Liquid material gasification device, control method thereof, and program storage medium

Abstract

The present invention provides a liquid material vaporization device, a control method thereof, and a program storage medium. The liquid material vaporization device comprises: a control valve (1) arranged in a flow channel through which a material fluid circulates, wherein the material fluid is a liquid material or a material gas obtained by vaporizing the liquid material; a pressure sensor (3) arranged on the downstream side of the control valve (1); a flow sensor (2) for measuring the flow rate of the material fluid; and a valve controller (4) for controlling the control valve so as to reduce the deviation between the set pressure and the measured pressure measured by the pressure sensor and to make the measured flow rate measured by the flow sensor below a limiting flow rate, wherein the limiting flow rate is a flow rate set according to the upper limit flow rate at which the liquid material can be vaporized.

Description

Technical Field

[0001] The present invention relates to a liquid material vaporization apparatus used in, for example, a semiconductor manufacturing process. Background Art

[0002] In ALD (Atomic Layer Deposition) and ALE (Atomic Layer Etching), achieving atomic-layer stacking and etching requires high-speed switching between the on period (when the material gas supply to the chamber is on) and the off period (when the material gas supply is stopped). Furthermore, the required constant amount of material gas must be supplied to the chamber with good reproducibility during the on period. Furthermore, these semiconductor processes use material gases vaporized from liquid materials.

[0003] When vaporizing a liquid material to generate a material gas, if, for example, the pressure or flow rate of the material gas fluctuates significantly, the liquid material may not be sufficiently vaporized and a desired amount of material gas may not be supplied into the chamber, or the liquid material may be supplied into the chamber as is.

[0004] Therefore, in semiconductor manufacturing systems used for ALD and ALE, for example, a liquid material vaporization device as shown in Patent Document 1 is used to control the material gas so that a constant flow rate is always generated, and the material gas is discharged during the shutdown period without being supplied to the chamber. Specifically, Figure 12 As shown, the semiconductor manufacturing system includes a liquid material vaporization apparatus 100A that mixes a liquid material with a carrier gas and vaporizes the liquid material; a supply line SL equipped with a first on-off valve V1 that connects the liquid material vaporization apparatus 100A to a chamber CN; and a drain line VL equipped with a second on-off valve V2 that branches off the supply line SL. The liquid material vaporization apparatus 100A uses a control valve 1A to control the supply of liquid material, maintaining a constant flow rate of the material gas flowing through the supply line SL. Furthermore, the first on-off valve V1 and the second on-off valve V2 are alternately opened and closed to achieve switching between open and closed periods specified by the manufacturing process method. This ensures that a constant amount of material gas is supplied to the chamber CN during the open period.

[0005] However, in such a method of supplying material gas, a large amount of expensive liquid material is wasted during the period of discarding the material gas. Specifically, as shown in the timing diagram showing the opening and closing states of the first opening and closing valve V1, the second opening and closing valve V2 and the control valve 1A, Figure 13 As shown in (a), with the first on-off valve V1 closed and the second on-off valve V2 open, the control valve 1A is also open, so the liquid material vaporizes in the region indicated by the hatched portion and is discharged directly from the discharge line VL.

[0006] On the other hand, when the batch size of substrates processed in the chamber CN is large and the opening period and closing period themselves are long, as shown in FIG. Figure 13 As shown in (b), the opening and closing of control valve 1A is synchronized with the opening and closing of second control valve V2 to reduce liquid material consumption. Even with this control method, in order to supply a constant flow rate of material gas during the open period, control valve 1A is opened before the open period begins, and a first-order lag is generated in the flow control. As a result, as indicated by the diagonal lines, some material gas must be discarded from exhaust line VL.

[0007] Patent Document 1: Japanese Patent No. 5350824 Summary of the Invention

[0008] The present invention is completed in view of the above problems and provides a liquid material vaporization device that can maintain a state in which the liquid material can be fully vaporized, and can control the flow rate and pressure of the material gas to change to the desired values, for example, it can reduce the amount of material gas discarded from the exhaust line.

[0009] That is, the liquid material vaporization device of the present invention includes: a control valve, which is arranged in a flow channel through which a material fluid circulates, and the material fluid is a liquid material or a material gas obtained by vaporizing a liquid material; a pressure sensor, which is arranged on a downstream side of the control valve; a flow sensor, which measures the flow rate of the material fluid; and a valve controller, which controls the control valve so that the deviation between the set pressure and the measured pressure measured by the pressure sensor becomes smaller, and the measured flow rate measured by the flow sensor becomes below a limiting flow rate, and the limiting flow rate is a flow rate set according to the upper limit flow rate at which the liquid material can be vaporized.

[0010] In addition, the control method of the present invention is a control method for a liquid material vaporization device, wherein the liquid material vaporization device includes: a control valve, which is arranged in a flow channel through which a material fluid circulates, and the material fluid is a liquid material or a material gas obtained by vaporizing the liquid material; a pressure sensor, which is arranged on a downstream side of the control valve; and a flow sensor, which measures the flow rate of the material fluid, wherein the control valve is controlled to reduce the deviation between the set pressure and the measured pressure measured by the pressure sensor, and to make the measured flow rate measured by the flow sensor below a limiting flow rate, and the limiting flow rate is a flow rate set according to the upper limit flow rate at which the liquid material can be vaporized.

[0011] According to this structure, even if the set pressure changes and the flow rate and pressure of the material gas supplied from the downstream side of the control valve change, the flow rate of the material fluid is limited to the flow rate at which the liquid material can be vaporized, thereby preventing the liquid material from being supplied to the downstream side of the control valve in its original state.

[0012] Furthermore, since liquid material can be prevented from being supplied downstream of the control valve, the control valve can be used to adjust the flow rate of the material gas even in processes such as ALD / ALE, where the material gas supply and stop are repeated. This eliminates the need for a drain line between the control valve and the target to be supplied, eliminating the need to discard the material gas during periods of supply cessation.

[0013] As a specific control structure for controlling by one of the control valves to make the flow rate of the material fluid below the limit flow rate, thereby ensuring the vaporization of the liquid material and keeping the pressure of the material fluid flowing through the downstream side of the control valve constant, it can be listed that the valve controller includes: a first operation quantity calculation unit, which calculates the first operation quantity as the operation quantity of the control valve based on the deviation between the measured flow rate and the limit flow rate; a second operation quantity calculation unit, which calculates the second operation quantity as the operation quantity of the control valve based on the deviation between the measured pressure and the set pressure; and an operation quantity determination unit, which compares the first operation quantity and the second operation quantity and inputs the operation quantity of either side into the control valve.

[0014] In order to control the control valve so that the manipulated variable determining unit adopts the target of the upper limit flow rate or the set pressure that deviates significantly from the measured value, thereby reducing any deviation in a short period of time, the manipulated variable determining unit may input the larger of the first manipulated variable and the second manipulated variable into the control valve, provided that the control valve is a normally open valve that is fully open when no voltage is applied. Similarly, the manipulated variable determining unit may input the smaller of the first manipulated variable and the second manipulated variable into the control valve, provided that the control valve is a normally closed valve that is fully closed when no voltage is applied.

[0015] As another control method for making the flow rate of the material fluid below the limit flow rate, ensuring the vaporization of the liquid material, and keeping the pressure of the material fluid on the downstream side of the control valve constant, it can be listed that the valve controller includes: a flow control unit, which controls the control valve according to the deviation between the measured flow rate and the set flow rate; and a flow setting unit, which sets the set flow rate below the limit flow rate in the flow control unit in a manner that reduces the deviation between the measured pressure and the set pressure.

[0016] As a specific structural example of making the pressure of the material fluid on the downstream side of the control valve follow the set pressure by changing the set flow, it can be cited that when the measured pressure is greater than the set pressure, the flow setting part changes the set flow in a decreasing direction, and when the measured pressure is less than the set pressure, the flow setting part changes the set flow in an increasing direction.

[0017] If the structure is such that liquid material flows on the upstream side of the control valve and material gas obtained by vaporizing the liquid material flows on the downstream side of the control valve, and the flow sensor is arranged on the upstream side of the control valve to measure the flow rate of the liquid material, then since the flow rate of the liquid material is directly measured, it is possible to more accurately prevent the liquid material from becoming a flow rate that cannot be vaporized.

[0018] For example, as a specific structural example of directly feeding back the flow rate of the material gas flowing through the downstream side of the control valve by adopting a flow sensor capable of coping with high temperatures, the flow rate of the material gas is less likely to be delayed in time, thereby preventing the vaporized material gas from being liquefied again. In this example, liquid material is circulated on the upstream side of the control valve, and material gas obtained by vaporizing the liquid material is circulated on the downstream side of the control valve, and the flow sensor is arranged on the downstream side of the control valve to measure the flow rate of the material gas.

[0019] For example, a heater heats the liquid material contained in a container, and the vaporized material gas is discharged from the container to the flow channel. The flow sensor is provided on the upstream side of the control valve to measure the flow rate of the material gas.

[0020] As a specific example of a structure that prevents the flow of liquid material downstream of the control valve by directly supplying material gas to the control valve, a heater heats the liquid material contained in a container, vaporizing the material gas and directing it from the container into the flow path. The flow sensor is positioned upstream of the control valve to measure the flow rate of the material gas. This structure controls the control valve to prevent the flow rate from exceeding the material gas flow rate that can be generated from the liquid material in the container. This prevents, for example, failures such as the control valve remaining fully closed or fully open due to insufficient vaporization supply capacity, resulting in a persistent deviation that does not decrease.

[0021] For example, in order to supply the vaporized material gas to multiple supply targets in parallel, the flow channel only needs to be composed of a main channel and multiple branch flow channels branching from the downstream side of the main channel, and each branch flow channel can be individually connected to the supply target of the material gas.

[0022] In order to supply material gases having different pressures to respective supply targets from one liquid material supply source, it is sufficient if the respective branch flow channels are provided with the control valves.

[0023] For example, in order to limit the flow rate of the material fluid after passing through the control valve to a predetermined value and stabilize the vaporization state, it is sufficient to further include a nozzle provided in the flow path.

[0024] In order to mitigate pressure fluctuations of the material gas supplied to the supply target, a buffer container provided on the downstream side of the control valve may be further provided.

[0025] If the downstream side of the control valve is connected to a supply target of a material fluid in a gaseous state, and all the material fluid passing through the control valve flows into the supply target, all the material gas will be supplied to the supply target, thereby eliminating waste of the material gas.

[0026] In order to obtain the same effect as the present invention by updating the program in an existing liquid material vaporization device, it is sufficient to adopt the program for the liquid material vaporization device of the present invention, wherein the program for the liquid material vaporization device is used for the liquid material vaporization device, and the liquid material vaporization device includes: a control valve, which is arranged in a flow channel through which a material fluid flows, and the material fluid is a liquid material or a material gas obtained by vaporizing the liquid material; a pressure sensor, which is arranged on the downstream side of the control valve; and a flow sensor, which measures the flow rate of the material fluid, wherein the program for the liquid material vaporization device enables the computer to function as a valve controller, and the valve controller controls the control valve to reduce the deviation between the set pressure and the measured pressure measured by the pressure sensor, and to make the measured flow measured by the flow sensor become below the limiting flow rate, and the limiting flow rate is the flow rate set according to the upper limit flow rate at which the liquid material can be vaporized.

[0027] In addition, the program for the liquid material vaporizing apparatus may be distributed electronically or stored in a program storage medium such as a CD, a DVD, or a flash memory.

[0028] Thus, according to the liquid material vaporization device of the present invention, the pressure of the material fluid on the downstream side of the control valve can be controlled to follow the set pressure, and the flow rate can be limited to the limited flow rate at which the liquid material can be vaporized. Therefore, it is possible to prevent the liquid material from being supplied to the downstream side of the control valve without being vaporized, and the desired pressure control can be achieved. Furthermore, the flow rate of the material gas supplied from the liquid material vaporization device does not need to be continuously maintained to maintain a constant vaporized state of the liquid material, as is conventionally required. Instead, the flow rate of the material gas can be varied. Therefore, it is not necessary to discharge the generated material gas from the exhaust line to stop the supply of the material gas to the supply target, as is conventionally required, thereby reducing the amount of liquid material wasted. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a diagram showing a liquid material vaporization device according to a first embodiment of the present invention.

[0030] Figure 2 This is a functional block diagram of the liquid material vaporization device according to the first embodiment.

[0031] Figure 3 This is a flowchart showing the operation of the liquid material vaporization device according to the first embodiment.

[0032] Figure 4 This is a first example of simulation results showing temporal changes in various measurement values and operation variables measured by the liquid material vaporization apparatus according to the first embodiment.

[0033] Figure 5 This is a second example of simulation results showing temporal changes in various measurement values and operation variables measured by the liquid material vaporization apparatus according to the first embodiment.

[0034] Figure 6 This is a third example of simulation results showing temporal changes in various measurement values and operation variables measured by the liquid material vaporization apparatus according to the first embodiment.

[0035] Figure 7 This is a fourth example showing simulation results of temporal changes in various measurement values and operation variables measured by the liquid material vaporization apparatus according to the first embodiment.

[0036] Figure 8 This is a schematic diagram showing a first modified example of the liquid material vaporization device according to the first embodiment of the present invention.

[0037] Figure 9 It is a schematic diagram showing a second modified example of the liquid material vaporization device according to the first embodiment of the present invention.

[0038] Figure 10 It is a schematic diagram showing a liquid material vaporization device according to a second embodiment of the present invention.

[0039] Figure 11 This is a functional block diagram of a liquid material vaporization device according to a second embodiment.

[0040] Figure 12 This is a schematic diagram showing a conventional liquid material vaporization device.

[0041] Figure 13 This is a timing chart showing the operation of a conventional liquid material vaporization device.

[0042] Description of Reference Numerals

[0043] 200 Semiconductor Manufacturing Systems

[0044] 100 Liquid material gasification device

[0045] 1 Control valve

[0046] 2 Flow sensor

[0047] 3. Pressure sensor

[0048] 4-valve controller

[0049] 41 First operation amount calculation unit

[0050] 42 Second operation amount calculation unit

[0051] 43 Operation amount determination unit

[0052] 44 Flow rate setting unit

[0053] 45 Flow Control Unit DETAILED DESCRIPTION

[0054] Reference Figures 1 to 7 A liquid material vaporizing apparatus 100 and a semiconductor manufacturing system 200 according to a first embodiment of the present invention will be described.

[0055] The semiconductor manufacturing system 200 of the first embodiment is used, for example, in an ALD / ALE process, and supplies a source gas obtained by vaporizing a liquid material to a chamber CN, which is the target of the supply. In this specification, the concept of source gas encompasses gases necessary for performing processes within the chamber CN, such as component gases for film formation and etching gases. Furthermore, the liquid material itself, source gas obtained by vaporizing the liquid material, and mixed gas obtained by mixing source gas with a carrier gas are collectively referred to as a material fluid.

[0056] The semiconductor manufacturing system 200 is as follows Figure 1 As shown, the liquid material vaporization device 100 is connected to the chamber CN by a supply line SL, and is provided with a buffer container BT and a supply valve V. In addition, depending on the purpose, the buffer container BT is sometimes not provided. In addition, for example, the opening or opening and closing of the supply valve V is controlled by a control device that uniformly controls the semiconductor manufacturing system 200, and the liquid material vaporization device 100 does not directly control the supply valve V. The liquid material vaporization device 100 can also be configured to control the supply valve V. In addition, when the supply of material gas is temporarily stopped during the process in the chamber CN, the exhaust line is not used. In other words, the semiconductor manufacturing system 200 of the first embodiment is configured so that the material gas is not discarded during the process in the chamber CN. Therefore, Figure 1 The exhaust line branched from the supply line SL is not shown in the figure.

[0057] Next, the liquid material vaporizing apparatus 100 will be described in detail. The liquid material vaporizing apparatus 100 is a jet-type vaporizing apparatus that supplies a liquid material without a carrier gas and vaporizes the liquid material by reducing the pressure.

[0058] The liquid material vaporization device 100 includes: a flow sensor 2, which is arranged on the liquid line LL for the liquid material to flow in the absence of a carrier gas, and measures the flow rate of the liquid material; a control valve 1, which is located between the liquid line LL and the supply line SL; a pressure sensor 3, which measures the pressure in the buffer container BT on the supply line SL on the downstream side of the control valve 1; and a valve controller 4, which controls the control valve 1 according to the measured values of the flow sensor 2 and the pressure sensor 3.

[0059] Here, the dry pump DP, located downstream of the control valve 1, in the chamber CN, is evacuated to a predetermined pressure (predetermined vacuum level). The liquid material, which has passed through the control valve 1 and been injected into the supply line SL, is vaporized by the reduced pressure, becoming a material gas. Furthermore, to facilitate vaporization of the liquid material, the supply line SL may be heated to a predetermined temperature.

[0060] The flow sensor 2 measures the flow rate of the liquid, and its measurement principle may be based on various methods such as pressure type, thermal type, and Coriolis flow type.

[0061] The control valve 1 is, for example, a piezoelectric valve capable of high-speed switching between open and close (fully open, fully closed). The control valve 1 of the first embodiment is a normally open valve that is fully open when no voltage is applied.

[0062] Valve controller 4 controls control valve 1 to maintain the pressure of the material gas in supply line SL at a constant predetermined pressure and to supply liquid material from liquid line LL to supply line SL at a flow rate within the upper limit of vaporization. More specifically, valve controller 4 controls control valve 1 to minimize the deviation between the set pressure and the pressure measured by pressure sensor 3 and to ensure that the flow rate measured by flow sensor 2 is below the flow rate set based on the upper limit of vaporization of the liquid material, i.e., the flow rate limit.

[0063] Specifically, in the first embodiment, a pressure feedback loop for controlling the pressure of the material gas within the supply line SL and a flow rate feedback loop for controlling the flow rate of the liquid material within the supply line SL are formed to control a single control valve 1. Both of these feedback loops act on the single control valve 1. By configuring the control system in this manner, two target values can be achieved using a single control valve 1.

[0064] Reference Figure 2 The valve controller 4 will be described in detail.

[0065] The valve controller 4 is a so-called computer equipped with a CPU, memory, A / D converter, D / A converter, and various input and output devices. It executes the program for the liquid material vaporization device stored in the memory, and functions as at least the first operation quantity calculation unit 41, the second operation quantity calculation unit 42, and the operation quantity determination unit 43 by making various devices cooperate.

[0066] The first manipulated variable calculation unit 41 calculates a first voltage as the first manipulated variable of the control valve 1 based on the deviation between the measured flow rate and the limited flow rate. The limited flow rate is set based on the upper limit flow rate at which the liquid material can be vaporized, and is set to a value less than the upper limit flow rate. The upper limit flow rate is determined in advance through experiments or simulations based on whether the liquid material remains after passing through the control valve 1. This upper limit flow rate or limited flow rate can be pre-stored in memory and automatically set to the first manipulated variable calculation unit 41. Alternatively, the limited flow rate can be set sequentially by a user or the like as an external input.

[0067] The second manipulated variable calculation unit 42 calculates a second voltage as a second manipulated variable of the control valve 1 based on the deviation between the measured pressure and the set pressure.

[0068] The manipulated variable determination unit 43 compares the first voltage and the second voltage, and inputs the larger voltage into the control valve 1 .

[0069] Reference Figure 4 The flow chart of FIG. 1 illustrates the operation of the liquid material vaporizing apparatus 100 configured in this manner.

[0070] The first operation amount calculation unit 41 and the second operation amount calculation unit 42 are synchronized and calculate the operation amounts in parallel.

[0071] Specifically, the first manipulated variable calculation unit 41 obtains the restricted flow rate (step S1) and the measured flow rate from the flow sensor 2 (step S2). Furthermore, the first manipulated variable calculation unit 41 calculates the deviation between the restricted flow rate and the measured flow rate, and performs a PID operation on the flow rate deviation to calculate a first voltage (step S3). In this manner, the first manipulated variable calculation unit 41 calculates the first voltage using flow rate feedback from the liquid material.

[0072] Similarly, the second manipulated variable calculation unit 42 obtains the set pressure (step S4) and the measured pressure from the pressure sensor 3 (step S5). Furthermore, the second manipulated variable calculation unit 42 calculates the deviation between the set pressure and the measured pressure, and performs a PID operation on the pressure deviation to calculate the second voltage (step S6). In this way, the second manipulated variable calculation unit 42 calculates the second voltage using pressure feedback from the downstream side of the control valve 1.

[0073] The operation amount determination unit 43 determines which of the first voltage and the second voltage is larger (step S7 ), and inputs the larger voltage into the control valve 1 (step S8 ).

[0074] Finally, it is determined whether the control is to be continued (step S9 ), and if the control is to be continued, steps S1 to S8 are repeated.

[0075] Next, refer to Figures 4 to 7 , based on the use of Figure 3 This section describes the changes in the first and second voltages calculated by valve controller 4 based on the control rules described in the flowchart, as well as the changes in pressure and flow rate based on the control results. Here, the solid-line portion of the graphs of measured pressure and flow rate indicates the voltage applied to control valve 1, calculated by feeding back the measured values. Furthermore, the dashed-line portion indicates the voltage applied to control valve 1, calculated by feeding back a measured quantity different from the control valve itself. Similarly, the solid-line portion of the graphs of each voltage indicates the voltage actually applied to control valve 1 by manipulated variable determiner 43, while the dashed-line portion indicates the voltage not applied to control valve 1.

[0076] Figure 4 The graph shows the changes in each voltage when the supply valve V is closed, the material gas does not flow into the chamber CN, and the measured pressure changes from zero to the set pressure. Figure 4 As shown, at the beginning of the control, since the calculated value of the first voltage is greater than the value of the second voltage, the first voltage calculated by the flow feedback is applied to the control valve 1. As a result, the flow rate of the liquid material rises rapidly from zero to the restricted flow rate and is maintained at the restricted flow rate. In addition, while the restricted flow rate is maintained, the material gas obtained by vaporizing the liquid material is continuously supplied to the downstream side of the control valve 1, so the measured pressure rises. Moreover, while maintaining a state in which the deviation between the restricted flow rate and the measured flow rate is small, the deviation between the set pressure and the measured pressure becomes relatively large, and the calculated second voltage becomes greater than the first voltage. As a result, the second voltage calculated by the pressure feedback is subsequently applied to the control valve 1. In this way, the flow rate of the liquid material is maintained below the restricted flow rate, and the pressure on the downstream side of the control valve 1 is maintained at the set pressure.

[0077] Figure 5 The graph shows changes in each voltage, pressure, and flow rate when the supply valve V is closed, the material gas flows into the chamber CN, and the measured pressure changes from zero to the set pressure. Figure 5 The coordinate diagram shows the Figure 4 The graph of is substantially the same as that of , except that it takes time for the material gas to flow into the chamber CN and for the pressure to rise accordingly. Therefore, the timing of switching from the first voltage to the second voltage is delayed.

[0078] Figure 6The graph shows the changes in each voltage, as well as the changes in pressure and flow rate, when the flow rate on the downstream side of the control valve 1 increases in multiple steps. Even if the flow rate on the downstream side of the control valve 1 increases, the second voltage calculated by pressure feedback is temporarily applied to the control valve 1. More specifically, if the flow rate on the downstream side of the control valve 1 increases, the value of the second voltage applied to the control valve 1 to maintain the measured pressure at the set pressure decreases in a step-like manner, and the opening gradually increases. As a result, since the flow rate of the liquid material passing through the control valve 1 increases, the amount of material gas flowing into the downstream side of the control valve 1 increases, and the measured pressure is maintained at the set pressure. On the other hand, if the flow rate on the downstream side of the control valve 1 becomes greater than a predetermined value, the measured flow rate of the liquid material becomes a value close to the limiting flow rate. Since the value of the first voltage calculated from this point on is greater than the value of the second voltage, flow feedback control is switched to maintain the measured flow rate at the limiting flow rate.

[0079] Figure 7 The graph shows the changes in various voltages, as well as the changes in pressure and flow rate, when the supply valve V is pulsed open and closed. In this case, since the flow rate on the downstream side of the control valve 1 hardly changes, the valve controller 4 continuously applies the second voltage based on pressure feedback to the control valve 1.

[0080] Thus, according to the liquid material vaporization apparatus 100 of the first embodiment, in a normally open control valve 1, a first voltage based on flow rate feedback and a second voltage based on pressure feedback are compared, and the larger voltage is applied to the control valve 1. As a result, the flow rate of the liquid material can be maintained within a restricted flow rate that is smaller than the upper limit flow rate at which the liquid material can be vaporized, while the pressure on the downstream side of the control valve 1 is maintained at the desired set pressure.

[0081] As a result, even if the supply valve V is opened and closed, or the flow rate of the material gas changes due to changes in opening, the flow rate of the liquid material can be kept below the limit flow rate, and the pressure of the material gas can be maintained constant. Therefore, in the ALD / ALE process, the desired amount of material gas can be supplied to the chamber CN without discarding any portion of the material gas, and the liquid material can be prevented from being supplied directly to the chamber CN.

[0082] A modification of the first embodiment will be described.

[0083] The control valve 1 may also be a normally closed valve that is fully closed when no voltage is applied. When a normally closed valve is used as the control valve 1, the operation variable determination unit 43 only needs to be configured to select the smaller of the first voltage and the second voltage and input it to the control valve 1.

[0084] The flow rate used for flow feedback is not limited to the flow rate measured by the flow sensor 2 provided on the liquid line LL where the liquid material flows. Figure 8 As shown, a flow rate measurement using a flow sensor 2 can also be used: this flow sensor 2 is located downstream of the control valve 1 and in the supply line SL to measure the flow rate of the material gas. In this case, an upper limit flow rate for vaporizing the liquid material is defined for the flow rate of the material gas, and a value less than this upper limit by a predetermined value is used as the limiting flow rate for the first manipulated variable calculation unit 41. In this liquid material vaporization apparatus 100, the supply line SL downstream of the control valve 1 is temperature-controlled to maintain a predetermined temperature or above. Therefore, a flow sensor 2 capable of operating at temperatures above the predetermined temperature can be used.

[0085] Furthermore, the liquid material vaporizing device 100 is not limited to the injection type, and may be of various types. Figure 9 As shown, a baking-type liquid material vaporization device 100 can also be configured. Specifically, the liquid material vaporization device 100 comprises a container TN for storing liquid material; a heater H for heating the container TN; a supply line SL connected to discharge the material gas obtained by vaporizing the liquid material from above the container TN; and a flow sensor 2 and a control valve 1 disposed on the supply line SL. In the liquid material vaporization device 100, the flow rate of the material gas is measured by the flow sensor 2 upstream of the control valve 1. In this case, an upper limit flow rate for vaporizing the liquid material in the container is defined for the material gas flow rate, and a value less than this upper limit flow rate by a predetermined value is used as the limiting flow rate in the first manipulated variable calculation unit 41. According to this device, since the vaporized material gas is supplied to the control valve 1, the liquid material can be reliably prevented from flowing downstream of the control valve 1. Furthermore, the control valve 1 is controlled by the valve controller 4 so as not to exceed the vaporization supply capacity of the material gas. This prevents the control valve 1 from becoming stuck in the fully open state and becoming uncontrollable due to, for example, insufficient vaporization supply capacity.

[0086] Alternatively, the liquid material vaporization apparatus 100 can generate the material gas by bubbling the liquid material with a carrier gas. In this case, an upper limit flow rate for vaporizing the liquid material is defined based on the flow rate of the mixed gas consisting of the material gas and the carrier gas. A value smaller than the upper limit flow rate by a predetermined value can be used as the limiting flow rate in the first manipulated variable calculation unit 41.

[0087] Then refer to Figure 10 A liquid material vaporizing apparatus 100 according to a second embodiment will be described.

[0088] Compared with the first embodiment, the structure of the valve controller 4 of the liquid material vaporization device 100 of the second embodiment is different. Specifically, Figure 10 As shown in the functional block diagram, the difference is that it includes: a flow control unit 45, which controls the control valve 1 according to the deviation between the measured flow and the set flow; and a flow setting unit 44, which sets a set flow below the limit flow in the flow control unit 45 in a manner that reduces the deviation between the measured pressure and the set pressure.

[0089] Here, when the measured pressure is greater than the set pressure, the flow rate setting unit 44 decreases the set flow rate, thereby reducing the flow rate of the liquid material and reducing the supply amount of the material gas. Alternatively, when the measured pressure is less than the set pressure, the flow rate setting unit 44 increases the set flow rate, thereby increasing the flow rate of the liquid material and increasing the supply amount of the material gas.

[0090] Reference Figure 11 The operation of the liquid material vaporizing apparatus 100 of the second embodiment configured as described above is described in the flowchart.

[0091] The flow setting unit 44 obtains the set pressure (step ST1) and the measured pressure from the pressure sensor 3 (step ST2). Furthermore, the flow setting unit 44 calculates the deviation between the set pressure and the measured pressure, and performs a PID operation on the pressure deviation to calculate the set flow rate (step ST3). If the calculated set flow rate is greater than the limited flow rate, the flow setting unit 44 inputs the limited flow rate as the set flow rate to the flow control unit 45. If the calculated set flow rate is less than the limited flow rate, the flow setting unit 44 inputs the calculated set flow rate unchanged to the flow control unit 45. In this way, the flow setting unit 44 uses pressure feedback from the downstream side of the control valve 1 to determine the set flow rate input to the flow control unit 45.

[0092] Next, the flow control unit 45 obtains the measured flow rate from the flow sensor 2 (step ST4). Furthermore, the flow control unit 45 calculates the deviation between the limited flow rate and the measured flow rate, and performs a PID operation on the flow rate deviation to calculate the voltage to be applied to the control valve 1 (step ST5). In this way, the flow control unit 45 calculates the voltage to be applied to the control valve 1 using the flow rate feedback of the liquid material, and applies the voltage to the control valve 1 (step ST6).

[0093] Finally, it is determined whether the control is to be continued (step ST7 ), and if the control is to be continued, steps ST1 to ST6 are repeated.

[0094] In the liquid material vaporization device 100 of the second embodiment thus constructed, since the set flow rate input from the flow setting unit 44 to the flow control unit 45 is below the limit flow rate, the pressure on the downstream side of the control valve 1 can follow the set pressure, and the control valve 1 can be prevented from flowing a flow rate above the limit flow rate.

[0095] Therefore, the liquid material passing through the control valve 1 can be inevitably vaporized into material gas, and the pressure can be maintained at the set pressure. Therefore, similar to the first embodiment, in the ALD / ALE process, a desired amount of material gas can be supplied to the chamber CN without discarding a portion of the material gas, and the liquid material can be prevented from being supplied to the chamber CN as is.

[0096] A modification of the second embodiment will be described.

[0097] In the second embodiment, similarly to the case described in the modification of the first embodiment, not only the injection-type liquid material vaporizing apparatus 100 but also various types of liquid material vaporizing apparatuses 100 may be used.

[0098] Furthermore, the flow rate measured by the flow sensor 2 may be any of the flow rate of the liquid material, the flow rate of the material gas, and the flow rate of the mixed gas consisting of the material gas and the carrier gas, and a corresponding limit flow rate may be set.

[0099] Other embodiments are described. In each embodiment, there is shown a case where there is only one chamber as the supply target of the material gas, but a plurality of supply lines provided with control valves and pressure sensors may be arranged in parallel. Specifically, the supply line may be composed of a main channel and a plurality of branch channels branching from the downstream side of the main channel, and each branch channel is separately connected to the supply target of the material gas. That is, it is possible to connect so that the material gas is supplied to one chamber from different locations, or to connect each branch channel to a different chamber. In addition, a separate control valve may be provided for each branch channel, and the pressure control of the material gas may be performed independently in each branch channel.

[0100] Furthermore, various modifications may be made without departing from the spirit of the present invention, or parts of the embodiments may be combined.

Claims

1. A liquid material gasification device, characterized in that: include: A control valve is provided in a flow channel through which a material fluid flows, wherein the material fluid is a liquid material or a material gas obtained by vaporizing the liquid material; a pressure sensor disposed downstream of the control valve; Flow sensor, measuring the flow rate of material fluid; as well as a valve controller for controlling the control valve so as to reduce a deviation between a set pressure and a measured pressure measured by the pressure sensor and to control the measured flow rate measured by the flow sensor to be below a limit flow rate, wherein the limit flow rate is a flow rate set according to an upper limit flow rate at which the liquid material can be vaporized; The valve controller comprises: a first operation variable calculation unit for calculating a first operation variable as an operation variable of the control valve based on a deviation between a measured flow rate and a limited flow rate; a second operation amount calculation unit that calculates a second operation amount as an operation amount of the control valve based on a deviation between a measured pressure and a set pressure; and The operation amount determination unit compares the first operation amount with the second operation amount and inputs either operation amount into the control valve. Or the valve controller includes: a flow control unit for controlling the control valve according to a deviation between a measured flow rate and a set flow rate; and The flow rate setting unit sets a set flow rate equal to or lower than a limit flow rate in the flow rate control unit so as to reduce a deviation between a measured pressure and a set pressure.

2. The liquid material gasification device according to claim 1, characterized in that: The control valve is a normally open valve that is fully open when no voltage is applied. The operation amount determination unit inputs a larger operation amount of a first operation amount and a second operation amount into the control valve.

3. The liquid material gasification device according to claim 1, characterized in that: The control valve is a normally closed valve that is fully closed when no voltage is applied. The operation amount determination unit inputs a smaller operation amount between a first operation amount and a second operation amount into the control valve.

4. The liquid material gasification device according to claim 1, characterized in that: When the measured pressure is higher than the set pressure, the flow rate setting unit changes the set flow rate in a decreasing direction, and when the measured pressure is lower than the set pressure, the flow rate setting unit changes the set flow rate in an increasing direction.

5. The liquid material gasification device according to claim 1, characterized in that: Liquid material flows on the upstream side of the control valve, and material gas obtained by vaporizing the liquid material flows on the downstream side of the control valve. The flow sensor is provided on the upstream side of the control valve and measures the flow rate of the liquid material.

6. The liquid material gasification device according to claim 1, characterized in that: Liquid material flows on the upstream side of the control valve, and material gas obtained by vaporizing the liquid material flows on the downstream side of the control valve. The flow rate sensor is provided on the downstream side of the control valve and measures the flow rate of the material gas.

7. The liquid material gasification device according to claim 1, characterized in that: The liquid material contained in the container is heated by a heater, and the vaporized material gas is discharged from the container to the flow channel. The flow rate sensor is provided on the upstream side of the control valve and measures the flow rate of the material gas.

8. The liquid material gasification device according to claim 1, characterized in that: The flow channel is composed of a main channel and a plurality of branch flow channels branched from the downstream side of the main channel, and each branch flow channel is individually connected to a supply destination of the material gas.

9. The liquid material gasification device according to claim 8, characterized in that: Each branch flow channel is respectively provided with the control valve.

10. The liquid material gasification device according to claim 1, characterized in that: It also includes a nozzle arranged in the flow channel.

11. The liquid material gasification device according to claim 1, characterized in that: The device further includes a buffer container disposed on the downstream side of the control valve.

12. The liquid material gasification device according to claim 1, characterized in that: The downstream side of the control valve is connected to a supply destination of the gaseous material fluid. All the material fluid that has passed through the control valve flows into the supply object.

13. A method for controlling a liquid material gasification device, the liquid material gasification device comprising: A control valve is provided in a flow channel through which a material fluid flows, wherein the material fluid is a liquid material or a material gas obtained by vaporizing the liquid material; A pressure sensor is provided on the downstream side of the control valve; and a flow sensor is provided to measure the flow rate of the material fluid. The control method of the liquid material vaporization device is characterized in that: The control valve is controlled so that a deviation between a set pressure and a measured pressure measured by the pressure sensor is reduced and the measured flow rate measured by the flow sensor becomes less than a limiting flow rate, wherein the limiting flow rate is a flow rate set according to an upper limit flow rate at which the liquid material can be vaporized. Controlling the control valve includes: calculating a first operation variable as an operation variable of the control valve based on a deviation between the measured flow rate and the limited flow rate; calculating a second operation variable as an operation variable of the control valve based on a deviation between the measured pressure and the set pressure; and Comparing the first operation amount with the second operation amount, and inputting either operation amount into the control valve, Alternatively, controlling the control valve includes: controlling the control valve according to the deviation between the measured flow rate and the set flow rate; and The set flow rate is set to a value equal to or lower than the limit flow rate so that the deviation between the measured pressure and the set pressure is reduced.

14. A program storage medium storing a program for a liquid material vaporization device, the liquid material vaporization device comprising: A control valve is provided in a flow channel through which a material fluid flows, wherein the material fluid is a liquid material or a material gas obtained by vaporizing the liquid material; A pressure sensor is provided on the downstream side of the control valve; and a flow sensor is provided to measure the flow rate of the material fluid. The program storage medium is characterized in that: The program of the liquid material vaporization device causes the computer to function as a valve controller, and the valve controller controls the control valve so that the deviation between the set pressure and the measured pressure measured by the pressure sensor is reduced, and the measured flow rate measured by the flow sensor is set to be below a limit flow rate, wherein the limit flow rate is a flow rate set according to the upper limit flow rate of the vaporizable liquid material. The valve controller comprises: a first operation variable calculation unit for calculating a first operation variable as an operation variable of the control valve based on a deviation between a measured flow rate and a limited flow rate; a second operation amount calculation unit that calculates a second operation amount as an operation amount of the control valve based on a deviation between a measured pressure and a set pressure; and The operation amount determination unit compares the first operation amount with the second operation amount and inputs either operation amount into the control valve. Or the valve controller includes: a flow control unit for controlling the control valve according to a deviation between a measured flow rate and a set flow rate; and The flow rate setting unit sets a set flow rate equal to or lower than a limit flow rate in the flow rate control unit so as to reduce a deviation between a measured pressure and a set pressure.

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