Apparatus, system and method for monitoring process drift in semiconductor processing system

Abstract

Load locking assemblies, semiconductor processing systems including such load locking assemblies, and related methods for monitoring process drift within a processing module of a semiconductor processing system are disclosed. The disclosed load lock assembly includes an indexer mechanism and a position sensor in communication with a controller in a feedback loop configuration to enable generation of a control parameter based on a weight or weight change of a substrate within the load lock assembly. The control parameter is used to signal when the process drift is detected to enable a corrective action to be carried out.

Description

Technical Field

[0001] The present disclosure relates generally to the field of semiconductor processing systems and processing methods, and to the field of device and integrated circuit manufacturing. More specifically, the present disclosure relates to apparatus, systems and methods for monitoring process drift in semiconductor processing systems. Background Art

[0002] Semiconductor devices and integrated circuits are typically manufactured on a semiconductor material substrate, commonly referred to as a substrate, wafer and / or workpiece. Processing methods commonly used to manufacture semiconductor devices and integrated circuits include, but are not limited to, vapor deposition processes (e.g., atomic layer deposition, chemical vapor deposition, etc.) and etching processes (e.g., chemical vapor etching, atomic layer etching, plasma-based etching, etc.). These processes typically involve forming a layer of material on an exposed surface of a substrate or removing a layer of material from it. The parameters that govern such a process are typically tightly controlled to ensure that each substrate subjected to a particular process has substantially the same amount of material added or removed, and any deviation from the expected process is typically referred to as "process drift."

[0003] In some semiconductor manufacturing processes, unprocessed substrates are transferred from a box to a load lock. The substrate is then transferred from the load lock to a processing module for processing. Once the process in a processing module is completed, the substrate can be transferred to a different processing module to continue processing the substrate. During the transfer of the substrate between different processing modules, the substrate can pass through the load lock multiple times. Once the processing of the substrate is completed, the substrate is usually moved back to the load lock for cooling, post-processing and transmission (e.g., moving out of the semiconductor processing system). Such a load lock can be combined with equipment and systems to allow the utilization of the semiconductor processing system to be improved. For example, cooling and heating the substrate in the load lock can be used to reduce the processing time in a separate processing module. However, there is still a need for an improved load lock, such as a load lock combined with additional functions, so that process drift can be monitored during the processing of multiple substrates. Therefore, there is a need for an improved load lock, a semiconductor processing system including such an improved load lock, and a related method for monitoring process drift in such an improved load lock.

[0004] Any discussion set forth in this section, including discussion of problems and solutions, has been included in the present disclosure merely to provide context for the present disclosure. Such discussion should not be construed as an admission that any or all information was known or constituted prior art when the present invention was made. Summary of the invention

[0005] This Summary may introduce some concepts in a simplified form that are further described in detail below. This Summary is not intended to necessarily identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0006] Various embodiments of the present disclosure relate to apparatus, systems and related methods for monitoring process drift in semiconductor processing systems, particularly in load locks. As described in more detail below, the apparatus of the present disclosure includes a load lock configured and arranged to monitor a parameter proportional to the weight of a substrate within the load lock by employing at least an indexer mechanism, a sensor and a controller in a feedback loop configuration. Such an apparatus is capable of generating a control parameter proportional to the weight or weight change of a substrate that has undergone a particular process in a processing module, and then comparing the control parameter to a predetermined expected value or acceptable value range.

[0007] According to an example of the present disclosure, a device for monitoring process drift within a semiconductor processing system is provided. The example device includes a load lock device, which includes a load lock body and an indexer mechanism connected to the load lock body, the indexer mechanism including a drive mechanism and a device for supporting a substrate. In such an example, the device also includes a position sensor, which is configured and arranged to measure the deflection distance of the indexer mechanism from a known neutral position when the substrate is placed on the indexer mechanism, and then the position sensor generates a feedback signal based on the deflection distance. In such an example, the device also includes a controller, which is configured and arranged to receive the feedback signal, and then the controller calculates an incremental drive current (ΔI) and provides the incremental drive current (ΔI) to the drive mechanism to reposition the indexer mechanism back to the known neutral position, wherein when the acceleration of the drive mechanism is zero and the vacuum load is constant, the incremental drive current (ΔI) is proportional to the weight of the substrate, so that the controller can generate a control parameter proportional to the weight of the substrate or the weight change of the substrate. In such an example, the device also includes an alarm system in communication with the controller, wherein if the controller determines that the control parameter is outside a predetermined acceptable value range, the alarm system is activated.

[0008] According to an additional example of the present disclosure, a semiconductor processing system is provided. In such an example, the semiconductor processing system includes a load lock body; an equipment front end module (EFEM) connected to the front side of the load lock body, the equipment front end module accommodating a front end substrate transfer robot; and a back end transfer module (BETM) connected to the back side of the load lock body, the back end transfer module coupling the processing module to the load lock body. In such an example, the semiconductor processing system also includes an indexer mechanism connected to the load lock body, the indexer mechanism including a drive mechanism and a device for supporting a substrate. In such an example, the semiconductor processing system also includes a position sensor configured and arranged to measure a deflection distance of the indexer mechanism from a known neutral position when the substrate is placed on the indexer mechanism, and then the position sensor generates a feedback signal based on the deflection distance. In such an example, the semiconductor processing system further includes a controller configured and arranged to receive the feedback signal, and the controller then calculates and provides an incremental drive current (ΔI) to the drive mechanism to reposition the indexer mechanism back to a known neutral position, wherein the incremental drive current (ΔI) is proportional to the weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load is constant, such that the controller can adjust the substrate by determining a first incremental drive current (ΔI) for the substrate transferred from the EFEM and placed on the indexer mechanism. 1 ) and a second incremental drive current (ΔI ) for a substrate that has been transferred from the BETM and placed on the indexer mechanism after the substrate has been subjected to one or more processes within the processing module. 2 ) to generate a control parameter proportional to the weight change of the substrate. In such an example, the semiconductor processing system also includes an alarm system in communication with the controller, wherein if the controller determines that the control parameter is outside a predetermined acceptable value range, the alarm system is activated.

[0009] According to additional examples of the present disclosure, a method for monitoring process drift in a semiconductor processing system is provided. In such an example, the method includes at an indexer mechanism connected to a load lock body, the indexer mechanism including a drive mechanism and a device for supporting a substrate. In such an example, the method also includes transferring the substrate into the load lock body and placing the substrate on the indexer mechanism. In such an example, the method also includes generating a first feedback signal from a position sensor, the position sensor being configured and arranged to measure a first deflection distance of the indexer mechanism from a known neutral position when the substrate is placed on the indexer mechanism; and calculating a first incremental drive current (ΔI) from the first feedback signal. 1 ) and the first incremental drive current (ΔI 1) is provided to the drive mechanism to reposition the indexer mechanism back to a known neutral position, wherein the first incremental drive current (ΔI) is proportional to the first weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load is constant. In such an example, the method also includes: transferring the substrate from the load lock body to the processing module and performing one or more processes on the substrate; and subsequently transferring the substrate from the processing module back to the load lock body and repositioning the substrate on the indexer mechanism. In such an example, the method also includes generating a second feedback signal from the position sensor, the position sensor being configured and arranged to measure a second deflection distance of the indexer mechanism from the known neutral position when the substrate is repositioned on the indexer mechanism. In such an example, the method also includes: calculating a second incremental drive current (ΔI) from the second feedback signal 2 ) and the second incremental drive current (ΔI 2 ) is provided to the drive mechanism to reposition the indexer mechanism back to a known neutral position, wherein the second incremental drive current (ΔI) is proportional to a second weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load is constant. In such an example, the method further includes: calculating a control parameter proportional to the change in weight of the substrate by determining a difference between the first incremental drive current (ΔI) and the second incremental drive current (ΔI); and activating an alarm system if the control parameter is outside of a predetermined acceptable value range.

[0010] In order to summarize the present invention and the advantages achieved relative to the prior art, certain objects and advantages of the present invention have been described above. Of course, it should be understood that not all of these objects or advantages may be achieved according to any particular embodiment of the present invention. Thus, for example, those skilled in the art will recognize that the present invention may be implemented or performed in a manner that achieves or optimizes one advantage or a group of advantages taught or suggested herein without having to achieve other objects or advantages taught or suggested herein.

[0011] All of these embodiments are within the scope of the invention disclosed herein. These and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments with reference to the accompanying drawings, the invention not being limited to any particular embodiment disclosed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To easily identify the discussion of any particular element or act, the most significant digit(s) in a reference number refers to the figure number in which the element is first introduced.

[0013] A more complete understanding of exemplary embodiments of the present disclosure may be obtained by referring to the detailed description and claims when considered in conjunction with the following illustrative drawings.

[0014] Figure 1A semiconductor processing system in accordance with at least one embodiment of the present disclosure is shown.

[0015] Figure 2 A load lock arrangement in accordance with at least one embodiment of the present disclosure is shown.

[0016] Figure 3 A dual chamber load lock apparatus is shown in accordance with at least one embodiment of the present disclosure.

[0017] Figure 4 A method for monitoring process drift in a semiconductor processing system in accordance with at least one embodiment of the present disclosure is shown.

[0018] It should be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the size of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of the illustrated embodiments of the present disclosure. DETAILED DESCRIPTION

[0019] The description of exemplary embodiments of the devices, systems, and methods provided below is merely exemplary and is for illustration purposes only. The following description is not intended to limit the scope of the present disclosure or the claims. In addition, the recitation of multiple embodiments having the indicated features or steps is not intended to exclude other embodiments having additional features or steps, or other embodiments incorporating different combinations of the described features or steps.

[0020] As used herein, the term "load lock apparatus" may refer to any chamber apparatus configured for handling, transferring, and / or storing substrates before and / or after processing in a process module (or reactor, reaction chamber, etc.).

[0021] As used herein, the term "substrate" may refer to any one or more underlying materials that can be used to form or can be formed on a device, circuit or film by a method according to an embodiment of the present invention. The substrate may include a bulk material, such as silicon (e.g., single crystal silicon), other IV group materials, such as germanium, or other semiconductor materials, such as II-VI or III-V semiconductor materials, and may include one or more layers covering or located below the bulk material. In addition, the substrate may include various features, such as depressions, protrusions, etc. formed in or on at least a portion of the substrate layer. For example, the substrate may include a bulk semiconductor material and an insulating or dielectric material layer covering at least a portion of the bulk semiconductor material. In addition, the term "substrate" may refer to any one or more underlying materials that can be used or on which a device, circuit or film can be formed. "Substrate" may be continuous or discontinuous; rigid or flexible; solid or porous. "Substrate" may be in any form, such as a powder, a plate or a workpiece. Plate-shaped substrates may include wafers of various shapes and sizes. The substrate may be made of materials such as silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride and silicon carbide. The continuous substrate can extend beyond the boundaries of the processing chamber where the deposition process occurs, and can be moved through the processing chamber so that the process continues until the end of the substrate is reached. The continuous substrate can be provided by a continuous substrate feeding system, which allows the continuous substrate to be manufactured and output in any suitable form. Non-limiting examples of continuous substrates may include sheets, nonwoven films, rolls, foils, nets, flexible materials, a bundle of continuous filaments or fibers (i.e., ceramic fibers or polymer fibers). The continuous substrate may also include a carrier or thin sheet on which a non-continuous substrate is mounted. For example, the substrate may include a semiconductor material. The semiconductor material may include or be used to form one or more of the source, drain or channel regions of the device. The substrate may also include an interlayer dielectric (e.g., silicon oxide) and / or a high dielectric constant material layer covering the semiconductor material. In this context, a high dielectric constant material (or high-k dielectric material) is a material whose dielectric constant is greater than the dielectric constant of silicon dioxide.

[0022] As used herein, the terms "film" and / or "layer" can be used interchangeably and can refer to any continuous or discontinuous structure and material, such as materials deposited by the methods disclosed herein. For example, the film and / or layer can include a two-dimensional material, a three-dimensional material, nanoparticles, a partial or complete molecular layer or a partial or complete atomic layer or a cluster of atoms and / or molecules. The film or layer can be composed, in part or in whole, of a plurality of dispersed atoms on the surface of a substrate and / or embedded in a substrate and / or embedded in a device manufactured on the substrate. The film or layer can include a material or layer having pinholes and / or islands. The film or layer can be at least partially continuous. The film or layer can be patterned, for example, subdivided, and can be composed of a plurality of semiconductor devices.

[0023] Various embodiments of the present disclosure relate to apparatus, systems and methods for monitoring process drift in semiconductor processing systems, particularly in load locks. As described in more detail below, the apparatus of the present disclosure includes a load lock configured and arranged to monitor a parameter proportional to the weight of a substrate. Thus, such an apparatus is capable of monitoring, for example, a change in weight of a substrate undergoing a deposition and / or etching process. When such a change in weight is compared to a predetermined expected value or acceptable range of values, the change in weight of a particular substrate before and after processing can be used to determine whether a process drift has occurred.

[0024] According to an example of the present disclosure, the load lock device of the present disclosure adopts an indexer mechanism, which combines a vertical actuator assembly including a drive mechanism, such as a servo system with a linear drive, and a high-precision position sensor to generate a control parameter based on the weight or weight change of the substrate. In various embodiments of the present disclosure, the indexer mechanism can be configured to maintain a substrate placed thereon at a known neutral position (i.e., a baseline vertical position within the load lock device), which is typically the position within the load lock device where the substrate is loaded or unloaded.

[0025] According to an example of the present disclosure, an indexer mechanism is controlled in a feedback loop configuration. In such an example, a position sensor measures a deflection distance of the indexer mechanism from a known neutral position, which is caused by placing a substrate on the indexer mechanism. In such an example, the position sensor generates a feedback signal based on the deflection distance, which is sent to a controller that communicates with the position sensor and the indexer mechanism. Next, the controller determines from the feedback signal a change in drive current (herein referred to as an incremental drive current) provided to the drive mechanism to enable the substrate to be repositioned back to the known neutral position. When controlling certain variables / parameters within the load lock device and the indexer mechanism, the incremental drive current (ΔI) is proportional to the weight of the substrate (to be described in more detail herein), thereby enabling the controller to generate a control parameter proportional to the weight of the substrate or the weight change of the substrate. If it is determined that the control parameter is outside a predetermined acceptable value or range of values, an alarm system connected to or integrated into the controller can be activated to warn that a process drift has been detected, thereby allowing appropriate corrective actions to be performed.

[0026] Previous apparatus, systems, and methods for determining process drift in semiconductor processing systems typically utilize ex-situ apparatus and methods. In such previous apparatus and methods, a substrate is typically removed from a semiconductor processing system and evaluated using an ex-situ metrology tool to determine whether the semiconductor processing system is experiencing process drift. For example, such ex-situ apparatus and methods disadvantageously result in reduced substrate yields, the need for expensive metrology tools, and exposure of the substrate to the atmosphere.

[0027] Embodiments of the present disclosure advantageously employ in-situ devices, systems, and methods to monitor process drift. For example, substrates are typically placed and relocated multiple times in the load lock apparatus of the present invention as they are transferred back and forth between various processing modules. Each placement and relocation of a substrate within the load lock apparatus of the present invention allows for a rapid determination of a weight change of a substrate immediately after a process is performed in a processing module. The determination of a substrate weight change is accurate and rapid, and therefore does not affect the throughput of substrates through a semiconductor processing system. In addition, process drift within a processing module can be quickly detected, resulting in immediate corrective action, thereby preventing scratched substrates, unnecessary expenses, and tool downtime.

[0028] Now turning to the attached figure, Figure 1 A semiconductor processing system 100 of the present disclosure is shown, including a load lock 106 for implementing process drift monitoring. The semiconductor processing system 100 includes a processing module 102, a back end transfer module 104, and a load lock 106 including a load lock body 108. The semiconductor processing system 100 also includes an equipment front end module (EFEM) 110, a controller 112, and an evacuation / exhaust source 114. In the example shown, the semiconductor processing system 100 includes a cluster platform 116 having four (4) processing modules, and the four (4) processing modules are configured to deposit material layers onto / etch material layers from a substrate 118 using a deposition and / or etching process, such as atomic layer deposition (ALD), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), plasma enhanced atomic layer deposition (PEALD), atomic layer etching (ALEt) process, chemical vapor etching (CVE) process, and plasma-based dry etching process. This is for illustration and description purposes only and is not limiting. In view of the present disclosure, those skilled in the art will appreciate that semiconductor processing systems configured for other material layer deposition / etching operations, as well as semiconductor processing systems configured for other processing operations, may also benefit from the present disclosure.

[0029] The process module 102 is coupled to the back-end transfer module 104 via a process module gate valve 120. The process module 102 includes a process chamber 122, a heater 124, and a reactant source 126. The process chamber 122 is disposed within the process module 102, houses the heater 124, and is configured to flow a precursor or reactant through the substrate 118 while being disposed on the heater 124 during deposition / etching of a material layer onto / from the substrate 118. The precursor / reactant source 126 is fluidly coupled to the process chamber 122 and is configured to provide a precursor / reactant to the process chamber 122 to deposit / etch one or more material layers onto / from the substrate 118. The process module gate valve 120 couples the process module 102 to the back-end transfer module 104 and is configured to provide selective communication between the process chamber 122 and the back-end transfer module 104. In this regard, it is contemplated that the process module gate valve 120 may be configured to allow transfer of the substrate 118 between the back end transfer module 104 and the process module 102 both before and after deposition of a material layer onto the substrate 118 .

[0030] According to examples of the present disclosure, the process chamber 122 may be a first process chamber, and the process module 102 may include one or more second process chambers. For example, the process module 102 may be a dual chamber module having two (2) process chambers or a quad chamber module having four (4) process chambers. According to certain examples, the process module gate valve 120 may be a first process module gate valve, and the process module 102 may include a second process module gate valve, which also couples the process module 102 to the back-end transfer module 104. It is contemplated that in certain examples, the reactants may include reactants or precursors suitable for deposition / etching of a material layer. It is also contemplated that, according to certain examples, the process module 102 includes a plasma unit configured to provide the reactants as a suitable plasma to the substrate 118. In this regard, as an example, the process module 102 may be configured to deposit / etch a material layer onto / from the substrate 118 using a plasma enhanced deposition / etching technique.

[0031] The back-end transfer module 104 is coupled to a back side 138 of the load lock body 108 and includes a back-end chamber body 128 and a back-end substrate transfer robot 130. The back-end chamber body 128 is arranged along a transfer axis 132. It is contemplated that the back-end substrate transfer robot 130 is arranged inside the back-end chamber body 128 and supported within the back-end chamber body 128 for movement relative to the back-end chamber body 128 to transfer substrates, such as substrates 118, between the load lock 106 and the processing module 102. In some examples, the back-end chamber body 128 can have a polygonal shape. In this regard, the back-end chamber body 128 can have five sides, less than five sides (e.g., a rectangle or a square), or more than five sides (e.g., a hexagon), and can have a regular polygonal shape or an irregular polygonal shape.

[0032] The equipment front end module (EFEM) 110 is coupled to the front face 140 of the load lock body 108 and includes a housing 144, a front end substrate transfer robot 146, and one or more load ports 148. The housing 144 houses the front end substrate transfer robot 146. The front end substrate transfer robot 146 is housed within the housing 144 for moving relative to the housing 144 or transferring a substrate, such as the substrate 118, between the one or more load ports 148 and the load lock 106. The one or more load ports 148 are connected to the housing 144 and are configured to house a cassette 150 therein that houses one or more substrates before and after depositing / etching a material layer onto / from the substrate. In some examples, the cassette 150 may include a standard mechanical interface cassette. According to some examples, the cassette 150 may include a front opening unified cassette. Although shown and described herein as having three (3) load ports, it should be understood and appreciated that the equipment front end module 110 may include fewer or more load ports and still be within the scope of the present disclosure.

[0033] The controller 112 is operably connected to the semiconductor processing system 100 and includes a device interface 152, a processor 154, a user interface 156, and a memory 158. The device interface 152 couples the processor 154 to the semiconductor processing system 100, for example, by (or via) a wired or wireless link 160. The processor 154 is operably connected to the user interface 156 and is configured to communicate with the memory 158. The memory 158 includes a non-transitory machine-readable medium having recorded thereon a plurality of program modules 162, which contain instructions that, when read by the processor 154, cause the processor 154 to perform certain operations. Among these operations are operations for monitoring process drift in the semiconductor processing system 100, as described below.

[0034] In some embodiments, the semiconductor processing system 100 may include substrate heating and / or substrate cooling within the load lock 106, for example, for throughput purposes. For example, in some semiconductor processing systems, substrate heating within the load lock may be implemented to limit processing time within a processing module, thereby shortening the time required for the substrate temperature to rise to a desired material layer deposition temperature. Alternatively or in addition, substrate cooling within the load lock 106 may be implemented to limit processing time within a processing module. According to an example of the present disclosure, the load lock 106 also includes an indexer mechanism, which, together with the controller 112 and the position sensor, can monitor process drift in the processing module 102 of the semiconductor processing system 100.

[0035] Figure 2 An exemplary load lock apparatus 200 is shown in accordance with an embodiment of the present disclosure, and a simplified cross-sectional view illustrating an exemplary internal configuration of load lock elements within the load lock apparatus 200 .

[0036] In more detail, the load lock device 200 includes a load lock body 108. Figure 1 As shown, the load lock body 108 includes a front face configured to couple with a front end module of the equipment and a back face configured to couple with a back end transfer module.

[0037] According to an example of the present disclosure, the load lock device 200 ( Figure 2 ) includes an indexer mechanism 202 coupled to the load lock body 108. In some embodiments, the indexer mechanism 202 is partially disposed in the load lock body 108 (e.g., Figure 2 108 ), or alternatively may be disposed entirely within the load lock body 108. According to an example of the present disclosure, the indexer mechanism 202 includes a vertical actuator assembly 204 that includes a drive mechanism 206. In such an example, the drive mechanism 206 is connected to a support arm 208 via a vertical support member 210. In some embodiments, the support arm 208 includes one or more substrate handling members 212 configured to position one or more substrates 118 within the load lock body 108. In some embodiments, the support arm 208 includes a plurality of substrate handling members 212 to enable a plurality of substrates to be stacked and spaced apart in a vertical stack.

[0038] According to an example of the present disclosure, the vertical actuator assembly 204 includes a drive mechanism 206 configured to translate a support arm 208 along a vertical axis 214. The support arm 208 can be cantilevered and extend from the vertical support member 210 along a horizontal axis 216. The vertical actuator assembly 204 can include any of a variety of drive mechanisms 206 known to those skilled in the art to achieve linear motion along the vertical axis 214, including but not limited to a voice coil, a servo motor, a linear motor, or other conventional mechanical linear actuation devices. In such an example, the drive mechanism 206 has a positioning accuracy of less than 1 nanometer or less.

[0039] According to an example of the present disclosure, the load lock device 200 also includes a position sensor 218. In some embodiments, the position sensor 218 is integrated into the indexer mechanism 202, such as Figure 2 As shown. In alternative embodiments, the position sensor 218 can be a separate unit from the indexer mechanism 202, but is linked (e.g., electrically, optically, wirelessly, etc.) to enable communication between the position sensor 218 and the indexer mechanism 202. In some embodiments, the vertical actuator assembly 204 can include two or more position sensors. In some embodiments, the position sensor 218 includes a linear position sensor. In such examples, the linear position sensor can be integrated into the indexer mechanism 202.

[0040] According to an example of the present disclosure, the position sensor 218 is configured and arranged to measure the deflection distance of the indexer mechanism 202 from a known neutral position when the substrate is seated on the indexer mechanism 202. In more detail, when the substrate 118 is transferred into the load lock body 108 and seated on the indexer mechanism 202, the weight of the substrate 118 causes the indexer mechanism 202 to deviate from the known neutral position, and the position sensor 218 measures the amount of deviation from the known neutral position as the deflection distance of the indexer mechanism 202 from the known neutral position. In such an example, the position sensor 218 converts the deflection distance into an electrical signal and thereby generates a feedback signal based on the deflection distance (described in more detail below).

[0041] According to an example of the present disclosure, the position sensor 218 may include any of a variety of position sensors known to those skilled in the art to determine the deflection distance of the indexer mechanism 202 from a known neutral position. In some embodiments, the position sensor 218 includes one or more of the following: an optical sensor (e.g., a laser interferometer / laser triangulation sensor, a Michelson interferometer, etc.), a magnetic sensor (e.g., a Hall effect / magnetostrictive sensor), an electrical sensor (e.g., a resistance / capacitance / inductance based sensor), or other known precise position sensors. In some embodiments, the position sensor is a capacitance-based sensor, such as a parallel plate capacitor sensor. In some embodiments, the position sensor is an optical sensor, such as a laser triangulation displacement sensor. In some embodiments, the position sensor has a measurement accuracy of less than 1 nanometer or less.

[0042] The load lock device 200 also includes a controller 112. In some embodiments, the controller is connected to a reference Figure 1 The controller 112 described above is the same as the controller 112 described above, or in alternative embodiments, a separate controller may be used. The controller 112 is operably connected to the load lock 200 and includes an equipment interface 152, a processor 154, a user interface 156, and a memory 158. The equipment interface 152 couples the processor 154 to the load lock 200, for example, via (or through) a wired or wireless link 160. The processor 154 is operably connected to the user interface 156 and is configured to communicate with the memory 158. The memory 158 includes a non-transitory machine-readable medium having a plurality of program modules 162 recorded thereon, which contain instructions that, when read by the processor 154, cause the processor 154 to perform certain operations. These operations include operations for monitoring process drift in the load lock 200, as described below.

[0043] According to an example of the present disclosure, the controller 112 may be configured in a feedback control loop with the position sensor 218, the indexer mechanism 202, and in particular the drive mechanism 206. In some embodiments, the controller 112 is configured and arranged to receive a feedback signal (generated by the position sensor 218), and then calculate and provide an incremental drive current (ΔI) to the drive mechanism 206 to reposition the indexer mechanism back to a known neutral position. In such an example, when the acceleration of the drive mechanism is zero and the vacuum load is constant, the incremental drive current (ΔI) is proportional to the weight of the substrate, enabling the controller to generate a control parameter that is proportional to the weight of the substrate or a change in the weight of the substrate.

[0044] In more detail, the indexer mechanism 202 is positioned at a known neutral position at zero substrate load (i.e., when no substrate is seated on the substrate handling member 212). The known neutral position is achieved by providing a drive current (I) to the drive mechanism 206 of the indexer mechanism 202. When the substrate 118 is transferred into the load lock body 108 and seated on the indexer mechanism 202, the weight of the substrate 118 causes the indexer mechanism 202 to deviate from the known neutral position, and the position sensor 218 measures the amount of deviation and generates a feedback signal based on the deviation. The feedback signal is transmitted to the controller 112, which calculates the current change required by the drive mechanism 206 to enable the indexer mechanism 202 to be repositioned back to the known neutral position. When the acceleration of the drive mechanism 206 is zero and the vacuum load on the indexer mechanism 202 is constant, this change in the drive current of the drive mechanism 206, i.e., the drive current increment (ΔI), is proportional to the weight of the substrate seated on the indexer mechanism 202. In such an example, the incremental drive current (ΔI) ∝ substrate weight (W s )(i.e. ΔI∝W s ) and knowing this relationship, the incremental drive current (ΔI) can be used as a control parameter to monitor and alert the user / controller of process drift. In an exemplary embodiment, the acceleration of the drive mechanism is defined herein as the inertial force exerted on the drive mechanism.

[0045] As a non-limiting example, the controller 112 may determine a first incremental drive current (ΔI 1 ) and a second incremental drive current (ΔI ) for the same substrate (re-positioned on the indexer mechanism 202) after processing in the process module. 2 ) to produce a control parameter proportional to the weight change of the substrate.

[0046] In some embodiments, the processing module may be configured to deposit a layer on the substrate by a deposition process. In such an example, the deposition process will increase the weight of the substrate. Under controlled process conditions to eliminate process drift, the increase in substrate weight due to the deposition process and thus ΔI 1 and ΔI 2 The difference between is a precisely known parameter (control parameter). Therefore, subsequent cycles of the same deposition process performed in a process module can be monitored for process drift, because if ΔI 1 and ΔI 2If the difference between (the control parameter) deviates from a predetermined acceptable value or a predetermined acceptable range of values, a process drift is identified. In such an example, the control parameter can be transmitted to an alarm system (e.g., the controller 112, an external alarm system or a user, etc.), wherein if the controller 112 determines that the control parameter is outside the predetermined value or value range, the alarm system is activated.

[0047] It should be noted that the exemplary apparatus and methods outlined above may also be used for substrates that undergo an etching process in a processing module, wherein the etching process will reduce the weight of the substrate.

[0048] According to an additional example of the present invention, one or more environmental sensors 230 may be disposed within the load lock body 108, such as Figure 2 As shown. In alternative embodiments, environmental sensor 230 may be constructed and arranged to monitor the environment within load lock body 108 from the outside (e.g., by using a viewing port, access line, etc.). According to examples of the present invention, environmental sensor 230 may be used to monitor a number of environmental factors within load lock body 108, including, but not limited to, temperature, humidity, and vacuum (i.e., pressure). In some embodiments, environmental sensor 230 communicates with controller 112 to allow monitoring of the environment within load lock body 108. In such examples, controller 112 may also intervene if the monitored environment is outside of optimal or predetermined conditions. For example, such intervention by controller 112 may include providing a control signal to the load lock body 108 via controller 112 and one or more heaters, humidifiers, and / or vacuum pumps ( Figure 2 ) to change the temperature, humidity and / or vacuum level within the load lock body 108.

[0049] According to an example of the present disclosure, the environmental sensor 230 is used in conjunction with the controller 112 and a device for changing the internal environment within the load lock body 108 (e.g., a heater, a humidifier, a vacuum pump, etc.) to maintain the internal environment within the load lock body 108 in a stable steady state between placement and re-placement of substrates on the indexer mechanism 202. In such an example, when the environment within the load lock body 108 is maintained in a stable steady state (i.e., while maintaining substantially equal temperature, humidity, and vacuum within the load lock body), the incremental drive current (ΔI) and, in particular, ΔI used to generate the control parameters is changed. 1 and ΔI 2 The difference between can be determined with higher precision. Thus, in such an example, the precision of the control parameter that is proportional to the weight or weight change of the substrate can be maintained or even improved. As a non-limiting example, the load lock apparatus 200 of the present disclosure can determine the weight change of the substrate (after deposition and / or etching) to be less than 1 microgram or less.

[0050] According to a further example of the present disclosure, Figure 2 The load lock apparatus 200 may also include a temperature control plate 222. The temperature control plate 222 may include a heating device and / or a cooling device (e.g., via a heating element, a cooling channel, etc.) to control the temperature of the substrate 118 within the load lock body 108. In some embodiments, the indexer mechanism 202 may be located near the temperature control plate 222 to improve thermal communication between the substrate 118 disposed on the indexer mechanism 202 and the temperature control plate 222. In such an example, the temperature control plate 222 may be used to maintain or change the temperature of the substrate 118 so that, for example, the steady-state evaluation of the substrate 118 (i.e., the determination of ΔI 1 and ΔI 2 During this period, the temperature of the substrate 118 is the same) to increase the control parameter (for example, by ΔI 1 and ΔI 2 The accuracy is determined by the difference between

[0051] It should be noted that although Figure 2 The load lock shown is shown as including a single chamber, but it should be understood that the above-described apparatus and method can be readily applied to a load lock including an upper load lock chamber and a lower load lock chamber (i.e., a dual chamber load lock). As a non-limiting example, Figure 2 The illustrated load lock apparatus 200 may include an upper load lock chamber of a dual chamber load lock apparatus, and the second indexer mechanism may be constructed and arranged to operate in the lower load lock chamber with minor changes to the location and configuration of the additional indexer mechanism.

[0052] As a non-limiting example, Figure 3 An exemplary dual load lock apparatus 300 is shown, which includes an upper load lock chamber 304 (equivalent to Figure 2 The load lock device 200) and the lower load lock chamber 306. Figure 3 The dual chamber load lock apparatus 300 has been simplified to better illustrate the configuration of components within the dual load lock apparatus 300, and the corresponding load lock components from the upper load lock chamber 304 that are present in the lower load lock chamber 306 have been numbered starting with "3" instead of "2" to indicate that the components are components of the lower load lock chamber 306. Figure 3 As shown, the lower indexer mechanism 302 for the lower load lock chamber 306 has been inverted (from Figure 2 ), to allow operation in the lower load lock chamber 306 of the dual load lock apparatus 300, except for a minor reconfiguration of the lower indexer mechanism 302 to better accommodate the substrate 318 and the lower temperature control plate 322.

[0053] According to an example of the present disclosure, the load lock device 200 ( Figure 2 ) can be used as part of a semiconductor processing system, e.g. Figure 1 1. In such an example, and with reference to Figure 1 and Figure 2 , the semiconductor processing system 100 includes a load lock apparatus 200 including a load lock body 108, an equipment front end module (EFEM) 110 connected to the front side 140 of the load lock body 108, the equipment front end module 110 accommodating a front end substrate transfer robot 146, and a back end transfer module (BETM) 104 connected to the back side 138 of the load lock body 108, the back end transfer module 104 coupling the processing module 102 to the load lock body 108. In such an example, an indexer mechanism 202 is connected to the load lock body 108, and the indexer mechanism 202 includes a drive mechanism 206 and a device for supporting a substrate (i.e., a substrate handling member 212). In such an example, a position sensor 218 is configured and arranged to measure a deflection distance of the indexer mechanism 202 from a known neutral position when a substrate 118 is placed on the indexer mechanism 202, and then generate a feedback signal based on the deflection distance. In such an example, the controller 112 is configured and arranged to receive the feedback signal, and the controller then calculates and provides an incremental drive current (ΔI) to the drive mechanism 206 to reposition the indexer mechanism 202 back to a known neutral position, wherein the incremental drive current (ΔI) is proportional to the weight of the substrate 118 when the acceleration of the drive mechanism 206 is zero and the vacuum load on the indexer mechanism 202 is constant. Under such conditions, the controller 112 generates a first incremental drive current (ΔI) for a substrate transferred from the equipment front end module (EFEM) 110 and placed on the indexer mechanism 202. 1 ) and a second incremental drive current (ΔI ) for a substrate that has been transferred from the back end transfer module (BETM) 104 and repositioned on the indexer mechanism 202 after the substrate has been subjected to one or more processes within the processing module 102. 2 ) to generate a control parameter proportional to the weight change of the substrate. In such an example, the semiconductor processing system 100 also includes an alarm system in communication with the controller 112, wherein the alarm system is activated if the controller 112 determines that the control parameter is outside a predetermined acceptable value or value range.

[0054] Embodiments of the present disclosure also include methods for monitoring process drift in a semiconductor processing system. According to an example of the present disclosure, Figure 4 A method 400 for monitoring process drift in a semiconductor processing system is shown. The method 400 includes providing an indexer mechanism coupled to a load lock body, the indexer mechanism including a drive mechanism and means for supporting a substrate.

[0055] According to an example of the present disclosure, the method 400 continues with step 402 which includes transferring the substrate into a load lock body and positioning the substrate on an indexer mechanism.

[0056] According to an example of the present disclosure, method 400 proceeds to step 404 which includes generating a first feedback signal from a position sensor configured and arranged to measure a first deflection distance of the indexer mechanism from a known neutral position when a substrate is positioned on the indexer mechanism.

[0057] According to an example of the present disclosure, the method 400 proceeds to step 406, which includes calculating a first incremental drive current (ΔI 1 ) and the first incremental drive current (ΔI 1 ) is provided to a drive mechanism to reposition an indexer mechanism to a known neutral position, wherein a first incremental drive current (ΔI) is proportional to a first weight of the substrate when an acceleration of the drive mechanism is zero and a vacuum load on the indexer mechanism is constant.

[0058] According to an example of the present disclosure, the method 400 proceeds to step 408 which includes transferring the substrate from the load lock body into a processing module and performing one or more processes on the substrate.

[0059] According to an example of the present disclosure, the method 400 may continue with step 410 which includes transferring the substrate from the process module into the load lock body assembly and repositioning the substrate on the indexer mechanism.

[0060] According to an example of the present disclosure, the method 400 proceeds to step 412 which includes generating a second feedback signal from a position sensor configured and arranged to measure a second deflection distance of the indexer mechanism from the known neutral position when the substrate is repositioned on the indexer mechanism.

[0061] According to an example of the present disclosure, the method 400 proceeds to step 414, which includes calculating a second incremental drive current (ΔI 2 ) and the second incremental drive current (ΔI 2 ) is provided to the drive mechanism to reposition the indexer mechanism to a known neutral position, wherein a second incremental drive current (ΔI) is proportional to a second weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load on the indexer is constant.

[0062] According to an example of the present disclosure, the method 400 proceeds to step 416, which includes determining a first incremental drive current (ΔI 1 ) and the second incremental drive current (ΔI 2 ) is used to calculate a control parameter that is proportional to the weight change of the substrate.

[0063] According to an example of the present disclosure, the method 400 may proceed to step 418 , which includes activating an alarm system if the control parameter is outside of a predetermined acceptable range of values.

[0064] According to an additional example of the present invention, the method 400 also includes using one or more environmental sensors that communicate with the controller, and the environmental sensors are configured and arranged to monitor one or more of the temperature, humidity, and vacuum degree in the load lock body. In such an example, the environmental sensor can be used to monitor many environmental factors in the load lock body, including but not limited to temperature, humidity, and vacuum degree (i.e., pressure). In such an example, the environmental sensor can communicate with the controller to allow monitoring of the environment in the load lock body. In addition, in such an example, the controller is configured to intervene if the monitored environment in the load lock body is outside the optimal or predetermined conditions. For example, such intervention by the controller can include changing the temperature, humidity, and / or vacuum degree in the load lock body 108 through communication between the controller 112 and one or more heaters, humidifiers, and / or vacuum pumps. Therefore, in some embodiments, the method 400 also includes maintaining the environment (i.e., temperature, humidity, vacuum degree, etc.) in the load lock body under steady-state conditions when calculating the first incremental drive current and the second incremental drive current. In such an example, the calculation of the first incremental drive current and the second incremental drive current is performed in a substantially identical environment in the load lock body.

[0065] According to further examples of the present disclosure, method 400 may further include maintaining the temperature of the substrate at a steady state (ie, at a constant temperature) while calculating the first incremental drive current and the second incremental drive current by positioning a temperature controller near the substrate, as described in detail above herein.

[0066] According to a further example of the present disclosure, the method 400 may further include performing one or more corrective measures to bring the control parameter within a predetermined acceptable value range when the alarm system is activated. For example, when the alarm system is activated, a process drift within the processing module is detected. In this way, a controller or user intervention may be activated to correct the process drift detected within the processing module. As non-limiting examples, the corrective measures may include, but are not limited to, cleaning of the processing module, evaluation of components within the processing module, evaluation of precursors and / or reactants supplied to the processing module, and abnormality inspection of the processed substrate.

[0067] Although certain embodiments and examples have been discussed, it will be understood by those skilled in the art that the scope of the claims extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses and obvious modifications and equivalents thereof. Indeed, various modifications of the present disclosure, such as alternative useful combinations of the described elements, in addition to those shown and described herein, will become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to fall within the scope of the appended claims.

[0068] In the present disclosure, where conditions and / or structures are not specified, those skilled in the art can readily provide such conditions and / or structures as routine experimentation in view of the present disclosure.

Claims

1. An apparatus for monitoring process drift in a semiconductor processing system, the apparatus comprising: A load lock device comprising a load lock body; an indexer mechanism coupled to the load lock body and including a drive mechanism and means for supporting a substrate; a position sensor configured and arranged to measure a deflection distance of the indexer mechanism from a known neutral position when a substrate is positioned on the indexer mechanism, and the position sensor then generates a feedback signal based on the deflection distance; a controller configured and arranged to receive the feedback signal and subsequently calculate and provide an incremental drive current (ΔI) to the drive mechanism to reposition the indexer mechanism back to a known neutral position, wherein the incremental drive current (ΔI) is proportional to the weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load is constant, enabling the controller to generate a control parameter that is proportional to the weight of the substrate or a change in the weight of the substrate; as well as An alarm system is in communication with the controller, wherein the alarm system is activated if the controller determines that the control parameter is outside of a predetermined range of acceptable values.

2. The device according to claim 1, wherein The position sensor comprises a linear position sensor.

3. The device according to claim 2, wherein: The linear position sensor is integrated into the indexer mechanism.

4. The device according to claim 2, wherein: The linear position sensor is a parallel plate capacitance sensor or a laser triangulation displacement sensor.

5. The device according to claim 1, wherein: The drive mechanism includes a linear motor drive.

6. The apparatus of claim 1, further comprising one or more environmental sensors in communication with the controller, the environmental sensors configured and arranged to monitor one or more of temperature, humidity, and vacuum within the load lock body.

7. The device according to claim 1, wherein: The load lock comprises a dual load lock including a lower indexer mechanism.

8. The apparatus of claim 1, further comprising a temperature control plate disposed proximate to the substrate, the temperature control plate configured to control a temperature of the substrate.

9. A semiconductor processing system comprising: A load lock device comprising a load lock body; an equipment front end module (EFEM) coupled to the front side of the load lock body, the EFEM housing a front end substrate transfer robot; a back end transfer module (BETM) connected to the back side of the load lock body, the BETM coupling the processing module to the load lock body; an indexer mechanism coupled to the load lock body and including a drive mechanism and means for supporting a substrate; a position sensor configured and arranged to measure a deflection distance of the indexer mechanism from a known neutral position when a substrate is positioned on the indexer mechanism, and the position sensor then generates a feedback signal based on the deflection distance; a controller configured and arranged to receive the feedback signal and subsequently calculate and provide an incremental drive current (ΔI) to the drive mechanism to reposition the indexer mechanism back to a known neutral position, wherein the incremental drive current (ΔI) is proportional to the weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load is constant, such that the controller can generate a control parameter proportional to the change in weight of the substrate by determining a difference between a first incremental drive current (ΔI1) for a substrate transferred from an EFEM and seated on the indexer mechanism and a second incremental drive current (ΔI2) for a substrate transferred from a BETM and seated on the indexer mechanism after the substrate has been subjected to one or more processes within a processing module; as well as An alarm system is in communication with the controller, wherein the alarm system is activated if the controller determines that the control parameter is outside of a predetermined range of acceptable values.

10. The semiconductor processing system of claim 9, wherein: The position sensor comprises a linear position sensor.

11. The semiconductor processing system of claim 10, wherein: The linear position sensor is integrated with the indexer mechanism.

12. The semiconductor processing system of claim 9, wherein: The drive mechanism includes a linear motor drive.

13. The semiconductor processing system of claim 9, further comprising one or more environmental sensors in communication with the controller, the environmental sensors configured and arranged to monitor one or more of temperature, humidity, and vacuum within the load lock body.

14. The semiconductor processing system of claim 9, further comprising a temperature control board disposed proximate to the substrate, the temperature control board configured to control a temperature of the substrate.

15. The semiconductor processing system of claim 9, wherein: The load lock comprises a dual load lock including a lower indexer mechanism.

16. A method of monitoring process drift in a semiconductor processing system, the method comprising: at an indexer mechanism coupled to the load lock body and comprising a drive mechanism and means for supporting a substrate; transferring the substrate into the load lock body and positioning the substrate on the indexer mechanism; generating a first feedback signal from a position sensor, the position sensor configured and arranged to measure a first deflection distance of the indexer mechanism from a known neutral position when a substrate is positioned on the indexer mechanism; calculating a first incremental drive current (ΔI1) from the first feedback signal and providing the first incremental drive current (ΔI1) to the drive mechanism to reposition the indexer mechanism back to a known neutral position, wherein the first incremental drive current (ΔI1) is proportional to a first weight of the substrate when acceleration of the drive mechanism is zero and the vacuum load is constant; transferring the substrate from the load lock body into the processing module and performing one or more processes on the substrate; transferring the substrate from the process module into the load lock body assembly and repositioning the substrate on the indexer mechanism; generating a second feedback signal from a position sensor, the position sensor configured and arranged to measure a second deflection distance of the indexer mechanism from a known neutral position when the substrate is repositioned on the indexer mechanism; calculating a second incremental drive current (ΔI2) from the second feedback signal and providing the second incremental drive current (ΔI2) to the drive mechanism to reposition the indexer mechanism back to a known neutral position, wherein the second incremental drive current (ΔI2) is proportional to a second weight of the substrate when acceleration of the drive mechanism is zero and the vacuum load is constant; calculating a control parameter proportional to a change in weight of the substrate by determining a difference between a first incremental drive current (ΔI) and a second incremental drive current (ΔI); as well as If the control parameter is outside a predetermined range of acceptable values, an alarm system is activated.

17. The method of claim 16, further comprising one or more environmental sensors in communication with the controller, the environmental sensors configured and arranged to monitor one or more of temperature, humidity, and vacuum within the load lock body.

18. The method of claim 17, further comprising maintaining an environment within the load lock body at a steady state condition while calculating the first incremental drive current and the second incremental drive current.

19. The method of claim 16, further comprising maintaining a temperature of a substrate at a steady state while calculating the first incremental drive current and the second incremental drive current by positioning a temperature controller proximate to the substrate.

20. The method of claim 16, further comprising executing one or more corrective actions to bring the control parameter within the predetermined acceptable range of values ​​when the alarm system is activated.

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