Process gas delivery control system with concentration monitoring

Abstract

The invention discloses a process gas delivery control system with concentration monitoring. A process gas delivery system includes a first mass flow controller configured to receive a carrier gas at an inlet and output a flow of the carrier gas to a first conduit coupled to the first mass flow controller; at least one second mass flow controller configurable to receive a preliminary process gas therein and to direct a flow of the preliminary process gas into a second conduit; a joint in fluid communication with the first conduit and the second conduit such that the carrier gas output from the first mass flow controller can be mixed with the preliminary process gas output from the second mass flow controller to form a process gas; a third conduit coupled to the joint and the process chamber to deliver the process gas to the process chamber; and at least one concentration detector adapted and configured to measure a concentration of the preliminary process gas or a precursor within the process gas.

Description

Background Technology

[0001] Many semiconductor deposition processes involve delivering gases into a process chamber to form various layers or structures for semiconductor devices. For example, chemical vapor deposition (CVD) is a common deposition method used to deposit layers on a substrate by introducing reactive precursors (or more simply, "precursors") into the process chamber and allowing the precursors to react with the substrate. Atomic layer deposition (ALD) is a variant of CVD that involves a sequence of steps involving the physical or chemical adsorption of precursor molecules onto the substrate in a monolayer. Both CVD and ALD technologies require precise control of the reactive precursors introduced into the process chamber to produce the desired layer with a uniform thickness.

[0002] Typically, precursors used in CVD or ALD processes are initially provided in a solid or liquid phase and then subsequently vaporized (e.g., sublimated or evaporated) and entrained in a carrier gas stream (e.g., Ar, N2, He, or H2) so that they can be delivered to the process chamber. The mixture of the carrier gas and the vaporized precursor is referred to herein as the "process gas". The rate at which the precursor source can be entrained by the carrier gas depends on factors such as the temperature of the precursor, the surface area of ​​the precursor, and the manner in which the carrier gas flows relative to the precursor source; all of these factors can vary over time and can be extremely difficult to control. Therefore, the concentration of precursor in the process gas delivered to the process chamber can vary over time, and thus it is extremely difficult to control the composition of the process gas to ensure that an appropriate, constant amount of precursor is delivered to the process chamber over time. If the process gas supplied to the process chamber is generated by adding additional carrier gas and / or other gases to the vaporized precursor / carrier gas mixture, accurately controlling the precursor concentration becomes more difficult. However, accurately controlling the precursor concentration in the process gas supplied to the process chamber is important. Summary of the Invention

[0003] This application discloses various embodiments of a process gas delivery control system with concentration monitoring for use with a gas system configured to deliver a process gas containing a precursor and a carrier gas to a process chamber. More specifically, in one embodiment, this application relates to a process gas delivery system comprising a first mass flow controller configured to receive a carrier gas at an inlet and output a flow of the carrier gas to a first conduit coupled to the first mass flow controller. At least one second mass flow controller may be configured to receive a preliminary process gas therein and output a flow of the preliminary process gas to a second conduit. The preliminary process gas contains a precursor and a carrier gas. A connector is in fluid communication with the first and second conduits such that the carrier gas output from the first mass flow controller and the preliminary process gas output from the second mass flow controller can be mixed to form a process gas. A connector is connected to a third conduit coupled to a process chamber such that the process gas is delivered to the process chamber. At least one concentration detector may be adapted and configured to measure the concentration of the preliminary process gas or the precursor within the process gas.

[0004] In another embodiment, this application discloses another embodiment of a process gas delivery control system, similar to the previous embodiment, wherein the process gas delivery control includes a first mass flow controller configured to receive a carrier gas at an inlet and output a flow of the carrier gas to a first conduit coupled to the first mass flow controller. Furthermore, at least one second mass flow controller may be configured to receive a preliminary process gas therein and output a flow of the preliminary process gas to a second conduit. A connector is in fluid communication with the first and second conduits, such that the carrier gas output from the first mass flow controller and the preliminary process gas output from the second mass flow controller can be mixed to form a process gas. A connector is connected to a third conduit coupled to a process chamber, such that the process gas is delivered to the process chamber. At least one concentration detector is adjustable and configured to measure the concentration of the preliminary process gas or a precursor within the process gas. Additionally, at least one controller is in communication with the first mass flow controller, the second mass flow controller, and the concentration detector. During use, the controller is configured to control the flow rate of gas through at least one of the first and second mass flow controllers in response to data received from the concentration detector.

[0005] Other features and advantages of the process gas delivery control system with concentration monitoring as disclosed herein will become apparent from consideration of the following detailed description. Attached Figure Description

[0006] The drawings illustrate illustrative embodiments and are not intended to depict all embodiments of the process gas delivery system. Details that may be obvious or unnecessary may be omitted to save space or for more efficient illustration. Instead, some embodiments may be practiced without all the details disclosed regarding a particular embodiment. When the same element symbols appear in different drawings, the element symbols refer to the same or similar components or steps. The novel aspects of the process gas delivery system disclosed herein will become clear by considering the following figures, in which:

[0007] Figure 1 A schematic diagram illustrating an embodiment of a process gas delivery system having a concentration detector located upstream of a second mass flow controller;

[0008] Figure 2 A schematic diagram illustrating an embodiment of a process gas delivery system having a concentration detector located after a second mass flow controller;

[0009] Figure 3 A schematic diagram illustrating an embodiment of a process gas delivery system with a concentration detector located after the connector; and

[0010] Figure 4 A schematic diagram illustrating an embodiment of a process gas delivery system having multiple concentration detectors and multiple mass flow controllers. Detailed Implementation

[0011] Exemplary embodiments are described herein with reference to the accompanying drawings. Unless otherwise expressly stated, the dimensions, positions, and any distances between components, features, elements, etc., in the drawings are not necessarily to scale, but are enlarged for clarity.

[0012] The terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well. It should be understood that the terms “comprises” and / or “comprising”, when used in this specification, designate the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. Unless otherwise specified, when describing a range of values, the range includes both the upper and lower limits of the range and any subranges therein. Unless otherwise indicated, terms such as “first,” “second,” etc., are used only to distinguish one element from another. For example, a node may be referred to as a “first node,” and similarly, another node may be referred to as a “second node,” or vice versa. Section headings used herein are for organizational purposes only and should not be construed as limiting the described subject matter.

[0013] Unless otherwise indicated, the terms “about,” “approximately,” “substantial,” etc., mean that quantities, dimensions, formulations, parameters, and other quantities and characteristics are not and need not be precise, but may be approximate and / or larger or smaller as required, thereby reflecting tolerances, conversion factors, rounding, measurement errors and the like, and other factors known to a person of ordinary skill in the art.

[0014] For ease of description, spatial relative terms such as “below,” “under,” “lower,” “above,” and “upper,” and the like, are used herein to describe the relationship between one element or feature and another element or feature illustrated in the diagrams. It should be understood that spatial relative terms are intended to encompass different orientations beyond those depicted in the diagrams. For example, if an object in the diagram is flipped, an element described as “below” or “under” other elements or features will then be oriented “above” other elements or features. Thus, the illustrative term “below” can encompass both the orientations above and below. Objects may be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein will be interpreted accordingly.

[0015] The same symbol is used throughout the text to refer to the same element. Therefore, the same or similar symbols may be described when referring to other figures, even if the symbol is not mentioned or described in the corresponding figure. In addition, even elements not indicated by element symbols may be described with reference to other figures.

[0016] It should be understood that many different forms and embodiments are possible without departing from the spirit and teachings of the invention, and therefore the invention should not be considered as limited to the exemplary embodiments set forth herein. In fact, such examples and embodiments are provided so that the invention will be thorough and complete, and will convey the scope of the invention to those skilled in the art.

[0017] Figure 1 An embodiment of a process gas delivery control system 100 is illustrated, which includes at least one mass flow controller, at least one concentration detector, and at least one controller. In the illustrated embodiment, the process gas delivery control system 100 includes a first mass flow controller (MFC1) 102, a concentration detector 106, a second mass flow controller (MFC2) 104, and at least one controller 108. The process gas delivery control system 100 may be incorporated into a gas system configured to deliver process gases to process chambers. The gas system may, for example, include a carrier gas source (not shown) and a precursor source system, the precursor source system comprising at least one pressure controller 116 and at least one precursor container 120 containing the precursor source.

[0018] Refer again Figure 1 At least one carrier gas (e.g., Ar, N2, He, or H2) flows from a carrier gas source through one or more conduit manifolds 112, and via at least one conduit 114 to the inlet of a pressure controller 116. The outlet of the pressure controller 116 is connected to a precursor container 120 via a pressure controller conduit 118, allowing the carrier gas to be delivered into the precursor container 120. The pressure controller 116 can operate in any suitable or known manner to regulate the pressure within the precursor container 120. The carrier gas flow delivered to the precursor container 120 carries a quantity of the precursor source (e.g., precursor "A"). Examples of precursors known in the art and that may be contained within the precursor container 120 include PDMAT, TDMAT, TiCl4, CCTBA, TMA, TEOS, TAETO, TEMAH, TEMAZ, BTBAS, or the like. Depending on the configuration of the precursor container 120, the carrier gas may be injected into the precursor source (e.g., in the case where the precursor source is liquid) or may be injected directly into the vaporized precursor material (e.g., in the case where the precursor source is liquid or solid).

[0019] like Figure 1As shown, the inlet of the first mass flow controller 102 is connected to the conduit manifold 112 via at least one MFC1 inlet conduit 130. The MFC1 102 is configured to receive the delivered carrier gas therein. The MFC1 102 is coupled to at least one connector 132 via at least one first modulated flow rate conduit 134. Generally, the first mass flow controller 102 may include any known or suitable means adapted and configured to control the flow of carrier gas within the first modulated flow rate conduit 134 to the connector 132. For the purposes of discussion, the flow rate of the carrier gas within the first modulated mass flow rate conduit 134 is also referred to as the "first mass flow rate Q1". The first mass flow rate Q1 can be controlled by the controller 108 in response to inputting a first mass flow control signal 102a to the first mass flow controller 102.

[0020] Refer again Figure 1 The inlet of concentration detector 106 is connected to the outlet of precursor container 120 to receive the flow of precursor entrained in the carrier gas delivered from the outlet of precursor container 120 via at least one precursor container conduit 122. Concentration detector 106 is adapted and configured in any known or suitable manner to measure the concentration of precursor entrained in the carrier gas (also referred to herein as the “preliminary process gas”) delivered from the outlet of precursor container 120. For example, concentration detector 106 may be provided as a nondispersive infrared (NDIR) sensor, an optical absorption spectrometer, an optical emission spectrometer, a Fourier transform infrared (FTIR) sensor, a tunable filter spectrometer (e.g., as disclosed in U.S. Patent No. 9,651,422, which is incorporated herein by reference), or the like or any combination thereof. Concentration detector 106 is also adapted and configured to output a measurement signal 106a to controller 108, the measurement signal representing the concentration of a precursor in the initial process gas. For the purposes of this discussion, the concentration of the precursor in the initial process gas measured by concentration detector 106 (e.g., the concentration of precursor A) may be represented by the symbol Xa'. In one embodiment, the measured concentration Xa' may be represented as a value between 0 (meaning the initial process gas contains no precursor, or 0%) and 1 (meaning the initial process gas contains only the precursor, or 100%), such as 0.1, 0.2, 0.4, 0.7, etc., or any of these values. Generally, concentration detector 106 is provided to continuously measure the concentration of the precursor in the initial process gas and output a corresponding measurement signal. The measurement signal may be output periodically, for example, every 10 ms to several (e.g., 1 to 3) seconds, or up or down.

[0021] The inlet of the second mass flow controller 104 is connected to the concentration detector 106 to receive the preliminary process gas via at least one conduit 124 after the concentration detector 106 has measured the concentration of the precursor in the preliminary process gas. The second mass flow controller 104 also includes an outlet connected (e.g., via a second modulated mass flow rate conduit) to the inlet of connector 132 via at least one second modulated flow rate conduit 126. Generally, the second mass flow controller 104 is adapted and configured to control the flow of the preliminary process gas within the second modulated flow rate conduit 126 to connector 132 using any known or suitable means. For the purposes of discussion, the mass flow rate of the preliminary process gas within the second modulated mass flow rate conduit is also referred to as the "second mass flow rate Q2". The second mass flow rate Q2 can be controlled by the controller 108 in response to inputting a second mass flow control signal 104a to the second mass flow controller 104.

[0022] like Figure 1 The diagram schematically illustrates that the first modulated mass flow rate conduit 134 and the second modulated mass flow rate conduit 126 are fluidly combined at connector 132. Thus, the carrier gas output from the first mass flow controller 102 and the preliminary process gas output from the second mass flow controller 104 are mixed together at connector 132 to form the process gas to be delivered to the process chamber (e.g., indicated by solid line 140). For the purposes of discussion, the mass flow rate of the process gas delivered to the process chamber within the process gas conduit is also referred to as the “total mass flow rate Qt”. For the purposes of discussion herein, the concentration of the precursor in the process gas (e.g., as delivered from connector 132 within the process gas conduit) may be represented by the symbol Xa. In one embodiment, the concentration Xa may be expressed as a value between 0 (meaning the process gas contains no precursor, or 0%) and 1 (meaning the process gas contains only the precursor, or 100%). Based on the above discussion, it should be understood that the concentration (Xa) of the precursor in the process gas will be less than or equal to the measured concentration (Xa') of the precursor in the initial process gas, depending on the amount of the mass flow rate Q1 of the carrier gas output by the first mass flow controller 102 and the second mass flow rate Q2 of the initial process gas output by the second mass flow controller 104.

[0023] As discussed above, controller 108 is communicatively connected to the first mass flow controller 102, concentration detector 106, and second mass flow controller 104 to send mass flow control signals (e.g., to the first mass flow controller 102 and the second mass flow controller 104) or receive measurement signals (e.g., from the concentration detector 106). In one embodiment, controller 108 may be configured to keep at least one of mass flow rate Q1 and second mass flow rate Q2 constant. If necessary, controller 108 may be configured to keep at least one of mass flow rate Q1 and second mass flow rate Q2 variable. Controller 108 is adapted and configured in any known or suitable manner to control the concentration of precursors in the process gas to be delivered to the process chamber, thereby generating a first mass flow control signal and a second mass flow control signal, which are output to the first mass flow controller 102 and the second mass flow controller 104, respectively. In one embodiment, controller 108 may be configured to keep the concentration of precursors constant. As needed, controller 108 can be configured to keep the precursor concentration variable. Controller 108 can be communicatively connected to the first mass flow controller 102, concentration detector 106, and second mass flow controller 104 via one or more wired or wireless communication links as known in the art.

[0024] Generally, a first mass flow control signal is transmitted to a first setpoint (SP1), and the first mass flow rate controller 102 operates at the first setpoint to generate a first mass flow rate Q1 within the first modulated mass flow rate conduit. Similarly, a second mass flow control signal is transmitted to a second setpoint (SP2), and the second mass flow rate controller 104 operates at the second setpoint to generate a second mass flow rate Q2 within the second modulated mass flow rate conduit. Therefore, the first setpoint SP1 is the value corresponding to the first mass flow rate Q1, and the second setpoint SP2 is the value corresponding to the second mass flow rate Q2. The controller 108 is configured to calculate the first setpoint SP1 and the second setpoint SP2 based on the predetermined or other desired concentration of the precursor in the process gas to be delivered to the process chamber (i.e., the aforementioned precursor concentration Xa), the predetermined or other desired mass flow rate of the process gas to be delivered to the process chamber (i.e., the aforementioned total mass flow rate Qt), and the measured concentration value (i.e., Xa') transmitted by the measurement signal output by the concentration detector 106.

[0025] The values ​​of precursor concentration Xa and total mass flow rate Qt can be stored locally at controller 108 in any suitable or known manner (e.g., in a table or other machine-readable data structure), or remotely stored but accessible by controller 108 (e.g., via one or more network connections). The first setpoint (SP1) can be calculated according to the following Equation 1:

[0026] …(Equation 1)

[0027] Similarly, the second setpoint (SP2) can be calculated according to the following Equation 2:

[0028] …(Equation 2)

[0029] In view of the above, it should be understood that when the desired concentration (Xa) of the precursor in the process gas is equal to (or intended to be equal to) the measured concentration (Xa') of the precursor in the initial process gas, the controller 108 calculates the first setpoint SP1 and transmits the first mass flow control signal that transmits the calculated first setpoint SP1 to the first mass flow controller 102, so that the first mass flow controller 102 prevents the carrier gas from flowing into the first modulated mass flow rate conduit (i.e., setting Q1=0).

[0030] When the desired concentration (Xa) of the precursor in the process gas is less than (or intended to be less than) the measured concentration (Xa') of the precursor in the initial process gas, the controller 108 calculates the first setpoint SP1 and the second setpoint SP2, respectively, and transmits the first mass flow control signal and the second mass flow control signal, which transmit the calculated first setpoint SP1 and second setpoint SP2, to the first mass flow controller 102 and the second mass flow controller 104, respectively. Therefore, the first mass flow controller 102 and the second mass flow controller 104 operate to regulate the gas flow through the mass flow controllers using the first mass flow rate Q1 and the second mass flow rate Q2, such that the combined mass flow rate (i.e., Q1 + Q2) is equal to the desired total mass flow rate Qt, while also ensuring that the concentration of the precursor in the process gas output from the connector 132 is equal to (or at least substantially equal to) Xa.

[0031] When the measured concentration (Xa') of the precursor in the initial process gas changes (e.g., from the first time when the first measurement signal is output from the concentration detector 106 to the second time when the second measurement signal is output from the concentration detector 106), the controller 108 calculates the first setpoint SP1 and the second setpoint SP2 respectively, and transmits the first mass flow control signal and the second mass flow control signal to the first mass flow controller 102 and the second mass flow controller 104 respectively, so as to maintain the process gas flow with the desired total mass flow rate Qt, while also ensuring that the concentration of the precursor in the process gas is equal to (or at least substantially equal to) Xa. For example, if the measured concentration Xa' transmitted by the first measurement signal is greater than the measured concentration Xa' transmitted by the second measurement signal, then the first setpoint SP1 calculated based on the measured concentration Xa' transmitted by the second measurement signal will be greater than the first setpoint SP1 calculated based on the measured concentration Xa' transmitted by the first measurement signal (and similarly, the second setpoint SP2 calculated based on the measured concentration Xa' transmitted by the second measurement signal will be less than the second setpoint SP2 calculated based on the measured concentration Xa' transmitted by the first measurement signal), but the total mass flow rate Qt flowing through the connector 132 and the precursor concentration Xa will remain constant (or at least substantially constant).

[0032] Because the concentration detector 106 and the second mass flow controller 104 are located downstream of the precursor container 120, they can quickly detect changes in the precursor concentration and quickly adjust the flow rate of the gas through the first and second variable flow rate conduits to maintain an ideal constant total flow rate Qt of the process gas with an ideal constant precursor concentration Xa.

[0033] refer to Figure 2 According to another embodiment of the present invention, the process gas delivery control system 200 can be arranged similarly to the process gas delivery control system 100, but the positions of the concentration detector 106 and the second mass flow controller (MFC2) 104 can be interchanged without changing the function of the system. Therefore, in this embodiment, the inlet of the second mass flow controller 104 is connected to the outlet of the precursor container 120 to receive the flow of preliminary process gas via the precursor container output conduit 122. The inlet of the concentration detector 106 is connected to the second mass flow controller 104 via conduit 124 to receive the preliminary process gas delivered by the second mass flow controller 104. A connector 132 is connected to the concentration detector 106 to receive the preliminary process gas after the concentration detector 106 has measured the concentration of the precursor within the preliminary process gas.

[0034] refer to Figure 3According to another embodiment of the invention, the process gas delivery control system 300 can be configured similarly to the process gas delivery control system 200, but the position of the concentration detector 106 can be moved downstream of the connector 132. Thus, the process gas to be delivered to the process chamber flows from the connector to the concentration detector 106 (e.g., indicated by 301), where the concentration of the precursor in the process gas is measured by the concentration detector 106 before the process gas is output to the process chamber (e.g., indicated by 140). Given the configuration of the process gas delivery control system 300, it should be clearly understood that the difference between the measured concentration Xa' (measured by the concentration detector 106) of the precursor in the process gas and the desired concentration Xa of the precursor in the process gas can respectively represent the operational drift of the first mass flow controller 102 or the second mass flow controller 104 (i.e., as an alternative to or supplement to any change in the precursor concentration in the initial process gas as discussed above). In this case, the controller 108 can be configured to implement proportional-integral-derivative (PID) control based on the error function of the measured concentration Xa' transmitted by the measurement signal output by the concentration detector 106, so as to fine-tune the first setpoint SP1 and the second setpoint SP2 respectively, thereby more accurately adjusting the concentration of the precursor in the process gas to better achieve the desired concentration Xa.

[0035] refer to Figure 4 According to yet another embodiment of the present invention, the process gas delivery control system 400 can be configured similarly to the process gas delivery control system 100, but can be adapted to be incorporated into a gas system configured to deliver multiple process gases to process chambers. For example, such as Figure 4 As shown, the gas system may include a carrier gas source (not shown) and multiple precursor source systems. For example, the gas system may include a first precursor source system and a second precursor source system. The first precursor source system comprises a first pressure controller 116-1 and a first precursor container 120-1 containing a first precursor source (e.g., precursor material "A" source). The second precursor source system comprises a second pressure controller 116-2 and a second precursor container 120-2 containing a second precursor source (e.g., precursor material "B" source). Generally, precursor material "A" is different from precursor material "B".

[0036] In the illustrated embodiment, the process gas delivery control system 400 includes a first mass flow controller 102, a first gas delivery control subsystem fluidly connecting the first precursor source system to the inlet of connector 132, and a second gas delivery control subsystem fluidly connecting the second precursor source system to the inlet of connector 132. Each of the first and second gas delivery control subsystems can be configured as the gas delivery control system 100. However, for clarity, Figure 4 The components described above are identical to those discussed in relation to the gas delivery control system 100, except that the component symbols are appended with "-1" or "-2" to indicate the subsystem to which the component belongs. For example, both concentration detectors 106-1 and 106-2 correspond to concentration detector 106 in the gas delivery control system 100, but concentration detector 106-1 is part of the first gas delivery control system, while concentration detector 106-2 is part of the second gas delivery control system. Therefore, each of the first and second gas delivery control subsystems can operate in the same manner as described above in relation to the gas delivery control system 100.

[0037] It should be understood that, for the illustrated embodiment, the controller 108 will calculate three setpoints (i.e., a first setpoint SP1 for controlling the operation of the first mass flow controller 102, a second setpoint SP2-1 for controlling the operation of the second mass flow controller 104-1, and a second setpoint SP2-2 for controlling the operation of the second mass flow controller 104-2). In this case, the second setpoint SP2-1 can be calculated according to the following equation 2-1:

[0038] …(Equation 2-1)

[0039] The second setpoint SP2-2 can be calculated according to the following equation 2-2:

[0040] (Equation 2-2)

[0041] Furthermore, the first setpoint SP1 can be calculated according to the following equation 1':

[0042] …(Equation 1')

[0043] Xa and Xb are the desired concentrations of precursors “A” and “B” in the process gas to be delivered to the process chamber, and Xa' and Xb' are the measured concentrations of precursors “A” and “B” present in their respective initial process gases before being mixed together at connector 114.

[0044] Although the process gas delivery control system 400 is described as including only two process gas delivery control subsystems, it should be understood that the process gas delivery control system 400 may include more than two process gas delivery control subsystems. Therefore, the process gas delivery control system 400 may include any number or variety of mass flow controllers (MFC1, MFC2, MFCn). Similarly, the process gas delivery control system 400 may include any number of pressure controllers 116-1 and 116-2, any number of precursor containers 120-1 and 120-2, any number of concentration detectors 106-1 and 106-2, and any number of controllers 108. Furthermore, although the process gas delivery control system 400 is described as including a process gas delivery control subsystem corresponding to the gas delivery control system 100, it should be understood that any of the process gas delivery control subsystems may replace the corresponding gas delivery control system 200 or gas delivery control system 300. Furthermore, although the process gas delivery control system 400 is described as having a process gas delivery control subsystem corresponding to the same type of process gas delivery control system (i.e., corresponding to the gas delivery control system 100), it should be understood that different process gas delivery control subsystems may correspond to different types of process gas delivery control systems. However, it should be recognized that if the process gas delivery control system 400 includes a process gas delivery control subsystem corresponding to the gas delivery control system 300, the relevant concentration detector used should be able to detect the concentrations of at least two different precursor materials.

[0045] The foregoing describes embodiments and examples of the present invention and should not be construed as limiting it. Although several specific embodiments and examples have been described with reference to the drawings, it will be readily understood by those skilled in the art that many modifications to the disclosed embodiments and examples, as well as other embodiments, are possible without significantly departing from the novel teachings and advantages of the invention. Therefore, all such modifications are intended to be included within the scope of the invention as defined in the claims. For example, it will be understood by those skilled in the art that the subject matter of any sentence, paragraph, example, or embodiment may be combined with some or all of the subject matter of other sentences, paragraphs, examples, or embodiments, unless such combinations are mutually exclusive. Therefore, the scope of the present invention should be determined by the following claims, and the equivalents of the claims are included within the scope of the present invention.

Claims

1. A process gas delivery system for use with a gas system configured to deliver a process gas containing a precursor and a carrier gas to a process chamber, the process gas delivery system comprising: A first mass flow controller is configured to receive the carrier gas at the inlet of the first mass flow controller and to output a flow of the carrier gas to a first conduit at the outlet of the first mass flow controller. At least one second mass flow controller is configured to receive a preliminary process gas at the inlet of the at least one second mass flow controller and to output a flow of the preliminary process gas to a second conduit at the outlet of the at least one second mass flow controller, the preliminary process gas containing the precursor and the carrier gas. A connector is in fluid communication with the first conduit and the second conduit, such that the carrier gas output from the first mass flow controller and the preliminary process gas output from the second mass flow controller can be mixed in the connector to form the process gas, wherein the outlet of the connector is connected to a third conduit so that the process gas can be delivered to the process chamber via the third conduit. as well as At least one concentration detector, adapted and configured to measure the concentration of the preliminary process gas or the precursor within the process gas.

2. The process gas delivery system of claim 1, further comprising at least one controller connected to the first mass flow controller, the at least one second mass flow controller and the at least one concentration detector, the at least one controller being configured to control the flow rate of gas through at least one of the first mass flow controller and the at least one second mass flow controller in response to data received from the at least one concentration detector.

3. The process gas delivery system of claim 2, wherein the at least one controller is configured to maintain a constant flow rate of at least one of the process gas and the carrier gas into the process chamber.

4. The process gas delivery system of claim 2, wherein the at least one controller is configured to maintain at least one of the process gas, the precursor, and the carrier gas in the process chamber at a constant concentration.

5. The process gas delivery system as claimed in claim 1, further comprising: A first mass flow controller, which is connected to the controller; A second mass flow controller is connected to the controller; A first concentration detector is in fluid communication with a second mass flow controller, and the first concentration detector is also in communication with the controller; At least one third flow controller, which is connected to the controller; At least one second concentration detector is in fluid communication with the at least one third mass flow controller, and the at least one second concentration detector is in communication with the controller.

6. The process gas delivery system of claim 1, wherein the at least one concentration detector is located between the precursor container and the at least one second mass flow controller.

7. The process gas delivery system of claim 1, wherein the at least one concentration detector is positioned between the at least one second mass flow controller and the connector.

8. The process gas delivery system of claim 1, wherein the at least one concentration detector is located between the connector and at least one process chamber.

9. A process gas delivery system for use with a gas system configured to deliver a process gas containing a precursor and a carrier gas to a process chamber, the process gas delivery system comprising: A first mass flow controller is configured to receive the carrier gas at the inlet of the first mass flow controller and to output a flow of the carrier gas to a first conduit at the outlet of the first mass flow controller. At least one second mass flow controller is configured to receive a preliminary process gas at the inlet of the second mass flow controller and to output a flow of the preliminary process gas to a second conduit at the outlet of the second mass flow controller, the preliminary process gas containing the precursor and the carrier gas; A connector is in fluid communication with the first conduit and the second conduit, such that the carrier gas output from the first mass flow controller and the preliminary process gas output from the second mass flow controller can be mixed in the connector to form the process gas, wherein the outlet of the connector is connected to a third conduit so that the process gas can be delivered to the process chamber via the third conduit. At least one concentration detector, adapted and configured to measure the concentration of the preliminary process gas or the precursor within the process gas; as well as At least one controller is connected to the first mass flow controller, the at least one second mass flow controller, and the at least one concentration detector, the at least one controller being configured to control the flow rate of gas through at least one of the first mass flow controller and the at least one second mass flow controller in response to data received from the at least one concentration detector.

10. The process gas delivery system of claim 9, further comprising: A first mass flow controller, which is connected to the controller; A second mass flow controller is connected to the controller; A first concentration detector is in fluid communication with a second mass flow controller, and the first concentration detector is also in communication with the controller; At least one third mass flow controller, which is connected to the controller; At least one second concentration detector is in fluid communication with the at least one third mass flow controller, and the at least one second concentration detector is in communication with the controller.

11. The process gas delivery system of claim 10, wherein the at least one controller is configured to maintain a constant flow rate of at least one of the process gas and the carrier gas into the process chamber.

12. The process gas delivery system of claim 10, wherein the at least one controller is configured to maintain at least one of the process gas, the precursor, and the carrier gas in the process chamber at a constant concentration.

13. The process gas delivery system of claim 9, wherein the at least one concentration detector is located between the precursor container and the at least one second mass flow controller.

14. The process gas delivery system of claim 9, wherein the at least one concentration detector is positioned between the at least one second mass flow controller and the connector.

15. The process gas delivery system of claim 9, wherein the at least one concentration detector is positioned between the connector and at least one process chamber.

Images