Crystal Microbalance Concentration Monitor

Abstract

A quartz crystal microbalance (QCM) device is described that is mounted within a heated sample chamber. The temperature of the sample chamber is maintained about 10°C to about 30°C higher than the temperature of the precursor vessel. The sample chamber is connected to a precursor delivery line and includes a high-temperature valve and a flow path to a foreline that also has a high-temperature valve to allow for the removal of excess material. The QCM device includes a heater and gas cooling channels that allow the device to be maintained at a temperature about 10°C to about 30°C lower than the temperature of the precursor vessel.

Description

Technical Field

[0001]

[0001] Embodiments of the present disclosure generally relate to semiconductor processing and other electronics manufacturing. More specifically, embodiments of the present disclosure are directed to methods and apparatus for controlling the delivery of chemical precursors to a processing chamber.

Background Art

[0002]

[0002] As the density of integrated circuits (ICs) increases, there is a growing need to improve the uniformity and process control regarding layer thickness. IC manufacturers are actively demanding that the semiconductor processing industry develop manufacturing tools that provide greater production yields while increasing the uniformity of layers deposited on substrates having ever larger surface areas. In response to these demands, various techniques have been developed for depositing layers on substrates in a cost-effective manner while maintaining control over the characteristics of the layers.

[0003]

[0003] To produce a desired layer of uniform thickness, both chemical vapor deposition (CVD) techniques and atomic layer deposition (ALD) techniques require precise control of the reactive precursors introduced into the processing chamber. In some applications of CVD and ALD, one or more of the precursors are in a solid or liquid state. Typically, the precursor changes state (vaporizes) from solid to gas at a specific pressure and temperature via a sublimation process that occurs within a storage container. The precursor may be delivered to the processing chamber via a process gas generated by flowing a carrier gas through the container, or the precursor may be delivered without processing. The process gas contains the vaporized precursor mixed with the carrier gas. The sublimation rate depends on the temperature of the precursor, the surface area and morphology of the precursor, and how the carrier gas flows through the container (flow dynamics and residence time), and it is very difficult to control each of these. Therefore, it is often difficult to deliver a predictable concentration of the precursor to the processing chamber.

[0004]

[0004] Accordingly, there is a need for an improved method for monitoring and adjusting the dosage / concentration of precursors into a processing chamber.

SUMMARY OF THE INVENTION

[0005]

[0005] One or more embodiments of the present disclosure are directed to a processing system. In one embodiment, the processing system includes a carrier gas source; a precursor container; a deposition chamber; and a sample chamber downstream of the precursor container and upstream of the deposition chamber, the sample chamber housing a quartz crystal microbalance (QCM) device.

[0006]

[0006] Another embodiment of the present disclosure is directed to a processing method. In one or more embodiments, the processing method includes heating a container containing a chemical precursor to a temperature in the range of from about 25°C to about 600°C, the container having a first precursor concentration; flowing a carrier gas through the container to form a precursor gas containing the chemical precursor; measuring the concentration of the chemical precursor in the precursor gas using a quartz crystal microbalance (QCM) device in a sample chamber, the precursor having a second precursor concentration and the sample chamber having a temperature in the range of from about 10°C to about 30°C higher than the temperature of the container; exposing a substrate to the precursor gas during a deposition process; and depositing a film on the substrate.

[0007]

[0007] Another embodiment of the present disclosure is a non-transitory computer-readable medium containing instructions that, when executed by a controller of a processing chamber, cause the processing chamber to perform the following operations: heating a container containing a chemical precursor to a temperature in the range of about 10°C to about 600°C; flowing a carrier gas into the container to form a precursor gas containing the chemical precursor; measuring the concentration of the chemical precursor in the precursor gas using a quartz crystal microbalance (QCM) device in a sample chamber, where the sample chamber has a temperature in the range of about 10°C to about 30°C higher than the temperature of the container; exposing a substrate to the precursor gas during a deposition process; and depositing a film on the substrate.

[0008]

[0008] To better understand the above-described features of the present disclosure, a more detailed description of the present disclosure, briefly summarized above, can be obtained by referring to the embodiments, some of which are shown in the accompanying drawings. However, it should be noted that since the present disclosure may admit other equally valid embodiments, the accompanying drawings show only typical embodiments of the present disclosure and should not be considered as limiting the scope of the present disclosure.

Brief Description of the Drawings

[0009]

Figure 1

[0009] A schematic diagram of a processing system according to one or more embodiments of the present disclosure is shown.

Figure 2

[0010] A schematic diagram of a quartz crystal microbalance (QCM) device according to one or more embodiments of the present disclosure is shown.

Figure 3

[0011] A process flow diagram of a processing method according to one or more embodiments of the present disclosure is shown.

Figure 4

[0012] A process flow diagram of a processing method according to one or more embodiments of the present disclosure is shown.

Modes for Carrying Out the Invention

[0010]

[0013] Before describing some exemplary embodiments of the present disclosure, it should be understood that the present disclosure is not limited to the details of the structures or processing steps disclosed in the following description. The present disclosure can also implement other embodiments and can be practiced or executed in various ways.

[0011]

[0014] As used in this specification and the appended claims, the terms "substrate" and "wafer" are used interchangeably and both refer to the surface or a part of the surface on which processing acts. As will also be understood by those skilled in the art, when reference is made to a substrate, it may refer only to a part of the substrate, unless otherwise specified in the context. Further, when reference is made to deposition on a substrate, it may mean both a bare substrate and a substrate on which one or more films or features have been deposited or formed.

[0012]

[0015] As used herein, the term "substrate" refers to any substrate on which film processing is performed during the manufacturing process or the surface of a material formed on a substrate. For example, the substrate surface on which processing can be performed includes, depending on the application, materials such as silicon, silicon carbide, silicon oxide, strained silicon, silicon on insulator (SOI), carbon-doped silicon oxide, silicon nitride, doped silicon, germanium, gallium arsenide, glass, sapphire, quartz, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. The substrate includes, but is not limited to, semiconductor wafers. The substrate may be exposed to a pretreatment process for polishing, etching, reducing, oxidizing, hydroxylation (or otherwise generating or grafting a target chemical moiety to impart chemical functionality), annealing, and / or baking the substrate surface. In addition to directly performing film processing on the surface of the substrate itself, in the present disclosure, any of the disclosed film processing steps may also be performed on a lower layer formed on the substrate, as will be disclosed in more detail below. The term "substrate surface" is intended to include such a lower layer as the context indicates. Thus, for example, when a film / layer or a partial film / layer is deposited on the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface. What a given substrate surface includes will depend on what films are deposited and the specific chemistry used.

[0013]

[0016] The terms "precursor", "reactant", "reactive gas", etc., as used in this specification and the appended claims, are used interchangeably to refer to any gas species that can react with the substrate surface.

[0014]

[0017] As used herein, "atomic layer deposition" or "cyclic deposition" refers to the sequential exposure of two or more reactive compounds to deposit a layer of material on a substrate surface. The substrate or a portion of the substrate is separately exposed to two or more reactive compounds introduced into the reaction zone of the processing chamber. In a time-domain ALD process, the exposure to each reactive compound is separated by a time delay such that each compound can adhere and / or react on the substrate surface and then be purged from the processing chamber. These reactive compounds are said to be sequentially exposed to the substrate. In a spatial ALD process, different portions of the substrate surface, or materials on the substrate surface, are simultaneously exposed to two or more reactive compounds such that any given point on the substrate is not substantially simultaneously exposed to multiple reactive compounds. As used in this specification and the appended claims, the term "substantially" as used in this context means that a small portion of the substrate may be exposed to multiple reactive gases simultaneously due to diffusion, and that simultaneous exposure is not intended, as would be understood by one of ordinary skill in the art.

[0015]

[0018] In one aspect of a time-domain ALD process, after a first reactive gas (i.e., a first precursor or compound A) is pulsed into the reaction zone, a first time delay ensues. Next, after a second precursor or compound B is pulsed into the reaction zone, a second delay occurs. During each time delay, a purge gas (such as argon) is introduced into the processing chamber to purge the reaction zone or otherwise remove any remaining reactive compounds or reaction by-products from the reaction zone. Alternatively, the purge gas may flow continuously throughout the deposition process such that only the purge gas flows during the time delay between pulses of the reactive compounds. The reactive compounds are pulsed alternately until a desired film or film thickness is formed on the substrate surface. In either case, an ALD process that pulses compound A, the purge gas, compound B, and then the purge gas is one cycle. The cycle can be initiated with either compound A or compound B, and each stage of the cycle can be continued until a film having a predetermined thickness is achieved.

[0016]

[0019] In an embodiment of the spatial ALD process, a first reactive gas and a second reactive gas (e.g., nitrogen gas) are delivered simultaneously to the reaction zone, but are separated by an inert gas curtain and / or a vacuum curtain. The substrate is moved relative to the gas delivery device such that any given point on the substrate is exposed to the first reactive gas and the second reactive gas.

[0017]

[0020] One or more embodiments advantageously provide a processing system that utilizes a quartz crystal microbalance (QCM) to monitor the precursor concentration output over the lifetime of the precursor within a container. By monitoring the precursor concentration, it is ensured that the same amount of precursor is delivered to the substrate from one pulse to another and from one wafer to the next, ensuring process quality and overall wafer yield. Also, by monitoring the precursor concentration, depletion of the source can be reliably recognized to prevent wafer scrap in the event of precursor shortage or depletion.

[0018]

[0021] As used herein, the term "quartz crystal microbalance (QCM)" refers to an electronic device conventionally used within a vacuum deposition chamber to measure the thickness of a thin film on a substrate. The QCM measures the film thickness by tracking the frequency response of the crystal during the coating process. This frequency change can be related to the amount of coating material on the crystal surface. The crystal monitors thickness at the angstrom level. This extreme level of accuracy is very important because a deviation in thickness of just 10 angstroms can potentially have a significant impact on product performance.

[0019]

[0022] Currently, the quartz crystal microbalance (QCM) system is located within the precursor container itself and does not provide information regarding the actual concentration output downstream of the container. Further, in the current system, the quartz crystal microbalance (QCM) occupies space within the container, increasing the footprint of the container and limiting the capacity of the container. Other concentration monitoring systems include optical (infrared and ultraviolet spectroscopy), acoustic, mass spectrometry, and gas chromatography systems. All of these system technologies have drawbacks and costs, including large footprints, inability to measure outside of narrow temperature flow or pressure ranges, carrier gas time dependence, and a maximum temperature limit of 150°C.

[0020]

[0023] Accordingly, one or more embodiments advantageously provide a quartz crystal microbalance (QCM) monitoring system that monitors upstream of the reaction chamber that houses the wafer / substrate but downstream of the container outlet, thus capturing both changes in sublimation / evaporation rate and physical failures (including, but not limited to, clogging or changes in valve conductance). The quartz crystal microbalance (QCM) monitoring system of one or more embodiments has a wide operating temperature, wide flow and pressure ranges, a small footprint, and is compatible with harsh chemistries. Without intending to be bound by theory, it is believed that placing the QCM upstream of the deposition chamber, as opposed to within or downstream of the deposition chamber in most applications, enables measurement of the condensed single precursor as opposed to the deposited film.

[0021]

[0024] FIG. 1 shows a schematic diagram of a processing system 100 according to one or more embodiments of the present disclosure. Referring to FIG. 1, system 100 includes a carrier gas source 106, a deposition chamber 118, an optional reservoir 114, a quartz crystal microbalance (QCM) sample chamber 128, a precursor container 102, and a controller 190.

[0022]

[0025] In one or more embodiments, the deposition chamber 118 can be any suitable semiconductor deposition chamber, such as a chemical vapor deposition (CVD) chamber, an atomic layer deposition (ALD) chamber, a plasma enhanced chemical vapor deposition (PECVD) chamber, or an etching chamber. Examples of suitable processing chambers include, but are not limited to, the PRODUCER™ series of CVD chambers, the SPRINT™ and ENDURA™ series of CVD / ALD chambers, and the CENTURA™ series of ALD / CVD and etching chambers available from Applied Materials, Inc. of Santa Clara, California.

[0023]

[0026] The system 100 transports the precursor 104 from the precursor container 102 to the deposition chamber 118 via the carrier gas store of the carrier gas source 106. In one or more embodiments, the carrier gas is optional if the precursor has a vapor pressure sufficient to provide a sufficient concentration in the reaction chamber. In one or more embodiments, the precursor 104 changes state from solid to gas (or vapor) within the container 102 by a sublimation process. Alternatively, the precursor 104 changes from liquid to gas within the container 102 by an evaporation process. The precursor 104 may be in a gaseous or fluid state. The vaporization process of the precursor 104 (i.e., sublimation or evaporation) may be initiated by any suitable known technique. For example, the precursor 104 can be heated to a predetermined temperature or mixed with a bubbling liquid within the container 102. In one or more embodiments, the temperature of the container 102 can be controlled to regulate the vaporization process. The container 102 and the precursor 104 are maintained in a temperature range of from about 10°C to about 600°C, or from about 25°C to about 300°C, or from about 50°C to about 150°C. In one or more embodiments, the precursor source can be cooled if the vapor pressure is sufficiently high. For example, in one or more embodiments, silicon tetrachloride (SiCl4) may be cooled to about 15°C because the resulting vapor pressure is sufficient to supply a 300 mm wafer.

[0024]

[0027] In one or more embodiments, the precursor container 102 can be any suitable container that can withstand, for example, the pressure and temperature required to vaporize the precursor 104. In some embodiments, the container 102 can include a bubbler (not shown). In one or more embodiments, the precursor container 102 is made of a material that is non-reactive with respect to the precursor 104. Materials suitable for manufacturing the precursor container 102 include, but are not limited to, steel (e.g., stainless steel), aluminum, aluminum alloys, or nickel. In one or more embodiments, the precursor container 102 can include a lining, such as, but not limited to, PTFE, nickel, magnesium fluoride, or glass, to enhance chemical protection. In one or more embodiments, the precursor container 102 can be an ampoule.

[0025]

[0028] In one or more embodiments, the carrier gas source 106 houses the carrier gas that flows through the first valve 108. As used herein, the term "carrier gas" refers to a fluid (either a gas or a liquid) that can move precursor molecules from one location to another. In some embodiments, the carrier gas is an inert gas. In one or more embodiments, the carrier gas is one or more of argon (Ar), helium (He), xenon (Xe), hydrogen (H2), or nitrogen (N2).

[0026]

[0029] In one or more embodiments, from the first valve 108, the carrier gas can move into the precursor container 102 through the second valve 138, mix with the vaporized precursor 104, and form a precursor gas. The precursor gas exits the precursor container 102 through the third valve 140. In one or more embodiments, the carrier gas has a flow rate in the range of from about 10 sccm to about 5000 sccm, or in the range of from about 50 sccm to about 1000 sccm. The carrier gas mixes with the precursor 104 and exits the precursor container 102 as a precursor gas.

[0027]

[0030] In other embodiments, the fourth valve 142 is a bypass valve that completely bypasses the container and only allows the carrier gas to flow into the deposition chamber 118. Thus, in one or more embodiments, the flow of the carrier gas bypasses the precursor container 102, flows through the fifth valve 110, and flows to the sample valve 112 through which the carrier gas flows into the sample chamber 128. In one or more embodiments, the sample valve 112 is a three-way valve as shown. In other embodiments, the sample valve 112 is a two-way valve. In one or more embodiments, the carrier gas has a flow rate in the range of about 10 sccm to about 5000 sccm, or in the range of about 50 sccm to about 1000 sccm. By mixing the carrier gas with the precursor 104, a process gas having a flow rate in the range of about 10 sccm to about 5,000 sccm, or in the range of about 50 sccm to about 1,000 sccm is formed.

[0028]

[0031] In one or more embodiments, the carrier gas source 106 supplies an inert carrier gas that flows through the precursor container 102. In one or more embodiments, the flow of the carrier gas pressurizes the precursor container 102 and entrains the sublimated precursor. In one or more embodiments, the concentration of the precursor 104 is defined as the ratio of the vapor pressure generated by heating the container 102 to the total pressure of the container supplied by the carrier gas. In one or more embodiments, the pressure drop occurs downstream of the container defined by the flow coefficient (Cv) of the delivery system and components, but the partial pressure of the precursor 104 is maintained. In ALD applications, the pulse sequence typically pulses the container inlet / outlet valves 108 / 110 and the sample valve 112 simultaneously to allow the precursor and carrier gas mixture to be delivered to the sample chamber 128. For solid precursors, the amount (pickup) contained in the carrier gas can vary depending on the temperature or the length of time in use. In one or more embodiments, the dosage variation can negatively affect the performance of the film and is typically only detected by in-situ measurements that can typically lead to multiple wafer scraps.

[0029]

[0032] In one or more embodiments, a quartz crystal microbalance (QCM) housing 132 is mounted within a quartz crystal microbalance (QCM) sample chamber 128. In one or more embodiments, the quartz crystal microbalance (QCM) sample chamber 128 is heated by a heater 124. In one or more embodiments, the temperature of the sample chamber 128 is maintained in a temperature range that is about 10°C to about 30°C higher than the temperature of the precursor vessel 102. In one or more embodiments, the QCM is maintained at a lower temperature that allows condensation. However, in one or more embodiments, it has the ability to not only clean the crystal but also heat it to a higher temperature. The sample chamber can be maintained at a higher temperature to ensure that condensation occurs on the crystal rather than on the sample chamber housing. In one or more embodiments, the sample chamber 128 is connected to a precursor delivery line 134, includes a hot valve 122, and has a flow path to a foreline 136 that includes the hot valve 122 to allow removal of excess material. In one or more embodiments, the QCM housing 132 includes a heater 124 and a gas cooling channel 126, enabling the QCM housing 132 to be maintained in a temperature range that is about 10°C to about 30°C lower than the temperature of the precursor vessel 102.

[0030]

[0033] In one or more embodiments, the QCM can measure the condensation of one species of precursor. This is different from the conventional use of QCM where film deposition is measured (i.e., not only one species but also the resulting film). The ability to measure a single species (through condensation) is important because it allows the QCM to be reset by heating the crystal and subliming the condensed precursor. This enables the crystal 146 to be operated indefinitely without the need to replace the crystal 146.

[0031]

[0034] In one or more embodiments, prior to the start of the deposition process, the sample valve 112 is opened for a period of time to allow a certain amount of precursor 104 in the carrier gas to flow or diffuse from the delivery line 134 into the sample chamber 128. Since the QCM housing 132 is maintained at a lower temperature compared to the precursor container 102, the precursor 104 will condense only on the QCM crystal 146, resulting in an increase in mass. Subsequently, the mass increase can be compared to the baseline reading. In one or more embodiments, if the concentration delivered from the precursor container 102 changes, the reported mass increase will deviate from the baseline, the deposition process can be interrupted, and damage to the wafer / substrate can be prevented. In one or more embodiments, a baseline is established and the QCM mass increase can be checked against the baseline prior to each wafer or each lot. In one or more embodiments, the QCM can be exposed to each ALD pulse to check for concentration changes for each pulse.

[0032]

[0035] In one or more embodiments, a quartz crystal microbalance (QCM) measures the concentration of precursor gas outside the precursor container. This measurement can occur in a time frame of less than about 100 milliseconds, or less than about 90 milliseconds, or less than about 80 milliseconds, or less than about 70 milliseconds, or less than about 60 milliseconds, or less than about 50 milliseconds. In one or more embodiments, the length of the pulse is between about 50 milliseconds and several seconds (up to about 20 seconds).

[0033]

[0036] In one or more embodiments, a reservoir 114 can be used to accumulate precursor doses and push larger doses into the deposition chamber 118. Alternatively, the reservoir 114 can be used to smooth out pressure variations during pulsed delivery. A purge gas can be introduced during the delivery of each precursor gas to ensure that reactions occur only on the substrate surface. In one or more embodiments, the purge gas includes any suitable gas including, but not limited to, argon (Ar), helium (He), nitrogen (N2), and hydrogen (H2). In some embodiments, the purge gas includes nitrogen (N2).

[0034]

[0037] In one or more embodiments, system 100 includes a controller 190. In an exemplary embodiment, controller 190 includes a hard disk drive, a floppy disk drive, and a processor.

[0035]

[0038] In one or more embodiments, controller 190 controls all of the movement of system 100. Controller 190 executes system control software, which is a computer program stored in a computer-readable medium. This medium can be a hard disk drive or other type of memory. The computer program includes a set of instructions that direct the timing of a particular process, the gas mixture, the chamber pressure, the chamber temperature, the RF power level, and other parameters. For example, other computer programs stored on other storage devices, including a floppy disk or other suitable driver, can also be used to direct the system controller.

[0036]

[0039] Controller 190 includes a central processing unit (CPU) 192, a memory 194, one or more support circuits 196 utilized to control the processing sequence and regulate the gas flow, and an input / output (I / O) 198. CPU 192 can be any form of general-purpose computer processor that can be used in an industrial environment. Software routines can be stored in memory 194 (e.g., random access memory, read-only memory, floppy, or hard disk drive, or other forms of digital storage). Support circuits 196 are conventionally coupled to CPU 192 and can include a cache, a clock circuit, an input / output system, a power supply, and the like.

[0037]

[0040] Memory 194 may include one or more temporary memories (e.g., random access memory) and non-temporary memories (e.g., storage). The memory 194 of the processor or the computer-readable medium may be one or more of readily available memories such as random access memory (RAM), read-only memory (ROM), floppy disks, hard disks, or any other form of local or remote digital storage. Memory 194 may hold an instruction set operable by the processor to control system parameters and components.

[0038]

[0041] The process may generally be stored in memory as a software routine. When executed by the processor, this software routine causes the process of the present disclosure to be executed in the processing chamber. This software routine may also be stored and / or executed by a second processor (not shown) located remotely from the hardware controlled by the processor. Part or all of the methods of the present disclosure can also be executed in hardware. Thus, the processing can be implemented in software and executed in hardware using a computer system, for example, as an application specific integrated circuit or other type of hardware implementation form, or as a combination of software and hardware. When executed by the processor, the software routine transforms a general-purpose computer into a special-purpose computer (controller 190) that controls the operation of the chamber so that the process is carried out.

[0039]

[0042] The controller 190 in some embodiments is configured to act with hardware to perform programmed functions. For example, the controller 190 may be configured to control one or more valves, motors, actuators, motors, power supplies, etc. In some embodiments, the controller 190 is connected to the deposition chamber 118. The controller 190 has one or more configurations for controlling various functions and processes.

[0040]

[0043] Figure 2 shows a schematic diagram of a quartz crystal microbalance (QCM) device 200 according to one or more embodiments of the present disclosure. A quartz crystal microbalance (QCM) is an electronic device used in a vacuum deposition chamber to measure the thickness of a thin film on a substrate.

[0041]

[0044] Referring to Figure 2, in one or more embodiments, the quartz crystal microbalance (QCM) device is partially contained within the vacuum chamber and partially outside. The components within the vacuum include the crystal 206, the crystal holder 204, the sensor head 202 (comprising electrical connections, a water supply line, a thermocouple, and a heating element), and the feedthrough 207, which connects the internal components to the air side. The external components include the cable and accessories (not shown) from the feedthrough 207, an oscillator 208 (which vibrates the crystal 206 and continuously measures the vibration), and a frequency counter 210 (which displays this information and operates based on it).

[0042]

[0045] In one or more embodiments, there are two types of crystals 206 used for measuring film thickness: the AT type and the RC type. The AT crystal is characterized by a molecular tetrahedral crystal structure and a single angle cut (35 or 15 units from the Z direction) and vibrates when a voltage is applied. The frequency naturally exhibited by the AT crystal remains constant until a material of a few angstroms is deposited thereon and its frequency changes. The frequency of the AT crystal is sensitive to temperature and the stress of the internal deposited material. The AT crystal can be used in processes up to 100°C, but is more suitable for low-temperature measurements. On the other hand, the RC crystal does not easily exhibit a frequency response to internal stress or high temperatures and mainly responds only to film accumulation on the surface. The RC crystal can effectively measure the film without compromising the integrity of the measurement. Furthermore, the frequency-temperature change curve of the RC crystal is 300°C.

[0043]

[0046] The crystal is shaped such that one side is flat and the other side is curved or plano-convex. The reason for this shape is to keep the vibration of the crystal at the center rather than at the ends. The plano-convex crystal can be mounted within the holder 204 without affecting the vibration. This curvature is essential for proper operation because flat or planar crystals do not vibrate accurately.

[0044]

[0047] In one or more embodiments, the sensor head 202 is a mechanical assembly where the crystal is disposed and the electrical contacts connect the crystal to the oscillator 208. In some embodiments, the sensor head 202 includes a water or air line for cooling, a heater for changing the temperature of the sensor head 202, and a thermocouple. The crystal is temperature-sensitive and always requires temperature control. In one or more embodiments, the sensor head 202 is "removable", which means that the crystal assembly is replaceable. This can be achieved by using a cap attached to the sensor body or a holder for the crystal itself. The sensor body has a central contact spring that presses against the back side of the crystal cap that makes the electrical circuit. The sensor body is an electrical "ground" or return path. In one or more embodiments, a heating element (not shown) is added to the sensor head 202. The heating element in combination with a thermocouple or temperature measurement device enables the temperature of the sensor head 202 to be controlled in real time. In one or more embodiments, the sensor head 202 can hold from 1 to 24 crystals. Thus, if a crystal 206 fails or stops operating, the process can continue to be monitored without opening the chamber. In one or more embodiments, the sensor head holds one crystal, and advantageously, only one crystal is used during the deposition process.

[0045]

[0048] In one or more embodiments, the feedthrough 207 is a metal assembly that connects the sensor head 202 and its electrical and liquid or air lines through the vacuum chamber wall. In one or more embodiments, the oscillator 208 is an electrical circuit that forces the crystal 206 to vibrate or "oscillate". The oscillator 208 does this by finding the natural or resonant frequency of the crystal 206 and tracking how this frequency changes with the addition of the coating. In one or more embodiments, since a crystal connection cable (not shown) forms part of the oscillation circuit, the oscillator 210 is placed near (within about 6 inches to about 10 inches) the feedthrough 207. If the crystal connection cable is too long, the strength of the vibration weakens, making the crystal measurement unstable.

[0046]

[0049] In one or more embodiments, the frequency counter 210 is a microprocessor-based electronic device that acquires frequency information from the oscillator 208 through a coaxial cable and uses it to calculate the deposited film thickness or the ratio of thickness. The algorithm or formula used is called the Sauerbrey equation or the modified Sauerbrey equation. This equation relates the mass or weight of the film to the change in the resonant frequency of the crystal. As the mass deposited on the crystal increases, the vibration slows down. This change can be used to calculate the thickness from the mass.

[0047]

[0050] In one or more embodiments, the frequency counter 210 can be coupled to the reaction chamber control architecture 190 so that it can read signals from the tool GUI. In this way, actions / modifications can be performed on the tool and the process can be adjusted according to the measurements on the QCM. Actions can include adjusting the carrier flow rate, adjusting the temperature of the precursor container, or stopping the processing of the current or future wafers if the concentration exceeds the required limits.

[0048]

[0051] FIG. 3 shows a process flow diagram of an exemplary method 300 for depositing a film according to one or more embodiments of the present disclosure. Referring to FIG. 3, in operation 302, a precursor container containing a chemical precursor is heated or cooled to a temperature in the range of about 10° C. to about 600° C., or in the range of about 25° C. to about 300° C., or in the range of about 50° C. to about 150° C. The precursor has a first precursor concentration. In operation 304, a precursor gas is formed by flowing a carrier gas through the precursor container containing the chemical precursor. In operation 306, the substrate is exposed to the precursor gas during the deposition process. In operation 308, after the precursor gas exits the precursor container, the concentration of the chemical precursor in the precursor gas is measured. The concentration measurement can be performed using a quartz crystal microbalance (QCM) device in a sample chamber. The precursor in the precursor gas has a second precursor concentration, and the sample chamber has a temperature in the range of about 10° C. to about 15° C. higher than the temperature of the precursor container. In one or more embodiments, the measurement of the concentration of the chemical precursor in the precursor gas is performed in a time frame of less than about 100 milliseconds, or in a time frame of about 50 milliseconds to about 20 seconds. In operation 310, a film is formed on the substrate. In some embodiments, the chemical precursor is vaporized by heating the container. In one or more embodiments, the quartz crystal microbalance (QCM) device has a temperature in the range of about 10° C. to about 30° C. lower than the temperature of the container.

[0049]

[0052] FIG. 4 shows a process flow diagram of an exemplary method 400 for depositing a film according to one or more embodiments of the present disclosure. In one or more embodiments, a QCM can be used to sense the concentration (as a health check of the precursor container) before moving the substrate into the reaction chamber. Referring to FIG. 4, in operation 402, a precursor container containing a chemical precursor is heated or cooled to a temperature in the range of about 10° C. to about 600° C., or in the range of about 25° C. to about 300° C., or in the range of about 50° C. to about 150° C. The precursor has a first precursor concentration. In operation 404, a precursor gas is formed by flowing a carrier gas through the precursor container containing the chemical precursor. In operation 406, after the precursor gas exits the precursor container, the concentration of the chemical precursor in the precursor gas is measured. The concentration measurement can be performed using a quartz crystal microbalance (QCM) device in a sample chamber. The precursor in the precursor gas has a second precursor concentration, and the sample chamber has a temperature in the range of about 10° C. to about 15° C. higher than the temperature of the precursor container. In one or more embodiments, the measurement of the concentration of the chemical precursor in the precursor gas is performed in a time frame of less than about 100 milliseconds, or in a time frame of about 50 milliseconds to about 20 seconds. In operation 408, the substrate is exposed to the precursor gas during the deposition process. In operation 410, a film is formed on the substrate. In some embodiments, the chemical precursor vaporizes by heating the container. In one or more embodiments, the quartz crystal microbalance (QCM) device has a temperature in the range of about 10° C. to about 30° C. lower than the temperature of the container.

[0050]

[0053] Throughout this specification, references to "one embodiment", "a particular embodiment", "one or more embodiments", or "an embodiment" mean that the particular features, structures, materials, or characteristics described in connection with the embodiment are included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases "in one or more embodiments", "in a particular embodiment", "in one embodiment", or "in an embodiment" in various places throughout this specification are not necessarily referring to the same embodiment of the present disclosure. Further, the particular features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments.

[0051]

[0054] Although the disclosure of this specification has been described with reference to particular embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the present disclosure. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatuses of the present disclosure without departing from the essence and scope of the present disclosure. Therefore, the present disclosure is intended to cover modifications and variations that come within the scope of the appended claims and their equivalents.

Claims

1. A processing system comprising: a carrier gas source; a precursor container; a deposition chamber; a sample chamber downstream of the precursor container and upstream of the deposition chamber, the sample chamber containing a quartz crystal microbalance (QCM) device; a heater within the sample chamber and wherein the quartz crystal microbalance (QCM) device includes a gas cooling channel; wherein the heater and the gas cooling channel are configured to maintain the quartz crystal microbalance (QCM) device at a temperature 10°C to 30°C lower than the temperature of the precursor container during processing; wherein the sample chamber is configured to be heated by the heater and to have a temperature in the range of 10°C to 30°C higher than the temperature of the precursor container during processing; A processing system.

2. The processing system according to claim 1, wherein the deposition chamber is selected from one or more of a chemical vapor deposition (CVD) chamber or an atomic layer deposition (ALD) chamber.

3. The processing system according to claim 1, further comprising a precursor delivery line and a three-way valve connecting the sample chamber to the precursor delivery line.

4. The processing system according to claim 1, wherein the sample chamber includes a high-temperature valve and a flow path to a foreline having the high-temperature valve to enable removal of excess material.

5. The carrier gas source contains a carrier gas selected from one or more of argon (Ar), helium (He), xenon (Xe), hydrogen (H ２ ), and nitrogen (N ２ ), and the processing system according to claim 1.

6. The processing system according to claim 1, wherein the quartz crystal microbalance (QCM) device includes one or more of a sensor head, a crystal holder, a crystal, a feedthrough, an oscillator, and a frequency counter.

7. The processing system according to claim 6, wherein the crystal includes one or more of an AT crystal or an RC crystal.

8. The processing system according to claim 6, including a crystal in the range of 1 to 24.

9. The processing system according to claim 1, further comprising a controller.

10. The processing system according to claim 9, wherein the controller includes a central processing unit (CPU), a memory, circuitry, and input / output.

11. The processing system according to claim 1, further comprising a purge gas source and a reservoir, the reservoir being downstream of the precursor container and the sample chamber and upstream of the deposition chamber.

12. The purge gas source includes a purge gas selected from one or more of argon (Ar), helium (He), xenon (Xe), hydrogen (H ２ ), and nitrogen (N ２ ), and the processing system according to claim 11.

13. The processing system according to claim 1, wherein the precursor container is an ampoule.

14. The processing system according to claim 1, wherein the chemical precursor in the precursor container is selected from one or more of a solid precursor and a liquid precursor.

15. A processing method using a processing system, wherein the processing system includes a carrier gas source; a precursor container; a deposition chamber; a sample chamber downstream of the precursor container and upstream of the deposition chamber, the sample chamber containing a quartz crystal microbalance (QCM) device; a heater in the sample chamber and the quartz crystal microbalance (QCM) device includes a gas cooling channel, the heater and the gas cooling channel are configured to maintain the quartz crystal microbalance (QCM) device at a temperature 10°C to 30°C lower than the temperature of the precursor container during processing, wherein the processing method includes heating the precursor container containing the chemical precursor to a temperature in the range of 10°C to 600°C, wherein the precursor container has a first precursor concentration; flowing a carrier gas from the carrier gas source to the precursor container to form a precursor gas containing the chemical precursor; measuring the concentration of the chemical precursor in the precursor gas using the quartz crystal microbalance (QCM) device in the sample chamber, wherein the chemical precursor in the precursor gas has a second precursor concentration, the sample chamber is heated by the heater, and the sample chamber has a temperature in the range 10°C to 30°C higher than the temperature of the precursor container; exposing a substrate to the precursor gas during a deposition process; depositing a film on the substrate and

16. The processing method according to claim 15, wherein heating the precursor container vaporizes the chemical precursor.

17. The processing method according to claim 15, wherein the quartz crystal microbalance (QCM) device has a temperature in the range 10°C to 15°C lower than the temperature of the precursor container.

18. The processing method according to claim 15, wherein measuring the concentration of the chemical precursor in the precursor gas is performed in a time frame of 50 milliseconds to 20 seconds.

19. A non-transitory computer-readable medium including instructions that, when executed by a controller included in a processing system, cause the processing system to perform operations, the processing system comprising: a carrier gas source; a precursor container; a deposition chamber; a sample chamber downstream of the precursor container and upstream of the deposition chamber, the sample chamber containing a quartz crystal microbalance (QCM) device; a heater within the sample chamber and further comprising, the quartz crystal microbalance (QCM) device including a gas cooling channel, the heater and the gas cooling channel configured to maintain the quartz crystal microbalance (QCM) device at a temperature 10°C to 30°C lower than the temperature of the precursor container during processing; the operations comprising: heating the precursor container containing a chemical precursor to a temperature in the range of 25°C to 600°C; flowing carrier gas from the carrier gas source to the precursor container to form a precursor gas containing the chemical precursor; measuring the concentration of the chemical precursor in the precursor gas using the quartz crystal microbalance (QCM) device within the sample chamber, the sample chamber being heated by the heater and having a temperature in the range 10°C to 30°C higher than the temperature of the precursor container; exposing a substrate to the precursor gas during a deposition process; depositing a film on the substrate and embodied on a non-transitory computer-readable medium. **Claim 20** The non-transitory computer-readable medium according to claim 19, wherein the quartz crystal microbalance (QCM) device has a temperature in the range 10°C to 30°C lower than the temperature of the precursor container. **Claim 21** The non-transitory computer-readable medium according to claim 19, wherein the operation of measuring the concentration of the chemical precursor in the precursor gas is performed in a time frame of less than 100 milliseconds.

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