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

Abstract

To provide an apparatus, system, and associated method for monitoring process drift in a semiconductor processing system.SOLUTION: Disclosed are a load lock assembly, a semiconductor processing system including such a load lock assembly, and associated methods for monitoring process drift within a process module of the semiconductor processing system. The disclosed load lock assembly includes an indexer mechanism and a position sensor configured to communicate with a controller in a feedback loop arrangement, enabling the generation of control parameters based on the weight or weight change of a substrate within the load lock assembly. The control parameters are used to issue a signal upon detection of process drift, allowing corrective actions to be implemented.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure generally relates to the fields of semiconductor processing systems and methods of processing, as well as the fields of device and integrated circuit manufacturing. More particularly, the present disclosure relates to apparatuses, systems, and methods for monitoring process drift in semiconductor processing systems.

Background Art

[0002] Semiconductor devices and integrated circuits are typically fabricated on a substrate of semiconductor material, often referred to as a substrate, wafer, and / or workpiece. Processing methods commonly used in the fabrication of semiconductor devices and integrated circuits include, but are not limited to, 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 generally involve forming or removing a layer of material on / from the exposed surface of the substrate. The parameters that govern these processes are generally tightly controlled to ensure that each substrate on which a particular process is performed has substantially the same amount of material added or removed, in which case any deviation from the expected process is generally referred to as "process drift".

[0003] In some semiconductor manufacturing processes, a raw substrate is transferred from a cassette to a load lock arrangement. The substrate is then transferred from the load lock arrangement to a process module for processing. Once the process is completed in one process module, the substrate can be transported to a different process module to continue processing the substrate. During the transfer of the substrate between different process modules, the substrate may pass through the load lock arrangement multiple times. When the processing of the substrate is complete, the substrate is typically returned to the load lock arrangement for cooling, post-processing, and transfer (e.g., out of the semiconductor processing system). Such load lock arrangements can incorporate devices and systems to enable improved utilization of the semiconductor processing system. For example, by using cooling and heating of the substrate within the load lock arrangement, the process time within individual process modules can be reduced. However, there remains a need for improved load lock arrangements, such as those incorporating additional functionality to enable monitoring of process drift during the processing of multiple substrates.

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] Accordingly, improvements to the load lock arrangement, semiconductor processing systems including such improved load lock arrangements, and related methods for monitoring process drift within such improved load lock arrangements are desired.

[0005] Any discussion, including discussion of problems and solutions described in this section, is included in this disclosure only for the purpose of providing context for this disclosure. Such discussion should not be construed as an admission that any or all of the information was known at the time the invention was made or otherwise constitutes prior art.

[0006] The summary of the invention may introduce selected concepts in a simplified form, which may be described in more detail below. The summary of the invention is not necessarily intended to identify the 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.

Means for Solving the Problems

[0007] Various embodiments of the present disclosure relate to semiconductor processing systems, particularly apparatuses, systems, and related methods for monitoring process drift in a load lock arrangement. As shown in more detail below, the apparatus of the present disclosure includes a load lock arrangement configured and arranged to monitor one or more parameters proportional to the weight of a substrate within the load lock arrangement by using at least an indexer mechanism, one or more sensors, and a controller in a feedback loop configuration. Such an arrangement can generate a control parameter proportional to the weight or change in weight of a substrate on which a particular process has been performed in a process module, and then compare the control parameter to a predetermined expected value or range of acceptable values.

[0008] According to an embodiment of the present disclosure, an apparatus for monitoring process drift within a semiconductor processing system is provided. An exemplary apparatus includes a load lock arrangement including a load lock body and an indexer mechanism connected to the load lock body, the indexer mechanism including a drive mechanism and means for supporting a substrate. In such embodiments, the apparatus also includes a position sensor configured and arranged to measure a deflection distance of the indexer mechanism from a known neutral position when seating a substrate on the indexer mechanism, and the position sensor then generates a feedback signal based on the deflection distance. In such embodiments, the apparatus also includes a controller configured and arranged to receive the feedback signal, and the controller then calculates and provides a delta drive current (ΔI) to the drive mechanism to reposition the indexer mechanism back to the known neutral position, where the delta 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, thereby enabling the controller to generate a control parameter proportional to either the weight of the substrate or a change in the weight of the substrate. In such embodiments, the apparatus also includes an alarm system in communication with the controller, and the alarm system is operative when the controller determines that the control parameter is outside a predetermined tolerance range.

[0009] According to a further example of the present disclosure, a semiconductor processing system is provided. In such an embodiment, the semiconductor processing system includes a load lock body, an equipment front end module (EFEM) connected to the front surface 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 rear surface of the load lock body, the back end transfer module coupling a process module to the load lock body, including a load lock arrangement. In such an embodiment, the semiconductor processing system also includes an indexer mechanism connected to the load lock body, the indexer mechanism including a drive mechanism and means for supporting a substrate. In such an embodiment, the semiconductor processing system also includes a position sensor configured and arranged to measure the deflection distance of the indexer mechanism from a known neutral position when seating a substrate on the indexer mechanism, and thereafter, the position sensor generates a feedback signal based on the deflection distance. In such an embodiment, the semiconductor processing system also includes a controller configured and arranged to receive the feedback signal, and thereafter, the controller calculates and provides a delta drive current (ΔI) to the drive mechanism to relocate the indexer mechanism to a known neutral position, where the delta 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, whereby the controller determines the first delta drive current (ΔI 1 ) of the substrate transferred from the EFEM and seated on the indexer mechanism and, after one or more processes are performed on the substrate in a process module, the second delta drive current (ΔI 2 ) of the substrate transferred from the BETM and reseated on the indexer mechanism, to enable generation of a control parameter proportional to the change in the weight of the substrate. In such an embodiment, the semiconductor processing system also includes an alarm system in communication with the controller, and when the controller determines that the control parameter is outside a predetermined acceptable value range, the alarm system is activated.

[0010] According to additional embodiments of the present disclosure, a method for monitoring process drift in a semiconductor processing system is provided. In such embodiments, the method includes an indexer mechanism including a drive mechanism and means for supporting a substrate being connected to a load lock body. In such embodiments, the method also includes transporting a substrate into the load lock body and seating the substrate on the indexer mechanism. In such embodiments, the method also 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 seating the substrate on the indexer mechanism, calculating a first delta drive current (ΔI 1 ), and providing the first delta drive current (ΔI 1 ) to the drive mechanism to relocate the indexer mechanism back to the known neutral position, wherein the first delta drive current (ΔI 1 ) is proportional to a first weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load is constant, and relocating. In such embodiments, the method also includes transporting the substrate from the load lock body into a process module, performing one or more processes on the substrate, and then transporting the substrate back into the load lock body from the process module and reseating the substrate on the indexer mechanism. In such embodiments, the method also 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 reseating the substrate on the indexer mechanism. In such embodiments, the method also includes calculating a second delta drive current (ΔI 2 ) from the second feedback signal and providing the second delta drive current (ΔI 2 ) to the drive mechanism to relocate the indexer mechanism back to the known neutral position, wherein the second delta drive current (ΔI 2 ) is proportional to a second weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load is constant, and relocating. In such embodiments, the method also includes the first delta drive current (ΔI 1 ) and the second delta drive current (ΔI2 ) calculating a control parameter proportional to the change in the weight of the substrate by determining the difference between [the weight of the substrate] and [the weight of the substrate at a previous time]; and operating an alarm system when the control parameter is outside a predetermined allowable value range.

[0011] For the purpose of summarizing the invention and advantages achieved over the prior art, certain objects and advantages of the present invention have been described above herein. It should of course be understood that not necessarily all of these objects or advantages need be achieved in any particular embodiment of the present invention. Therefore, those skilled in the art will recognize that the present invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein, without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0012] All of these embodiments are intended to be within the scope of the invention disclosed herein. Those skilled in the art will readily appreciate from the following detailed description of certain embodiments of the invention, with reference to the accompanying drawings, that these and other embodiments are not limited to any particular embodiment disclosed.

[0013] To easily identify the discussion of any particular element or action, the most significant digit of the reference number refers to the figure number in which that element is first introduced.

[0014] A more complete understanding of the exemplary embodiments of the present disclosure can be derived by referring to the "Detailed Description of the Invention" and the "Claims", when considered in connection with the following exemplary figures.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

DETAILED DESCRIPTION OF THE INVENTION

[0016] Of course, the elements in the figures are illustrated for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to assist in understanding the illustrated embodiments of the present disclosure.

[0017] The following description of exemplary embodiments of the apparatus, system, and method is merely exemplary and is intended for illustrative purposes only. The following description is not intended to limit the scope of the present disclosure or the scope of the claims. Further, the listing of a number of embodiments having the recited features or steps is not intended to exclude other embodiments having additional features or steps, or other embodiments incorporating different combinations of the recited features or steps.

[0018] As used herein, the term "load lock arrangement" can refer to any chamber arrangement configured for the handling, transfer, and / or storage of substrates before and / or after processing in a process module (such as a reactor and reaction chamber).

[0019] As used herein, the term "substrate" can refer to any underlying material(s) that can be used or formed into a device, circuit, or film by a method according to an embodiment of the present disclosure. The substrate can include a bulk material such as silicon (e.g., single-crystalline silicon), other Group IV materials such as germanium, or other semiconductor materials such as Group II-VI or Group III-V semiconductor materials, and can include one or more layers on or under the bulk material. Further, the substrate can include various features such as recesses, protrusions, and the like formed in or on at least a portion of the layers of the substrate. By way of example, the substrate can include a bulk semiconductor material and an insulating or dielectric material layer on at least a portion of the bulk semiconductor material. Further, the term "substrate" can refer to any underlying material that may be used or on which a device, circuit, or film may be formed. The "substrate" may be continuous or discontinuous, rigid or flexible, solid or porous. The "substrate" may be in any form such as a powder, plate, or workpiece. A substrate in the form of a plate may include wafers of various shapes and sizes. The substrate may be made of materials such as, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide. A continuous substrate may extend beyond the boundaries of the process chamber in which the deposition process occurs and may move through the process chamber, whereby the process continues until it reaches the end of the substrate. The continuous substrate may be supplied from a continuous substrate supply system that enables the manufacture and output of the continuous substrate in any suitable form. Non-limiting examples of continuous substrates can include sheets, non-woven membranes, rolls, foils, webs, flexible materials, bundles of continuous filaments or fibers (i.e., ceramic fibers or polymer fibers). The continuous substrate may also include a carrier or sheet on which the discontinuous substrates are placed. By way of example, the substrate can include a semiconductor material.A semiconductor material may include or be used to form one or more of a source, drain, or channel region of a device. The substrate may further include an interlayer dielectric (e.g., silicon oxide) and / or a high-k material layer that overlays the semiconductor material. In this context, a high-k material (or high-k dielectric material) is a material having a dielectric constant greater than that of silica.

[0020] As used herein, the terms “film” and / or “layer” can be used interchangeably and refer to any continuous or discontinuous structure and material, such as a material deposited by the methods disclosed herein. For example, “film” and / or “layer” may include two-dimensional materials, three-dimensional materials, nanoparticles, partial or complete molecular layers, or partial or complete atomic layers, or clusters of atoms and / or molecules. A film or layer may be partially or completely composed of a plurality of atoms dispersed on the surface of a substrate, and / or may be embedded within the substrate, and / or may be embedded within a device fabricated on the substrate. A film or layer may comprise a material or layer having pinholes and / or isolated islands. A film or layer may be at least partially continuous. A film or layer may be patterned, e.g., subdivided, and may be included in a plurality of semiconductor devices.

[0021] Various embodiments of the present disclosure relate to semiconductor processing systems, particularly apparatus, systems, and methods for monitoring process drift in a load lock configuration. As shown in more detail below, the apparatus of the present disclosure includes a load lock configuration configured and arranged to monitor a parameter (s) proportional to the weight of a substrate. Accordingly, such an apparatus enables, for example, monitoring of weight changes of a substrate on which a deposition and / or etching process has been performed. The weight change of a particular substrate before and after processing can be used to determine whether a process drift has occurred when comparing such weight changes to a predetermined expected value, or range of acceptable values.

[0022] According to an embodiment of the present disclosure, the load lock arrangement of the present disclosure uses an indexer mechanism incorporating a vertical actuator assembly including a drive mechanism such as a servo system having a linear drive, and a high-precision position sensor for generating control parameters based on the weight or change in weight of the substrate. In various embodiments of the present disclosure, the indexer mechanism can be configured to maintain the substrate at a known neutral position (i.e., the vertical position of the baseline within the load lock arrangement), typically a position within the load lock arrangement where the substrate is loaded or unloaded, such that the substrate is seated thereon.

[0023] According to an embodiment of the present disclosure, the indexer mechanism is controlled in a feedback loop configuration. In such embodiments, the position sensor measures the deflection distance of the indexer mechanism from a known neutral position caused by seating the substrate on the indexer mechanism. In such embodiments, the position sensor generates a feedback signal based on the deflection distance that is transmitted to a controller that communicates with the position sensor and the indexer mechanism. The controller then determines from the feedback signal a change in drive current (referred to herein as delta drive current) provided to the drive mechanism to enable repositioning the substrate back to the known neutral position. When controlling certain variables / parameters within the load lock arrangement and the indexer mechanism, since the delta drive current (ΔI) is proportional to the weight of the substrate (explained in more detail herein), the controller can generate a control parameter that is proportional to either the weight of the substrate or a change in the weight 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 with the controller can be activated to alert that a process drift has been detected, thereby enabling appropriate corrective action(s) to be implemented.

[0024] Previous apparatuses, systems, and methods for determining process drift in semiconductor processing systems generally utilize off-site apparatuses and methods. In such previous apparatuses and methods, substrates are generally removed from the semiconductor processing system and evaluated using off-site metrology tools to determine whether the semiconductor processing system is experiencing process drift. Such off-site apparatuses and methods are disadvantageous, for example, resulting in a reduction in substrate throughput, the need for costly metrology tools, and exposure of the substrate to the atmosphere.

[0025] Embodiments of the present disclosure advantageously utilize in-situ apparatuses, systems, and methods for monitoring process drift. For example, a substrate is generally seated and reseated multiple times in a load lock arrangement of the present disclosure as it is transported back and forth between various process modules. Each seating and reseating of the substrate within the load lock arrangement of the present disclosure enables a rapid determination of a change in the weight of the substrate immediately after a process has been performed in one of the process modules. The determination of the change in the weight of the substrate is accurate and rapid, and thus does not affect the throughput of the substrate through the semiconductor processing system. Additionally, process drift in one of the process modules can be detected quickly, resulting in the immediate introduction of corrective measures, thereby preventing substrate scratches, undesirable costs, and tool downtime.

[0026] Referring now to the figures, FIG. 1 shows a semiconductor processing system 100 of the present disclosure that includes a load lock arrangement 106 to enable monitoring of process drift. The semiconductor processing system 100 includes a load lock arrangement 106 that includes a process module 102, a back-end transfer module 104, and a load lock body 108. The semiconductor processing system 100 also includes an equipment front-end module (EFEM) 110, a controller 112, and an exhaust / vent source 114. In the illustrated embodiment, the semiconductor processing system 100 includes a cluster-type platform 116 having four process modules configured to deposit / etch a material layer onto / from a substrate 118 using deposition processes and / or etching processes such as, for example, atomic layer deposition (ALD), chemical vapor deposition (CVD), plasma-enhanced chemical vapor deposition (PECVD), plasma atomic layer deposition (PEALD), atomic layer etching (ALEt) processes, chemical vapor etching (CVE) processes, and plasma-based dry etching processes. This is for illustrative and descriptive purposes only and is non-limiting. As will be understood by those skilled in the art from the present disclosure, not only semiconductor processing systems configured for other material layer deposition / etching operations, but also semiconductor processing systems configured for other processing operations can benefit from the present disclosure.

[0027] The process module 102 is coupled to the back-end transfer module 104 by a process module gate valve 120. The process module 102 includes a process chamber 122, a heater 124, and a precursor 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 across the substrate 118 while seated 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 for deposition / etching of 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 can be configured to permit transfer of the substrate 118 between the back-end transfer module 104 and the process module 102 before and after deposition of a material layer (s) onto the substrate 118.

[0028] According to an embodiment of the present disclosure, the process chamber 122 may be a first process chamber, and the process module 102 may also include one or more second process chambers. For example, the process module 102 may be a dual-chamber module having two process chambers, or a quad-chamber module having four process chambers. According to a particular embodiment, the process module gate valve 120 may be a first process module gate valve, and the process module 102 may also include a second process module gate valve that also couples the process module 102 to the back-end transfer module 104. In a particular embodiment, it is contemplated that the reactant may include a reactant or precursor suitable for deposition / etching of the material layer. According to a particular embodiment, it is also contemplated that the process module 102 includes a plasma unit configured to provide the reactant as a suitable plasma to the substrate 118. In this regard, the process module 102 may be configured to deposit / etch a material layer onto / from the substrate 118, for example, using plasma-enhanced deposition / etching techniques.

[0029] The back-end transfer module 104 is coupled to the rear surface 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 disposed along a transfer axis 132. The back-end substrate transfer robot 130 is disposed within the back-end chamber body 128 and is contemplated to be supported within the back-end chamber body 128 for movement relative to the back-end chamber body 128 for the transfer of substrates, such as substrate 118, between the load lock arrangement 106 and the process module 102. In certain embodiments, the back-end chamber body 128 may have a polygonal shape. In this regard, the back-end chamber body 128 may have five sides, less than five sides (e.g., rectangular or square shape), or more than five sides (e.g., hexagonal shape), and may have a regular or irregular polygon shape.

[0030] The equipment front-end module (EFEM) 110 is coupled to the front face 140 of the load lock body 108 and includes an enclosure 144, a front-end substrate transfer robot 146, and one or more load ports 148. The enclosure 144 houses the front-end substrate transfer robot 146. The front-end substrate transfer robot 146 is housed within the enclosure 144 for movement relative to the enclosure 144 or for transfer of substrates, such as substrate 118, between one or more load ports 148 and the load lock arrangement 106. The one or more load ports 148 are connected to the enclosure 144 and are configured to seat a pod 150 containing one or more substrates therein before and after deposition / etching of material layers onto / from the substrate. In certain embodiments, the pod 150 may include a standard mechanical interface pod. According to certain embodiments, the pod 150 may include a front opening integrated pod. Although shown and described herein as having three load ports, it is understood and recognized that the equipment front-end module 110 may include fewer or additional load ports and still fall within the scope of the present disclosure.

[0031] 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, via (or over) a wired or wireless link 160. The processor 154 is operably connected to the user interface 156 and is communicatively disposed with the memory 158. The memory 158 includes a non-transitory machine-readable medium having a plurality of program modules 162 recorded thereon that contain instructions that, when read by the processor 154, cause the processor 154 to perform certain operations. Among the operations are operations for monitoring process drift in the semiconductor processing system 100, as described below.

[0032] In some embodiments, the semiconductor processing system 100 can include substrate heating and / or substrate cooling within the load lock arrangement 106, for throughput purposes and the like. For example, in some semiconductor processing systems, substrate heating within the load lock arrangement can be implemented to limit the processing time within the process module and shorten the time taken to gradually raise the substrate temperature to the desired material layer deposition temperature. Alternatively, or additionally, substrate cooling within the load lock arrangement 106 may be implemented to limit the processing time within the process module. According to an embodiment of the present disclosure, the load lock arrangement 106 further includes an indexer mechanism that can monitor process drift in the process module 102 of the semiconductor processing system 100 in conjunction with the controller 112 and the position sensor(s).

[0033] FIG. 2 shows an exemplary load lock arrangement 200 according to an embodiment of the present disclosure, and a simplified cross-sectional view of an exemplary internal configuration of the load lock elements within the load lock arrangement 200.

[0034] More specifically, the load lock arrangement 200 includes a load lock body 108. The load lock body 108 includes a front face configured to couple to the equipment front end module and a rear face configured to couple to the back end transfer module, as shown in FIG. 1.

[0035] According to an embodiment of the present disclosure, a load lock arrangement 200 (FIG. 2) includes an indexer mechanism 202 connected to a load lock body 108. In some embodiments, the indexer mechanism 202 is partially disposed on the load lock body 108 (as shown in FIG. 2) or alternatively is fully disposed within the load lock body 108. According to an embodiment of the present disclosure, the indexer mechanism 202 comprises a vertical actuator assembly 204 including a drive mechanism 206. In such embodiments, the drive mechanism 206 is connected to a support arm 208 by a vertical support member 210. In some embodiments, the support arm 208 includes one or more substrate handling members 212 configured to seat 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 stacking and spacing of a plurality of substrates vertically side by side.

[0036] According to an embodiment of the present disclosure, the vertical actuator assembly 204 includes a drive mechanism 206 configured to translate the support arm 208 along a vertical axis 214. The support arm 208 may be cantilevered and may extend along a horizontal axis 216 from the vertical support member 210. The vertical actuator assembly 204 can include any of a variety of drive mechanisms 206 known to those skilled in the art to provide linear motion along the vertical axis 214, including but not limited to voice coils, servo motors, linear motors, or other conventional mechanical linear actuators. In such embodiments, the drive mechanism 206 has a positioning accuracy of 1 nanometer or less.

[0037] According to an embodiment of the present disclosure, the load lock arrangement 200 also includes a position sensor 218. In some embodiments, the position sensor 218 is integrated into the indexer mechanism 202 as shown in FIG. 2. In an alternative embodiment, the position sensor 218 can be a separate unit from the indexer mechanism 202 but can be 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 more than one position sensor. In some embodiments, the position sensor 218 includes a linear position sensor. In such embodiments, the linear position sensor can be integrated within the indexer mechanism 202.

[0038] According to an embodiment 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 seating a substrate on the indexer mechanism 202. More specifically, when the substrate 118 is transported 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 a 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 embodiments, the position sensor 218 converts the deflection distance into an electrical signal, thereby generating a feedback signal based on the deflection distance (described in more detail below).

[0039] According to an embodiment of the present disclosure, the position sensor 218 can include any of various 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 is 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 one or more of other known precision position sensors. In some embodiments, the position sensor is a capacitive 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 1 nanometer or less.

[0040] The load lock arrangement 200 further includes a controller 112. In some embodiments, the controller is the same as the controller 112 described with reference to FIG. 1, or in an alternative embodiment, a separate controller may be used. The controller 112 is operably connected to the load lock arrangement 200 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 load lock arrangement 200, for example, via (or on) a wired or wireless link 160. The processor 154 is operably connected to the user interface 156 and is communicatively disposed with the memory 158. The memory 158 includes a non-transitory machine-readable medium having a plurality of program modules 162 recorded thereon that contain instructions that cause the processor 154 to perform certain operations when read by the processor 154. Among the operations are operations for monitoring process drift in the load lock arrangement 200 as described below.

[0041] According to an embodiment of the present disclosure, the controller 112 can be configured with a feedback control loop having a position sensor 218, an indexer mechanism 202, particularly a drive mechanism 206. In some embodiments, the controller 112 receives a feedback signal (generated by the position sensor 218), and then calculates and provides a delta drive current (ΔI) to the drive mechanism 206 to reposition the indexer mechanism back to a known neutral position. In such embodiments, the delta 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, thereby enabling the controller to generate a control parameter proportional to either the weight of the substrate or a change in the weight of the substrate.

[0042] More specifically, the indexer mechanism 202 is positioned at a known neutral position when the substrate load is zero (i.e., when the substrate is not seated on the substrate handling member 212). This known neutral position is achieved by supplying a drive current (I) to the drive mechanism 206 of the indexer mechanism 202. When the substrate 118 is transported 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 this deviation. The feedback signal is transmitted to the controller 112, which calculates the change in current required by the drive mechanism 206 to enable repositioning of the indexer mechanism 202 back to the known neutral position. This change in drive current to the drive mechanism 206, i.e., the delta drive current (ΔI), is directly proportional to the weight of the substrate seated on the indexer mechanism 202 when the acceleration of the drive mechanism 206 is zero and the vacuum load on the indexer mechanism 202 is constant. In such embodiments, the delta drive current (ΔI) ∝ weight of the substrate (W s )(i.e., ΔI ∝ W sGiven this relationship, the delta drive current (ΔI) can be used as a control parameter to monitor process drift and alert the user / controller. In an exemplary embodiment, the acceleration of the drive mechanism is defined herein as the inertial force acting on the drive mechanism.

[0043] As a non-limiting example, the controller 112 can generate a control parameter proportional to the change in the weight of the substrate by determining the difference between a first delta drive current (ΔI 1 ) of the substrate (seated on the indexer mechanism) before being processed by the process module and a second delta drive current (ΔI 2 ) of the same substrate (reseated on the indexer mechanism 202) after being processed by the process module.

[0044] In some embodiments, the process module can be configured for depositing a layer on a substrate by a deposition process. In such an example, the deposition process will increase the weight of the substrate. Under controlled process conditions that eliminate process drift, the increase in substrate weight due to the deposition process, and thus the difference between ΔI 1 and ΔI 2 is a precisely known parameter (control parameter). Thus, if the difference (control parameter) between ΔI 1 and ΔI 2 deviates from either a predetermined tolerance value or a predetermined tolerance value range, a process drift is identified, and subsequent cycles of the same deposition process implemented by the process module can monitor for process drift. In such an example, the control parameter can be communicated to an alarm system (such as the controller 112, an external alarm system, or the user), and if the controller 112 determines that the control parameter is outside a predetermined value or range of values, the alarm system is activated.

[0045] Note that the exemplary apparatus and method outlined above can also be used for substrates on which an etching process is performed in a process module where the etching process reduces the weight of the substrate.

[0046] According to an additional embodiment of the present disclosure, one or more environmental sensors 230 can be disposed within the load lock body 108, as shown in FIG. 2. In an alternative embodiment, the environmental sensor 230 can be constructed and arranged to monitor the environment within the load lock body 108 from the outside (e.g., by use of viewing ports and access lines, etc.). According to an embodiment of the present disclosure, the environmental sensor 230 can be used to monitor some environmental factors within the load lock body 108, including but not limited to temperature, humidity, and vacuum level (i.e., pressure). In some embodiments, the environmental sensor 230 communicates with the controller 112 to enable monitoring of the environment within the load lock body 108. In such embodiments, the controller 112 can also intervene when the monitored environment is outside of optimal or predetermined conditions. For example, such intervention by the controller 112 can include changing the temperature, humidity, and / or vacuum level within the load lock body 108 by communication between the controller 112 and one or more heaters, humidifiers, and / or vacuum pumps (not shown in FIG. 2).

[0047] According to an embodiment of the present disclosure, the internal environment within the load lock body 108 can be maintained in a stable steady state between seating and reseating of the substrate on the indexer mechanism 202, using the environmental sensor 230 in conjunction with the controller 112 and means for changing the internal environment within the load lock body 108 (e.g., heaters, humidifiers, and vacuum pumps, etc.). In such embodiments, the delta drive current (ΔI) used to generate control parameters, particularly ΔI 1 and ΔI 2The difference between them can be determined with higher precision when the environment having the load lock body 108 is maintained in a stable steady state (i.e., while maintaining substantially equal temperature, humidity, and vacuum levels within the load lock body). Thus, in such embodiments, the accuracy of the control parameter that is directly proportional to either the weight of the substrate or the weight change can be maintained or even improved. As a non-limiting example, the load lock arrangement 200 of the present disclosure can determine a weight change of a substrate (after deposition and / or etching) to be less than 1 microgram.

[0048] According to a further embodiment of the present disclosure, the load lock arrangement 200 of FIG. 2 may also include a temperature control plate 222. The temperature control plate 222 can incorporate heating means and / or cooling means (e.g., via heating elements and cooling channels, etc.) to control the temperature of the substrate 118 within the load lock body 108. In some embodiments, the indexer mechanism 202 can be positioned proximate to the temperature control plate 222 for improved thermal communication between the substrate 118 disposed on the indexer mechanism 202 and the temperature control plate 222. In such embodiments, the temperature control plate 222 can be used to maintain or vary the temperature of the substrate 118 such that the accuracy (determined by the difference between, for example, ΔI 1 and ΔI 2 ) of the control parameter is improved, for example, by enabling a steady-state evaluation of the substrate 118 (i.e., the temperature of the substrate 118 is the same during the determination of ΔI 1 and ΔI 2 ).

[0049] The load lock arrangement shown in FIG. 2 is illustrated as including a single chamber, but of course the apparatus and method described above are readily applicable to a load lock arrangement that includes an upper load lock chamber and a lower load lock chamber (i.e., a dual chamber load lock arrangement). As a non-limiting example, the load lock arrangement 200 shown in FIG. 2 could comprise the upper load lock chamber of a dual chamber load lock arrangement, and the second indexer mechanism could be structured and positioned for an operator in the lower load lock chamber with only minor changes to the position and configuration of the additional indexer mechanism.

[0050] As a non-limiting example, FIG. 3 shows an exemplary dual load lock arrangement 300 that includes an upper load lock chamber 304 (equivalent to the load lock arrangement 200 of FIG. 2) and a lower load lock chamber 306. The dual chamber dual load lock arrangement 300 of FIG. 3 is simplified to better illustrate the configuration of the elements within the dual load lock arrangement 300, and the corresponding load lock elements from the upper load lock chamber 304 that are present in the lower load lock chamber 306 are numerically labeled to begin with “3” instead of “2” to indicate that the elements are components of the lower load lock chamber 306. As shown in FIG. 3, the lower indexer mechanism 302 of the lower load lock chamber 306 is inverted (from that shown in FIG. 2) to enable operation in the lower load lock chamber 306 of the dual load lock arrangement 300 in addition to a minor reconfiguration of the lower indexer mechanism 302 to better accommodate the substrate 318 and the lower temperature control plate 322.

[0051] According to an embodiment of the present disclosure, a load lock arrangement 200 (FIG. 2) can be utilized as part of a semiconductor processing system such as the exemplary semiconductor processing system 100 of FIG. 1. In such an embodiment, referring to FIGS. 1 and 2, the semiconductor processing system 100 includes a load lock arrangement 200 including a load lock body 108, and an equipment front end module (EFEM) 110 connected to the front face 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 rear face 138 of the load lock body 108, the back end transfer module 104 coupling a process module 102 to the load lock body 108. In such an embodiment, an indexer mechanism 202 is connected to the load lock body 108, and the indexer mechanism 202 includes a drive mechanism 206 and means for supporting a substrate (i.e., a substrate handling member 212). In such an embodiment, a position sensor 218 is configured and arranged to measure a deflection distance of the indexer mechanism 202 from a known neutral position when seating a substrate 118 on the indexer mechanism 202, and then generate a feedback signal based on the deflection distance. In such an embodiment, a controller 112 is configured and arranged to receive the feedback signal, and then the controller calculates a delta drive current (ΔI) and provides it to the drive mechanism 206 to relocate the indexer mechanism 202 back to a known neutral position, where the delta 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 determines a first delta drive current (ΔI 1 ) of a substrate transferred from the equipment front end module (EFEM) 110 and seated on the indexer mechanism 202, and a second delta drive current (ΔI of a substrate transferred from the back end transfer module (BETM) 104 and reseated on the indexer mechanism 202 after one or more processes have been performed on the substrate in the process module 102 2By determining the difference between [substrate weight] and [reference weight], a control parameter proportional to the change in the weight of the substrate is generated. In such embodiments, the semiconductor processing system 100 further includes an alarm system that communicates with the controller 112, and the alarm system is activated when the controller 112 determines that the control parameter is outside a predetermined allowable value or range of values.

[0052] Embodiments of the present disclosure also include a method for monitoring process drift in a semiconductor processing system. According to an embodiment of the present disclosure, FIG. 4 shows a method 400 for monitoring process drift in a semiconductor processing system. The method 400 includes providing or providing with an indexer mechanism connected to the load lock body, the indexer mechanism including a drive mechanism and means for supporting a substrate.

[0053] According to an embodiment of the present disclosure, the method 400 proceeds to step 402, which includes transporting a substrate into the load lock body and seating the substrate on the indexer mechanism.

[0054] According to an embodiment of the present disclosure, the 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 seating the substrate on the indexer mechanism.

[0055] According to an embodiment of the present disclosure, the method 400 calculates a first delta drive current (ΔI 1 ) from the first feedback signal and provides the first delta drive current (ΔI 1 ) to the drive mechanism to relocate the indexer mechanism to a known neutral position, where the first delta drive current (ΔI 1 ) is proportional to the first weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load on the indexer mechanism is constant.

[0056] According to an embodiment of the present disclosure, method 400 proceeds to step 408, which includes transporting a substrate from a load lock body into a process module and performing one or more processes on the substrate.

[0057] According to an embodiment of the present disclosure, method 400 can proceed to step 410, which includes transporting a substrate from a process module into a load lock body assembly and re-seating the substrate on an indexer mechanism.

[0058] According to an embodiment of the present disclosure, 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 a known neutral position when re-seating the substrate on the indexer mechanism.

[0059] According to an embodiment of the present disclosure, method 400 2 calculates a second delta drive current (ΔI 2 ) from the second feedback signal and provides the second delta drive current (ΔI 2 ) to a drive mechanism to reposition the indexer mechanism to a known neutral position, where the second delta drive current (ΔI

[0060] 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. 1 According to an embodiment of the present disclosure, method 400 proceeds to step 416, which includes calculating a control parameter proportional to a change in weight of the substrate by determining a difference between a first delta drive current (ΔI 2 ) and the second delta drive current (ΔI

[0061] According to an embodiment of the present disclosure, method 400 can proceed to step 418, which includes operating an alarm system when the control parameter is outside a predetermined allowable value range.

[0062] According to an additional embodiment of the present disclosure, method 400 further includes using one or more environmental sensors that communicate with a controller, the environmental sensors being configured and arranged to monitor one or more of temperature, humidity, and vacuum level within the load lock body. In such embodiments, the environmental sensors can be used to monitor some environmental factors within the load lock body, including but not limited to temperature, humidity, and vacuum level (i.e., pressure). In such embodiments, the environmental sensors can communicate with the controller to enable monitoring of the environment within the load lock body. Further, in such embodiments, the controller is configured to intervene when the monitored environment within the load lock body is outside of optimal or predetermined conditions. For example, such intervention by the controller can include changing the temperature, humidity, and / or vacuum level within the load lock body 108 through communication between the controller 112 and one or more heaters, humidifiers, and / or vacuum pumps. Thus, in some embodiments, method 400 further includes maintaining the environment (i.e., temperature, humidity, and vacuum level, etc.) within the load lock body in a steady state when calculating the first delta drive current and the second delta drive current. In such embodiments, the calculation of the first delta drive current and the second delta drive current is performed in substantially the same environment within the load lock body.

[0063] According to an additional embodiment of the present disclosure, method 400 can further include maintaining the temperature of the substrate in a steady state (i.e., a constant temperature) when calculating the first delta drive current and the second delta drive current by positioning a temperature control plate in proximity to the substrate, as described in detail above herein.

[0064] According to a further embodiment of the present disclosure, method 400 can further include implementing one or more corrective actions to keep control parameters within a predetermined tolerance range when the alarm system is operating. For example, when the alarm system is operating, a process drift within a process module is detected. Thus, intervention by a controller or a user can be activated to correct the process drift detected within the process module. By way of non-limiting example, corrective actions can include, but are not limited to, cleaning of the process module, evaluation of components within the process module, evaluation of precursors and / or reactants supplied to the process module, and inspection for abnormalities of the processed substrates.

[0065] Although certain embodiments and examples have been discussed, those skilled in the art will understand that the claims extend beyond the specifically disclosed embodiments to cover other alternative embodiments and / or uses and obvious modifications and their equivalents. Indeed, various modifications of the present disclosure, such as alternative useful combinations of the described elements, may become apparent to those skilled in the art from the description. Such modifications and embodiments are also intended to be included within the scope of the appended claims.

[0066] 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 in view of the present disclosure as a matter of routine experimentation.

Claims

1. 1. An apparatus for monitoring process drift in a semiconductor processing system, comprising: a load lock arrangement including a load lock body; an indexer mechanism connected to the load lock body and including a drive mechanism and a means for supporting a substrate; a position sensor constructed and arranged to measure a deflection distance of the indexer mechanism from a known neutral position when seating the substrate on the indexer mechanism, the position sensor then generating a feedback signal based on the deflection distance; a controller constructed and arranged to receive the feedback signal and thereafter calculate and provide a delta drive current (ΔI) to the drive mechanism to reposition the indexer mechanism back to the known neutral position, the delta drive current (ΔI) being proportional to the weight of the substrate when the acceleration of the drive mechanism is zero and a vacuum load is constant, thereby enabling the controller to generate a control parameter proportional to either the weight of the substrate or a change in weight of the substrate; an alarm system in communication with the controller, the alarm system being activated if the controller determines that the control parameter is outside a predetermined tolerance range.

2. The apparatus of claim 1 , wherein the position sensor comprises a linear position sensor.

3. The apparatus of claim 2 , wherein the linear position sensor is integrated within the indexer mechanism.

4. The apparatus of claim 2 , wherein the linear position sensor is a parallel plate capacitor sensor or a laser triangulation displacement sensor.

5. The apparatus of claim 1 , wherein the drive mechanism comprises a linear motor drive.

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

7. The apparatus of claim 1 , wherein the load lock arrangement comprises a dual load lock arrangement with 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. 1. A semiconductor processing system comprising: a load lock arrangement including a load lock body; an Equipment Front End Module (EFEM) connected to a front side of the load lock body, the EFEM housing a front end substrate transport robot; a back-end transport module (BETM) connected to a rear surface of the load lock body, the back-end transport module (BETM) coupling a process module to the load lock body; an indexer mechanism connected to the load lock body and including a drive mechanism and a means for supporting a substrate; a position sensor constructed and arranged to measure a deflection distance of the indexer mechanism from a known neutral position when seating the substrate on the indexer mechanism, the position sensor then generating a feedback signal based on the deflection distance; a controller configured and arranged to receive the feedback signal and thereafter calculate and provide a delta drive current (ΔI) to the drive mechanism to reposition the indexer mechanism back to the known neutral position, the delta drive current (ΔI) being proportional to a weight of the substrate when the acceleration of the drive mechanism is zero and a vacuum load is constant, whereby the controller calculates a first delta drive current (ΔI) for the substrate transferred from the EFEM and seated on the indexer mechanism. １ ), and a second delta drive current (ΔI) for the substrate transferred from the BETM and seated on the indexer mechanism after the substrate has undergone one or more processes in the process module. ２ a controller capable of determining a difference between the weight of the substrate and the mass of the substrate, thereby generating a control parameter proportional to a change in weight of the substrate; an alarm system in communication with the controller, the alarm system being activated if the controller determines that the control parameter is outside a predetermined tolerance range.

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 said linear position sensor is integrated with said indexer mechanism.

12. 10. The semiconductor processing system of claim 9, wherein said drive mechanism comprises a linear motor drive.

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

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

15. 10. The semiconductor processing system of claim 9, wherein the load lock arrangement comprises a dual load lock arrangement with a lower indexer mechanism.

16. 1. A method for monitoring process drift in a semiconductor processing system, comprising: An indexer mechanism connected to a load lock body and including a drive mechanism and a means for supporting a substrate, transporting the substrate into the load lock body and seating the substrate on the indexer mechanism; generating a first feedback signal from a position sensor constructed and arranged to measure a first deflection distance of the indexer mechanism from a known neutral position when seating the substrate on the indexer mechanism; A first delta drive current (ΔI １ ) and calculating the first delta drive current (ΔI １ ) to the drive mechanism to reposition the indexer mechanism back to the known neutral position, １ ) is proportional to a first weight of the substrate when the acceleration of the drive mechanism is zero and a vacuum load is constant; and transferring the substrate from the load lock body into a process module and performing one or more processes on the substrate; transferring the substrate from the process module into the load lock body and re-seating the substrate on the indexer mechanism; generating a second feedback signal from the position sensor constructed and arranged to measure a second deflection distance of the indexer mechanism from the known neutral position upon re-seating the substrate on the indexer mechanism; A second delta drive current (ΔI ２ ) and the second delta drive current (ΔI ２ ) to the drive mechanism to reposition the indexer mechanism back to the known neutral position, ２ ) is proportional to a second weight of the substrate when the acceleration of the drive mechanism is zero and the vacuum load is constant; and The first delta drive current (ΔI １ ) and the second delta drive current (ΔI ２ ) calculating a control parameter proportional to the change in weight of the substrate by determining the difference between and activating an alarm system if the control parameter is outside a predetermined tolerance range.

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

18. 20. The method of claim 17, further comprising maintaining an environment within the loadlock body at a steady state when calculating the first delta drive current and the second delta drive current.

19. 17. The method of claim 16, further comprising maintaining a temperature of the substrate at a steady state when calculating the first delta drive current and the second delta drive current by positioning a temperature control plate proximate to the substrate.

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

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