KR100684874B1 - Mass Flow Controller and Method Operating it - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mass flow controller that is widely used in semiconductor manufacturing. The mass flow controller of the present invention has an inlet and an outlet and a main flow path through which gas flows during the main process, and both ends of the main flow path. A body having a purge flow path connected to the gas flow only during the purge process; A sensor installed on the main flow path for sensing and providing a gas flow rate on the main flow path; A control valve controlling a flow rate of gas flowing into the main channel; An on / off valve installed in the purge passage; And a control unit for adjusting the control valve so as to correspond to the gas flow rate and the hydraulic data provided from the sensor, and providing a control signal for opening the on / off valve during the purge process.

Description

Mass Flow Controller and Method of Operation

1 shows a gas supply line with two mass flow controllers;

2 is a schematic cross-sectional view for explaining a mass flow controller according to a preferred embodiment of the present invention;

3 is a flowchart for explaining a method of operating a mass flow controller according to a preferred embodiment of the present invention;

4A shows a gas flow from a mass flow controller to a main flow in accordance with a preferred embodiment of the present invention;

Figure 4b is a view showing the gas flow from the mass flow controller to the purge passage in accordance with a preferred embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

110: body

112: main euro

116: purge euro

120: sensor

130: control valve

140: on-off valve

150: orifice

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to semiconductor processing equipment, and more particularly, to a mass flow controller and a method of operating the same.

Process equipment that performs metal contact (MC) and via processes purges the process chamber regularly (85 hours) in order to prevent quality degradation due to polymer deposition and equipment utilization. PM is performed.

As shown in FIG. 1, in the process facility 10, oxygen (O 2) gas is used for the process treatment and the process chamber 18 purge, and the capacity of the oxygen gas used for the process process is very small, 20 sccm or less. The amount is used, and the amount of oxygen gas used to purge the polymer (open the valve for cleaning or other purposes to flow a large flow rate) is very large amount of more than 500sccm. Therefore, two mass flow controllers 14 and 16 are inevitably used due to the difference between the capacity used for the process and the capacity used for the purge with the same oxygen gas.

As described above, in the semiconductor processing equipment using the same gas for the process and purge, the mass flow controller 14 for controlling the gas flow rate in the process processing mode and the mass flow controller for controlling the gas flow rate in the purge process mode. Since (16) must be used together, there was an inconvenience in configuring a mass flow controller suitable for each use, and therefore, there was a problem in that the cost of the equipment configuration was high.

SUMMARY OF THE INVENTION The present invention has been made to solve such a conventional problem, and an object thereof is to provide a new type of mass flow controller capable of controlling the microcapacity required in the main process mode, and the large-capacity control required in the purge process mode, and an operation method thereof. have.

The mass flow controller of the present invention for achieving the above object has a main flow passage having an inlet and an outlet and a gas flowing in the main process, and a purge flow in which the gas flows only during the purge process, connected to both ends of the main flow path. Having a body; A sensor installed on the main flow path for sensing and providing a gas flow rate on the main flow path; A control valve controlling a flow rate of gas flowing into the main channel; An on / off valve installed in the purge passage; And a control unit for adjusting the control valve so as to correspond to the gas flow rate and the hydraulic data provided from the sensor, and providing a control signal for opening the on / off valve during the purge process.

In an embodiment of the present invention, the mass flow controller further includes an orifice installed in the purge so that a constant gas flow rate flows into the purge flow path.

The operation method of the mass flow controller of the present invention comprises the steps of: setting a purge process mode or a main process mode; Closing the main flow path and opening the purge flow to allow a quantity of gas to flow when in a purge process mode; In the main process mode, the purge flow path is closed and the flow rate on the main flow path is checked, and the control is installed in the main flow path so that the predetermined flow rate value flows on the main flow path by comparing the checked flow rate value with a preset flow rate value. Controlling the valve.

For example, the embodiments of the present invention may be modified in various forms, and the scope of the present invention should not be construed as being limited by the embodiments described below. These examples are provided to more fully explain the present invention to those skilled in the art. Accordingly, the shape of the elements in the drawings and the like are exaggerated to emphasize a clearer description.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to FIGS. 2 to 4B. In addition, in the drawings, the same reference numerals are denoted together for components that perform the same function.

2 is a schematic cross-sectional view for explaining a mass flow controller according to a preferred embodiment of the present invention. 3 is a flowchart illustrating a method of operating a mass flow controller according to a preferred embodiment of the present invention.

2 and 3, the mass flow controller 100 has a main body 112 having a bypass portion 114 and a body 110 having a purge flow passage 116 bypassing the main flow passage 112. Has The main flow path 112 is provided with a sensor 120 for sensing a gas mass flow rate, and a control valve 130 (for example, a solenoid valve) for controlling the flow rate of the gas flowing into the main flow path. The purge flow passage 116 is provided with an on-off valve 140 and an orifice 150 that limits the amount of gas flow so that a predetermined amount or more of gas does not flow into the purge flow passage. The control valve 130 and the opening and closing valve 140 is controlled by the controller 160, the control unit 160 compares the preset value and the value detected by the sensor 120 and the control valve (according to the comparison result) 130). And, in the purge process mode, the control unit 160 closes the control valve 130 and opens the on-off valve 140, a large amount of gas through the purge passage (1000-2000sccm in the case of the purge process ) Flows.

The main passage 112 has a bypass portion 114 located adjacent to the inlet of the body, the sample tube 115 is connected to the main passage 112. Specifically, the sample tube 115 is connected between the portion adjacent to the inlet end of the bypass portion 114 and the portion adjacent to the outlet end of the bypass portion, and samples the gas passing through the bypass portion 114. .

The sensor 120 includes a sensing coil wound and installed on the sample tube 115 made of metal or the like. The sensor 120 is heated by a magnetic invention resistor when a voltage is applied, detects the temperature difference generated at both sides of the sensing coil in accordance with the flow of gas flowing through the sample tube 115, the controller 160 controls the value Will output

The control valve 130 adjusts the flow rate of the gas according to the control of the controller 160 for measuring the actual mass flow rate of the gas flowing through the mass flow controller based on the value of the temperature difference by the gas flow input from the sensor 120 Done.

The open / close valve 140 opens and closes the purge flow path 116 according to a control signal from the control unit 160, and the gas flowing into the purge flow path 116 flows by the orifice 150.

The controller 160 determines whether the main process mode or the purge process (s10), and in the case of the main process, adjusts the control valve 130 so that a predetermined flow rate flows on the main flow path in a state in which the open / close valve is closed. (s30). If it is changed to the purge process mode, the main passage is closed, and the on / off valve 140 is opened to allow gas to flow through the purge passage (S20).

For example, when oxygen gas is used in both the main process and the purge process in the semiconductor process, a small flow rate (for example, 5 to 20 sccm) of the oxygen gas must be supplied in the main process mode, and in the purge process mode for the chamber purge, Oxygen gas must be supplied at a flow rate (eg 1000 to 2000 sccm). Conventionally, the mass flow controller must be separately installed and used, but the mass flow controller of the present invention is capable of controlling the microcapacity required for the main process and the large capacity control required for the purge process. For reference, the maximum value of the mass flow rate of the fluid that can be controlled by the mass flow controller (full scale) is determined according to the capacity of the bypass unit 120. In the present invention, the maximum value of the bypass unit is about 5-20 sccm. It may be used, the flow rate of the orifice may be used that is 1000 to 2000sccm.

4A and 4B, the gas flow in the main process mode flows through the main flow path 112, and the gas flow in the purge process mode flows through the purge flow path 116. Since the precision is not required in the purge process mode, the orifice 150 is installed to prevent the gas from flowing over a predetermined amount.

In the above, the configuration and operation of the mass flow controller according to the present invention is shown in accordance with the above description and drawings, but this is merely an example, and various changes and modifications can be made without departing from the technical spirit of the present invention. Of course.

According to the present invention, the mass flow controller according to the present invention is capable of controlling the microcapacity required in the general main process mode and the large capacity control required in the purge process mode by using one mass flow controller, thereby reducing manufacturing costs. Can be.

Claims (3)

In a mass flow controller that regulates the flow rate of gas used in semiconductor manufacturing: A body having an inlet and an outlet and a main flow path through which gas flows during the main process processing, and a purge flow path connected to both ends of the main flow path and flowing gas only during the purge process processing; A sensor installed on the main flow path for sensing and providing a gas flow rate on the main flow path; A control valve controlling a flow rate of gas flowing into the main channel; An on / off valve installed in the purge passage; And controlling the control valve to correspond to the gas flow rate and the hydraulic data provided from the sensor, and providing a control signal for opening the on / off valve during the purge process. Mass flow controller. The method of claim 1, The flow controller And a orifice installed in the purge so that a constant gas flow rate flows into the purge flow path. In a method of operating a mass flow controller having a main flow path used in the main process mode and a purge flow path used in the purge process mode: Determining whether to set a purge process mode or a main process mode; Closing the main flow path and opening the purge flow to allow a quantity of gas to flow when in a purge process mode; In the main process mode, the purge flow path is closed and the flow rate on the main flow path is checked, and the control is installed in the main flow path so that the predetermined flow rate value flows on the main flow path by comparing the checked flow rate value with a preset flow rate value. And controlling the valve.

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