Device front-end module and method for controlling humidity in device front-end module

Abstract

The invention discloses a device front-end module and a method for controlling humidity in the device front-end module. A device front-end module according to one aspect of the present invention comprises: a load port; a transfer frame; a buffer unit; a fan filter unit; a gas supply unit; a differential pressure sensor mounted on a portion of the transfer frame and configured to measure a differential pressure, the differential pressure being a value obtained by subtracting an external pressure from an internal pressure of the transfer frame; a humidity sensor mounted on a portion of the transfer frame and configured to measure a humidity inside the transfer frame; and a control unit configured to control a rotational speed of the fan filter unit and a flow rate of the gas supplied into the transfer frame by the gas supply unit based on information received from the humidity sensor and the differential pressure sensor.

Description

[0001] Cross - reference to related applications

[0002] This application claims the benefit under 35 U.S.C. 119 of Korean Patent Application No. 10 - 2023 - 0183359, filed with the Korean Intellectual Property Office on December 15, 2023, the entire disclosure of which is hereby incorporated by reference in its entirety. Technical Field

[0003] The present invention relates to an equipment front - end module (EFE) that forms part of a semiconductor manufacturing facility, and more particularly, to an EFE having a configuration that allows control of internal humidity and a method for controlling the humidity inside the EFE. Background Art

[0004] In processes for manufacturing semiconductor devices, etching processes, ion implantation processes, thin - film deposition processes, and other processes process substrates in a vacuum atmosphere. These processes are performed in one or more process units composed of chambers capable of maintaining a vacuum. Substrates to be processed can be stored in a cassette and transferred to the process unit through an equipment front - end module (EFE). The equipment front - end module serves as an interface module connecting the cassette containing the substrate and the process unit, and the equipment front - end module includes: a load port module that houses the cassette; a transfer frame configured to transfer substrates within the cassette housed in the load port module; and a buffer unit capable of storing substrates transferred by the transfer frame. Substrates transferred or stored inside the equipment front - end module may form particles on their surfaces or be contaminated by infiltration of external moisture. Therefore, the humidity inside the equipment front - end module must be kept below a reference value. However, due to various environmental factors or equipment problems, the internal humidity may increase. For example, when the load port module is opened to transfer a substrate, a sudden change in the internal pressure of the equipment front - end module may cause the humidity to increase. If the humidity increases significantly, a large number of particles may form on the substrate or contamination due to oxidation may occur. Summary of the Invention

[0005] The present invention is designed to solve various problems including the foregoing problems of the prior art, and an object of the present invention is to provide an equipment front-end module (EFEM) equipped with a humidity control device capable of effectively controlling the humidity inside the equipment front-end module and maintaining the cleaning condition of the substrate, and a method of controlling the humidity inside the equipment front-end module using the humidity control device. However, this object is merely illustrative, and the scope of the present invention is not limited thereto.

[0006] According to an aspect of the present invention, there is provided an equipment front-end module including: a load port on which a tray for accommodating a substrate is placed; a transfer frame including a space for introducing and transferring the substrate accommodated in the load port; a buffer unit including an open surface formed on a surface facing the transfer frame; a fan filter unit having one end connected to the other end of a circulation pipeline connected to an exhaust port of the buffer unit, the fan filter unit being configured to introduce the gas supplied from the circulation pipeline into the transfer frame; a gas supply unit configured to supply gas into the transfer frame; a differential pressure sensor installed on a part of the transfer frame and configured to measure a differential pressure which is a value obtained by subtracting the external pressure from the internal pressure of the transfer frame; a humidity sensor installed on a part of the transfer frame and configured to measure the humidity inside the transfer frame; and a control unit configured to control the rotation speed of the fan filter unit and the flow rate of the gas supplied into the transfer frame through the gas supply unit based on the information received from the humidity sensor and the differential pressure sensor.

[0007] The equipment front-end module may include a fan filter unit control unit configured to receive a fan filter unit control signal transmitted from the control unit and control the rotation speed of the fan filter unit according to the fan filter unit control signal.

[0008] The equipment front-end module may include a mass flow controller configured to receive a gas flow control signal transmitted from the control unit and control the flow rate of the gas flowing through the gas supply unit according to the gas flow control signal.

[0009] The gas supplied into the transfer frame may flow into the buffer space through the open surface and may be discharged through the exhaust port of the buffer unit.

[0010] The control unit may determine whether the differential pressure information received from the differential pressure sensor satisfies a preset standard when the control unit determines that the humidity information received from the humidity sensor deviates from a preset standard.

[0011] When the control unit determines that the differential pressure information does not meet the preset standard, the control unit can execute control to simultaneously increase the rotational speed of the fan filter unit and the flow rate of the gas flowing through the gas supply unit.

[0012] When the control unit simultaneously generates a gas flow control signal and transmits the gas flow control signal to a mass flow controller configured to control the flow rate of the gas flowing through the gas supply unit, the control unit can generate a fan filter unit control signal and transmit the fan filter unit control signal to a fan filter unit control unit configured to control the rotational speed of the fan filter unit.

[0013] The fan filter unit control signal and the gas flow control signal can be generated as values proportional to the differential pressure measured by the differential pressure sensor.

[0014] The gas supply unit can include: a gas nozzle configured to discharge gas into the internal space of the transfer frame; a gas supply pipeline connected to the gas nozzle; and a mass flow controller configured to receive a gas flow control signal from the control unit and control the flow rate of the gas flowing through the gas supply pipeline according to the received gas flow control signal.

[0015] According to an aspect of the present invention, there is provided a method for controlling humidity in a front-end module of a device, the front-end module of the device including: a transfer frame including a space for introducing and transferring a substrate accommodated in a load port; and a buffer unit having an open surface formed on a surface facing the transfer frame.

[0016] According to an embodiment, the method for controlling humidity in the front-end module of the device includes: measuring a differential pressure, which is a value obtained by subtracting the external pressure from the internal pressure of the transfer frame; comparing the measured differential pressure with a reference value according to a preset standard; and when it is determined that the measured differential pressure does not meet the preset standard, changing the internal pressure of the transfer frame by changing the flow rate of the gas supplied to the transfer frame through the gas supply unit and changing the rotational speed of a fan filter unit configured to supply gas to the transfer frame.

[0017] The method may further include: before measuring the differential pressure, measuring the humidity inside the transfer frame; comparing the measured humidity with a reference value according to a preset standard; and determining that the measured humidity does not meet the preset standard.

[0018] The change in the flow rate of the supplied gas and the change in the speed of supply of the gas can be performed simultaneously.

[0019] In comparing the measured pressure difference with a reference value according to a preset standard, the preset reference may indicate whether the measured pressure difference has a value less than or greater than the reference value.

[0020] Changing the flow rate of the supply gas may include increasing the flow rate of the supply gas, and changing the supply rate of the gas may include increasing the supply rate of the supplied gas.

[0021] The method may further include opening the loading port to reduce the internal pressure of the transfer frame before measuring the pressure difference. In this case, changing the flow rate of the supply gas may be to increase the flow rate of the supply gas, and changing the supply rate of the gas may be to increase the supply rate of the supply gas.

[0022] The method may further include closing the loading port to increase the internal pressure of the transfer frame before measuring the pressure difference. In this case, changing the flow rate of the supply gas may be to reduce the flow rate of the supply gas, and changing the supply rate of the gas may be to reduce the supply rate of the supply gas.

[0023] The method may include a step in which the gas supplied to the transfer frame flows into the buffer space through an open surface and is discharged through the discharge port of the buffer unit.

[0024] According to an aspect of the present invention, there is provided a front-end module of a device, the front-end module of the device including: a loading port on which a carrier for accommodating a substrate is disposed; a transfer frame including a space for introducing and transferring the substrate accommodated in the loading port; a buffer unit including an open surface formed on a surface facing the transfer frame and a space for temporarily storing the substrate; a fan filter unit, one end of which is connected to the other end of a circulation pipeline connected to the discharge port of the buffer unit, the fan filter unit being configured to introduce the gas supplied from the circulation pipeline into the transfer frame; a gas supply unit configured to supply gas to the transfer frame; a differential pressure sensor configured to measure the pressure difference between the inside and the outside of the transfer frame; a humidity sensor configured to measure the humidity inside the transfer frame; and a control unit configured to control the rotation speed of the fan filter unit and the flow rate of the gas supplied through the gas supply unit based on the information received from the humidity sensor and the differential pressure sensor, wherein the control unit is configured to determine whether the differential pressure information received from the differential pressure sensor meets a preset standard when the control unit determines that the humidity information received from the humidity sensor deviates from a preset standard, and to control the rotation speed of the fan filter unit and the flow rate of the gas flowing through the gas supply unit to change simultaneously when the control unit determines that the differential pressure information does not meet the preset standard. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 FIG. 1 is a schematic view showing a semiconductor manufacturing apparatus according to an embodiment of the present invention.

[0026] Figure 2 FIG. 2 shows Figure 1 a schematic view of a transfer frame and a buffer unit shown in FIG. 1.

[0027] Figure 3 FIG. 3 is a diagram showing a method for generating a fan filter unit control signal and a gas flow control signal.

[0028] Figure 4 and 5 FIGS. 4, 5, and 6 are step-by-step process flowcharts showing a method for controlling humidity and differential pressure according to an embodiment of the present invention.

[0029] Figure 7 FIG. 7 shows experimental results of measuring humidity based on differential pressure control of a front end module of the apparatus.

[0030] Throughout the drawings and the detailed description of the specification, unless otherwise specified, the same reference numerals are understood to refer to the same elements, features, and structures. For clarity, illustration, and convenience, the relative dimensions and descriptions of these elements may be exaggerated. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.

[0032] However, the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of the invention to those of ordinary skill in the art. In addition, in the drawings, the thickness or dimensions of layers are exaggerated for clarity and ease of explanation.

[0033] The terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the present invention. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will also be understood that when used in this specification, the terms "comprises" and / or "comprising" specify the presence of the stated features, integers, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0034] Embodiments of the present invention are described with reference to the accompanying drawings which are schematic illustrations of idealized embodiments of the present invention. Thus, for example, variations in the shape of the drawings can be expected as a result of manufacturing techniques and / or tolerances. Accordingly, embodiments of the inventive concept should not be construed as limited to the specific shapes of the regions shown herein, but include, for example, shape deviations resulting from manufacturing.

[0035] Figure 1 is a schematic diagram showing a semiconductor manufacturing apparatus 1. Referring to Figure 1 , the semiconductor manufacturing apparatus 1 includes an equipment front end module (EFEM) 10, a process module 20, and a load module 30.

[0036] The EFEM 10 includes a load port 120, a transfer frame 140, and a buffer unit 2000. The load port 120, the transfer frame 140, and the process module 20 are arranged in a line in sequence. Hereinafter, the arrangement direction of the load port 120, the transfer frame 140, the load module 30, and the process module 20 is referred to as a first direction 12. When viewed from above, the direction perpendicular to the first direction 12 is referred to as a second direction 14, and the direction perpendicular to the plane formed by the first direction 12 and the second direction 14 is referred to as a third direction 16.

[0037] A carrier 18 containing a plurality of substrates is placed on the load port 120. A plurality of load ports 120 are provided and the plurality of load ports can be arranged in a line along the second direction 14. In Figure 1 , three load ports 120 are shown. However, the number of load ports 120 can be increased or decreased according to conditions such as the process efficiency of the process module 20 and the floor area. The carrier 18 may have grooves (not shown) provided to support the edges of the substrates. A plurality of grooves are provided along the third direction 16, and the substrates are positioned inside the carrier 18 such that the carriers are stacked together with spaces between the substrates along the third direction 16. The carrier 18 may be a front opening unified pod (FOUP).

[0038] The transfer frame 140 transfers substrates between the carrier 18 placed on the load port 120, the buffer unit 2000, and the load module 30. The transfer frame 140 is provided with an index track 142 and an index robot 144. The index track 142 is provided such that its length direction is parallel to the second direction 14. The index robot 144 is mounted on the index track 142 and linearly moves along the index guide rail 142 in the second direction 14. The index robot 144 may be composed of a base 144a, a body 144b, and an index arm 144c. The base 144a is mounted to be movable along the index track 142. The body 144b is coupled to the base 144a. The body 144b is provided to be movable along the third direction 16 on the base 144a.

[0039] In addition, the main body 144b is provided to be rotatable on the base 144a. The indexing arm 144c is engaged with the main body 144b and is provided to be movable forward and backward relative to the main body 144b. A plurality of indexing arms 144c are provided to be driven individually. The indexing arms 144c are arranged to be configured in a stacked manner and spaced apart from each other along the third direction 16. When transferring the substrate from the process module 20 to the carrier 18, some of the indexing arms 144c are used. However, when transferring the substrate from the carrier 18 to the process module 20, other indexing arms 144c are used. This structure can prevent particles generated by the substrate before the processing process from adhering to the substrate after the processing process during the feeding and discharging of the substrate by the indexing robot 144.

[0040] The loading module 30 is provided between the transfer frame 140 and the transfer chamber 242. The loading module 30 provides a space in which the substrate W stays before being transported between the transfer chamber 242 and the transfer frame 140. The loading module 30 includes a loading lock chamber 32 and an unloading lock chamber 34. The loading lock chamber 32 and the unloading lock chamber 34 are each configured to allow the atmosphere inside thereof to be switched between a vacuum atmosphere and an atmospheric pressure atmosphere.

[0041] The loading lock chamber 32 temporarily holds the substrate transferred from the equipment front end module 10 to the process module 20. When the substrate is transferred into the loading lock chamber 32, the internal space of the loading lock chamber 32 is sealed from both the equipment front end module 10 and the process module 20. Thereafter, the internal space of the loading lock chamber 32 is switched from an atmospheric pressure atmosphere to a vacuum atmosphere, and it opens the process module 20 while remaining sealed from the equipment front end module 10.

[0042] The unloading lock chamber 34 temporarily holds the substrate transferred from the process module 20 to the equipment front end module 10. When the substrate is transferred into the unloading lock chamber 34, the internal space of the unloading lock chamber 34 is sealed from both the equipment front end module 10 and the process module 20. Thereafter, the internal space of the unloading lock chamber 34 is switched from an atmospheric pressure atmosphere to a vacuum atmosphere, and it opens the equipment front end module 10 while remaining sealed from the process module 20.

[0043] The process module 20 includes a transfer chamber 242 and a plurality of process units 260.

[0044] The transfer chamber 242 transfers the substrate W between the load lock chamber 32, the unload lock chamber 34, and the plurality of process units 260. When viewed from above, the transfer chamber 242 may have a hexagonal shape. Alternatively, the transfer chamber 242 may have a quadrilateral shape or a pentagonal shape. The load lock chamber 32, the unload lock chamber 34, and the plurality of process units 260 are located around the transfer chamber 242. A transfer robot 250 is disposed in the transfer chamber 242. The transfer robot 250 may be located at the center of the transfer chamber 242. The transfer robot 250 may have a plurality of hands 252 that are movable in horizontal and vertical directions and capable of moving forward, backward, or rotating on a horizontal plane. Each of the hands 252 can be independently operated, and the substrate W can be placed horizontally on the hands 252.

[0045] The gas processing apparatuses provided in each of the process units 260 perform an etching or deposition process on the substrate. According to one embodiment, each gas processing apparatus may perform different gas processing operations. The first apparatus may perform a first process of supplying a first gas, and the second apparatus may perform a second process of supplying a second gas. The first gas may include fluorine (F), chlorine (Cl), or bromine (Br), and the second gas may include ammonia (NH3).

[0046] Hereinafter, the transfer frame 140 and the buffer unit 2000 provided in the equipment front end module 10 will be described in detail with reference to the drawings.

[0047] Figure 2 shows Figure 1 a schematic diagram of the transfer frame and the buffer unit shown in

[0048] Referring to Figure 2 , a fan filter unit (FFU) 146 and an FFU control unit 145 are installed in the transfer frame 140. The FFU 146 may be installed on the top plate surface of the transfer frame 140. The FFU 146 introduces the gas supplied from the circulation pipeline 2460 described below into the internal space of the transfer frame 140 using a rotating fan. At this time, the FFU 146 may form a downward air flow in the internal space of the transfer frame 140. The operation of the FFU 146 is controlled by the FFU control unit 145. By controlling the rotation speed of the FFU 146 (i.e., the rotation speed of the fan), the speed of the gas introduced into the transfer frame 140 can be controlled.

[0049] The transfer frame 140 is provided with a gas supply unit 148. The gas supply unit 148 is installed on the side wall of the transfer frame 140 and can be positioned so as not to affect the buffer unit 2000. The gas supply unit 148 includes a gas nozzle 148a, a gas supply line 148b, a mass flow controller (MFC) 148c, and a gas valve 148d designed to shut off the supply of gas from the gas source 148e.

[0050] The gas nozzle 148a discharges gas into the internal space of the transfer frame 140. The gas nozzle 148a can be installed on the side wall of the transfer frame 140. The gas supply line 148b is connected to the gas nozzle 148a. The gas supply line 148b is connected to the MFC 148c and supplies a constant amount of gas from the gas source 148e. The MFC 148c can receive a gas flow control signal from the control unit 150 and control the flow rate of the gas flowing through the gas supply line 148b according to the signal. The gas discharged from the gas nozzle 148a can include, for example, nitrogen gas (N2 gas).

[0051] The transfer frame 140 is equipped with a humidity sensor 152 and a differential pressure sensor 154. The humidity sensor measures the humidity inside the transfer frame 140, and the differential pressure sensor measures the pressure difference (referred to as differential pressure) between the inside and the outside of the transfer frame 140. Here, the differential pressure is defined as the value obtained by subtracting the external pressure (e.g., atmospheric pressure) from the internal pressure of the transfer frame 140. Therefore, a positive differential pressure means maintaining the internal pressure of the transfer frame 140 higher than the external pressure.

[0052] The humidity sensor 152 and the differential pressure sensor 154 transmit the measured humidity information and the measured differential pressure information to the control unit 150 in real time. The control unit 150 can receive the measured information and perform control based on the information to maintain the humidity and the differential pressure inside the transfer frame 140 at a predetermined reference value.

[0053] Specifically, the control unit 150 compares the humidity information received from the humidity sensor 152 with a pre-determined humidity reference value to determine the subsequent operation to be performed. For example, if the humidity measured by the humidity sensor 152 is higher than the reference value, an operation is performed to check whether there is a problem with the differential pressure in the transfer frame 140.

[0054] To this end, the control unit 150 performs the step of comparing the differential pressure information received from the differential pressure sensor 154 with a preset reference value of the differential pressure. If the comparison result shows that the measured differential pressure is lower than the reference value (e.g., a positive or negative value lower than the reference value), the control unit generates an FFU control signal and a gas flow control signal to restore the differential pressure to the reference value.

[0055] Transmit the generated FFU control signal to the FFU control unit 145, and once this signal is received, the FFU control unit 145 performs control to increase the rotational speed of the FFU 146.

[0056] Transmit the generated gas flow control signal to the MFC 148c, and once this signal is received, the MFC 148c performs control to increase the flow rate of the gas supplied to the transfer frame 140.

[0057] The FFU control signal and the gas flow control signal can be generated as a function of the pressure difference in the transfer frame 140. For example, as Figure 3 shown, the FFU control signal can be set to a value obtained by multiplying the difference between the actual pressure difference in the transfer frame 140 measured by the pressure difference sensor 154 and the reference value by the control constant K1. Additionally, the gas flow control signal can be set to a value obtained by multiplying the difference between the actual pressure difference in the transfer frame 140 measured by the pressure difference sensor 154 and the reference value by the control constant K2.

[0058] In this way, the control unit 150 can control the rotational speed of the FFU 146 and the flow rate of the gas supplied to the transfer frame 140 to ensure that the pressure difference in the transfer frame 140 reaches the reference value as soon as possible.

[0059] The control unit 150 can perform control to increase or decrease the rotational speed of the FFU and the gas flow rate through the mass gas controller based on the change in the pressure difference received from the pressure difference sensor, in order to quickly recover from the sudden change in the pressure inside the transfer frame 140 caused by the opening and closing of the load port 120.

[0060] The buffer unit 2000 temporarily stores the substrates processed in the process module 20. The buffer unit 2000 removes residual process by-products from the surface of the substrates. The removal of the process by-products is performed in the buffer unit 2000 by raising or lowering the pressure in the buffer unit 2000. Multiple buffer units 2000 can be provided. For example, 2 buffer units 2000 can be provided. The two buffer units 2000 can be placed on both sides of the transfer frame 140, facing each other with the transfer frame 140 sandwiched between them. Alternatively, the buffer unit 2000 can be provided only on one side of the transfer frame 140.

[0061] Specifically, the buffer unit 2000 includes a housing 2100 and an exhaust circulation unit 2400 formed on one side of the housing 2100 for exhausting gas from the interior of the housing 2100. The buffer unit 2000 further includes a substrate support unit formed inside the housing 2100 for storing substrates.

[0062] The housing 2100 is configured in the shape of a tube having a buffer space 2120 inside. The housing 2100 has a length in the direction of the third direction 16. The buffer space 2120 is configured as a space capable of accommodating a plurality of substrates. The housing 2100 has an open surface 2140 facing the transfer frame 140. The open surface 2140 serves as an entrance through which substrates are transferred between the transfer frame 140 and the buffer space 2120. Through the open surface 2140, gas is supplied from the internal space of the transfer frame 140 into the buffer space 2120.

[0063] The exhaust circulation unit 2400 can exhaust the atmosphere of the buffer space 2120. The exhaust circulation unit 2400 can include an exhaust port 2410, an exhaust pipeline 2420, an exhaust member 2430, a valve 2440, a flow control valve 2450, and a circulation pipeline 2460.

[0064] The exhaust port 2410 serves as a passage through which the atmosphere of the buffer space 2120 is exhausted. Particles and fumes removed from the substrate are exhausted through the exhaust port 2410. The exhaust port 2410 can be located at the center of the bottom plate of the housing 2100. The exhaust port 2410 can be configured as a hole through which the atmosphere of the buffer space 2120 is exhausted.

[0065] The exhaust port 2410 is connected to the exhaust pipeline 2420. The exhaust pipeline 2420 connects the exhaust port 2410 to the exhaust member 2430. The exhaust pipeline 2420 transmits the suction pressure from the exhaust member 2430 to the exhaust port 2410. In this way, suction pressure is provided to the buffer space 2120, which decompresses the buffer space 2120, thereby allowing particles in the buffer space 2120 or particles attached to the substrates stored in the buffer space 2120 to be exhausted. The exhaust member 2430 can include a decompression member (such as a vacuum pump).

[0066] The valve 2440 is installed at the junction of the exhaust pipeline 2420 and the circulation pipeline 2460. For example, the valve 2440 can be a three-way valve that controls the flow of gas in three directions. The valve 2440 can selectively open or close the exhaust pipeline 2420 and the circulation pipeline 2460 under the control of the control unit 150.

[0067] The flow control valve 2450 can be a throttle valve. The flow control valve 2450 is installed between the valve 2440 and the exhaust member 2430. The flow control valve 2450 controls the internal flow rate of the buffer space 2120 by adjusting the opening / closing speed of the exhaust pipeline 2420. This allows particles (such as fumes) to be removed from the substrate surface.

[0068] The circulation pipeline 2460 branches off from the discharge pipeline 2420. One end of the circulation pipeline 2460 is connected to the valve 2440, and the other end is connected to the FFU 146 of the transfer frame 140. The control unit 150 can control the discharge circulation unit 2400 to operate in a discharge mode or a circulation mode. In the discharge mode, the buffer space 2120 is discharged through the discharge pipeline 2420. In the circulation mode, gas is supplied to the internal space in the transfer frame 140 through the circulation pipeline 2460. The control unit 150 controls the valve 2440 to ensure that only one of the discharge mode or the circulation mode is maintained. The selection between the circulation mode and the discharge mode can vary according to the type of gas used to process the substrate before the substrate is stored in the buffer space 2120. According to one embodiment, the circulation mode can be maintained for the substrate undergoing the first process, while the discharge mode can be maintained for the substrate undergoing the second process.

[0069] When the discharge mode is selected by the control unit 150, the control unit 150 controls the valve 2440 to open the discharge pipeline 2420 and close the circulation pipeline 2460. At this time, the flow control valve 2450 can adjust the opening / closing rate of the discharge pipeline 2420 to control the flow rate inside the buffer space 2120. By controlling the flow rate, particles (such as fumes) on the substrate surface can be removed.

[0070] When the circulation mode is selected by the control unit 150, the control unit 150 controls the valve 2440 to close the discharge pipeline 2420 and open the circulation pipeline 2460. One end of the circulation pipeline 2460 is connected to the discharge port 2410, and the other end is connected to the FFU 146. Therefore, the gas passing through the discharge port 2410 flows into the circulation pipeline 2460 through the valve 2440, and via the circulation pipeline 2460, the gas is supplied to the internal space of the transfer frame 140 through the FFU 146. The gas entering the internal space of the transfer frame 140 flows into the buffer space 2120 through the open surface 2140. The gas flowing into the buffer space 2120 then re-enters the circulation pipeline 2460 through the discharge port 2410 and returns to the FFU 146, thus establishing the circulation mode.

[0071] The control unit 150 may select between a discharge mode and a circulation mode based on the type of process fluid used in the processing step immediately before the substrate is stored in the buffer unit 2000. The control unit 150 may select between the discharge mode and the circulation mode according to the type of residual process by-products remaining on the substrate. For example, if polymer particles remain on the substrate, the control unit 150 may select the discharge mode. In another example, if the process fluid used in the substrate processing step includes fluorine (F), hydrogen bromide (HBr), or chlorine (Cl), etc., the control unit 150 may select the discharge mode. Alternatively, if the process fluid used in the processing step is ammonia (NH3), the control unit 150 may select the circulation mode.

[0072] When the transfer frame 140 is used to transfer the substrate to the process module 20 for processing, or when the substrate is transferred to the buffer unit 2000 to be stored therein, the internal pressure of the transfer frame 140 must always be maintained at a pressure higher than the external pressure. Additionally, during this process, in order to prevent particles from adhering to the substrate or forming a large amount of flue gas, the humidity inside the transfer frame 140 must be controlled to avoid sudden fluctuations and should always be kept constant.

[0073] In order to maintain a low level of humidity inside the transfer frame 140, the pressure difference must be managed to meet a preset standard. For example, by maintaining the pressure difference at a value higher than the reference value, external moisture infiltration into the interior of the transfer frame 140 can be effectively prevented.

[0074] To manage the pressure difference, an operation is performed to set a reference value for the pressure difference according to a preset standard and compare this reference value with the actual pressure difference measured by the pressure difference sensor 154. If the comparison result shows that the measured pressure difference meets the preset standard, the current state is maintained. However, if it is determined that the standard is not met, control may be executed to make the pressure difference meet the predetermined standard.

[0075] If the humidity inside the transfer frame 140 rises above the reference value, there is a possibility that there is a problem with the pressure difference management in the transfer frame 140. Therefore, the pressure difference must be appropriately controlled to normalize the humidity by reducing the humidity below the reference value.

[0076] Figure 4 is a flowchart showing the steps for controlling humidity and pressure difference according to an embodiment of the present invention. Below, reference will be made to Figure 2 and Figure 4 to describe the method for controlling the humidity inside the transfer frame 140.

[0077] When the circulation mode is selected by the control unit 150, the exhaust gas discharged through the exhaust port 2410 flows into the circulation pipeline 2460 via the valve 2440, is supplied to the internal space of the transfer frame 140 via the circulation pipeline 2460, and then flows into the buffer space 2120.

[0078] Perform the step of measuring humidity using the humidity sensor 152. The humidity sensor 152 measures the humidity inside the transfer frame 140 in real time and transmits the measured humidity information to the control unit 150 in real time.

[0079] The control unit 150 that receives the measured humidity information compares the received humidity information with a preset reference value and determines whether the received humidity information is greater than or equal to the reference value. For example, if it is determined that the measured humidity is lower than the reference value, the control unit continues to measure the humidity without taking further action because the humidity of the transfer frame 140 is normally maintained.

[0080] However, if the humidity measured by the humidity sensor 152 is greater than or equal to the reference value, the control unit 150 determines that there is a problem with the humidity control inside the transfer frame 140 and continues to execute the step of obtaining differential pressure information. To this end, the control unit 150 performs the step of comparing the differential pressure information received from the differential pressure sensor 154 with a preset reference value.

[0081] As a result of the comparison, if it is determined that the differential pressure measured by the differential pressure sensor 154 is lower than the reference value, the control unit 150 generates an FFU control signal to increase the rotation speed of the FFU 146 and transmits the signal to the FFU control unit 145. At the same time, the control unit 150 generates a gas flow control signal to increase the flow rate of the gas flowing into the transfer frame 140 and transmits the signal to the MFC 148c. The FFU control unit 145 increases the rotation speed of the FFU 146 according to the received FFU control signal. Additionally, the MFC 148c that receives the gas flow control signal increases the flow rate of the gas flowing through the gas supply pipeline 148b, thereby increasing the flow rate of the gas supplied to the transfer frame 140.

[0082] Due to the increase in the rotation speed of the FFU 136 and the increase in the flow rate of the gas flowing into the transfer frame 140, the pressure inside the transfer frame 140 increases, resulting in an increase in the differential pressure. This increase in the differential pressure prevents moisture from seeping into the inside of the transfer frame 140 from the outside.

[0083] If the humidity information measured by the humidity sensor 152 is significantly higher than the reference value, but the pressure difference measured by the differential pressure sensor 154 is determined to exceed the reference value, the following conclusion can be drawn: there is an operation error in the humidity sensor 152, or even if the pressure difference is maintained, another problem will prevent the humidity from being properly maintained. In this case, the entire transfer frame 140 system can be checked.

[0084] According to an embodiment of the present invention, if the pressure difference of the transfer frame 140 is lower than the reference value, the pressure inside the transfer frame 140 can be quickly increased by increasing the rotation speed of the FFU 146 while increasing the flow rate of the gas supplied to the transfer frame 140. The longer the pressure difference remains at a value lower than the reference value, the worse the effect of preventing moisture from infiltrating into the transfer frame 140 from the outside.

[0085] According to an embodiment of the present invention, increasing the flow rate of the gas supplied to the transfer frame 140 while increasing the rotation speed of the FFU can cause the speed of supplying the gas to the transfer frame 140 to increase faster. Therefore, compared with the conventional technology that only increases the gas supply flow rate, the pressure difference can be increased faster. This rapid increase in the pressure difference significantly reduces the possibility of moisture infiltrating into the transfer frame 140, which is beneficial to controlling the humidity at a low level.

[0086] In another example, the humidity inside the transfer frame 140 may be affected by the opening and closing of the loading port 120. For example, when the loading port 120 is opened to transfer the substrate to the process module 20 and insert the carrier 18 containing the substrate, the internal pressure of the transfer frame 140 connected to the loading port 120 may drop, allowing air from the outside to quickly flow into the transfer frame 140. The air that quickly flows into the transfer frame 140 may contain a high level of moisture. Therefore, the internal pressure of the transfer frame 140 must be restored to its original state as soon as possible to prevent the humidity inside the transfer frame 140 from increasing due to the introduction of moisture from the outside.

[0087] Figure 5 and 6 shows a method for controlling the pressure difference according to an embodiment of the present invention. Referring to Figure 1 and Figure 5 , when the cycle mode is selected, the loading port 120 is opened. Once the loading port is opened, the pressure inside the transfer frame 140 that maintains a pressure higher than the external atmospheric pressure decreases.

[0088] In this case, the differential pressure sensor 154 that measures the pressure difference of the transfer frame 140 in real time measures the pressure difference and transmits the measured pressure difference information to the control unit 150. The control unit 150 that receives the pressure difference information performs the step of comparing the pressure difference information with a preset reference value.

[0089] As a result of the comparison, if it is determined that the differential pressure measured by the differential pressure sensor 154 is lower than the reference value, the control unit 150 generates an FFU control signal to increase the rotational speed of the FFU 146 and transmits the FFU control signal to the FFU control unit 145. At the same time, the control unit 150 generates a gas flow control signal to increase the flow rate of the gas flowing into the transfer frame 140 and transmits this signal to the MFC 148c. The FFU control unit 145 increases the rotational speed of the FFU 146 according to the received FFU control signal. Additionally, the MFC 148c that has received the gas flow control signal increases the flow rate of the gas flowing through the gas supply line 148b, thereby increasing the flow rate of the gas supplied to the transfer frame 140.

[0090] Due to the increase in the rotational speed of the FFU and the increase in the flow rate of the gas flowing into the transfer frame 140, the internal pressure of the transfer frame 140 rapidly increases, resulting in an increase in the differential pressure and reaching the reference value. This increase in the differential pressure prevents moisture from seeping into the interior of the transfer frame 140 from the outside.

[0091] Figure 6 A method for controlling the differential pressure after the previously opened loading port is closed again is shown.

[0092] Refer to Figure 1 and Figure 6 , the previously opened loading port 120 is closed again. Since the rotational speed of the FFU and the gas flow rate remain unchanged even after the loading port is closed, the internal pressure of the transfer frame 140 continues to increase to a higher level. If the internal pressure of the transfer frame 140 becomes too high, the device may become unstable due to the large differential pressure. Therefore, it is necessary to reduce the differential pressure to an appropriate level.

[0093] The differential pressure sensor 154 that measures the differential pressure of the transfer frame 140 in real time measures the differential pressure and transmits the measured differential pressure information to the control unit 150. The control unit 150 that has received the differential pressure information performs the step of comparing the differential pressure information with a preset reference value.

[0094] As a result of the comparison, if it is determined that the differential pressure measured by the differential pressure sensor 154 exceeds the reference value, the control unit 150 generates an FFU control signal to decrease the rotational speed of the FFU 146 and transmits the FFU control signal to the FFU control unit 145. At the same time, the control unit 150 generates a gas flow control signal to decrease the flow rate of the gas flowing into the transfer frame 140 and sends the gas flow control signal to the MFC 148c.

[0095] The FFU control unit 145 reduces the rotational speed of the FFU 146 in accordance with the received FFU control signal. Additionally, the MFC 148c that receives the gas flow control signal reduces the flow rate of the gas flowing through the gas supply line 148b, thereby reducing the flow rate of the gas supplied into the transfer frame 140.

[0096] Due to the reduction in the rotational speed of the FFU and the decrease in the gas flow rate flowing into the transfer frame 140, the internal pressure of the transfer frame 140 rapidly decreases, resulting in a decrease in the pressure difference and reaching the reference value.

[0097] According to the present embodiment, even if a rapid decrease in the internal pressure of the transfer frame occurs due to the opening of the loading port, or a rapid increase in the internal pressure occurs due to the closing of the loading port, simultaneously controlling the rotational speed of the fan unit and the gas supply flow rate can cause the pressure difference deviating from the reference value to quickly return to the reference value. The rapid recovery of the pressure difference means that the time for external moisture to penetrate into the interior of the transfer frame is reduced, contributing to maintaining an appropriate humidity level inside the transfer frame.

[0098] Figure 7 The results of controlling the internal pressure of the transfer frame using the FFU and the MFC according to the technical concept of the present invention are shown.

[0099] Figure 7 The chart in shows, from top to bottom in sequence, the following: the change over time (increments of 0.1 second) in the pressure difference (unit: mmAq) of the transfer frame 140, the change in the flow rate of nitrogen gas (unit: LPM) through the MFC 148c, the change in the humidity inside the transfer frame 140 (unit: percentage), and the change in the rotational speed (unit: rpm) of the FFU 146. The pressure difference reference value for controlling the FFU and the MFC is set to 3.5 mmAq.

[0100] Referring to Figure 7 , when the loading port 120 is opened, the internal pressure of the transfer frame 140 that maintains a pressure higher than the external atmospheric pressure rapidly drops. The pressure difference sensor 154 detects this change and measures the pressure difference. When the control unit 150 receives the real-time pressure difference measured by the pressure difference sensor 154 and determines that the pressure difference is lower than the reference value of 3.5 mmAq, the control unit 150 controls the FFU control unit 145 and the MFC 148c to increase the internal pressure of the transfer frame 140. As a result of the control, the rotational speed of the FFU 146 increases, and the flow rate of nitrogen gas supplied to the transfer frame 140 through the MFC 148c also increases. Therefore, the internal pressure of the transfer frame 140 rapidly increases, and the pressure difference quickly returns to the reference value.

[0101] When the loading port 120 is closed again, the differential pressure starts to increase due to the rising internal pressure of the transfer frame 140. When the control unit 150 that receives the measured real-time differential pressure from the differential pressure sensor 154 determines that the differential pressure exceeds the reference value of 3.5 mmAq, the control unit controls the FFU control unit 145 and the MFC 148c to reduce the internal pressure of the transfer frame 140. As a result of this control, the rotation speed of the FFU 146 decreases, and the flow rate of nitrogen gas supplied to the transfer frame 140 through the MFC 148c also decreases. Therefore, the internal pressure of the transfer frame 140 rapidly decreases, and the differential pressure rapidly returns to the reference value.

[0102] In this way, by simultaneously controlling the FFU 146 and the MFC 148c based on the differential pressure measured by the differential pressure sensor 154, it can be confirmed that the time required for the differential pressure in the transfer frame 140, which changes due to the opening and closing of the loading port 120, to return to the reference value is less than 30 seconds. In particular, throughout the process, it can be confirmed that the humidity inside the transfer frame 140 remains extremely stable, varying within the range of 0.11% to 0.12%.

[0103] According to various embodiments of the present invention as described above, by simultaneously controlling the rotation speed of the FFU and the flow rate supplied through the gas supply unit based on the differential pressure information obtained from the differential pressure sensor, an increase in humidity inside the equipment front-end module caused by a change in differential pressure can be effectively suppressed. This, in turn, can allow for the effective maintenance of the cleanliness of the substrate. Obviously, the scope of the present invention is not limited by these effects.

[0104] Although the present invention has been specifically shown and described with reference to the embodiments of the present invention, those of ordinary skill in the art will understand that various changes in form and detail may be made therein without departing from the scope of the present invention as defined by the following claims.

Claims

1. A device front-end module, the device front-end module comprising: a load port on which a carrier for receiving a substrate is disposed; a transfer frame including a space for introducing and transferring a substrate received in the load port; a buffer unit including an open surface formed on a surface facing the conveying frame; a fan filter unit having one end connected to the other end of a circulation line connected to a discharge port of the buffer unit, the fan filter unit being configured to introduce gas supplied from the circulation line into the conveying frame; a gas supply unit configured to supply gas into the conveying frame; a differential pressure sensor installed on a portion of the conveying frame and configured to measure a differential pressure, the differential pressure being a value obtained by subtracting an external pressure from an internal pressure of the conveying frame; a humidity sensor mounted on a portion of the conveyor frame and configured to measure humidity inside the conveyor frame; as well as A control unit configured to control a rotation speed of the fan filter unit and a flow rate of gas supplied into the conveying frame through the gas supply unit based on information received from the humidity sensor and the differential pressure sensor.

2. The device front-end module according to claim 1, wherein: The device front end module further includes a fan filter unit control unit configured to receive a fan filter unit control signal transmitted from the control unit and control a rotation speed of the fan filter unit according to the fan filter unit control signal.

3. The device front-end module according to claim 1, wherein: The device front-end module also includes a mass flow controller, which is configured to receive a gas flow control signal transmitted from the control unit and control the flow of the gas flowing through the gas supply unit according to the gas flow control signal.

4. The device front-end module according to claim 1, wherein: The gas supplied into the conveying frame flows into a buffer space through the open surface and is discharged through a discharge port of the buffer unit.

5. The device front-end module according to claim 1, wherein: The control unit is configured to determine whether the pressure difference information received from the pressure difference sensor satisfies a preset standard when the control unit determines that the humidity information received from the humidity sensor deviates from the preset standard.

6. The device front-end module according to claim 5, wherein: The control unit is configured to perform control to simultaneously increase the rotation speed of the fan filter unit and a flow rate of gas flowing through the gas supply unit when the control unit determines that the pressure difference information does not satisfy the preset standard.

7. The device front-end module according to claim 5, wherein: The control unit is configured to generate a fan filter unit control signal and transmit the fan filter unit control signal to a fan filter unit control unit while simultaneously generating a gas flow control signal and transmitting the gas flow control signal to a mass flow controller configured to control the flow of gas flowing through the gas supply unit, and the fan filter unit control unit is configured to control the rotation speed of the fan filter unit.

8. The device front-end module according to claim 7, wherein: The fan filter unit control signal and the gas flow rate control signal are generated as values ​​proportional to the pressure difference measured by the pressure difference sensor.

9. The device front-end module according to claim 1, wherein: The gas supply unit includes: a gas nozzle, which is configured to discharge gas into the internal space of the conveying frame; a gas supply pipeline, which is connected to the gas nozzle; and a mass flow controller, which is configured to receive a gas flow control signal from the control unit and control the flow of gas flowing through the gas supply pipeline according to the received gas flow control signal.

10. A method for controlling humidity in a device front-end module, the device front-end module comprising: a transfer frame including a space for introducing and transferring a substrate received in the load port; and a buffer unit having an open surface formed on a surface facing the conveying frame, the method comprising: measuring a pressure difference, the pressure difference being a value obtained by subtracting an external pressure from an internal pressure of the conveying frame; comparing the measured pressure difference with a reference value according to a preset standard; and When it is determined that the measured pressure difference does not meet the preset standard, the internal pressure of the conveying frame is changed by changing the flow rate of gas supplied to the conveying frame through a gas supply unit and changing the rotation speed of a fan filter unit configured to supply gas to the conveying frame.

11. The method according to claim 10, wherein: The method further comprises: before measuring the pressure difference, measuring the humidity inside the conveyor frame; comparing the measured humidity with a reference value according to a preset standard; and It is determined that the measured humidity does not meet the preset standard.

12. The method according to claim 10, wherein: Changing the flow rate of the supplied gas and changing the supply speed of the gas are performed simultaneously.

13. The method according to claim 10, wherein: In the comparison of the measured pressure difference with the reference value according to the preset standard, the preset standard indicates whether the measured pressure difference has a value smaller than or greater than the reference value.

14. The method according to claim 13, wherein: Changing the flow rate of the supplied gas includes increasing the flow rate of the supplied gas, and changing the supply speed of the gas includes increasing the supply speed of the supplied gas.

15. The method according to claim 10, wherein: The method also includes opening the load port to reduce the internal pressure of the transfer frame before measuring the pressure differential.

16. The method according to claim 15, wherein: The flow rate of the supply gas is changed to increase the flow rate of the supply gas, and the supply speed of the gas is changed to increase the supply speed of the supply gas.

17. The method according to claim 10, wherein: The method also includes closing the loadport to increase the internal pressure of the transfer frame before measuring the pressure differential.

18. The method according to claim 17, wherein: The flow rate of the supply gas is changed to reduce the flow rate of the supply gas, and the supply speed of the gas is changed to reduce the supply speed of the supply gas.

19. The method according to claim 10, wherein: The gas supplied into the conveying frame flows into a buffer space through the open surface and is discharged through a discharge port of the buffer unit.

20. A device front-end module, the device front-end module comprising: a load port on which a carrier for receiving a substrate is disposed; a transfer frame including a space for introducing and transferring a substrate received in the load port; a buffer unit including an open surface formed on a surface facing the conveying frame and a space for temporary storage of the substrate; a fan filter unit having one end connected to the other end of a circulation line connected to a discharge port of the buffer unit, the fan filter unit being configured to introduce gas supplied from the circulation line into the conveying frame; a gas supply unit configured to supply gas into the conveying frame; a differential pressure sensor configured to measure a pressure difference between an interior and an exterior of the conveyor frame; a humidity sensor configured to measure the humidity inside the conveyor frame; as well as a control unit configured to control a rotation speed of the fan filter unit and a flow rate of the gas supplied through the gas supply unit based on information received from the humidity sensor and the pressure difference sensor, Wherein, the control unit is configured to determine whether the pressure difference information received from the pressure difference sensor meets the preset standard when the control unit determines that the humidity information received from the humidity sensor deviates from the preset standard, and to control the rotation speed of the fan filter unit and the flow rate of the gas flowing through the gas supply unit to change simultaneously when the control unit determines that the pressure difference information does not meet the preset standard.

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