TWI278606B - Method and system for flow measurement and validation of a mass flow controller - Google Patents

Abstract

Systems and methods for flow verification and validation of mass flow controllers are disclosed. A mass flow controller may be commanded to a specified flow and flow measurement commenced. During an interval, gas is accumulated in a first volume and measurements taken within this volume. The various measurements taken during the interval may then be used to calculate the flow rate. The flow rate, in turn, may be used to determine the accuracy of the mass flow controller relative to a setpoint.

Description

1278606 IX. DESCRIPTION OF THE INVENTION: TECHNICAL FIELD OF THE INVENTION The present invention generally relates to methods and systems for verifying the performance of a mass flow controller, and more particularly, the present invention relates to the use of a rise Rate. Flow rate criteria to verify the performance of a mass flow controller. [Prior Art] Modern manufacturing methods sometimes require precise stoichiometric ratios of chemical elements during a particular manufacturing stage. To achieve these precise ratios, different process gases can be delivered into the processing chamber during a specific manufacturing process. A gas panel can be used to deliver the process gases to a processing tool having one or more self-chambers or counters. A gas panel is an outer casing containing one or more particulate foams that are dedicated to delivering process gases to the processing tool. The gas panel in turn includes a plurality of particulate blowing agents which themselves comprise a set of gas bars. A gas rod assembly can contain a number of discrete components, such as - inlet tube isolation isolation valve, binary control pneumatic isolation valve, gas filter, force eliminator, pressure sensor, in-line (four) heart pressure display, mass flow control And a discharge fitting. Each of these components is connected in series as: a universal flow path or a dedicated channel for special processing gases. A manifold and a valve matrix form a channel between the discharge tube of each gas column and the processing chamber. The material is stoichiometrically ratio--the cookware controller is the mass flow confirmation 疋 疋 ' 且 and is sorted by the door matrix'. This is associated with a specific gas rod. The indicated flow value is determined by each gas rod. The mass flow controller loses 103147.doc 1278606 out and is monitored by the processing tool controller.

A mass flow controller (MFC) is constructed by establishing a flow sensor and a proportional control valve with a control system. The flow sensor is coupled to the control system by a analog/digital converter. The control valve is driven by a current controlled solenoid valve drive circuit. A mass flow measurement system is located upstream of the control valve. The control system monitors the input of the set point and the output of the flow sensor while updating the input of the control valve and the indicated flow output. A closed loop control algorithm executed by the embedded control system is operable to meet the proportional control valve and the exhaust pipe joint to regulate the mass flow from the process gas at the inlet pipe joint such that the set point is input and indicated The instantaneous difference or error between the flow outputs is close to zero or null as quickly as possible' with minimal spikes and as little control time as possible. Since more than 500 gases are available for the manufacture of specific electronic components, the operation of each of the individual mass flow controllers is critical. Typically, the processing chamber itself is used to verify the mass flow controllers. The figure depicts a prior art system in which the processing chamber 130 acts as a flow collation tool. To verify the mass flow controller 12, a set point signal is input to the mass flow controller 120, which in turn begins to flow the gas to the processing chamber 13A. Since the volume of the processing chamber 130 is known, a preliminary flow measurement technique known as the rate of rise can be used to determine the flow into the volume. This method uses the mass conservation principle and the gas state equation to derive the relationship between the pressure in a fixed volume and the flow (mass flow) into the volume. The equation is given as follows: Δρ v Δί Eq. (1) 103147.doc !278606 where ΔΡ is the change in pressure during the time interval At, R is the general gas constant, T is the absolute temperature of the gas, and v is the volume of the measurement chamber . i Use this ideal gas equation as the equation of state; similar equations can be derived for other equations of state. Unfortunately, the volume of a typical processing chamber 130 (which can range from about 2 Torr to about 6 liters) makes the measurement of small flows extremely time consuming. In addition, the processing chamber 13 can exhibit a large temperature gradient throughout its volume, thereby distorting the measurement and calculation of the mass flow into the processing chamber 130. Figure 2 shows the amount of time required to achieve a given pressure change for some typical flow rates using a typical processing chamber 13 20 between 20 and 60 liters. This is due to the fact that many other constraints 'may require a minimum pressure to initiate the measurement' and require a minimum accumulated pressure of 0.3 Torr to make the determination. As a result, verification of a single flow point for 2 SCCm traffic can take up to 5 minutes, and a quality flow controller can take up to 3 minutes to verify. This lengthy verification cycle reduces the availability of tools and adds cost to the user. In addition to the slowness of the assay, the accuracy of the assay is usually no more than 读数5. /. Better. The main errors are: temperature error, chamber volume error, and unconsidered gas (adsorption or desorption). Other methods of verifying the mass flow controller 12 may utilize a second volume in parallel with the processing chamber 13A to determine the flow rate. However, this # method does not allow for the determination of the transient (non-敎 state) effect of the mass flow controller (3), and the many steps required for the volume upstream of the mass flow controller 120 make this technique difficult to integrate into existing systems and This can exacerbate the need for very long verification times. 103147.doc 1278606 Therefore, there is a need for systems and methods for verifying a mass flow controller 'these systems and methods can quickly measure dynamic performance and verify a flow controller' while simultaneously reducing the measurement Determining the factors improves the accuracy of the verification process. SUMMARY OF THE INVENTION The present invention discloses a system and method for traffic verification and verification of a mass flow controller. These systems and methods can measure the dynamic effect of a mass flow controller

The flow check and measurement can be performed in one step. According to a real example, two volumes can be used in combination to accurately determine the total volume between a given sequence j, minimizing false flow conditions and reducing sensitivity to pressure transients. The mass flow controller can be coupled to a measurement system. The mass flow controller can be commanded to generate a specific flow rate and the system can begin flow measurement. Gas accumulates in a volume between the mass flow controller and the assay system and the pressure is measured within this volume. The gas can then flow into the human-known volume within the sub-measurement pressure. The various measurements made during the two time intervals can then be used to calculate the volume and flow rate between the mass flow controller and the test system. This flow rate can in turn be used to determine the accuracy of the mass flow controller relative to a set point. In a known example, a first data for a first volume is collected during a first time interval, a second data for a first volume is collected during a second time interval, the first volume is determined and the flow is calculated. In another example, the first volume includes the first volume calculated based on the first data. In another embodiment, the first data includes a change in pressure between the first time interval: 103147.doc 1278606, and the second data includes a change in pressure during the second time interval. In another embodiment, the first volume is determined by receiving an input. In other embodiments, a system for determining a flow through a mass flow controller is coupled to the mass flow controller downstream of the mass flow controller, the system including a chamber, and a a valve connected to the chamber upstream of the chamber, a second valve connected to the chamber downstream of the chamber, and a pressure sensing coupled to the chamber upstream of the first valve Device. In other embodiments, the system is operative to collect first data for a first volume during a first time interval and to collect second data for a second volume during a second time interval. In some embodiments, the second data is collected prior to collecting the first data. In some embodiments, the first data is collected prior to collecting the second material. According to another embodiment, a ch〇king orifice can be used in conjunction with a volume to accurately determine a flow rate regardless of the geometry or pressure of the volume upstream of the occlusion hole. Alternatively, an error curve can be derived and fitted using the error points determined using the blocked holes. The flow can then be calculated without the use of a stop hole and the flow rate can be adjusted based on the resulting and fitted error curve. A mass flow controller can be coupled to a measurement system. The mass flow controller can be commanded to generate a particular flow rate and the system can begin flow measurement. The various measurements made during this time interval can then be used to calculate the relative flow rate of the 103147.doc -10 - 1278606 device. The flow rate is used to determine the accuracy of the mass flow control at a set point. In the consistent application of the syllabus, during the interval between j and the team, the first sign of the volume, the first data of the volume, and then the calculation of a _, the dan dan / claw, the sub-based error line adjusts the first flow. In another embodiment, the error curve is determined by fitting a set of error curves to the set of error curves by Jiang Yiqi and Hunting. The set w and the difference include the group-determined error. The error point is determined by the following steps: collecting the second data about the first volume during the second time interval, wherein the blocking hole is in the -open position; a second flow; collecting a third data about the first volume during the third set interval, wherein the blocked hole is in a blocked position; calculating a third flow based on the third data; comparing the The second flow rate and the third flow rate. In other embodiments t, the blocking aperture is operable to generate a -pressure gradient in the blocking position, wherein the pressure upstream of the blocking aperture is about twice the pressure downstream of the blocking aperture. This first set point indicates that in another embodiment, the blocking aperture is operable to generate a pressure gradient when the point is at least 500 seem. In other embodiments, each of the determined error points of the set of points is at least 500 seem. In another embodiment, wherein each of the viewers is set to be at - the set of error points includes a set of observed errors and the error points are determined by the following steps: A fourth data about the first volume 103147.doc -11 - 1278606 is collected during the interval; and a fourth flow rate is calculated based on the fourth data. In another embodiment, the error curve is adjusted based on the type of gas. In one embodiment, a system is coupled to the mass flow controller downstream of the mass flow controller, the system including a chamber, a first valve coupled to the chamber upstream of the chamber, and a A pressure sensor coupled to the chamber downstream of the chamber and a blocking aperture joined to the chamber upstream of the pressure sensor. In a particular embodiment, the system is operative to deflate the first data for a first volume and calculate a first amount of flow during a first time interval. These and other aspects of the present invention will be better understood and understood from the <RTIgt; The following description, while indicating the various embodiments of the invention, Many alternatives, modifications, additions or rearrangements are possible within the scope of the invention, and the invention includes all such alternatives, modifications, additions or re-configurations. [Embodiment] This application is related to U.S. Patent No. 6,343,617 to the name of &quot;System and Method of Operation of a Digital Mass Flow Controller&quot; of Tinsley et al., issued February 5, 2002; November 4, 2003 U.S. Patent No. 6,640,822 issued to Tinsley et al., entitled &quot;System and Method of Operation of a Digital Mass Flow Controller&quot; issued by Jansley et al., issued Jan. 27, 2004 entitled "System and Method of Operation" US Patent No. 103147.doc -12- 1278606 6,681,787 of the a Digital Mass Flow Controller; title of ¥丫6^ promulgated on May 14, 2002

U.S. Patent No. 6,3,89,364 to &quot;System and Method for a Digital Mass Flow Controller; U.S. Patent No. 6,714,878, entitled "'System and Method for a Digital Mass Flow Controller" by Vyers, issued March 30, 2004. U.S. Patent; U.S. Patent No. 6,445,980 entitled "System and Method for a Variable Gain Proportional-Integral (PI) Controller" issued by Vyers, September 3, 2002; Tariq et al., issued on September 10, 2002 U.S. Patent No. 6,449,571 to &quot;System and Method for Sensor Response Linearization&quot;; U.S. Patent No. 6,575,027 to Larsen et al., issued June 10, 2003, entitled &quot;Mass Flow Sensor Interface Circuit&quot;; U.S. Patent No. 5,901,741 to Mudd et al., issued May 11, 1999, entitled "'Flow Controller, Parts of Flow Controller, and Related Method"; Mudd, issued on December 22, 1998, titled 1 'Flow Controller, Parts of Flow Controller, and Related Method', US Patent No. 5,850,850; June 1998 U.S. Patent No. 5,765,283, the entire disclosure of which is incorporated herein by reference in its entirety herein in The invention and its various features and advantageous details are explained more fully in the non-limiting embodiments, which are illustrated in the Detailed Description, which is described in the following description. Descriptions of well-known starting materials, processing techniques, components and devices are omitted. In order not to unnecessarily obscure the present invention in detail, 103147.doc -13·1278606. However, it should be understood that although the detailed description and specific examples indicate the present embodiment, the embodiment is only The Detailed Description and specific examples are given by way of illustration and not limitation. Various alternatives, modifications, additions and rearrangements of the present disclosure will become apparent to those skilled in the art. Attention is now directed to the use of flow checks and verification of mass flow controllers, methods, and methods that determine the dynamics of the _ mass flow controller. Embodiments of such systems and methods allow for capture of their transient flow behavior in addition to allowing the steady state j of a flow controller to be captured, and are operable to account for traffic having an update rate of at least 5 〇 ms. As such, the sputum measurement system and the method can determine the spurt of the mass flow controller, the settling time, the response time, the repeatability of the variables mentioned, and the quantitative determination of the volume under dynamic flow conditions, And can be used for initial volume correction. According to one embodiment, two volumes can be used together to accurately determine the total volume during a measurement sequence, minimize false flow conditions and reduce sensitivity to pressure transients. The mass flow controller can be coupled to a measurement system. The mass flow controller can be commanded to generate a specific flow rate and the system can begin flow measurement. Gas can accumulate in the integral between the mass flow controller and the assay system and the pressure is measured within this volume. The gas can then flow into a known volume and the pressure is measured. The various measurements performed during the two time intervals can then be used to account for the volume and flow rate between the mass flow controller and the assay system, which in turn can be used to determine a mass flow controller relative to a The accuracy of the set point. Similarly, such systems and methods may also permit testing of leaks through valves within the mass flow controller. By passing a zero flow 103147.doc -14 - 1278606 rate to the billiard controller, the so-called measured force changes can be attributed to leakage through their valves. A匕 and other methods can be measured by the ascending rate technique—the efficiency of the mass flow controller, combined with the gas state equation and the principle of mass obscurity—similar to the equation of Eq·1, where the mass flow can be determined by:

mS~ZRT 一^ΖΓ~ Eq. (2) where ΔΡ is the pressure change during the time interval ,, r is the general gas constant T is the absolute temperature of the gas, 2 is the gas compression factor, and v is the measurement chamber The volume. The gas pressure and shrinkage factor Z is generally equal to the unit of light gas (mnty) and can be significantly less than the unit of heavier molecules such as WF6. The use of compression factors improves the accuracy of flow measurements with non-ideal compressed gases. Turning now to Figure 3, an exemplary embodiment of a system in which the present invention and the hardware configuration of the methods can be incorporated into a gas stream in parallel with a processing chamber is depicted. The rate of rise system (〇) ^) 3〇〇 can be used to determine the accuracy of the mass flow controller 120 relative to a set point. The rate of rise system 3〇〇 can be incorporated into the gas stream passing through the gas rod 302 to the processing chamber 130. In a particular embodiment, valves 350, 370 are downstream of mass flow controller 12 and upstream of processing chamber 130. The ROR 300 can include a chamber 305 between the valves 33A, 31A and a pressure sensor 32A downstream of the valve 310. Pressure sensors are a type generally known in the art that can measure the pressure from 〇·丨托 to 丨〇〇〇. The chamber 305 typically has a volume of from 10 cc up to one liter of any of 103147.doc -15-1278606 compared to a typical volume between the 1 〇 and 6 〇 liters for the processing chamber 13〇. The ROR 300 can be coupled to the gas stream downstream of the mass flow controller 120 and the valve 35A and upstream of the valve 370 and the processing chamber 130. The volume of solids connected between valves 350, 370 and 3 10 is represented by a volume of 36 。. While other materials such as nickel or tungsten may be used in the condition that the gas rod 302 is being used to transport a particular gas, in many cases, a 316 L stainless steel tube having a leaf diameter of · 2 $ to · $ will be used for R〇r 300 is attached to the gas rod. The gas flows from the gas supply unit 110 to a shell control state 1^0 that is responsive to a set point to regulate the volume of gas passing therethrough, which is typically between 1 liter and 1 liter per minute. If the valves 310, 350 are open and the valve 37 is closed, the gas flows from the mass flow controller 120 into the chamber 305. However, if the valves 350, 370 are open and the valve 310 is closed, the gas is self-quality. The flow controller 120 flows into the processing chamber 13A. In the special example, in order to be able to perform flow measurement with ROR 300, valve 370 is closed to processing chamber 130, valve 350 is open to mass flow controller 12, and valve 3 10 within ROR 3 00 is closed. The mass flow controller 12 is commanded to generate a specific flow rate&apos; and the ROR system 300 begins flow measurement. The gas accumulates in a volume 36 之间 between the valves 350, 370 and the valve 310 in the ROR system 300. The pressure sensor 320 within the ROR 300 is located upstream of the valve 31, and this geometry enables the determination of the pressure in the volume 360. The change in pressure as a function of time can be determined for later use in the quantification of flow measurements. At a certain time, valve 330 is closed and valve 310 is opened to allow gas to flow into (a known volume) chamber 3〇5 of ROR 300. The pressure as a function of time is monitored by the pressure sensor 320 in r〇r 300. 103147.doc -16- 1278606 A typical curve of the pressure change as a function of time is given in Figure 4. In the map, the initial pressure change of the depicted edge appears in the same volume 36 ,, and the pressure change and time interval are Δ1 &gt; 1 and . The first ramp that begins at about 1 second is when valve 3 1 〇 opens and valve 330 closes. In this case, the accumulation volume is a combination of the volume 360 and the known volume of the chamber 3〇5. The pressure change over time is Δρ2 during the time interval At2.

The volume 36 接着 can then be calculated using the following expression. Δρ2 ·v Ί -Δ^2 ΔΛ ap2 - eat △, 丨At2

The Eq·3 can then be used in conjunction with Eq·2 to determine the flow rate. The determined flow rate can then be compared to the set point of the mass flow controller to determine the accuracy of the mass flow controller 120. Turning now to Figure 5, a flow diagram of an embodiment of a method for determining flow attributes and verifying the accuracy of a mass flow controller is depicted. This particular method can be advantageous when measuring large flows (greater than 20 〇 sccm) because of the flow rate

The uncertainty of the measurement is reduced by using a larger volume t during the initial transient measurement. In a particular embodiment, the valve 37〇 can be closed by a control system that does not test or verify the inlet and outlet flow controller. To begin the test, the valves 310, 330' are opened and a vacuum is applied by the pump 38 (step $1〇). The valve 330' is then closed and the initial status information can be retrieved (step 520). The mass flow controllers 1-20 are based on a particular set point flow, and then the data for the first time interval can be collected (step 530). Using an induction sensor such as an external force sensor, it is possible to monitor the day (4), M force and temperature - for a specific period of time. In some embodiments, a pressure or time checkpoint may be used to determine the length of the time period. For example, when the pressure within the volume reaches a particular load, the first time interval can be ended. Although the pressure at the end of the first time interval may vary drastically depending on the measured flow rate, this pressure is typically between ι Torr and 1000 Torr. The first time interval may also be ended after a predetermined amount of time, which is typically at least 10 seconds but no more than 60 seconds. After the end of the first time interval (step 530), the trick 3 10 can then be closed (step 540) and the data for the second time interval is collected (step 55A). This data may include pressure, temperature, and time during the first time interval, and the length of the second time interval may be determined using the same criteria as discussed with respect to the first day interval between the above. After the end of the second time interval (step 550), the volume 360 and flow properties can then be calculated using Eq. 2 and Eq. 3 (steps 57, 58). Alternatively, volume 360 can be entered (step 590) and the flow attribute can then be calculated using the input volume (step 580). The flow rate can then be compared to the original set point of the mass flow controller 120 to determine the accuracy of the mass flow controller 12. Those skilled in the art will appreciate that a variety of steps, measurements, and calculations can be performed and executed in a number of ways, including by a control system embedded in the r〇r system 300, or by incorporating a mass flow controller. 120, gas bar 302 and processing chamber 130 are used to control and execute the control system. Similarly, Figure 6 is a flow diagram of a method for determining flow and verifying a mass flow controller 12 that can facilitate medium flow (20 SCCm to 200 sccm), wherein a larger volume is used during the initial transient phase. The chamber 3〇5 is not necessarily useful. 103147.doc -18- 1278606 In the implementation of the shot, the shot 1 370 can be controlled by a control system, which will perform the flow measurement or verification of the mass flow controller 12〇. For the test of the mass flow controller, the valves 310, 330 are opened and the vacuum is taken from the 38 〇. Valve 310 is then closed and the data can be retrieved for initial use (step 620). The slave stream controller 12 is based on the flow of a particular set point, and then the data can be collected during the first time interval (step 63A). Time, pressure and temperature can be monitored for a specific period of time using an inductor known in the art, such as pressure sensor 320. As discussed above with respect to Figure 5, the length of the time period can be determined by a pressure or time checkpoint. After the end of the first time interval (step 63A), valve 330 can then be closed, valve 310 opened (step 64A), and data collected during the second time interval (step 550). During this first time interval, this data may include pressure, temperature, and time, and the length of the second time interval may be determined using the same criteria as discussed with respect to the first time interval above. After the end of the second time interval (step 65A), the volume 360 and flow properties can then be calculated using Eq. 2 and ^3 (steps 67, 68). Alternatively, volume 360 may be entered (step 690), and then the input volume metered flow attribute may be used (step 680). The flow rate can then be compared to the original set point of the mass flow controller 12 to determine the accuracy of the mass flow controller 12. Once the volume 36 阀门 between the valves 350, 370 and 31 判定 is determined, the volume measurement can be performed using only the volume 360. In many assemblies, the volume 36〇 is J (&gt;\20 cc) 'so it is easier to determine the pressure change for a particular flow rate, typically reducing the measurement time for a given flow rate to 1/5 . 103147.doc -19- 1278606 Figure 7 illustrates a method of utilizing volume 360 to determine flow properties or collate mass flow controller 120. This method is particularly effective for flow rates less than 2 〇 sccm and allows for a much shorter measurement interval. Valve 37〇 can be closed by a control system that will perform flow measurement or verification of the mass flow controller 12〇. To perform the test of the mass flow controller, the valves 310, 330 are opened and the pump 380 is evacuated (step 71). The trick 310 is then closed and the data is retrieved for initial use (step 72). As discussed above, as the mass flow controller 120 is based on the flow of a particular set point, the data can then be collected during the first time interval (step 〇). After the end of the first time interval (step 730), the valve 3ι can be opened and the valve 330 closed (step 740). Under certain conditions, it may be advantageous to open the valve 330 prior to opening the valve 31, so that the pressure will remain in the volume 360 throughout the first time interval. After the end of the first time interval (step 730), the flow attributes can then be calculated using Eq·2 and £3 and the pre-determined volume publication (step 770) (step 78). Alternatively, volume 360 can be manually entered by the user (step 79A) and then the flow attribute can be calculated (step 780). The calculated flow rate can then be compared to the set point of the mass flow controller to determine the accuracy of the mass flow controller 12. Additionally, once the volume 360 between the mass flow controller valve and the valve is determined, flow measurement can be performed using the known volume and volume 36 of the chamber 305. This can be useful for high flow volumes where a large assay volume is desirable. Figure 8 illustrates a method of combining flow volume 360 and chamber 305 for flow measurement or verification of mass flow control 120. Valve 37〇 can be closed by a control system 103147.doc -20. 1278606, which will perform flow measurement or verification of the mass flow controller 12〇. For testing of the mass flow controller, valves 31, 33 are opened and vacuum is applied by pump 380 (step 81). The valve 33 is then closed and the data is retrieved for use in the initial state (step 820). As discussed above, as the mass flow controller 120 is based on the flow of a set point, the data may then be collected during the first time interval (step 830). After the end of the first time interval (step 830), valve 330 can then be opened (step 840), and then shame 2 and shame 3, pre-determined volume 360 determination (_step 87 〇) and chamber 3 可 can be used. A known volume of 5 is used to calculate the flow attribute (step 880). Alternatively, the volume 36 手动 can be manually entered by the user (step 890) and then the flow attribute is calculated (step 88 〇). The flow rate can then be compared to the set point of the mass flow controller 12G to determine the accuracy of the flow controller 12. However, in many cases, the error introduced in the rise rate calculation can be significant. More specifically, 'when the flow rate increases, the length of the line containing volume 360 or other fluid elements such as valve 35〇 in the path can be varied in volume relative to the rate of change of pressure within a known volume of 305 to 305. The rate of pressure change. The change in rate of change in volume 36 取决于 depends on the geometry of the volume 360, the flow rate of the mass flow controller 120, and on the characteristics of the gas flowing through the body rod 302, and thus allows the flow rate to be measured differently and qualitatively. The commensurate check of the flow controller 120 becomes difficult. These effects can become especially noticeable at flow rates above 200 seem. Therefore, when measuring pressure and pressure changes or calculating volume and flow rate, a method is needed to eliminate or compensate for these effects. 103147.doc -21- 1278606 In a particular embodiment of the disclosed method; 5, the dream + a, and the 4 4 method, a blocked hole can be used in combination with a volume to block the upstream of the hole The volumetric geometry or pressure to accurately determine a flow/claw rate. In addition, the error determined by using the blocked hole is taken up by the left point T and an error curve is fitted. Subsequently, it is not necessary to use a blocked hole to calculate the flow rate of the αL, and the flow rate can be adjusted based on the resulting and predicted error curves. Figure 9 depicts an embodiment of a hardware configuration that can be incorporated into a gas stream in parallel with a processing chamber that can substantially compensate for upstream pressure dependence by fluid shorting or by measuring the flow at the upstream of the device and plugging . As described above with respect to Figure 3, the rate of rise system (R〇R) 3〇〇 can be incorporated into the gas stream passing through the gas rod 302 to the processing chamber 130. In the particular embodiment depicted in Figure 9, a blocking aperture 322 is coupled between r〇r 300 and valve 350, abutting ROR 300. The occlusion hole 322 can be used to reduce the effect of the geometry of the volume 360 on the left force measurement and to improve the usability and accuracy of the ROR 300. By using a term "fluid short circuit," the technique of blocking the aperture 322 can reduce the sensitivity of the ROR 300 to the geometry of the volume 360. This technique narrows the fluid path such that the pressure in the volume 360 is greater than the upstream of the blocking aperture 322. Pressure. Although many pressure gradients can be used to reduce the effect of a volumetric geometry of 36 ,, for the desired effect, the venting orifice 322 should generate a pressure gradient such that the pressure in the volume 360 is at least the pressure upstream of the venting orifice 322. This may cause the pressure upstream of the blocking aperture 322 to remain substantially constant during a constant flow rate. In one embodiment, the blocking aperture 322 may be a multi-position valve that may be based on the flow rate of the mass flow controller 120 Positioning to generate a suitable pressure gradient between volume 360 and ROR 300. 103147.doc -22- 1278606 In another embodiment, the occlusion hole 322 can be a three-way valve having the opening known in the art. , closing and blocking the position. The gas bar 3〇2 and the processing chamber 130 can generally operate with the blocking hole 322 in the closed position. When the blocking hole 322 is When the position is opened, the 'ROR 300 can operate with the gas bar 302 and the processing chamber 13A as described with respect to Figures 5 through 8. However, by placing the blocking hole 322 in the blocking position, it can be in a volume of 36 〇 A pressure gradient is generated between the RORs 300 that allows the flow rate in the ROR 300 to be determined independently of the upstream pressure or volume. Since the flow rate in the ROR 30Q can be determined independently of the volume 36, there is no need to make a determination for volume 360. Determination of the geometry. For example, steps 54 〇 _ 57 〇 and 590 are not required with respect to Figure 5. In this condition using the occlusion hole 322, the valve 37 〇 can be closed by a control system, this indication will proceed Testing or verification of the mass flow controller. To begin the test, the valves 310, 330 are opened and the pump 38 is evacuated (step 51). Then the valve 330 is closed, the blocking hole 322 can be set to the blocking position and the data can be taken out. Used for the initial state (step 52〇). (3) Based on the -specific setting (four), then the data can be collected at the first time - interval = (step 530). Time, pressure and temperature monitoring - special sections can be used using an induction enthalpy known in the art, such as a force sensor 32 。. In some embodiments, the time period is determined by a pressure or time checkpoint: length. For example, the first time interval may be ended when the pressure within the volume of the chamber 3〇5 reaches a specific support. Although the pressure at the end of the first time interval may vary greatly depending on the measured flow rate, this pressure U is between 10 Torr and 1000 Torr. The first time interval may also be ended after a predetermined amount of time 103147.doc -23- 1278606, the predetermined amount of time being more than 60 seconds. After the end of the time interval (step 53〇), the flow attribute can be calculated using 2 and ^. 3 (step 5), without considering the volume 360. Therefore, a second time interval is not required, and steps 540-570 and 590 can be eliminated only by using the blocking hole 322. A skilled person will understand that by using the blocking hole M2, a similar step reduction can be achieved by the method described in the following:: to 8, and the volume of the chamber 3G5 can be used to determine the quality during a single transient phase. The flow controller 12 is closed. In addition, the shore can be solved. You can see the hand and check the mouth. You should not consider the construction of the blocking hole 322 (for example, three-position door or multi-position door) to achieve the same step reduction. Although the occlusion hole 322 can be adjusted for any flow rate, in a particular embodiment, the occlusion hole 322 can be a three position readout, wherein the occlusion hole is adjusted for generating a pressure gradient, wherein Or greater flow rate, the pressure in volume 360 is greater than twice the pressure upstream of blocking orifice 322. Then for a flow rate below 500 sccm, the error introduced by volume 360 can be mathematically compensated. In order to mathematically compensate for the error, the volume-specific geometry can be derived as a formula for the error term as a function of the main variable of the flow rate, geometry and gas-like shape. This equation gives the shape of the curve that is deviated by the particular geometry of volume 360. For example, for a volume 360 similar to the volume depicted in Figure 1 (the volume of 360147 is a constant diameter pipe in 103147.doc -24 - 1278606), an equation can be derived for a flow correction term. . More specifically, an equation showing the relationship between the average pressure in the volume 36 与 and the average pressure in the chamber 305 measured can be developed. This equation is given as follows:

Eq. (4) ^vg=l/3(Pl-P2)+i&gt;2 The above equation can be used in combination with other equations to arrive at a flow rate that is determined using Eq. (2) and the expected real flow rate. Flow correction

Item 'expected real flow and additional information about the expected average pressure in volume 36 _ : Momentum equation 〇 = lifetime + &quot; + dx 2x2 2z2 Eq. (4·1) For cylindrical geometry:

RdR dR u dx Eq. (4.2) Since the pressure gradient is independent of R, Eq·4.2 can be integrated to give u{R)-ldpRl u dx 4

+ A\ogR + B

Eq. (4.3) Boundary conditions u(0) = finite = &gt; A = 0 μ(α) = 0 = &gt; Β = - - ^L· \ dx ) A μ u{R) 1 dp 4u dx ( A2 - R2)

Eq. (4.4) 103147.doc -25 1278606 2\\μ{κ)^θ dp R: 2\)rdrde ^ 8// 0 0 ώ = i4 p SMRf dx (note that X is the radius) Eq. (4_5) Pdp = m = dx [π R )

μ avg

i pdp = i m --- RT 4 assumes that T is a constant Λ ο π R

ΊP P

Rn L π R 4

P l - rn L π

R

2 . 16 uRT

Pq - soil

L

Eq. (5.1)

p dL 2 avg

Eq. (5.2) P avg L 1

J dL is generally a quadratic function: P = αχ2 + b

Where x = 0 P = P. Time; c = i P = PL 103147.doc -26- 1278606 P — all + PQ 5 a — L2 P = ^^x2+P〇

Eq. (5.4)

Pdx

P avg

Eq. (5.5)

P dx Pl^ Po 2 τ2 X +Ρ〇 dx Pl-Ρ. { L ) 1 L J 'X3 + P〇x/L^

L

Avg (P^Po) (l3) l L2 J l3J P〇L

L P avg = L ~ Po) + 2

P avg P^^Pl

Eq. (5.6) P〇

Pa ^+pl π

R 2 • \6jjRT T 2 L+p] + -

Pl

Eg. (5.7)

nR

Eq. (5.8) π

R If P1 is a function of time, then in an embodiment, if P = 0, then PfPi+At 103147.doc -27- 1278606 4(')=譬((9) 十(4) + A A Eq. (6.1) Usually When the m term approaches zero, the error becomes smaller. For a given quality; the L error can be increased due to the increase in gas viscosity, so the entire volume includes two parts · volume 360 and chamber 305. RT'

RT

At +

At If the temperature is assumed to be the same, then:

Eq. (6.3) Usually ΔΡ(〇ν =^(0, so that m〇

RAtT

Eq. (6.4) The error in the calculated mass flow can then be estimated by subtracting the two equations. 1 m〇

RAtT iApM^ApJdv]

Eq. (7.1) For the sake of brevity, the change in mean pressure can be replaced by Eq. 7". If we assume that AP(t)f starts when t = 0 and P = 0, then (sheng) wide rhe

RT see a dt 2

At V,

Eq. (7.2)

Eq· 7.2 seems to perform well. When the variable volume Vv—〇, 103, 103147.doc -28- 1278606 A 4 0,me-&gt; 0 Μ

Eq. (7.3)

R is simplified, if VT=Vv+Vf then m (AFt)

M RTL (four) ▼

RT

L π

R ^)fVr RTAt

Eq. (7.4) Eq. (7.5)

The derivative of Eq.6.1 will produce: d ρανβ A avg

+ -At dt dp if) ^ avg a 2 f \ A2t + i , • dt 3 1 (MHAtfy) 3

Eq. (8.1) me

Eq. (8.2) 103147.doc -29- 1278606

/ f \ \ V A 2 A2t — Λ — 3 \ V '♦+v)^f+(5)2} ^ ηκ ) J 3 J

Eq. (9) 2 where Vv = (m3), i? = 8.3149(^^), Γ(8), L(m), R(m)5 t(s)5 m(—\ \ sscm^lAUW1 \s) s • Eight items are the pressure derivatives in chamber 305. The desired flow rate is then given by adding the result of Eq. 9 to Eq·2.

16L . ~ΓΤ variable; Γ if is equivalent to the geometric shape term of a fluid path, and it is represented by the gas viscosity as the gas dependent term represented by G. Can rewrite Eq·9 to:

Unfortunately, most of the geometries measured with you, ώ 0, and 1 will not be used in order: the geometry is as simple as it is, however, the appropriate equation for the same open shape can be used. As shown in the figure, the shape of the valve 310 can be just introduced into the chamber: 103147.doc &gt;30-1278606 upstream. In this case, the average pressure in the pipe (volume 36 〇) is given by the following equation 11.

Pavg- 1/3(P1-P3)+P3 where P3=Pv+P2, and Pv is the pressure drop value through valve 3. For the equation developed by Eq 9, the same technique can be used to develop an alternative equation that depicts this particular geometry, and the equation is given below.

Ma

RT 2 + λ

Eq. (11) vv π

R where A: is the pressure derivative just upstream of valve 330

Once an equation for a particular geometry of volume 3 60 has been derived, the actual error induced by a flow of more than 500 seem can be obtained by empirically observing a particular instance of volume 36 by using ROR 3 00. The flow rate is calculated for the mass flow controller 12 in a series of flows while the blocking hole 322 is in the open position. This calculation calculates the flow rate at the same series of flow settings while the blocking hole 322 is in the blocking position. relatively. A set of points corresponding to an error curve above the flow rate of 5 〇〇 sccm can be determined by comparing the two maneuver rates calculated under each of the flow settings. The curve described by the resulting equation (e.g., Eq. 10) 103147.doc 1278606 can then be fitted to an empirically determined error point appearing above 500 seem to produce an error equation, which depicts a representation by volume 36. A curve of the error induced by the geometry at all flow rates. In addition, in many cases, the error induced by volume 36 〇 versus 2 〇〇 sccm or less is statistically insignificant. Therefore, the actual flow observed at these flow rates can also be used to establish the point at which the error curve described by the equation fits. Although the curve described by Fang and Fang is fitted to the empirically determined curve, the variables in the error square of the error curve describing a particular example of the volume geometry may be calculated, and the variables include the geometric shape item (H). . This = difference curve can then be applied to the future measurements and (9) L motion rates performed or calculated by R0R 3 , to correct the error induced by the volume 36 ,, thereby allowing the flow rate of the mass flow controller 120 to be more Accurate calculations. It should be understood that this error curve can be used; ^ when the blocking hole 322 is in the open position by the volume 36 〇: the error introduced at all flow rates, thereby allowing the volume to be utilized between the single transient stage slaves to 305 to be more The flow rate is accurately determined and the mass flow controller 120 is verified. Figure 12 depicts an embodiment of a method for calculating the flow rate using R 〇 R 3 〇〇 and the equation describing the error curve as described in detail above. In this condition, valve 370 can be closed by a control system that will test or verify the mass flow controller. To begin the test, valves 31, 330 are opened and a vacuum is applied by line 380 (step 121). The valve is then closed and the capital is removed from the initial state (step 1220). With the flow control (4) based on a certain: L move can then collect data during the first time interval (step 103147.doc -32 - 1278606

Step 1230). Time, pressure and temperature can be monitored for a specific period of time using an inductor known in the art, such as pressure sensor 320. In some embodiments, the length of the time period can be determined by a pressure or time checkpoint. For example, the first time interval may be ended when the pressure within the volume reaches a particular load. Although the pressure at the end of the first time interval may vary greatly depending on the measured flow rate, this pressure is typically between 1 Torr and 1 Torr. The first time interval may also be terminated after a predetermined amount of time, which is typically at least 1 second, but no more than 6 seconds. After the end of the first time interval (step 1230), Eq·2 Eq·3 can then be used to account for the different stream 1 attribute (step 1240) without regard to volume 360. As described above, this constant flow attribute can then be corrected for the error introduced by volume 360 by using a pre-determined error equation (step 1250). Therefore, a second time interval is not required and the hole μ can be blocked. When in the open position i, the flow rate is set at any (four) amount setting. In addition, in most cases, the equations may be modified to be introduced when determining the flow rate using the ROR 300: The gas flowing through the gas rod 302 is considered in the determination of the difference. This can be done by using the gas viscosity term (as indicated by G in the middle), and the value of the gas viscosity term is determined based on the gas flowing through the gas bar 3〇2 or r〇r 3〇〇. For example, the gas term (6) can be one value for nitrogen and the other for the type of fluorinated gas. By using a different value depending on the G of the gas, the resulting block of scars is that the curve not only corrects the calculated flow for the shape of the volume 360, * the square T weight is calculated for the gas viscosity of the gas bar 312. flow. 103147.doc •33 - 1278606 Those of ordinary skill in the art will appreciate that a variety of steps, measurements, and calculations can be performed and executed in a number of ways, including by means of a control system embedded in the ROR system 300, or by combining The mass flow controller 12, the gas bar 302, and the processing chamber 130 are controlled and executed using a control system. It should also be understood that the point of empirical determination for fitting the curve depicted by the equation will be determined based on the adjustment and optimization of the occlusion hole 322. For example, if the blocking hole 322 is adjusted to generate a pressure gradient, where the pressure in the volume 36 大于 is greater than twice the pressure upstream of the blocking hole 322 for a seek or greater flow rate, empirically determined The point can be at a flow rate of seem or higher. It should be noted that not all of the steps described with respect to Figures 5 through 8 and 12 are necessary, a single step may not be required, and other steps may be used in addition to those described, including additional measurements, additional time intervals, and the like. In addition, the order in which each of the elements of the methods are described is not necessarily in the order of use. After reading this specification, those skilled in the art will be able to determine which arrangement of steps will be most appropriate for a particular embodiment. In the foregoing specification, the invention has been described with reference to the specific embodiments. However, it will be apparent to those skilled in the art that various modifications and changes can be made without departing from the scope of the invention as set forth in the following claims. Accordingly, the specification and drawings are to be regarded as a Benefits, other advantages, and solutions to the problems have been described above with regard to specific embodiments. However, these benefits, advantages, solutions to the problems of 103 U7.doc • 34-1278606, and any components that may appear or become more apparent to any benefit, advantage, or solution should not be construed as any or all. A key, required or essential feature or component of the scope of the patent application. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 includes an illustration of a prior art system for verifying a mass flow controller by using a processing chamber. Figure 2 includes a graph of the time required to achieve pressure changes for certain typical flow rates when utilizing a processing chamber during flow collation. Figure 3 includes a block diagram of an embodiment of a system for verification of a mass flow controller. Figure 4 includes a graph of the pressure as a function of time using an embodiment of the depicted method. Figures 5 through 8 include flow diagrams depicting various embodiments of a method to perform flow verification or verify operation of a mass flow controller. Figure 9 includes a block diagram of an embodiment of a system for verification of a mass flow controller. Figure 10 includes a block diagram of one embodiment of the geometry of a path, the path between a mass flow controller and a system as depicted in Figure 9. Figure 11 includes a block diagram of one embodiment of a geometry of a path between the mass flow controller and a system as depicted in Figure 9. Figure 12 includes a flow chart depicting an embodiment of a method for performing flow verification or verifying operation of a mass flow controller using the system depicted in Figure 9. [Main component symbol description] 110 gas supply device 103147.doc -35 - 1278606 120 mass flow controller 130 processing chamber 300 ascending rate system 302 gas bar 305 chamber 320 pressure sensor 322 blocking hole 310, 330, 350, 370 Valve 360, volume 380 pump 103147.doc -36-

Claims (1)

1278606 X. Patent application scope: 1. A method for determining a flow rate through a flow controller, comprising: 'collecting first data about a first volume during a first time interval; during a second time interval Collecting a second data about the second volume; determining the first volume; and calculating the flow rate. 2. The method of claim 1, wherein determining the first volume comprises calculating the first volume. 3. The method of claim 2, wherein the first volume is calculated based on the first data and the second data. 4. The method of claim 3, wherein the first data comprises a pressure change over a first time interval and the second data comprises a pressure change over a second time interval. 5. The method of claim 4, wherein the second data collection is performed prior to collecting the first data. 6. The method of claim 4, wherein collecting the first data is performed prior to collecting the second data. 7. The method of claim 1, wherein the determining that the first volume comprises receiving an input 0. 8. The method of claim 7, wherein the first data comprises a change in pressure over a first time interval, and the second data Includes pressure changes over the second time interval. 103147.doc 1278606 9. The method of claim 8 wherein the execution is performed prior to receipt. ', the younger brother is in the collection of the first-investigation method... collecting the first-data before the collection of the first implementation of the η. kind of a method of flow through a flow controller, at 1-time interval _ receiving material; The coin II data contains the calculation based on the first data 兮π 4 4s, where the decision is received or received as an input. The volume is a method of 12 in advance, wherein the first determination: the accumulation is performed by the following steps in a first time period; the first material of the first volume is collected during the interval: during the second time interval Collecting a second volume based on the first data and the second data meter 13. A method for measuring a flow rate of the first stream; a flow controller of the second stream controller, comprising: The first resource for collecting the -first volume during the interval is determined based on the calculation of the first data in advance or as a round-robin reception. 14 · As in the case of claim 13, the wood volume is at the first time • 猎, where the hunting is determined by the following steps to collect the first volume of the first volume during the interval between the collections of the 103147.doc 1278606; And storing the second volume for the second volume based on the first data or the second data. 15 - a system for determining the flow of the system through the flow controller, _, and Liu Ling, wherein the system includes: a private node connected to the flow controller The first valve of the chamber is immersed in the chamber to the upstream of the chamber; the second valve at the downstream of the chamber is located at -, ,, ° to the chamber; and at the first Pressure sensing on the valve above, and thus in the private part of the chamber. 16. The system of claim 15 wherein 糸, 先, can be used first to collect the relevant material during the -first time interval; Volume first Collecting a second volume corresponding to a second volume during a second time interval corresponding to the first valve and the second volume corresponding to the data included in the first time two data included in the second time 17. The system of claim 16, wherein the volume between the first and the flow controller, the first volume, and a volume of the chamber. 18. The system of claim 17, wherein the change in pressure during the first interval and the change in pressure during the inter-interval. 19. The system of claim 18, wherein the second data collection is performed prior to collecting the first data 103147.doc 1278606. 2〇. As in the system of claim 18, the 1 φ team is at # ’, and the collection of the second data is performed in the collection of the second data. v 21. The system of claim 18, wherein M w , , is further operable to: determine the first volume, and calculate the flow. 22. If the system of claim u is reclaimed, the first volume is determined based on the calculation of the first data and the second data. 23. The system of claim 21, wherein the system determines the first volume by receiving-inputting. 24. A method of determining a flow rate through a mass flow controller, 1 comprising: collecting a first data relating to a - volume during a first time interval; calculating a first flow rate; and based on an error curve Adjust the first flow rate. 25. The method of claim 24, further comprising determining the error curve. 26. The method of claim 25, wherein determining the error curve comprises fitting a derived error curve to a set of error points, the set of error points comprising a set of error points that have been determined. 27. The method of claim 25, wherein each of the determined error points is determined by: collecting a second data about the first volume during a second time interval at the first set point, wherein - And occluding a second flow rate based on the second data; 103147.doc 1278606 collecting a third data about the first volume during the third set time at the first set point, wherein the blocked hole In a blocking position; calculating a third flow rate based on the third data; and comparing the second flow rate with the third flow rate. 28. The method of claim 27, wherein the blocking aperture is operable to generate a pressure gradient when in the blocking position, wherein the pressure upstream of the blocking aperture is about two of the pressure downstream of the blocking aperture Times. The method of claim 28, wherein the blocking aperture is operable to generate the pressure gradient when the first set point is at least 500 seem. 30. The method of claim 28, wherein each point of the error point determined by the group represents an error when the first set point is at least 500 seem. 31. The method of claim 30, wherein the set of error points comprises a set of observed error points. 32. The method of claim 26, wherein each observed error point is determined by: collecting a fourth data about the first volume during a fourth time interval at a second set point, and A fourth flow rate is calculated based on the fourth data. 33. The method of claim 32, wherein each point of the error point observed by the group represents an error when the sigh point is 2 〇〇 sccm or less. The method of claim 26 wherein determining the error curve further comprises adjusting the error curve based on the type of gas. 35\ A system for determining a flow rate through a mass flow controller, wherein the °H system is coupled to the mass flow controller downstream of the mass flow controller, 103147.doc !2786〇6 The system comprises: a chamber; a first valve coupled to the chamber upstream of the chamber; a pressure sensor coupled to the chamber downstream of the chamber; and: upstream of the pressure sensor Connected to the blocking hole of the chamber. The system of claim 35, wherein the system is operative to: collect a first data relating to a first volume during a first time interval; and, calculate a first flow rate. The system of monthly claim 36 wherein the blocking aperture is operable to generate a pressure gradient 'where the pressure upstream of the blocking aperture is about twice the pressure downstream of the blocking aperture. A. The system of 37, wherein calculating the first flow rate step comprises adjusting the first flow rate based on an error curve. The system of claim XX is wherein the system is further operable to determine the error curve. The system of claim 39, wherein determining the error curve comprises fitting a derived error curve to a set of error points, the set of error points comprising a set of rank differences that have been determined. • The system of claim 40, wherein The system is operable to determine, by the step, each of the determined error points: - collecting a first lean material for the volume of the brother during a second time interval, wherein the blocked hole is in a light An open position; calculating a second flow based on the second data; 103147.doc 1278606 collecting a second negative for the first volume during the third set (five) interval at the first set point, The blocking hole is in a blocking position; calculating a third flow rate based on the third data; and comparing the second flow rate with the third flow rate. 2. The system of claim 40, wherein the error point determined by the group Each point represents an error when the first set point is at least 500 sccm. 43. The system of claim 42, wherein the set of error points comprises a set of observed error points. , wherein the system is operative to determine each observed error point by: collecting a fourth data about the first volume during a fourth time interval at a second set point; and based on the The fourth data is calculated as a fourth flow. 45. The system of claim 44, wherein each point of the set of observed error points represents an error when the second set point is 200 seem or less. The system of claim 45, wherein determining the error curve further comprises adjusting the error curve based on a gas type. 47. The system of claim 37, wherein the first data is collected when the blocked hole is in the blocked position. The system of claim 47, wherein the blocking aperture is a three-way valve operable to generate the pressure gradient when the first flow rate is above 5 〇〇 sccrn. 49_ A measurement is performed by a mass flow controller a method of flow, comprising: collecting a first resource 103147.doc 1278606 for a first volume during a first time interval, wherein the first data is collected when a blocked hole is in a blocking position, and The blocking aperture is operable to generate a pressure gradient when in the blocked position, wherein the pressure upstream of the blocking aperture is approximately twice the pressure downstream of the blocking aperture; and calculating a first flow rate. The method of claim 49, wherein the blocking hole is a three-way valve operable to generate the pressure gradient when the first flow rate is above 500 seem. 103147.doc