Systems and methods for controlling vapor phase processing

Abstract

A semiconductor processing device may include a reactor assembly comprising a reaction chamber sized to accommodate a substrate internally. An exhaust line is fluidly connected to the reaction chamber and configured to transfer gas out of the reaction chamber. A valve may be positioned along the exhaust line to regulate the flow of gas along the exhaust line. A control system may be configured to operate in an open-loop control mode to control the operation of the valve.

Description

Technology Field

[0001] This relates to a system and method for controlling a gas phase process, and in particular, to a system and method for controlling a gas phase process in which the total flow rate changes during the process. Background Technology

[0002] Atomic Layer Deposition (ALD) is a method for growing highly uniform thin films on a substrate. In a time-division ALD reactor, the substrate is placed within an impurity-free reaction space, and at least two different volatile precursors (reaction vapors) are alternately and repeatedly injected into the reaction space in the gas phase. Since film growth is based on self-limiting surface reactions occurring on the surface of the substrate to form a solid-state layer of atoms or molecules, the reactants and temperature of the substrate are selected so that molecules of the selectively injected gas-phase precursor react only on the substrate with that surface layer. The reactants are injected at a sufficiently high injection volume during each injection cycle so that the surface is substantially saturated. Thus, the process is highly self-regulating and does not depend significantly on the concentration of the starting materials, temperature, or exposure duration (at least within a relatively wide process window), thereby enabling the achievement of very high film uniformity and thickness accuracy of single atomic or molecular layers. Similar results can be obtained in a space-division ALD reactor, where the substrate is moved to zones that are alternately exposed to different reactants. Reactants can contribute to the growing membrane (precursor) and / or perform other functions, such as degrading ligands from adsorbed species of the precursor to promote the reaction or adsorption of subsequent reactants.

[0003] The ALD method can be used to grow both elemental and compound thin films. ALD can involve two or more different reactants that are repeated in a cycle, and different cycles can have different numbers of reactants. Pure ALD reactions tend to produce less than a single layer per cycle, but variations of ALD can deposit more than a single layer per cycle.

[0004] Growing films using the ALD method can be a slow process due to its stepwise (layer-by-layer) nature. At least two gas pulses are alternated to form a single layer of the desired material, and the pulses are kept separated from each other to prevent uncontrolled film growth and contamination of the ALD reactor. After each pulse, excess gaseous reactants, as well as gaseous reaction products of the thin film growth process, are removed from the reaction space or from the zone where the substrate contains them. In time-segmented examples, this can be achieved by vacuuming the reaction space, purging the reaction space with an inert gas flow between consecutive pulses, or both. Purge utilizes a column of inert gas in the conduit between reactant pulses. Purge is widely used at manufacturing scale due to its efficiency and the ability to form an effective diffusion barrier between consecutive pulses. Typically, an inert purge gas is used as a carrier gas during the reactant pulses to dilute the reactant vapors before they are supplied to the reaction space. The problem to be solved

[0005] Controlling the transition from purge to injection and / or vice versa while ensuring high film quality and efficiency for the sake of reactant time and consumption can be a challenge. Therefore, improved systems and methods for controlling the deposition process are continuously required. means of solving the problem

[0006] The systems and methods of the present disclosure have several features, and no single one is solely responsible for their desirable attributes. Without limiting the scope of the present disclosure as expressed by the following claims, various features will now be briefly discussed. After considering this discussion, and in particular after reading the section titled "Detailed Description," you will understand how the features described herein provide several advantages over traditional gas delivery methods and systems.

[0007] In one embodiment, an atomic layer deposition (ALD) apparatus is disclosed. The ALD apparatus may include a reactor assembly comprising a reaction chamber having a size to accommodate a substrate inside. The ALD apparatus may include an exhaust line fluidly communicating with the reaction chamber, and the exhaust line is configured to deliver gas out of the reaction chamber. The ALD apparatus may include a valve disposed along the exhaust line to control the flow of gas along the exhaust line, and the valve has a plurality of flow conduction settings. The ALD apparatus may include a control system configured to control the operation of the valve. During the dose state of the ALD apparatus, the control system may be configured to transmit a first signal to a valve corresponding to a first flow conduction of the plurality of flow conduction settings. During the purge state of the ALD apparatus, the control system may be configured to transmit a second signal to a valve corresponding to a second flow conduction of the plurality of flow conduction settings.

[0008] In another embodiment, a semiconductor processing device is disclosed. The semiconductor processing device may include a reactor assembly comprising a reaction chamber having a size to accommodate a substrate inside. The semiconductor processing device may include an exhaust line fluidly communicating with the reaction chamber, and the exhaust line is configured to deliver gas out of the reaction chamber. The semiconductor processing device may include a valve disposed along the exhaust line to control the gas flow along the exhaust line. The semiconductor processing device may include a control system configured to operate in an open-loop control mode to control the operation of the valve.

[0009] In another embodiment, a method for controlling an atomic layer deposition (ALD) apparatus is disclosed. The ALD apparatus may include a reaction chamber, an exhaust line for delivering gas out of the reaction chamber, and a valve along the exhaust line. The method may include a step of determining a first flow conduction setting of the valve corresponding to a first flow conduction based at least partially on a first desired pressure in the reaction chamber and a first gas load for the injection state for an injection state of the ALD apparatus. The method may include a step of determining a second flow conduction setting of the valve corresponding to a second flow conduction based at least partially on a second desired pressure in the reaction chamber and a second gas load for the purge state for a purge state of the ALD apparatus. The method may include a step of positioning the valve to the first flow conduction setting for at least a portion of the injection state. The method may include a step of pulsed a first reactant vapor into the reaction chamber during the injection state. The method may include a step of positioning the valve to the second flow conduction setting for at least a portion of the purge state. The method may include a step of purging the reaction chamber by supplying an inert gas to the reaction chamber during the purge state. Brief explanation of the drawing

[0010] These and other features, aspects, and advantages of the present invention will now be described with reference to the drawings of several embodiments, which are intended for illustration and not to limit the invention. FIG. 1a is a schematic side view of a semiconductor processing apparatus including a reactor assembly illustrated during the processing step. FIG. 1b is a schematic side view of the semiconductor processing device of FIG. 1a shown during the loading / unloading phase. FIG. 2 is a table showing representative values ​​of the difference between the measured wafer pressure and the control pressure for the semiconductor processing device shown in FIG. 1a and FIG. 1b, and the gas load (flow rate), valve control pressure, valve set point or position, the measured pressure in the reaction chamber. Figure 3 is an example of a graph illustrating the set point of a valve versus the measured reaction chamber pressure along the exhaust line of a semiconductor processing device, schematically across multiple gas loads. Figure 4 is a schematic system diagram of a control system that communicates electrically with a valve. FIG. 5 is a flowchart illustrating a method for operating an ALD device according to various embodiments. FIG. 6a is a schematic plan view of a valve in a fully open configuration according to various embodiments disclosed herein. Fig. 6b is a schematic plan view of the valve of Fig. 6a in a fully closed configuration. FIG. 7 is a graph of relative flow conduction over time for a purge cycle, an injection cycle, and another purge cycle using the valves shown in FIG. 6a and 6b. Specific details for implementing the invention

[0011] The various embodiments disclosed herein relate to systems and methods for controlling a deposition process in a semiconductor processing apparatus. While the embodiments are described in the context of a deposition apparatus (e.g., atomic layer deposition (ALD) apparatus, chemical vapor deposition (CVD) apparatus, etc.), those skilled in the art will understand the applications of the principles and advantages taught herein for other types of processing where the total flow rate and / or pressure may vary frequently during the process.

[0012] FIG. 1a is a schematic side view of a semiconductor processing apparatus (18) including a reactor assembly shown during the processing step of the apparatus (1). FIG. 1b is a schematic side view of the semiconductor processing apparatus (1) of FIG. 1a shown during the loading step of the apparatus (1). While the embodiments shown in FIG. 1a and 1b illustrate an ALD apparatus, it should be understood that the embodiments disclosed herein may be used with any suitable type of semiconductor processing apparatus (e.g., any suitable type of deposition apparatus). Additionally, the semiconductor processing apparatus, control system, and method are described in U.S. Patent No. 8,211,230, U.S. Patent No. 8,216,380, U.S. Patent Application No. 15 / 803,615 filed November 3, 2017, and U.S. Patent Application No. 15 / 785,231 filed October 16, 2017; and may be used with the processing system described in U.S. Patent No. 9,574,268, the full contents of each of which are incorporated herein by reference for all purposes.

[0013] The reactor assembly (18) may include an upper reaction chamber (2) positioned above a lower loading chamber (8). The reaction chamber (2) may be sized to accommodate a substrate for processing (e.g., a semiconductor wafer). To load into the reactor assembly (18), a susceptor (5), supported by a movable arm (6) as shown in FIG. 1b, is lowered so that the susceptor (5) is placed within the loading chamber (8). In an embodiment, the susceptor (5) may include an internal heating mechanism, such as a resistive heater. A substrate (e.g., a wafer) may be positioned on the susceptor (5), although not shown. The movable arm (6) may be raised vertically to position the substrate (not shown) within the reaction chamber (2). For example, the movable arm (6) may be raised so that the upper surface of the susceptor (5) is exposed to the reaction chamber (2). The partition (9) can separate the reaction chamber (2) and the loading chamber (8). In an embodiment, there may be some restricted fluid communication between the loading chamber (8) and the reaction chamber (2) at the process location (Fig. 1a), such as through a small gap or a series of openings shown between the susceptor (5) and the partition (9). As shown in Figs. 1a and 1b, a lower chamber (LC) pressure transducer (16) may be provided within the loading chamber (8) to measure the pressure within the loading chamber (8). In the illustrated embodiment, a pressure measuring device is not present in the reaction chamber (2) to avoid undesirable effects on the gas flow in the reaction chamber (2).

[0014] During deposition processes such as ALD, the gas g affecting i(e.g., reactants and / or inert gases) can be supplied alternately and repeatedly to the reactor assembly (18) through the inlet manifold (7). For example, during the pulsed or injection state of the ALD process, reactant gases can be supplied to the reactor assembly (18) through the inlet manifold (7). The reactant gases can react with target species on the substrate to form a monolayer of the desired reactant. During the purging state, inert gases can be supplied to the reactor assembly (18) through the inlet manifold (7) to purge excess reactant (and other) gases from the reaction chamber (2). The injection and purging steps can be repeated alternately to grow the layer at once until the layer reaches the desired full thickness. Affecting gases g i The gas g affecting the substrate in FIG. 1a can be dispersed across the substrate by a showerhead assembly comprising a showerhead plate (3) and a showerhead plenum (4) disposed on the showerhead plate (3). The showerhead plate (3) is a gas g affecting the substrate. i It may include a plurality of openings (not shown) capable of dispersing the water evenly and uniformly. Although the showerhead assembly is illustrated in FIG. 1a and FIG. 1b, it should be understood that other types of reactors, such as a horizontal flow reactor, may be used with the disclosed embodiments.

[0015] The reactants and / or inert gas in the reaction chamber (2) can be removed from the reactor assembly (18) along the exhaust line (17) by a vacuum source (10) (e.g., a vacuum pump). Exhaust gas g from the reactor assembly (18) eThe vacuum source (10) can be activated to apply negative pressure to the exhaust line (17) and the reaction chamber (2) to draw out gas. As illustrated in FIG. 1a, gas can exit the reaction chamber (2) through one or more exhaust port(s) (13) that provide fluid communication between the reaction chamber (2) and the exhaust line (17). In the illustrated embodiment, the exhaust port(s) (13) supply an exhaust ring communicating with the exhaust line (17). A valve (14) (e.g., a flow control valve) directs exhaust gas g along the exhaust line (17). e To meter the flow of, it can be adjustablely opened and closed at a plurality of set points or locations. The plurality of set points or locations may correspond to a plurality of corresponding flow conductions of the valve (14). The valve (14) illustrated in FIGS. 1a and 1b is exhaust gas g e It includes a throttle valve that can be opened at multiple positions to increase or decrease the flow of through the exhaust line (17). For example, the valve (14) may be located between 0% and 100% open, where 0% indicates complete closure and 100% indicates complete opening, and is at any of the various positions in between. In another embodiment, as described below in relation to FIGS. 6a and 6b, the valve (14) is for exhaust gas g e It may include a ball valve configured to control the flow of through the exhaust line (17). As shown in FIGS. 1a and 1b, an exhaust line pressure transducer (15) is provided along the exhaust line (17) so that exhaust gas g along the exhaust line (17) e The pressure can be measured.

[0016] As described herein, the control system (19) may be configured to control the operation of the semiconductor processing device (1). The control system (19) may include a module controller (11) and a valve controller (12). Although not illustrated, the control system (19) may include additional controllers for controlling the overall operation of the device (1). The module controller (11) may be configured to select (automatically or manually) a processing control mode, a processing type, a recipe used, and other parameters for a specific process. The module controller (11) may communicate with the valve controller (12), which is configured to control the operation of the valve (14). For example, as described below, the module controller (11) may transmit commands to the valve controller (12) regarding a stage or state of the process (e.g., injection or purge), the operation of the control mode of the device (1) (e.g., whether the device (1) should be operated in an open or closed loop control mode), a control pressure setting point (e.g., for closed loop control), and a plurality of valve position setting points (e.g., fixed control positions of the valve (14). Additionally, as described below and based on commands from the module controller (11), the valve controller (12) may transmit commands to the valve (14) to position the valve at one of a plurality of setting points corresponding to a plurality of flow conductions of the valve (14). Such commands may be based, for example, on a lookup table having a plurality of flow conductions or conduction ranges and a plurality of corresponding valve positions. The module controller (11) and the valve controller (12) may include any suitable processing electronic device to control the operation of the valve (14) and / or other components of the processing device (1). For example, the module controller (11) and / or valve controller (12) may include a related non-transient computer-readable memory device(s) and processor(s) configured to execute instructions stored on the related memory device(s).In various embodiments, for example, the valve controller (12) may include a programmable logic controller (PLC). Any other suitable type of controller or processing electronics may be used.

[0017] In multi-stage processes such as atomic layer deposition (ALD), it may be desirable for the total flow rate and its conduction through the reaction chamber (2) and exhaust line (17) to vary. For example, to maximize throughput and reduce reactant / byproduct residence time during the purging phase, it may be desirable to use a high flow rate (gas load) to rapidly purge excess gas or waste gas from the reaction chamber (2). However, during deposition stages such as the ALD injection phase, it may be desirable to use a longer reactant residence time at a lower flow rate (gas load) to achieve saturation (or sub-saturation) with minimal waste of reactants. Many ALD processes aim to maintain a relatively constant total flow rate and / or uniform pressure in the reaction chamber (2) during injection and purging to avoid pressure fluctuations and cavity contaminant problems (e.g., spalling). Therefore, many ALD recipes use a constant total gas load or flow rate. However, using a constant gas load may result in a sacrifice in purging efficiency and / or the quality of the film deposition.

[0018] In some arrangements, the pressure inside the reaction chamber (2) can be controlled using a closed-loop control mode. For example, in some arrangements, the exhaust line pressure transducer (15) is exhaust gas g eThe pressure can be used to measure along the exhaust line (17). The pressure measured along the exhaust line (17) can be fed back to the control system (19). Various control algorithms (e.g., proportional-derivative or PID control algorithms) can be used to adjust the set point of the valve (14) to control the pressure measured by the transducer (15). However, relying on closed-loop feedback control on the pressure measurement taken by the exhaust line pressure transducer (15) along the exhaust line (17) may be inaccurate and may not accurately reflect the pressure (or pressure change) of the gas within the reaction chamber (2), resulting in inaccurate or less optimal control of the pressure within the reaction chamber (2). Similarly, due to limited fluid communication between chambers and different flow rates during the process, the pressure within the loading chamber (8) may not accurately reflect the pressure within the reaction chamber (2), and the aforementioned pressure measuring device within the reaction chamber may disrupt the desired flow dynamics by creating dead legs or turbulence.

[0019] For example, the exhaust port (13) may act as a limit on gas outflow from the reaction chamber (2) to the exhaust line (17). The contraction of the exhaust port (13) may result in a pressure reading from the exhaust line pressure transducer (15) that is different (e.g., lower) from the actual pressure inside the reaction chamber (2). Additionally, as illustrated in FIGS. 1a and 1b, the exhaust line pressure transducer (15) may be separated from the reaction chamber (2) by an intermediate flow volume, for example, through the exhaust section (13) (and any intermediate exhaust plenum) and the volume of the exhaust line (17) upstream of the transducer (15). This additional volume upstream of the transducer (15) within the space between the transducer (15) and the reaction chamber (2) may slow down the response of the closed-loop control method. Furthermore, since the gas load may vary every 200 to 500 milliseconds, closed-loop feedback control of the valve (14) may not be suitable in a high-speed ALD process. Some throttle valves cannot or may not be able to switch at such high speeds, or such rapid switching may damage the valve. Additionally, it may not be desirable to place the pressure transducer within the reaction chamber (2) itself, because the presence of the pressure transducer (15) within such a small space may interfere with the flow pattern on the wafer and have a negative effect on film growth.

[0020] Therefore, there is a continued need for an improved method of controlling the pressure in the reaction chamber (2). Various embodiments disclosed herein indirectly control the pressure in the reaction chamber (2) during the injection and purge states by using open-loop control (e.g., control of a fixed position of the valve (14)). For example, in some embodiments, an LC converter (16) may be used to measure the pressure in the loading chamber (8) at various gas loads (flow rates) applied by the vacuum pump (10), and the measured pressure in the loading chamber (8) may be correlated with a corresponding set point or a set position of the valve (indicating the corresponding fluid conduction of the valve). In various embodiments, a flow controller (e.g., a pressure controller or a main flow controller, or an MFC) may be provided upstream of the reaction chamber (2) to adjust and / or provide the desired gas load. As described herein, the valve (14) may act as a limiter on the flow through the exhaust line (17) which can change the pressure in the chamber (2) (see example, FIG. 3). In the embodiments disclosed herein, the vacuum pump (10) may be activated at a constant speed unless otherwise noted. However, in other embodiments, the speed of the vacuum pump (10) may vary during the process.

[0021] During the processing step in which the substrate undergoes a deposition process (Fig. 1a), the LC converter (16) placed in the loading chamber (8) cannot accurately represent the pressure in the upper reaction chamber (2). For example, the reaction chamber (2) and the loading chamber (8) may be separated during the process to prevent gas from flowing from the reaction chamber (2) into the loading chamber (8). As shown in Fig. 1a, the partition (9) and the susceptor (5) may be spaced close to each other laterally by a small gap or by a number of openings in the space between the partition (9) and the susceptor (5). In some arrangements, the pressure in the loading chamber (8) may be set higher than that in the reaction chamber (2) to prevent gas from flowing into the loading chamber (8) in combination with the close spacing between the partition (9) and the susceptor (5). Other arrangements for minimizing contamination may also be compatible with the embodiments taught herein, but preventing gas from entering the loading chamber (8) may be advantageous for reducing contamination of the loading chamber (8) and the LC converter (16) while transferring wafers to and / or from the loading chamber.

[0022] To calibrate the device (1) for open-loop control, the movable arm (6) and the susceptor (5) can be moved vertically downward so that the susceptor (5) is inside the loading chamber (5), which breaks the fluid seal between the reaction and loading chambers (2, 8) and limits the reaction and loading chambers (2, 8) to a continuous volume or chamber. Thus, when the susceptor (5) is in the position shown in FIG. 1b, the LC converter (16) can display the pressure inside the reaction chamber (2), which is fluidly connected to and open with the loading chamber (8) in the position shown in FIG. 1b. The pressure in the reaction chamber (2) can be measured by the LC converter (16) for a plurality of set points or positions of the valve (14) at both ends of a plurality of gas loads (flow rates). The measured reaction chamber pressure, valve set points, and gas loads can be stored in a lookup table (LUT) and / or plotted as a graph to provide input data to the control system (19). In other embodiments, the pressure within the reaction chamber can be measured directly by a susceptor at a process location for calibration, such as a temporary or permanent instrument for direct pressure measurement within the reaction chamber.

[0023] FIG. 2 is a table showing representative values ​​for gas load (flow rate), valve control pressure, valve setpoint or position, measured wafer pressure (i.e., pressure within the reaction chamber (2)), and the difference between the measured wafer pressure and the control pressure. The table shown in FIG. 2 represents values ​​obtained for a closed-loop control system. As shown in FIG. 2, when the valve (14) is set to a control pressure of 1 Torr, the pressure in the reaction chamber (2) can vary by more than 800 mTorr as the gas load increases by at least 10 times. Such changes in gas load can result in large changes in the reaction chamber (2) during the closed-loop control mode. As shown in FIG. 2, the valve setpoint is typically opened to a higher gas load (e.g., purge load at a high flow rate) to match the wafer pressure under a lower gas load (e.g., injection load at a low flow rate). As shown in FIG. 2, it may be important to improve pressure fluctuation control to change the gas load.

[0024] FIG. 3 is an example of a graph plotting the measured reaction chamber pressure versus the set point of the valve (14) across multiple gas loads. Although the graph shown in FIG. 3 is schematic, it can be considered representative of the data provided in the LUT. As previously mentioned, the graph in FIG. 3 (and the corresponding LUT) can be generated by measuring the pressure of the reaction chamber (2) (directly or indirectly) at multiple set points or locations of the valve (14) at a first specific gas load or flow rate F1. The gas load or flow rate F1 can be increased to a second gas load or flow rate F2, and the pressure of the reaction chamber (2) can be measured at multiple set points of the valve (14) at the second flow rate F2. All desired flow rates F NCalibration may continue until the pressure and valve position are determined. Thus, the LUT may include a matrix containing a correction value for pressure versus valve set point (related to valve flow conduction) versus gas load applied to device (1) (e.g., by a controller provided upstream of the chamber (such as an MFC or pressure controller)). The total gas load or flow rate F may represent the total flow rate into the reaction chamber (2). In other embodiments, an analysis function or curve fitting may be determined to relate the reaction chamber set pressure, the valve set (conduction of the valve (14)), and the gas load (flow rate) provided by the pump (5). As illustrated in FIG. 3, for a specific flow rate, the pressure inside the chamber may decrease with increasing flow conduction of the valve (e.g., related to the method of opening the valve).

[0025] Accordingly, given the gas load provided by the recipe for these injection and purging states, during the ALD process, the control system (19) (or user) sets the desired set pressure P for the reaction chamber (2) in the injection or purging state. set You can select. For example, when a low first flow rate F1 is used during the injection state (as a controller controlling the flow rate F1 according to the process recipe), the control system (19) (or user) can determine the first conduction setting of the valve (14), for example. about P setA first set position V1 (position 1) of the valve (14) can be determined along the curve for the first flow rate F1 that creates pressure in the reaction chamber (2). The control system (19) can command the valve (14) to move to the first set position V1 during injection. After injection is completed, the control system (19) can cut off the flow of the reactant gas. When a high second flow rate F2 is used during the purge state (as a controller controlling the flow rate F2 according to the recipe), the control system (19) (or user) can determine the second conduction setting of the valve, for example. Approx. P set A second set position V2 (position 2) of the valve (14) can be determined along the curve for the second flow rate F2 that creates pressure in the reaction chamber (2). The control system (19) can command the valve (14) to move to the second set position V2 during purging. Although the above embodiment describes one valve (or conduction) setting per state (injection or purging), it should be understood that in various embodiments, multiple valve or conduction settings may be used per state (injection or purging).

[0026] The example illustrated in FIG. 3 and described above assumes that the pressure of the reaction chamber (2) is to be maintained at approximately a constant pressure during purging and injection to minimize pressure fluctuations and cavity contamination problems. Of course, the open-loop control described herein may also be adopted with different pressure set points at different stages of the process if desired. Additionally, although only one purging and one injection stage has been described in this exemplary ALD process, it should be understood that a specific cycle of the deposition process may include one or more injection stages and / or one or more purging stages. For example, some deposition processes (e.g., ALD processes) may include a cycle having four phases, for example, including two different reactant vapors (which may use different valve conductions and durations) and two different purgings (which may or may not have the same valve conduction and duration). Additionally, some deposition processes (e.g., ALD processes) may include a cycle pulsed with three different reactant vapors having one, two, or three purging phases in each cycle. Other deposition processes (e.g., ALD processes) may include cycles that pulse four different reactant vapors, each having one, two, three, or four purge phases in each cycle.

[0027] Beneficially, the LUT described herein and the graph illustrated in FIG. 3 may enable the use of an open loop or a fixed position, and may be controlled so that no active feedback is provided to the control system (19) by the exhaust line pressure transducer (15) (or other sensor) prior to switching the valve position. Thus, when the device (1) is placed in a purge state, the valve (14) may be set to a valve position or a set position based on the desired pressure at the purge flow rate. Thus, when the device (1) is placed in an injection state, the valve (14) may be set to a valve position or a set position based on the desired pressure at the purge flow rate. The open loop control method described herein may be superior to the closed loop control method because, in contrast to the pressure measurement taken in real time along the exhaust line (17) by the transducer (15), the valve set position corresponds more accurately to the pressure in the reaction chamber (2) at various flow rates. Additionally, the technology disclosed herein [regarding] exhaust gas g e The need for a pressure transducer (15) exposed to the gas can be eliminated, and it is more advantageous to use an LC transducer (16) isolated from the gas in the reaction chamber (2) which could damage the transducer. Accordingly, the open-loop control method disclosed herein can improve pressure control in the reaction chamber (2) during gas phase processing, particularly for processes having different desired total flow rates at different stages, and more particularly for processes having rapid switching between phases. For example, in various ALD processes, the injection stage may last for a period of about 50 msec to 5 sec.

[0028] Additionally, the various embodiments disclosed herein address additional disadvantages of closed-loop pressure control systems regarding the digital output of control signals. The set point or position of the valve (14) shown in FIGS. 1a and 1b (e.g., throttle valve) can control the position of other structural members or plates of the valve (14) to adjustably restrict the flow through the valve (14) and the exhaust line (17). However, many closed-loop control systems use digital outputs, which can make it difficult to accurately set the position of the valve (14) at a desired analog set point calculated by the closed-loop control system. For example, in a closed-loop control system, the control system may calculate an analog set point for the valve (14) that is not closely correlated with the digital output of the control system.

[0029] FIG. 4 is a schematic system diagram of a control system (19) that communicates electrically with a valve (14). As described above in relation to FIG. 1a and 1b, a module controller (11) may be configured to control the operation of a valve controller (12), which in turn may be configured to control the operation of a valve (14). In FIG. 4, the module controller (11) may include output signal blocks (11a to 11e), each of which includes a digital or analog output value to be transmitted to the valve controller (12) through a first communication channel (20a). The first communication channel (20a) may include any suitable wired or wireless electrical or data connection between the module controller (11) and the valve controller (12).

[0030] For example, in the first output signal block (11a) of the module controller (11) for the ALD process, a digital output DO2 may be provided to indicate whether the semiconductor processing device (1) is placed in an injection process that supplies reactant gas to the chamber (2) or in a purging process that removes excess gas from the chamber (2). For example, if the module controller (11) determines that the device (1) should be placed in an injection state, the DO2 signal may be set to 0 (zero) to indicate an injection state with low flow conduction corresponding to position 1 of the valve (14) (e.g., V1 in FIG. 3). In contrast, if the module controller (11) determines that the device (1) should be placed in a purging state, the DO2 signal may be set to 1 to indicate a purging state with high flow conduction corresponding to position 2 of the valve (14) (e.g., V2 in FIG. 3). It should be understood from the entire description of FIG. 4 that the signal can be set to 0 for the purging state and to 1 for the injection state. Accordingly, the digital output DO2 of block (11a) can command the valve controller (12) whether the device (1) is placed in an injection state or a purge state.

[0031] In the second output block (11b) of the module controller (11), the digital output DO1 may contain a command related to the control mode of the process, for example, whether the device (1) operates in closed-loop feedback control (DO1=0) where pressure setpoint control is provided, or in open-loop (fixed position) control (DO1=1) where the valve position is changed without real-time feedback. Static analog variables AO1-AO3 may be defined by the recipe step before processing, and, for example, AO1-AO3 may be set manually by the control system (19) or by the user (e.g., via a user interface). In the third block (11c), the analog output AO1 may represent a closed-loop control pressure point representing the desired setpoint pressure when closed-loop control is selected. In the fourth block (11d), the analog output AO2 may represent position 1 of the valve (14), for example, position V1 shown in FIG. 3. As previously mentioned, position 1 may represent a low flow conduction state to be used while pulsed with the reactant gas in the reaction chamber (2). In the fifth block (11e), the analog output AO3 may represent position 2 of the valve (14), for example, position V2 shown in FIG. 3. As previously mentioned, position 2 may represent a high flow conduction state to be used while purging excess gas from the reaction chamber (2). Digital and analog outputs from blocks (11a to 11e) may be transmitted to the valve controller (12) via the first communication channel (20a).

[0032] Returning to the valve controller (12), commands transmitted by the module controller (11) can be received by analog or digital input blocks (12a to 12e). In the first block (12a), the digital input DI2 can correspond to the digital output DO2 from the module controller (11). Since the injection and purge steps alternate rapidly, the output and input blocks (11a, 12a) can be provided as relatively high-speed communication channels. In the second to fifth input blocks (12b-12e), DI1 can represent a digital mode selection transmitted from block (11b) of the module controller (11). AI1 can represent an analog pressure setting control point transmitted from block (11c) of the module controller (11). AI2 can represent the position (1) of the valve (14) transmitted from block (11d) of the module controller (11). And AI3 can indicate the position (2) of the valve (14) transmitted from the block (11e) of the module controller (11). Since the values ​​of the blocks (11b to 11e, and 12b to 12e) can be used for the entire process (or multiple processes), a slower communication network may be used.

[0033] The valve controller (12) may also include a plurality of logic blocks (12f, 12g, and 12h). The processing electronic device executes commands stored in the memory device(s) of the valve controller (12) to determine, among other things, the control mode of the device, the process state (e.g., purge or injection), the valve setting position, and the pressure setting point for closed-loop control. For example, when DI1=0 (indicating closed-loop control with a pressure setting point) in the first logic block (12f), the digital output DO1 (see block (12i)) of the valve controller (12) may be set to 0 to indicate closed-loop control, and the analog output (AO1) (see block (12j)) of the valve controller (12) may be set to the pressure control setting point stored in AI1. In this arrangement, the valve controller (12) can transmit DO1 and AO1 to the blocks (14a, 14b) of the valve (14), respectively, via the second communication channel (20b). Thus, with the digital input DI=0 in the valve (14), the valve (14) can operate in a closed-loop feedback mode. With an analog input AI, such as the pressure setting control point in the valve (14), the device (14) can drive the closed-loop feedback of the deposition process using the pressure setting control point.

[0034] Alternatively, in the second logic block (12g) of the valve controller (12), when DI1=1 (indicating open-loop control with a position setting point) and DI2=0 (indicating that the valve should be positioned at position 1), the digital output DO1 of block (12i) is set to 1 and the analog output AO1 of block (12j) is set to AI2 to indicate position 1 of the valve (14) (e.g., V1). When DO1 and AO1 of the valve controller (12) are transmitted to the respective blocks (14a, 14b) of the valve (14) via the second communication channel (20b), the digital input DI=1 in the valve (14) places the valve (14) into an open-loop control mode (e.g., no feedback). With the analog input AI, which is position 1, the valve (14) moves to position 1, indicating a low-flow conduction reactant pulse state, as illustrated in FIG. 3 (V1).

[0035] Similarly, in the third logic block (12h) of the valve controller (12), when DI1=1 (indicating open-loop control with a position setting point) and DI2=1 (indicating that the valve should be positioned at position 2), the digital output DO1 of block (12i) is set to 1 and the analog output AO1 of block (12j) is set to AI3 to indicate position 2 of the valve (14) (e.g., V 2 When DO1 and AO1 of the valve controller (12) are transmitted to the respective blocks (14a, 14b) of the valve (14) via the second communication channel (20b), the valve (14) is placed in an open-loop control mode (e.g., no feedback) with an analog input AI such as position 2, the valve 14 can move to position 2 (V2), which indicates a high flow conduction fuzzy state as shown in FIG. 3.

[0036] Accordingly, the embodiments disclosed herein may utilize a digital control system to operate a valve (14) having an advantageously continuous range of valve positions. The embodiments disclosed herein may select whether to operate in a closed-loop control mode or an open-loop control mode.

[0037] FIG. 5 is a flowchart illustrating a method (50) for operating an ALD device according to various embodiments. In particular, the method (50) illustrates various steps for controlling the pressure within the reaction chamber (2) using an open-loop control method. Starting from block (51), a first conduction setting of the valve corresponding to the first flow conduction can be determined. For example, for the embodiments of FIG. 1a and 1b and FIG. 3 and 4, a pre-programmed first setting point of the valve (14) is determined along the exhaust line (17). The pre-programmed first setting point may indicate a movable member position within the valve (14) indicating how much the valve (14) is open (e.g., 0% to 100% open). The pre-programmed first setting point may correspond to the first flow conduction setting of the valve (14) based at least partially on the first desired pressure in the reaction chamber (2) and the first gas load applied to the exhaust line (17). The LUT (or graph representing the LUT) described above may be used to determine a pre-programmed first set point or set position of the valve (14) based on the desired pressure and the gas load (flow rate) applied to the device, for example, through a controller upstream of the reaction chamber (2). Other arrangements, empirically designed functions, or curve fitting (e.g., based on a curve similar to that in FIG. 3) may be used to relate the desired pressure in the reaction chamber (2), the first flow conduction setting of the valve (14), and the gas load. For example, the pre-programmed first set point may correspond to a relatively low flow conduction used while pulseing the reactant gas into the reaction chamber (2). Returning to the example illustrated in FIG. 3, the pre-programmed first set point of the valve may be determined to correspond to position 1 (or V1).The LUT described above can be generated by using an LC converter (16) to measure the pressure of the reaction chamber (2) and the pressure of the loading chamber (8) when the susceptor (5) is placed in the loading chamber (8) below the reaction chamber (2). Alternatively, the pressure can be measured directly in the reaction chamber (2) for calibration, for example, using a temporary or permanent device for this purpose.

[0038] Returning to block (52), a second conduction setting of the valve corresponding to the second flow conduction can be determined. For example, a pre-programmed second setting point of the valve (14) can be determined along the exhaust line (17). The pre-programmed second setting point can correspond to the second flow conduction setting of the valve (14) based at least partially on the second desired pressure and the second gas load in the reaction chamber (2). In some embodiments, as described above, the second desired pressure may be approximately equal to the first desired pressure, thereby maintaining a generally constant pressure in the reaction chamber (2) during the injection and purge phases. The LUT (or graph representing the LUT) described above can be used to determine the pre-programmed second setting point or setting position of the valve (14) based on the second desired pressure and the applied gas load (flow rate). For example, the pre-programmed second setting point can correspond to a relatively high flow conduction used while purging excess or waste gas from the reaction chamber (2). Returning to the example illustrated in FIG. 3, the pre-programmed second set point of the valve can be determined to correspond to position 2 (or V2).

[0039] In block (53), the module controller (11) may command the valve controller (12) to place the valve (14) in an injection state, for example, in a first conduction setting. For injection, the valve controller (12) commands the valve (14) to move to position 1 (V1) to provide relatively low flow conduction during injection. In block (54), the control system (19) can allow the semiconductor processing device (1) to pulse the reactant gas into the reaction chamber (2) to grow a layer of reactant on the substrate. After injection, in block (55), the module controller (11) may command the valve controller (12) to place the valve (14) in a second flow conduction state, for example, in a purged state valve setting. For purging, the valve controller (12) commands the valve (14) to move to position 2 (V2) to provide relatively high flow conduction during purging. In block (56), the control system (19) can cause the semiconductor processing device (1) to purge excess or waste gas from the reaction chamber (2). When moving to block (57), the control system (19) can determine whether the process is repeated. If the determination is yes, the method (50) returns to block (53) and places the valve (14) to a pre-programmed set point (position 1), for example, a first flow conduction setting, to pulse additional reactant gas into the chamber (2). If the determination is no, then the method (50) is terminated.

[0040] FIG. 6a is a schematic plan view of a valve (14) in a fully open configuration according to various embodiments disclosed herein. FIG. 6b is a schematic plan view of the valve (14) of FIG. 6a in a fully closed configuration. In some embodiments, the valve (14) shown in FIG. 6a and FIG. 6b may be used in connection with the semiconductor processing device (1) described above in connection with FIG. 1a through FIG. 5. In other embodiments, the semiconductor processing device (1) of FIG. 1a through FIG. 5 may use a different type of valve, such as the throttle valve described above. Additionally, it should be understood that the valve (14) of FIG. 6a and FIG. 6b may be used in any suitable type of semiconductor processing system comprising a device different from the semiconductor processing device (1) described above. In fact, the valve (14) of FIGS. 6a and 6b can be used in an ALD device, a CVD device, other types of deposition devices, non-deposition equipment (e.g., etching equipment), or any other suitable device that utilizes variable flow conduction through a conduit or pipe.

[0041] As previously mentioned, it may be desirable to have a variable flow conduction system for semiconductor processing devices. For example, as previously mentioned, it may be desirable to have high flow conduction (high flow rate) during the purging of the reaction chamber to improve throughput and remove excess gas prior to the subsequent injection step. Additionally, it may be desirable to have low flow conduction (low flow rate) during injection to increase the residence time of the reactant gas within the reaction chamber. Furthermore, recent semiconductor devices utilize numerous layers, for example, exceeding 100 layers, with various surface topologies. To fabricate devices with multiple layers and complex surface topologies, it may be important to further increase the residence time of the reactant gas within the reaction chamber to ensure that a larger surface area is covered by the reactant layer, while simultaneously having a low residence time in other phases of the process, such as ALD purging. Different vapor processing may similarly require different total flow rates at different stages of the process. Therefore, there remains a continuous demand for improved variable conduction devices for semiconductor processing.

[0042] In particular, in a deposition reactor where the valve suffers adverse effects (e.g., accumulation of a layer that can close the valve) due to exposure of the reaction gas in the reactor's exhaust line, the valve (14) may include a valve particularly suitable for variable conductor processing and / or processing. In the illustrated embodiment, the valve (14) includes a ball valve having a round valve body (31) having a bore (32) provided through the valve body (31). In the illustrated embodiment, the round valve body (31) includes a ball-shaped member (e.g., nearly spherical). A flange (35) may be provided on or around the exhaust line (17). The valve body (31) may be seated within the flange (35) with a gap provided between the valve body (31) and the inner surface of the flange (35) to allow rotation of the valve body (31) relative to the flange (35). The motor (30) can be operably coupled to the valve body (31) via the motor output shaft (36). For example, the output shaft (36) can be welded to the valve body (31) or otherwise mechanically connected. When activated, the motor (30) imparts rotation to the output shaft (36) and, in turn, to the valve body (31), causing the valve body (31) to rotate (R) about a longitudinal axis or rotation axis x parallel to the output shaft (36). The motor (30) can operate at a high speed (e.g., at least about 1000 rpm) to create a fast purge-injection-purge-injection cycle (e.g., 60 ms per cycle).

[0043] As illustrated in FIGS. 6a and 6b, the bore (32) formed through the valve body (31) may be oriented parallel to (e.g., perpendicularly) the rotational axis or longitudinal axis x of the motor (30). In FIG. 6a, the motor (30) may position the bore (32) so that it is parallel to the flow axis y of the exhaust line (17). When the bore (32) is parallel to the flow axis y of the exhaust line (17), the valve (14) may be considered to be in a state of maximum flow conduction, and the valve (14) is fully open to allow gas to flow through the exhaust line (17). In contrast, in FIG. 6b, the motor (30) may position the bore (32) so that it is oriented perpendicular to the flow axis y of the exhaust line (17). In the arrangement of FIG. 6b, the vertically oriented bore (32) can block substantially all gas from flowing through the valve (14) and the exhaust line (17). Thus, when the bore (32) is oriented parallel to the flow axis y of the exhaust line (17), the valve (14) can be considered to be in a state of minimal flow conduction, and the valve (14) substantially blocks gas from flowing through the exhaust line (17). As will become apparent from the following description, the valve (14) is not limited to these two states, but instead can rotate at a variable rotational speed through an infinite degree of opening.

[0044] As illustrated in FIGS. 6a and 6b, the valve (14) may further include an inert gas curtain region (33) positioned around the periphery of the valve body (31). The inert gas curtain region (33) may include a region of inert gas supplied into the gap between the flange (35) and the outer periphery of the valve body (31) through an inlet port. The inert gas curtain (33) may include an outer purge region around the valve body (31) that generates ballast around the valve body (31). When the valve (14) is in the open configuration illustrated in FIG. 6a, the inert gas curtain region (33) advantageously prevents reactants or other gases from entering the gap on the outer periphery of the valve body (31), thereby reducing the risk of contamination and maintaining the rapid performance of the valve (14). The inert gas curtain (33) may allow low friction rotation around the rotation axis x.

[0045] FIGS. 6a and 6b illustrate two states of the valve (maximum and minimum flow conduction, respectively), but the valve (14) may be positioned in multiple orientations with respect to the rotation axis x for benefit. In various embodiments, the valve body (31) and bore (32) may be positioned in a continuous orientation or within a range of angles, e.g., from 0° to 360°, around the rotation axis x. The valve body (31) and bore (32) may be rotated in two directions with respect to the rotation axis x. The valve body (31) and bore (32) may be positioned in numerous orientations such that the bore (32) is exposed to gas along the exhaust gas line (17). If the bore (32) forms an angle with respect to the gas line (17) so that only a small area of ​​the bore (32) is exposed to the exhaust gas line (17), the flow rate through the valve (14) will be relatively low. When the bore (32) forms an angle with respect to the gas line (17) so that a relatively large area of ​​the bore (32) is exposed to the exhaust gas line, the flow rate through the valve (14) will be relatively high. The motor (30) can accurately control the orientation of the valve body (31) and the bore (32) around the axis of rotation x, and this orientation can be correlated with the flow rate through the bore (32). Thus, through the ability to advantageously orient the bore (32) at multiple angles with respect to the axis of rotation x, the valve (14) illustrated in FIGS. 6a and 6b can provide variable flow conduction through the exhaust gas line (17). In some embodiments, the valve (14) can provide a continuous angle with respect to the axis of rotation x, and thus can provide a continuous range of flow rates through the valve (14) and the gas line (17).

[0046] To control the orientation of the valve body (31) and the bore (32), an orientation sensor (34) may be provided on a flange (35) near the valve body (31). The orientation sensor (34) may remain stationary as the valve body (31) rotates. The orientation sensor (34) may measure the orientation by detecting the leading edge (37) of the bore (32), the trailing edge (38) of the bore, and the area of ​​the bore (32) between the leading edge and the trailing edge (37, 38). In various embodiments, the orientation sensor (34) may include a magnetic sensor, but other types of sensors may be used. In various embodiments, for example, a motor encoder may be used to detect the orientation of the valve body (31). A control system (19) may also be used to control the orientation of the valve body (31) and the bore (32). For example, the control system (19) may include processing electronics configured to control the operation of the motor (30) and / or receive a signal converted by the orientation sensor (34). In some embodiments, the control system (19) may use a feedback control technique in which an orientation setting point for the valve (14) is provided that corresponds to a desired flow conduction. The control system (19) may receive a signal from the orientation sensor (34) indicating the current orientation of the valve body (31) and the bore (32). Based on the difference between the orientation setting point and the current orientation, the control system may use various control techniques (e.g., including PID control techniques) to transmit a command signal to the motor (30) so that the motor (30) rotates the valve body (31) to a desired orientation setting point corresponding to a desired flow conduction.

[0047] During a purge cycle or state, the control system (19) may command the motor (30) to rotate the valve body (31) and bore (32) in one or more orientations corresponding to a desired or pre-programmed relatively high flow conduction. Thus, during a specific stage (injection or purge), the average conduction may be changed by controlling the rotational speed. For example, the rotational speed of the valve body (31) and bore (32) may be slowed during injection to reduce the average conduction and / or increased during purge to increase the average conduction. In some embodiments, the motor (30) may continuously rotate the valve body (31) and bore (32) during the purge and injection states. For example, the motor (30) may rotate the valve body (31) and bore (32) at a higher speed during purge and / or expose a larger area of ​​the bore (32) to the exhaust line (17) during purge. In some embodiments, the motor (30) may rotate the valve body (31) and bore (32) at a lower speed during injection and / or expose a smaller area of ​​the bore (32) to the exhaust line (17) during injection. In some embodiments, the motor (30) may stop the rotation of the valve body (31) and bore in a specific orientation during purging and / or injection. For example, during purging, the motor (30) may stop the rotation of the valve body (31) and bore (32) in an orientation that maximizes or increases flow conduction (e.g., as shown in FIG. 6a). As another example, during injection, the motor (30) may stop the rotation of the valve body (31) and bore (32) in an orientation that minimizes or decreases flow conduction to increase the residence time of the reactant vapor in the reaction chamber (2). As described above, the control system (19) can use feedback control technology based on a signal from the orientation sensor (34).

[0048] FIG. 7 is a graph of relative flow conduction over time for a purge cycle, an injection cycle, and another purge cycle using the valve (14) illustrated in FIG. 6a and 6b. As illustrated for the purge pulse, the control system (19) can command the motor (30) to position the valve (14) in one or more conduction settings that increase or maximize flow conduction, for example, so that the bore (32) is generally parallel to the flow axis y of the exhaust gas line (17) and the orientation illustrated in FIG. 6a. Providing high flow conduction setting(s) during the purge results in a high flow rate during the purge cycle. As described herein, during a specific process processing phase (injection or purge) and / or between processing phases, the control system (19) and the motor (30) can control the angular velocity and acceleration of the valve body (31) and the bore (32) with respect to the rotation axis x. In order to end the purge cycle before the next injection cycle, the motor (30) can rotate the valve body (31) at high speed during the purge.

[0049] In contrast, the valve (14) during injection can be set to one or more relatively low flow conduction settings, resulting in a relatively low flow rate as illustrated in FIG. 7. For example, the bore (32) can be moved in a manner that reduces the flow through the valve (14). For example, in some embodiments, the rotational speed of the valve (14) may be slowed and / or the area of ​​the bore (32) exposed to the exhaust line (17) may be relatively small, for example, at a relatively large angle (but less than 90°) with respect to the flow axis y in various orientations of the valve body (31) during injection. A relatively large angle and / or low angular velocity exposes a small portion of the bore (32) to the exhaust line (17) for a longer period of time, resulting in a low flow rate and a long residence time during injection. In addition, the angular velocity of the valve body (31) and the bore (32) during injection can be relatively low so that the reactant gas in the reaction chamber (2) is relatively stopped, thereby increasing the residence time in the chamber (2) and improving the formation of the layer.

[0050] Accordingly, the ball valve (14) illustrated in FIGS. 6a through 7 can advantageously provide high-speed variable flow conduction for any suitable type of semiconductor processing device. In some embodiments, the valve (14) of FIGS. 6a through 7 may be positioned along the exhaust line (17) of the semiconductor vapor processing device. In some embodiments, the device is a vapor deposition device. In some embodiments, the device is a periodic CVD device. In some embodiments, the device is an ALD device. Additionally, an inert gas curtain (33) can advantageously block reactant gas from contaminating the outer circumference of the valve body (31) when the bore (32) is at least partially exposed to the exhaust line (17).

[0051] Although the foregoing has been described in detail by way of illustration and example for the purpose of clarity and understanding, it is obvious to those skilled in the art that specific changes and modifications may be made. Accordingly, the description and examples should not be interpreted as limiting the scope of the invention to the specific embodiments and examples described herein, but rather should be interpreted as encompassing all variations and alternatives that come into the true scope and spirit of the invention. Furthermore, not all features, aspects, and advantages described herein are required to practice the invention.

Claims

Claim 1 An atomic layer deposition (ALD) apparatus comprising: a reaction chamber receiving a substrate therein; a loading chamber disposed below the reaction chamber; a susceptor configured to support the substrate and move between the reaction chamber and the loading chamber; and a lower chamber (LC) pressure transducer exposed to the loading chamber; an exhaust line fluidly communicating with the reaction chamber and configured to deliver gas out of the reaction chamber; and a valve disposed along the exhaust line to regulate the flow of the gas along the exhaust line and having a plurality of flow conduction settings. An atomic layer deposition apparatus comprising an open loop control system configured to control the operation of the valve without active feedback regarding the operations of the valve and the reaction chamber during the operation of the open loop control system, wherein during the injection state of the atomic layer deposition apparatus, the open loop control system controls the valve to have a pre-programmed first set point corresponding to a first flow conduction setting among the plurality of flow conduction settings, and during the fuzzy state of the atomic layer deposition apparatus, the open loop control system controls the valve to have a pre-programmed second set point corresponding to a second flow conduction setting among the plurality of flow conduction settings. Claim 2 An atomic layer deposition apparatus according to claim 1, wherein the open loop control system is configured to determine each of the pre-programmed first set point and the pre-programmed second set point using a lookup table (LUT), and the lookup table provides a mapping between pressures pre-measured by the lower chamber pressure transducer and a plurality of flow conduction settings of the valve based on a plurality of gas loads to the reaction chamber. Claim 3 In paragraph 2, the pressures are pre-measured by the lower chamber pressure transducer when the reaction chamber is in fluid communication with the loading chamber, and the reaction chamber is sealed from the loading chamber during the deposition process of the atomic layer deposition apparatus. Claim 4 An atomic layer deposition apparatus, wherein, in paragraph 2, the pressures are pre-measured by the lower chamber pressure transducer when the susceptor is placed within the loading chamber. Claim 5 An atomic layer deposition apparatus according to claim 1, wherein the open-loop control system comprises a module controller and a valve controller, the module controller is configured to control the operation of the valve controller, and the valve controller is configured to control the operation of the valve. Claim 6 An atomic layer deposition apparatus according to claim 5, wherein the module controller transmits one or more digital outputs representing a control mode for a deposition process to the valve controller, and transmits one or more analog inputs representing a control set point of the valve for the deposition process to the valve controller. Claim 7 An atomic layer deposition apparatus according to claim 1, wherein the valve comprises a ball valve, the ball valve comprises a valve body and a bore formed through the valve body, and the valve body and the bore are configured to rotate about a rotation axis to provide the plurality of flow conduction settings along the exhaust line. Claim 8 An atomic layer deposition apparatus according to claim 7, further comprising a motor configured to rotate the valve body and bore about the rotation axis. Claim 9 In claim 8, the atomic layer deposition apparatus is configured such that, during the purge state of the atomic layer deposition apparatus, the open loop control system instructs the motor to move the valve body and bore at a higher speed than during the injection state of the atomic layer deposition apparatus. Claim 10 An atomic layer deposition apparatus according to claim 8, further comprising an orientation sensor configured to detect the orientation of the bore with respect to the rotation axis, and the open loop control system configured to control the operation of the motor based on a signal transmitted from the orientation sensor. Claim 11 In claim 7, the atomic layer deposition apparatus, wherein the valve body is seated with a gap within a flange provided on or around the exhaust line and allows rotation of the valve body relative to the flange. Claim 12 An atomic layer deposition apparatus according to claim 11, wherein the valve comprises an inert gas curtain region disposed around the periphery of the valve body, and the inert gas curtain region comprises a region of inert gas supplied into the gap between the flange and the valve body through an inlet port.

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