TW202308761A - Purge controlling system - Google Patents

Abstract

A purge controlling system is connected with a wafer loading device, including a purge module and a controlling module, in which the purge module is arranged in the wafer loading device and is connected with the controlling module. The purge module includes an air curtain unit, a flow control unit and a sensing unit. The controlling module controls the purge module to provide purge gas into the air curtain unit according to the displacement value of the door assembly.

Description

Blow off control system

The invention relates to the technical field of semiconductors, in particular to a blowing control system for cleaning a wafer carrying device by controlling gas flow in laminar or uniform air flow when a wafer is carried by a wafer cassette.

In the existing semiconductor production plant, there are many kinds of equipment for transferring wafer boxes, and most of these equipments are produced by different manufacturers. Therefore, when the wafer boxes are transferred among the equipment produced by different manufacturers, it may happen When the door of the wafer box is opened, the inside of the wafer box is directly in contact with or communicated with the external environment. Accordingly, dirt or particles outside the wafer box can easily enter the wafer box, resulting in Wafer is contaminated.

According to the shortcomings of the prior art, the main purpose of the present invention is to use the control module to control the air curtain unit to adjust the flow of clean gas according to the displacement value of the door assembly of the wafer carrier device, so as to avoid the impact of the clean gas with a large gas flow on the wafer. Turbulent flow is generated when the box is inflated, causing dirt or particles in the environment to be brought into the wafer box due to gas turbulence and pollute the semiconductor elements in the wafer box.

Another object of the present invention is to control the flow rate and pressure of the clean gas entering the air curtain unit to regulate the clean gas blown out by the air curtain unit to flow in a laminar flow state, so as to solve the turbulent flow of the clean gas and bring dirt into the wafer cassette And the technical problem of contaminating the semiconductor components in the wafer cassette.

Another object of the present invention is to use the sensing unit on the wafer carrying device to detect the displacement value of the door assembly, and adjust the gas flow rate of the clean gas sent into the air curtain unit according to the displacement value of the door assembly , to solve the problem in the prior art that regardless of the displacement of the door assembly of the wafer carrier device after opening the door body, the air curtain device provides clean gas with the same gas flow rate, resulting in waste of clean gas and increased use costs.

Another object of the present invention is that the air-permeable plate of the air curtain device has a plurality of air holes, and the air-permeable plate can be stainless steel or ultra-high molecular weight polyethylene (UPE, ultra-high molecular weight polyethylene) to increase the pressure resistance of the air-permeable plate and can Increase the gas flow of clean gas.

According to the above purpose, the present invention provides a blowing control system, which is connected with the wafer carrying device. The blowing control system includes: a blowing module and a control module, wherein the blowing module is arranged in the wafer carrying device and the control module The group is electrically connected with the blowing module. The blowing module includes an air curtain unit, a flow control unit and a sensing unit. The air curtain unit is aligned and arranged above the door assembly of the wafer carrier; the flow control unit is connected to the air curtain unit; and the control module is electrically connected to the blowing module, and the control module controls the blowing according to the displacement value of the door assembly The module provides a gas flow with corresponding clean gas into the curtain unit.

In a preferred embodiment of the present invention, the blowing module includes a sensing unit, which is arranged on the wafer carrier, and the sensing unit is used to detect the displacement state of the door assembly of the wafer carrier for the control module Determine the gas flow rate of the supplied clean gas.

In a preferred embodiment of the present invention, the air curtain unit includes: a body and a breathable plate, wherein at least one air inlet is provided on the upper end and/or side of the body, and the air inlet communicates with the blowing module through a pipeline. The clean gas of the air curtain unit enters the main body through the pipeline and the air inlet; and at least one layer of air-permeable plate is arranged in the main body, and the air-permeable plate has a plurality of air holes for passing the clean gas through the air-permeable plate from the body to the air. Exhaust outside, so that an air flow wall is formed between the air curtain unit and the door assembly of the wafer carrier.

In a preferred embodiment of the present invention, the material of the air-permeable plate can be stainless steel, antistatic and corrosion resistant fiber material or composite material, ceramics, resin, or ultra-high molecular weight polyethylene.

In a preferred embodiment of the present invention, when the air-permeable plate is made of stainless steel, the air-permeable plate with a plurality of pores can be made by metal sintering.

In a preferred embodiment of the present invention, the air holes can be formed by mechanical drilling or laser drilling.

In a preferred embodiment of the present invention, the air-permeable plate is a plurality of air-permeable plates, each air-permeable plate has a plurality of air holes, and these air-permeable plates form at least one closed space in the body.

In a preferred embodiment of the present invention, the flow velocity range of the clean gas blown out by the air curtain unit is 0.1 m/s-2 m/s (meter/second).

In a preferred embodiment of the present invention, the gas supply equipment is connected to the blowing control system, wherein the gas supply equipment is used to provide clean gas, and the clean gas can be clean dry air (CDA, clean dry air), ultra-pure dry air Gas (X-CDA, extreme clean dry air) or inert gas.

In a preferred embodiment of the present invention, the gas flow range of the clean gas supplied from the gas supply equipment to the purge control system is 0-800 LPM (liter/minute).

First, refer to Figure 1. FIG. 1 is a schematic block diagram showing a blowdown control system disclosed in the present invention. In FIG. 1, the blowing control system 1 is connected to the wafer carrier 500, wherein the blowing control system 1 is at least composed of a control module 2 and a blowing module 4, and the control module 2 is used to control the blowing module 4 Inflate the semiconductor elements (not shown in the figure) in the wafer cassette 300 placed on the wafer carrier 500 to achieve the purpose of inflating/cleaning.

Next, please refer to Figure 2. FIG. 2 is a detailed block diagram showing the blowdown control system disclosed in the present invention. In FIG. 2, the blowing module 4 in the blowing control system 1 is at least composed of an air curtain unit 42, a sensing unit 44, and a flow control unit 46, wherein the flow control unit 46 is connected to the air curtain unit 42 and the control module 2 respectively. connected, the sensing unit 44 is used to detect the displacement value of the door assembly 502 arranged on the wafer carrying device 500, and transmit the sensing signal corresponding to the displacement value of the door assembly 502 to the control module 2, and the control module 2 The flow rate or pressure of the gas sent to the air curtain unit 42 by the flow control unit 46 can be adjusted according to the sensing signal, so as to control the opening side of the air curtain unit 42 above the door assembly 502 of the wafer carrier 500 toward the wafer cassette 300 The blown gas flow rate. It should be explained here that the gas flow control method of the present invention, for example, writes each gas flow into the control module 2 in the form of a recipe, such as recipe A, recipe B, recipe C, ..., recipe Z , each recipe corresponds to a gas flow, and each gas flow value corresponds to the displacement value of the door assembly 502 . Therefore, when the sensing unit 44 detects that the displacement value of the door assembly 502 changes, the control module 2 will adjust the flow control unit 46 according to the displacement value of the door assembly 502 and the corresponding recipe, and make the air curtain according to the recipe. The unit 42 provides the gas flow corresponding to the recipe, so the control module 2 in the present invention controls the gas flow provided to the air curtain unit 42 in a multi-stage regulation manner. For example, the gas flow rate corresponding to recipe A, recipe B, recipe C, ..., recipe Z can be from small to large, when the displacement value of the door assembly 502 is small (small displacement), the air curtain unit 42 blows is the gas flow rate corresponding to recipe A; when the displacement value of the door assembly 502 becomes larger (large displacement) to a certain range, the air curtain unit 42 blows out the gas flow rate corresponding to recipe C. In the present invention, the calculation of the displacement value is based on the time when the door assembly 502 is not opened. That is to say, when the displacement value of the door assembly 502 gradually increases, the gas flow rate of the clean gas can be fixed at a preset flow rate when the displacement value of the door assembly 502 is within a certain range.

In addition, it is further explained that in the present invention, the calculation method of the displacement value of the door assembly 502 is set as P ₀ when the door assembly 502 is not opened in the present invention, and when the door assembly 502 moves from P ₀ to the first position At point P ₁ , the size of the first displacement value of the door assembly 502 is P ₁ -P ₀ ; when the door assembly 502 moves from the first positioning point P ₁ to the second positioning point P ₂ , then the door assembly 502 at this time The magnitude of the second displacement value is P ₂ -P ₀ .

A more specific example is that when the door assembly 502 is opened to the first positioning point _P1 , the air curtain unit 42 blows out the first gas flow corresponding to the recipe A. When the door assembly 502 is opened to the second positioning point _P2 , what the air curtain unit 42 blows out is the second gas flow rate corresponding to recipe B; when the door assembly 502 is opened to the third positioning point _P3 , what the air curtain unit 42 blows out is The third gas flow rate corresponding to recipe C, and so on. When the second displacement value (P ₂ -P ₀ ) of the door assembly 502 at the second positioning point P ₂ is greater than the first displacement value (P ₁ -P ₀ ) of the door assembly 502 at the first positioning point P ₁ , at this time The second gas flow is greater than the first gas flow. In another embodiment, when the second displacement value (P 2 −P ₀ ) of the door assembly 502 at the second positioning point P ₂ is smaller than the first displacement value ₍ P ₁ −P 0 ) of the door assembly 502 at the first positioning point P ₁ P ₀ ), at this time the second gas flow rate is smaller than the first gas flow rate. Of course, the present invention is not limited to the aforementioned multi-stage regulation method. In another embodiment, it may also be a stepless and continuous regulation method of gas flow, that is, when the displacement value of the door assembly 502 becomes larger gradually, that is, As the opening on the opening side of the wafer cassette 300 gradually increases, the gas flow rate of the clean gas also gradually increases. Conversely, when the displacement of the door assembly 502 becomes smaller gradually, that is, the opening of the opening side of the wafer cassette 300 becomes smaller gradually, the gas flow rate of the cleaning gas also gradually decreases. The invention can effectively save the usage amount of the clean gas and reduce the usage cost of the clean gas.

Next, please refer to Figure 3. 3 is a side view showing a wafer carrier with a blowdown control system. In Fig. 3, the wafer carrying device 500 has a carrier plate 510 for carrying the wafer cassette 300, and the wafer carrying device 500 also has a door assembly 502 and a door frame (not shown in the figure), and this door assembly 502 will be arranged on Open the door 302 of the wafer cassette 300 on the carrier plate 510, and take the door 302 away from the wafer cassette 300 and move it down by a displacement value, so that the inside of the wafer cassette 300 communicates with the external environment. At this time, the wafer cassette 300 exposes an opening, whereby external robotic arms or workers can place semiconductor components such as wafers (not shown in the figure) in the wafer cassette 300 or place semiconductor components according to requirements through the opening. (not shown in the figure) is taken out from the wafer box 300.

Please continue to refer to Figure 3. The air curtain unit 42 in the blowing control system 1 of the present invention is correspondingly arranged above the door assembly 502 of the wafer carrier 500, and has a distance from the door assembly 502. This distance is when the air curtain unit 42 faces the door assembly. When the clean gas is sprayed continuously and evenly in the direction of 502, the clean gas will form an airflow wall AF at this distance. This airflow wall AF is preferably a laminar airflow, which can reduce external dirt or particles being brought into the crystal Round box 300. In addition, the air flow rate blown out by the air curtain unit 42 will vary with the displacement of the door assembly 502 . In addition, a sensing unit 46 may be provided around the door assembly 502 (such as the upper end 5022 and/or the bottom 5024) or on the door frame (not shown in the figure), and the sensing unit 46 is used to detect the door assembly 502 The change of the displacement state (from closed to open) or the predetermined displacement value is moved, and then the sensing signal corresponding to the displacement value is sent to the control module 2 (as shown in Figure 2), and then the control module 2 The flow rate of gas blown by the air curtain unit 42 is adjusted.

Therefore, the control module 2 (as shown in FIG. 2 ) controls the gas supply equipment (not shown in the figure) to provide a gas supply device corresponding to the displacement according to the displacement value of the door assembly 502 of the wafer carrier 500 detected by the sensing unit 44 The clean gas of the gas flow rate of the value enters the air curtain unit 42 of the blowing module 4, and the control module 2 can regulate the clean gas blown out by the air curtain unit 42 according to the flow rate or pressure of the clean gas into the air curtain unit 42. laminar flow. In addition, the change of the displacement value of the door assembly 502 does not have to be detected by the sensing unit 46. In another embodiment, the opening time of the door assembly 502 can also be directly calculated to determine the variation of the displacement value. The method of knowing the displacement value of the door assembly 502 is not limited.

Next, please refer to Figure 4. Fig. 4 is a schematic view showing the structure of the air curtain unit in the blowing module. In Fig. 4, the air curtain unit 42 is composed of a body 420, a cover 420a, a ventilating plate 422, and air inlets 4202, 4204, wherein the outline of the body 420 is rectangular, and the interior enclosed by the body 420 and the cover 420a A breathable plate 422 with a plurality of air holes 4222 is disposed in the space, and the shape of the breathable plate 422 can be set in accordance with the body 420 of the air curtain unit 42 . The air-permeable plate 422 forms a closed space in the air curtain unit 42 , and the closed space can communicate with the air inlets 4202 , 4204 . The pores 4222 of the air-permeable plate 422 may have a diameter ranging from 0.001 micron (µm) to 10 millimeters (mm), preferably 0.001 micron (µm) to 1 micron (µm). In this embodiment, the number and distribution of the air holes 4222 are not limited, for example, they may be distributed regularly or irregularly. The existence of these tiny air holes 4222 can make the airflow passing through the air-permeable plate 422 form a uniform airflow or even a laminar airflow. In a preferred embodiment of the present invention, the material of the air-permeable plate 422 with multiple air holes 4222 can be stainless steel, antistatic and corrosion resistant fiber material or composite material, such as but not limited to glass fiber, epoxy resin glass fiber , Teflon (PTFE), ceramics, resin, or ultra-high molecular weight polyethylene (UPE, ultra-high molecular weight polyethylene), so that the original flow rate is increased from 0-400LPM to 0-800LPM, and the degree of resistance to gas pressure is also high. Relatively improved, to avoid bursting of the ventilated panel due to the large flow of gas.

In another preferred embodiment of the present invention, there can be one or two or more air-permeable panels 422 arranged in the body 420, and the air-permeable panels 422 in the main body 420 can be changed according to the needs of users. quantity. For example, in an embodiment not shown, two air-permeable panels are arranged at intervals to form two closed spaces in the air curtain unit 42 . In another embodiment not shown, two air-permeable panels are stacked to form a closed space in the air curtain unit 42 . In addition, air intake holes 4202 and 4204 are provided on the upper side and/or the longer side of the rectangular body 420. On the side, the air inlets 4202 and 4204 can also be arranged on the shorter side and the longer side respectively, and the number of the air inlets 4202 and 4204 is not limited. In addition, the air inlets 4202 and 4204 provided on the main body 420 are also connected to an air supply device (not shown in the figure) through the pipe body 7 . It should be noted that the gas supply equipment (not shown in the figure) is used to provide various clean gases, such as clean dry air (CDA, clean dry air), ultra-pure dry air (X-CDA, Extreme clean dry air) Or the inert gas enters the air curtain unit 42 through the pipe body 7 . In addition, in the embodiment of the present invention, when the material of the air-permeable plate 422 is stainless steel, the manufacturing method of the air-permeable plate 422 with a plurality of pores 4222 can be formed by metal sintering, that is, sintered metal powder can be used to sinter A stainless steel air permeable plate 422 is formed. These air holes 4222 can be formed by laser drilling or mechanical drilling. And these air holes 4222 can be arranged regularly or irregularly, which is not limited.

Next, an embodiment is given to illustrate the blowing steps of the blowing control system of the present invention for an embodiment of the wafer carrier device. Please refer to FIG. 2-FIG . Firstly, the sensing unit detects the displacement value of the gate assembly of the wafer carrier. In this step, when the door assembly 502 of the wafer carrier 500 is turned from closed to open, the sensor provided around the door assembly 502 (such as the upper end 5022 and/or the bottom 5024) or on the door frame (not shown in the figure) When the detection unit 44 detects the state change of the door assembly 502 of the wafer carrier 500, the moving distance of the door assembly 502 is defined as the first displacement value. At this time, the sensing unit 44 will correspond to the detection of the wafer carrier. The first signal of the first displacement value of the door assembly 502 of 500 is sent to the control module 2, and the control module 2 will control the air supply equipment (not shown in the figure) to provide a gas supply device corresponding to the first displacement according to the first signal. The clean gas of the gas flow rate of the value enters the blowing module 4, and the flow control unit 46 sends the clean gas corresponding to the first displacement value of the door assembly 502 into the air curtain unit 42, and then the air curtain unit 42 The clean gas of the first flow rate is blown toward the direction where the door assembly 502 is provided on the wafer carrier 500 , and a first filling step is performed on the wafer cassette 300 .

In a preferred embodiment of the present invention, when the air supply equipment (not shown in the figure) provides clean gas (not shown in the figure) to enter the air curtain unit 42 through the air inlets 4202, 4204, it will pass through the air curtain unit 42 The plurality of air holes 4222 of the air-permeable plate 422 in the interior can make the passing fluid even and even filter tiny particles, so as to improve the cleanliness and uniformity of the gas when it is blown out by the air curtain unit 42, and the clean gas with the first gas flow rate can be evenly distributed. is blown out from the side of the body 420 opposite to the cover 420 a and toward the door assembly 502 of the wafer carrier 500 .

Next, when the moving distance of the door assembly 502 is the second displacement value, the sensing unit 44 sends a second signal corresponding to the second displacement value to the control module 2, and the control module 2 adjusts the flow control unit according to the second signal 46 provides the clean gas with the gas flow rate corresponding to the second signal to the air curtain unit 42 , so that the air curtain unit 42 blows the clean gas with the second gas flow rate toward the door assembly 502 of the wafer carrier 500 . It should be noted that although the gas flow rate of the clean gas provided by the flow control unit 46 changes with the displacement value of the door assembly 502, the clean gas is continuously directed towards the door assembly 502 of the wafer carrier 500 via the air curtain unit 42. direction, and perform the second inflation step on the wafer box 300 . In the present invention, no matter how much the displacement value of the door assembly 502 is, the clean gas blown out by the air curtain unit 42 preferably flows in a laminar flow state, and the flow velocity range of the clean gas blown out by the air curtain unit 42 is 0.1m/s -2m/s (meter/second).

From the above, it can be known that the displacement of the door assembly 502 of the wafer carrier 500 is related to the gas flow rate blown by the air curtain unit 42 (or the formed airflow wall AF). In the present invention, the clean gas blown out by the air curtain unit 42 can be controlled to flow in a laminar flow state by regulating the flow rate or/and pressure of the clean gas sent into the air curtain unit 42, and can be adjusted according to the displacement value of the door assembly 502. The flow rate of the clean gas blown out by the air curtain unit 42 can avoid the generation of turbulent gas near the door assembly 502 of the wafer carrier 500 and bring the dirt or particles near the door assembly 502 into the wafer cassette 300 to cause pollution. .

In addition, because the material of the air-permeable plate 422 in the air curtain unit 42 is stainless steel, antistatic and corrosion-resistant fiber material or composite material, ceramics, resin, or ultra-high molecular weight polyethylene, the characteristics of the material of the air-permeable plate 422 can be used to Increase the gas flow rate to 0-800LPM (liter/minute), that is to say, the gas flow range provided by the gas supply equipment to the purge control system can be controlled between 0-800LPM, and its tolerance to gas pressure is higher. The air curtain unit 42 has a longer service life.

1: Blowing control system 2: Control module 4: Blowing off the module 42: Air curtain unit 420: Ontology 420a: cover body 4202, 4204: air intake hole 422: breathable board 4222: stomata 44: Sensing unit 46: Flow control unit 300: wafer box 302: door body 500: Wafer Carrier 502: door assembly 5022: Upper end of door assembly 5024: Bottom of door assembly 510: carrier plate AF: Airflow Wall

FIG. 1 is a schematic block diagram showing a blowdown control system according to the technology disclosed in the present invention. FIG. 2 is a schematic block diagram showing each unit in the purge control system according to the technology disclosed in the present invention. 3 is a side view of a wafer carrier with a controlled blowdown system according to the techniques disclosed herein. FIG. 4 is a schematic diagram showing the structure of the air curtain unit in the blowing module according to the technology disclosed in the present invention.

1: Blowing control system

2: Control module

4: Blowing off the module

42: Air curtain unit

44: Sensing unit

46: Flow control unit

300: wafer box

302: door body

500: Wafer Carrier

Claims (10)

A blowing control system is connected with a wafer carrying device, the wafer carrying device is used to carry a wafer box, the blowing control system includes: A blow-off module, arranged in the wafer carrier, the blow-off module includes: an air curtain unit disposed above a door assembly of the wafer carrier; a flow control unit connected to the air curtain unit; and A control module is electrically connected with the blowing module, and the control module controls the air curtain unit to blow out a gas flow with a corresponding clean gas according to a displacement value of the door assembly, wherein when the displacement value changes When it is large, the gas flow rate becomes larger accordingly. The blowing control system as described in Claim 1, wherein the blowing module includes a sensing unit disposed on the wafer carrier, and the sensing unit is used to detect the door assembly of the wafer carrier A displacement state is used for the control module to judge the gas flow rate for supplying the clean gas. The blowing control system as claimed in item 1, wherein the air curtain unit includes at least: A body, at least one air inlet is provided on an upper end and/or one side of the body, and the air inlet communicates with a pipeline in the blowing module so that the clean gas of the air curtain unit passes through the the piping and the air inlet enter the body; and A gas-permeable plate is arranged in the body, and the gas-permeable plate has a plurality of air holes, which are used to discharge the clean gas through the air holes of the gas-permeable plate from the body, so that the air curtain unit and the wafer carrier device An airflow wall is formed between the door assemblies. The blowing control system as described in claim 3, wherein the material of the air-permeable plate with these pores can be stainless steel, antistatic and corrosion-resistant fiber material or composite material, ceramics, resin, or ultra-high molecular weight polyethylene . The purging control system according to claim 4, wherein when the air-permeable plate is the stainless steel plate, the air-permeable plate with the pores is formed by metal sintering. The blowing control system according to claim 4, wherein when the air-permeable plate is the stainless steel plate, the air holes are achieved by laser drilling or mechanical drilling. The purging control system according to claim 4, wherein the diameters of the pores range from 0.001 micron (µm) to 10 millimeters (mm). The blowing control system according to claim 1, wherein when the door assembly moves to a first positioning point, the air curtain unit blows a first gas flow rate, and when the door assembly moves to a second positioning point, The air curtain unit blows out a second gas flow, Wherein, when a second displacement value of the door assembly at the second positioning point is greater than a first displacement value of the door assembly at the first positioning point, the second gas flow rate is greater than the first gas flow rate, and when When the second displacement value of the door assembly at the second positioning point is smaller than the first displacement value of the door assembly at the first positioning point, the second gas flow rate is smaller than the first gas flow rate. The purging control system according to claim 1, wherein the flow rate of the clean gas blown out by the air curtain unit is in the range of 0.1m/s-2m/s (meter/second). The purging control system as described in claim 1 further comprises a gas supply device connected to the purging control system, and the gas supply device is used to provide the clean gas, which can be a pure dry gas (CDA, clean dry air), ultra-pure dry gas (X-CDA, extreme clean dry air) or inert gas, wherein the flow range of the clean gas is 0-800LPM (liter/minute).

Images