JP2020105577A - Fluid supply device - Google Patents

Abstract

To provide a fluid supply device capable of supplying mixed gas to a plurality of regions by dividing it into a plurality of systems by comparatively few numbers of mass flow controllers, and controlling a flow quantity with high accuracy.SOLUTION: The device includes: a connection pipe part 30 having multiple first stage mass flow controllers 20A to 20C for controlling flow quantity of gas supplied from multiple fluid supply sources 10A to 10C, mixing pipes for mixing fluid flowing out from the multiple first stage mass flow controllers 20A to 20C, and multiple branch pipes 331 to 333 which branch from the mixing pipes in order to distribute the mixed fluid; multiple second stage mass flow controllers 401 to 403 respectively connected to multiple branch pipes 331 to 333, which control flow quantity of each distributed mixed fluid; and a pressure control mechanism 100 connected to the branch pipes 331 to 333, which commonly controls the branch pipes 331 to 333 so as to become a target pressure.SELECTED DRAWING: Figure 1

Description

The present invention relates to a fluid supply device, a semiconductor manufacturing device, and a semiconductor manufacturing method.

In a semiconductor manufacturing process, a mass flow controller (MFC) is used to control the supply flow rates of various process gases with respect to a chamber of a semiconductor manufacturing apparatus. In various semiconductor processes, it is required to highly accurately control and supply a mixed gas, which is a mixture of a plurality of kinds of process gases at a predetermined mixing ratio, to a plurality of regions in a common chamber.
Therefore, conventionally, as shown in FIG. 2, from each gas supply source 10A to 10C, a pipe for connecting each supply point P1 to P3 in the chamber is provided, and the flow rate of the gas is controlled by the MFC 90 for each pipe to mix them. It was supplying to the chamber.

However, when x kinds of gas are mixed and the mixed gas is supplied to the y supply points of the chamber, the (x·y) pieces of the x gas supply sources and the y supply points are connected. Piping is required, and (x·y) MFCs are required. Therefore, there is a problem that the number of MFCs increases.
To solve this problem, in order to reduce the number of MFCs, for example, Patent Document 1 mixes gases whose flow rates are adjusted by MFCs and branches the mixed gas into a plurality of systems by a flow splitter so that a plurality of regions are formed in a chamber. Discloses the technology to supply.

JP 2017-155313 JP

However, in the technique disclosed in Patent Document 1, the mixed gas can be distributed to the plurality of gas inlets of the chamber at a predetermined ratio with a small number of MFCs, but the flow rate of the mixed gas at each of the plurality of gas inlets is independent. In addition, it cannot be controlled with high precision.

The object of the present invention has been made in view of the above problems, and a mixed gas can be branched into a plurality of systems by a relatively small number of MFCs and supplied to a plurality of regions, and a flow rate can be controlled with high accuracy. Another object of the present invention is to provide a fluid supply device, a semiconductor manufacturing method using the same, and a semiconductor manufacturing device.

The fluid supply device of the present invention is
A plurality of first stage mass flow controllers for controlling the flow rate of the fluid supplied by being respectively connected to the plurality of fluid supply sources,
A mixing pipe connected to the outflow sides of the plurality of first-stage mass flow controllers for mixing fluids respectively discharged from the plurality of first-stage mass flow controllers, and the mixing pipe for distributing the mixed fluid mixture. A connecting pipe portion having a plurality of branch pipes branched from
A plurality of second-stage mass flow controllers that are respectively connected to the plurality of branch pipes and control the flow rates of the respective distributed mixed fluids;
A pressure control mechanism that is connected to the branch pipe and commonly controls the pressure in the plurality of branch pipes so that the pressure in the plurality of branch pipes becomes a target pressure.
It is characterized by

Preferably, at least the plurality of second stage mass flow controllers may be a thermal type mass flow controller.

Preferably, when the detected pressure exceeds a target pressure, the pressure control mechanism releases the mixed gas to the outside of the connecting pipe so that the pressures in the plurality of branch pipe portions become the target pressure. Can be adopted.

A semiconductor manufacturing apparatus of the present invention uses the above-described fluid supply device for supplying the process gas to the chamber in a manufacturing process of a semiconductor device that requires a process step using a process gas in a closed chamber.

The semiconductor manufacturing method of the present invention is characterized in that the above-mentioned fluid supply device is used for supplying the process gas to the chamber in a manufacturing process of a semiconductor device that requires a process step of processing gas in a closed chamber. ..

According to the present invention, the plurality of first-stage MFCs, the plurality of second-stage MFCs, and the connecting pipe portion for connecting these and mixing the gas are used, so that the mixed gas is relatively small in number. Can be branched into a plurality of systems and supplied to a plurality of regions, and highly accurate flow rate control can be performed.

Further, since the pressure control mechanism connected to the connection pipe section and commonly controlling the pressure in the branch pipe is provided, even when there is a sudden change in the gas flow rate, fluctuations in the supply pressure to the second stage MFC are suppressed. Therefore, stable flow rate control can be maintained.

The block diagram which shows the flow control apparatus which concerns on one Embodiment of this invention. The block diagram which shows the conventional flow control apparatus. The block diagram which shows the semiconductor manufacturing apparatus of this invention.

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing a gas (fluid) supply device according to an embodiment of the present invention.
The gas supply device 1 includes first-stage mass flow controllers (first-stage MFCs) 20A to 20C that receive gas from gas supply sources 10A to 10C, a connecting pipe section 30, and second-stage mass flow controllers (second-stage MFC) 401. .About.403.

The gas supply sources 10A to 10C are gas cylinders and tanks for the process gases and gases GA to GC that are purge gases. The gases GA to GC are set to a predetermined pressure by a regulator and are supplied through a gas supply pipe or the like of a factory.

The first-stage MFCs 20A to 20C are connected to the pipes from the gas supply sources 10A to 10C, respectively, and supplied with the gases GA, GB, and GC so that the gases GA, GB, and GC have a predetermined mixing ratio. These gases are caused to flow at a predetermined flow rate ratio. The first-stage MFCs 20A to 20C may be thermal (thermal) MFCs or pressure MFCs. The flow rate of each MFC is set by an external controller (not shown).

The connecting pipe portion 30 is a connecting pipe portion that mixes the gases GA to GC from the first-stage MFCs 20A to 20C and distributes the mixed gas GA to GC to the second-stage MFCs 401 to 403. Collection pipes 31A to 31C for collecting the gases GA to GC respectively flowing out from the eyes MFC 20A to 20C, a mixing pipe 32 for mixing these gases GA to GC, and a plurality of the pipes branched from the mixing pipe 32. It has a plurality of branch pipes 331 to 333 which are respectively connected to the inflow sides of the second-stage MFCs 401 to 403, and a branch pipe 100a which is further connected to a pressure control mechanism 100 described later.

The second-stage MFCs 401 to 403 receive the mixed gas MG and flow it to the supply points P1 to P3 on the chamber side at respective predetermined flow rates, and the inflow side is connected to the branch pipes 331 to 333 of the connection pipe section 30, The outflow side is connected to the supply points P1 to P3 of the chamber 50 by piping. The second-stage MFCs 401 to 403 may be thermal (thermal) MFCs or pressure MFCs, but are preferably thermal MFCs that can exert the effects of the present invention more effectively.

The gas supply device of the present embodiment includes the pressure control mechanism 100 that commonly controls the pressure in the branch pipes 331 to 333 so that the pressure in the branch pipes 331 to 333 becomes the target pressure.
This is to suppress the pressure fluctuation that occurs when the flow rate flowing through any of the second-stage MFCs 401 to 403 changes abruptly, for example, to suppress the influence on the other second-stage MFCs 401 to 403. ..
Here, as the second-stage MFCs 401 to 403, either a thermal MFC or a pressure MFC can be used, but when the supply pressure is stable, the thermal MFC has a higher flow rate control than the pressure MFC. It excels in accuracy. On the other hand, the thermal MFC has a drawback that the flow rate error increases when the supply pressure changes. Therefore, when the thermal MFC is used as the second-stage MFCs 401 to 403, the pressure control mechanism 100 is especially required.

As the pressure control mechanism 100, any one can be used as long as it can control the pressure in the branch pipe to a predetermined pressure, but a gas flow rate from the upstream side such as a general regulator or a check valve is adjusted. The type cannot be used. This is because the flow rate of the gas from the upstream is precisely controlled by the first-stage MFCs 20A to 20C as described above. Therefore, the pressure control mechanism 100 detects the pressure in the branch pipe, and when the pressure exceeds the target pressure, discharges the mixed gas MG to the outside (downstream) so that the pressure becomes the target pressure. Type is preferred. As such a pressure control mechanism 100, for example, the Fujikin UPCUS (registered trademark) series can be used. A discharge pipe 100b is connected to the secondary side of the pressure control mechanism 100, and the gas to be discharged is discharged to an exhaust treatment device (not shown) without being supplied to the chamber.

Next, the operation of the gas supply device of the present embodiment configured as described above will be described with reference to FIG.
Gases GA, GB, GC supplied from gas supply sources 10A, 10B, 10C are mixed in a predetermined ratio, and the mixed gas MG is distributed to supply points P1, P2 at predetermined flow rates Q1, Q2, Q3. , P3, respectively.

First, the gases GA, GB, and GC are supplied from the gas supply sources 10A to 10C to the first-stage MFCs 10A to 10C, respectively, through pipes.
The first-stage MFCs 10A to 10C flow the respective gases GA, GB, GC at respective flow rates QA, QB, QC set by an external controller (not shown). Here, the ratio of QA, QB, and QC corresponds to the target mixing ratio of the mixed gas MG.

The gases GA, GB, and GC that have flowed out from the first-stage MFCs 10A to 10C pass through the collection pipes 31A, 31B, and 31C of the connection pipe portion 30, merge at the junction 32a, and mix while passing through the mixing pipe 32. The mixed gas MG having a mixing ratio (QA:QB:QC) is generated.
The mixed gas MG is distributed at the branch point 32b and is supplied to the second-stage MFCs 401 to 403 through the respective branch pipes 331 to 333.

The second-stage MFCs 401 to 403 flow the mixed gas MG at respective flow rates Q1, Q2, Q3 set by an external controller (not shown).
Thereby, the mixed gas MG in which the gases GA, GB, GC are mixed at the mixing ratio (QA:QB:QC) can be supplied to the supply points P1, P2, P3 at the predetermined flow rates Q1, Q2, Q3, respectively. it can.

Here, in the present embodiment, the pressure control mechanism 100 that commonly controls the pressure in the branch pipes 331 to 333 is provided, and the discharge pipe from the branch pipe 100a is arranged so that the pressure in the branch pipes 331 to 333 becomes a predetermined pressure. The amount of gas discharged to the exhaust treatment device (not shown) through 100b is adjusted.
As a result, even if there is a sudden change in the gas flow rate, the second-stage MFCs 401 to 403 can suppress fluctuations in the pressure in the branch pipes 331 to 333, which is the primary side pressure, and stable flow rate control. Can be maintained.

In the embodiment described above, the pressure control mechanism 100 is of the upstream pressure control type that adjusts the amount of gas discharged downstream, but is not limited to this. For example, the pipe capacity of the connecting pipe portion 30 is controlled. You may use the apparatus which controls a pressure by doing.

Next, the semiconductor manufacturing apparatus of the present invention will be described.
FIG. 3 is a block diagram of a semiconductor manufacturing apparatus according to an embodiment of the present invention.
A semiconductor manufacturing apparatus 980 shown in FIG. 3 is an apparatus for executing a semiconductor manufacturing process by an atomic layer deposition method (ALD: Atomic Layer Deposition method), 981 is a process gas supply source, 982 is a gas box, and 983 is A tank, 984 are opening/closing valves, 985 is a control unit, 986 is a processing chamber, and 987 is an exhaust pump. For example, in the ALD method or the like, it is required to stably supply a processing gas used in a processing process for depositing a film on a substrate at a higher flow rate.
The gas box 982 is an integrated gas system in which various fluid devices such as an on-off valve, a regulator, a mass flow controller, etc. are integrated and housed in a box in order to supply an accurately metered process gas to the processing chamber 986.
The tank 983 functions as a buffer that temporarily stores the processing gas supplied from the gas box 982.
The open/close valve 984 is a diaphragm valve that incorporates the displacement magnifying mechanism described above.
The control unit 985 executes flow rate adjustment control by controlling the supply of the operation gas to the opening/closing valve 984.
The processing chamber 986 provides a closed processing space for forming a film on a substrate by the ALD method.
The exhaust pump 987 evacuates the inside of the processing chamber 986.
The present invention is applicable as a constituent element of the gas box 982 described above.

According to the system configuration as described above, if the control command is sent from the control unit 985 to the opening/closing valve 984, the flow rate of the processing gas can be controlled.

The present invention is not limited to the above embodiment. Those skilled in the art can make various additions and changes within the scope of the present invention.

1: Gas supply devices 10A, 10B, 10C: Gas supply sources 20A, 20B, 20C: First stage mass flow controller (first stage MFC)
30: Connection pipe parts 31A, 31B, 31C: Collection pipe 32: Mixing pipe 32a: Confluence point 32b: Branch point 50: Chamber 90: Mass flow controller (MFC)
100: Pressure control mechanism 100a: Branch pipe 100b: Discharge pipes 331, 332, 333: Branch pipes 401, 402, 403: Second stage mass flow controller (second stage MFC)
980: Semiconductor manufacturing apparatus 981: Process gas supply source 982: Gas box 983: Tank 984: Open/close valve 985: Control unit 986: Processing chamber 987: Exhaust pumps GA, GB, GC: Gas MG: Mixed gas P1, P2, P3 : Supply points Q1, Q2, Q3: Flow rate

Claims (5)

A plurality of first stage mass flow controllers for controlling the flow rate of the fluid supplied by being respectively connected to the plurality of fluid supply sources,
A mixing pipe connected to the outflow sides of the plurality of first-stage mass flow controllers for mixing fluids respectively discharged from the plurality of first-stage mass flow controllers, and the mixing pipe for distributing the mixed fluid mixture. A connecting pipe portion having a plurality of branch pipes branched from
A plurality of second-stage mass flow controllers that are respectively connected to the plurality of branch pipes and control the flow rates of the respective distributed mixed fluids;
A pressure control mechanism that is connected to the branch pipes and commonly controls the pressures in the plurality of branch pipes so that the pressures in the plurality of branch pipes become a target pressure. The fluid supply device according to claim 1, wherein at least the plurality of second stage mass flow controllers are thermal mass flow controllers. The pressure control mechanism discharges the mixed fluid to the outside of the connecting pipe so that when the detected pressure exceeds a target pressure, the pressure in the plurality of branch pipe portions becomes the target pressure. The fluid supply device according to. A semiconductor manufacturing apparatus that uses the fluid supply device according to claim 1 for supplying the process gas to the chamber in a manufacturing process of a semiconductor device that requires a process gas treatment step in a sealed chamber. 4. A semiconductor manufacturing method using a fluid supply device according to claim 1, for supplying the process gas to the chamber in a semiconductor device manufacturing process that requires a process gas treatment step in a sealed chamber.

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