it is possible to prevent clogging of the exhaust pipe and vacuum pump and The consumption of the equipment can be reduced, and as a result, the operation rate of the vacuum processing apparatus is improved.

[Brief description of drawings]

FIG. 1 is a flow chart showing a procedure of a slow introduction step which is an example of a vacuum processing method of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a control system of the vacuum processing apparatus according to the first embodiment of the present invention.

FIG. 3 is a flowchart showing a procedure of a purging step which is an example of the vacuum processing method of the present invention.

FIG. 4 is a schematic diagram showing an example of a vacuum processing apparatus including a vacuum gauge in an exhaust pipe.

FIG. 5 is a block diagram showing a schematic configuration of a control system of a vacuum processing apparatus according to a second embodiment of the present invention.

FIG. 6 is a flowchart showing a procedure of a slow introducing step which is an example of the vacuum processing method of the present invention.

FIG. 7 is a flowchart showing a procedure of a purging step which is an example of the vacuum processing method of the present invention.

FIG. 8 is a schematic diagram showing changes in the pressure in the exhaust pipe when the slow introduction step shown in FIG. 1 is performed.

FIG. 9 is a schematic diagram showing a change in pressure in the exhaust pipe when a plurality of gases are exhausted at the same time.

10 is a schematic diagram showing a change in pressure inside the exhaust pipe when the slow introduction step shown in FIG. 6 is performed.

FIG. 11 is a schematic diagram showing an example of a vacuum processing apparatus that vacuum-processes a substrate to form a device.

[Explanation of symbols]

1 electrode 2 dummy 3 lids 4 nozzles 5 heater 6 vacuum vessels 7 Base 9 rotation axis 10 gears 12 motors 15 Exhaust pipe 18 base plate 19 shield 20 power supplies 21 Matching Box 22 Branch pipe 23 discharge space 25 branch board 29 connection terminals 30 capacitors 32 orifice 50 Vacuum processing equipment 100 source gas supply means 101-104 cylinder 105-108 Pressure regulator 109-112, 117-129 valves 113-116 Mass flow controller 130 vacuum pump 132 plumbing 133 Exhaust pipe 134 Pressure gauge

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Daisuke Tazawa             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 4K030 AA01 AA06 DA06 EA03 EA12                       JA09                 5F045 AA08 AB04 AC01 AC09 AC11                       BB20 EE01 EG05

Claims (11)

[Claims] 1. A raw material gas supply means for supplying at least two kinds of raw material gas that react with each other when mixed to a vacuum processing furnace capable of reducing pressure, and an exhaust means for exhausting the raw material gas remaining in the raw material gas supply means. And a control unit that controls exhaust of the source gas by the exhaust unit so that the source gas is exhausted separately. 2. A type of gas to be exhausted when the control means has a timer for counting a time required for exhausting the raw material gas by the exhaust means, and the gases which react with each other when mixed are exhausted separately by the exhaust means. 2. The vacuum processing apparatus according to claim 1, wherein whether or not to switch is determined based on whether or not the time counted by the timer has reached a predetermined time. 3. A pressure gauge for measuring the pressure in the exhaust passage, the pressure gauge being attached to a predetermined position of an exhaust passage for exhausting the raw material gas remaining in the raw material gas supply means, Then, whether or not to switch the type of the gas to be exhausted when the gases that react with each other are separately exhausted by the exhaust means is determined by whether or not the pressure value of the pressure gauge becomes a predetermined value or less. The vacuum processing apparatus according to claim 1. 4. The gas which reacts with each other when mixed contains a combustible gas and a combustion-supporting gas.
4. The vacuum processing apparatus according to any one of 3 to 3. 5. The vacuum processing apparatus according to claim 4, wherein the combustible gas is a gas having self-combustibility. 6. A step of supplying at least two kinds of raw material gases, which react with each other when mixed, from a raw material gas supply apparatus to a vacuum processing furnace capable of reducing the pressure, and the raw material gas supply apparatus before or after the supply of the raw material gas. A step of evacuating the raw material gas remaining therein for each of the raw material gases separately. 7. The method according to claim 1, further comprising the step of determining whether or not to switch the gases to be exhausted when the gases that react with each other when being mixed are separately exhausted, based on whether or not the gases have been exhausted for a predetermined time. 6. The vacuum processing method according to item 6. 8. The predetermined time is a time required for the pressure in the exhaust passage for exhausting the raw material gas remaining in the raw material gas supply device to fall below a preset pressure value. The vacuum processing method according to claim 7. 9. The pressure in the exhaust passage for exhausting the raw material gas remaining in the raw material gas supply device is determined in advance by determining whether to switch the exhaust gas when exhausting the gases that react with each other when mixed. The vacuum processing method according to claim 6, further comprising a step of determining whether or not the pressure value has become equal to or lower than a set pressure value. 10. The vacuum processing method according to claim 6, wherein the gases that react with each other when mixed include a flammable gas and a combustion-supporting gas. 11. The vacuum processing method according to claim 10, wherein the combustible gas is a gas having self-combustibility.