Detection and repair of substrate carrier damage

Abstract

Procedure with the following steps: Receiving (202) a carrier (22) containing several wafers; Supply (204) of a purge gas to an inlet (46) of the carrier (22); Discharge (206) of an exhaust gas from an outlet (48) of the carrier (22); and Generating (210) a status indicator of the carrier (22) during the supply of the purge gas and the discharge of the exhaust gas, wherein the carrier has at least one air filter (32, 26) and the status indicator indicates whether the air filter needs to be replaced; the procedure, in the event that the condition indicator shows that the air filter needs to be replaced, further includes the following: Receiving the carrier (22) by a carrier repair station (18); and Automatic replacement of the air filter with a new air filter.

Description

Background of the invention

[0001] In semiconductor manufacturing, a wafer undergoes many processing steps to create integrated circuits (ICs). These process steps are performed by various processing equipment. When one or more wafers are transported between processing equipment, they are placed in a wafer carrier to protect them from external contamination. Furthermore, the wafer carrier (and the wafers inside) is purged with an inert gas to remove chemical residues on the wafers. Otherwise, these chemical residues could interfere with subsequent processing.

[0002] Wafer carriers usually have one or more air filters. These air filters can become damaged (e.g., torn or clogged) after repeated purging of the wafer carrier. If the damaged air filter is not replaced in a timely manner, the wafer carrier will not be purged effectively, which can lead to wafer contamination and manufacturing defects.

[0003] DE 10 2016 205 597 A1 describes a purge measurement system for FOUPs positioned in a FOUP nest. In addition to at least one free / occupied sensor for the FOUP nest, at least one gas supply and one gas outlet are provided for the supply and discharge of purge gas. Each gas supply line contains at least one pressure sensor, one flow meter, and one controllable valve. The valve is controlled based on the measurement results from the pressure sensor and flow meter. At least one humidity sensor and / or one oxygen sensor are provided in each gas outlet.

[0004] EP 1 343 202 A1 describes a method for using a substrate transport capsule suitable for the production of semiconductor devices with copper wiring and low-dielectric insulating film with dielectric constants of less than 3. The method is based on loading the substrates into a capsule from an atmosphere of a first process and circulating a gaseous atmosphere through the interior of the capsule to selectively remove at least one contaminant, including moisture, particulate substances or chemical substances, and temporarily or continuously exposing the substrates to a controlled atmosphere while the substrates are held in the capsule before they are unloaded from the capsule and introduced into a second process.In a capsule used to contain substrates for storage or transportation, the capsule has a capsule main body and a door that provides hermetic sealing, and the capsule is mainly made of a material that has a moisture absorption factor of less than 0.1%, and the capsule can directly or indirectly contact the substrates and has a conductive area to enable the dissipation of static charges from the capsule.

[0005] US 2015 / 0 303 041 A1 discloses a system for substrate processing with a carrier maintenance station.

[0006] The invention is defined in the claims. Short description of the drawings

[0007] Aspects of the present invention can best be understood from the following detailed description when taken in conjunction with the accompanying drawings. It should be noted that, in accordance with standard industry practice, various elements are not drawn to scale. Rather, for the sake of clarity of discussion, the dimensions of various elements may be exaggerated or reduced as desired. Fig. 1 shows a schematic representation of a portion of a semiconductor manufacturing system according to various aspects of the present invention. Fig. Figure 2 shows a schematic representation of a substrate carrier rinsing station according to various aspects of the present invention. Fig. 3 shows a substrate carrier repair station and an associated workflow, according to various aspects of the present invention. Fig. 4 shows a more detailed illustration of the substrate carrier repair station according to one embodiment. Fig. 5 shows a flowchart of a method for automatically detecting air filter damage in a substrate carrier, according to various aspects of the present invention. Fig. 6 shows a flowchart of a method for automatically replacing a substrate carrier, according to various aspects of the present invention. Fig. 7 shows a flow diagram of a method for automatically replacing parts in a substrate carrier, according to various aspects of the present invention. Detailed description

[0008] The following description provides many different embodiments or examples for implementing various features of the provided subject matter. Specific examples of components and arrangements are described below to facilitate the present invention. These are, of course, merely examples and are not intended to be limiting. For example, the fabrication of a first element over or on a second element in the following description may include embodiments in which the first and second elements are formed in direct contact, and may also include embodiments in which additional elements may be formed between the first and second elements such that the first and second elements are not in direct contact. Furthermore, in the present invention, reference numerals and / or letters may be repeated in the various examples.This repetition is for simplicity and clarity and does not, in itself, prescribe any relationship between the various embodiments and / or configurations discussed.

[0009] Furthermore, spatially relative terms such as "beneath," "under," "lower," "above," "upper," and the like may be used herein to conveniently describe the relationship of one element or structure to one or more other elements or structures illustrated in the figures. The spatially relative terms are intended to encompass other orientations of the device in use or operation, in addition to the orientation illustrated in the figures. The device may be oriented differently (rotated 90 degrees or in a different orientation), and the spatially relative descriptors used herein may be interpreted accordingly.

[0010] The present invention relates generally to semiconductor manufacturing, and more particularly to systems and methods for handling substrate carriers, such as wafer carriers, during semiconductor manufacturing. One object of the present invention is to automatically detect damage in a substrate carrier, automatically replace the damaged substrate carrier with a new substrate carrier, and automatically repair the damaged substrate carrier. The present invention offers numerous advantages for semiconductor manufacturing. First, it increases production output and reduces production costs (e.g., it requires less labor and less manual work). Second, it is more reliable and reduces operational errors. Third, it detects substrate carrier damage in a timely manner and reduces wafer defects.The substrate used herein may be: a wafer (such as a silicon wafer having a diameter of 125 mm, 150 mm, 200 mm, 300 mm, or 450 mm), a semiconductor substrate or wafer, a mask, a reticle, a plasma filter plate, an adsorption pad, a base material that is processed to produce new material layers, and / or combinations thereof.

[0011] Fig. 1 shows a schematic representation of a portion of a semiconductor manufacturing system 10 configured according to aspects of the present invention. In Fig. 1, the system 10 comprises a plurality of semiconductor processing tools 12 with a processing tool 1, a processing tool 2, ..., a processing tool N. The system 10 further comprises one or more substrate carrier rinsing stations 14, one or more substrate carrier changing stations 16, and one or more substrate carrier repair stations 18. The system 10 further comprises an overhead hoist transport (OHT) 20 that runs like a road past the various tools and stations to transport one or more substrate carriers 22. The system 10 further comprises an automatic controller 24, such as an automated materials handling system (AMHS), for transporting the substrate carriers 22 between the tools and stations. In various embodiments, the system 10 may include additional components not shown here, or some of the components discussed here may be omitted.

[0012] The processing tools 12 may each perform one or more tasks related to the fabrication of integrated circuits on substrates, such as semiconductor wafers. The tasks may include front end of line (FEOL) processing, middle end of line (MEOL) processing, and back end of line (BEOL) processing. The tasks may include, for example, substrate cleaning; material deposition, such as epitaxy, chemical vapor deposition (CVD), physical vapor deposition (PVD), atomic layer deposition (ALD), and metal plating; etching, such as dry etching, wet etching, reactive ion etching, and atomic layer etching (ALE); chemical mechanical planarization (CMP); curing; photoresist coating, exposure, development, and stripping; and various other tasks. The processing tool 12 may process one substrate individually or multiple substrates as a stack.In one embodiment, the processing system 12 may include loading and unloading docks that act as buffers for collecting multiple substrates before and after processing.

[0013] One or more substrates are conveyed from one processing facility to another according to a manufacturing process. Typically, after a processing step, a substrate is removed from a processing facility that has performed the processing step and conveyed to a substrate carrier 22, in which the substrate temporarily remains until further processing. The substrate carrier 22 provides a protective housing for receiving one or more substrates, such as 1, 12, 13, or 25 substrates. In some embodiments, the substrate carrier 22 is a Front Opening Unified Pod (FOUP). Fig. 1 shows a substrate carrier 22 as part of the system 10. In various embodiments, the system 10 may include multiple substrate carriers 22, and the substrate carriers may be of different types. For example, substrate carriers for FEOL processing may differ from substrate carriers for BEOL processing. For example, the former may provide a cleaner environment for substrates housed therein than the latter.

[0014] Furthermore, Fig. 1, the carrier purge station 14 is configured to purge the substrate carrier 22 with an inert gas to ensure that the substrate carrier 22 continues to provide a clean and safe environment for substrates housed therein. A typical semiconductor manufacturing process may include numerous (e.g., approximately 70 to 100) purge steps. For example, the substrate carrier 22 may be purged after each of the processes dry etch, wet etch, stripping, dry cleaning, wet cleaning, deposition, CMP, and plating, among other processes. For example, the substrate carrier 22 may be conveyed (via the OHT 20) to the carrier purge station 14 after a certain number of substrates have accumulated and been processed by the processing tool 12. The carrier purge station 14 then purges the substrate carrier 22 with an inert gas, such as nitrogen, or with high-purity dry air. Flushing removes chemical residues (e.g. NH3, SO4, F, Cl, NO3, PO4, etc.) is removed from the substrate carrier 22. The substrate carrier 22 is then transported (by means of the OHT 20) to the next processing system 12 for further processing. In some steps of the manufacturing process, the substrate carrier 22 can be transported (by means of the OHT 20) from one processing system 12 to another processing system 12 without being rinsed in the carrier rinsing station 14.

[0015] In the present embodiment, the substrate carrier 22 includes one or more air filters that contribute to a clean housing. These air filters may become damaged (e.g., torn or clogged) after repeated purging. The carrier purge station 14 is configured to detect damage to these air filters, and further details will be discussed in connection with Fig. 2. When the carrier purge station 14 detects that the air filters (and other parts connected to the air filters) are no longer safe for the substrate carrier 22, it can report this to the automatic controller 24, which can then transport the substrate carrier 22 to the carrier exchange station 16 via the OHT 20. The carrier purge station 14 can communicate with the automatic controller 24 via one or more wireless or wired communication channels.

[0016] The carrier exchange station 16 is configured to replace a damaged substrate carrier with a new substrate carrier. For example, it is operable to move all substrates housed in the damaged substrate carrier into the new substrate carrier. It can also purge the new substrate carrier with an inert gas before it is returned to production (i.e., conveyed to the processing equipment 12). Alternatively, it can convey the new substrate carrier back to the carrier purge station 14, which purges the new substrate carrier. In some embodiments of the system 10, the carrier purge station 14 and the carrier exchange station 16 can be implemented as a single device or as separate devices.

[0017] Damaged substrate carriers are conveyed (e.g., from the carrier rinsing station 14 or the carrier exchange station 16) to the carrier repair station 18 by means of the OHT 20. In one embodiment, the carrier repair station 18 is configured to receive the damaged substrate carrier; loosen one or more screws and / or open one or more lids and / or housings covering the air filters in the substrate carrier; remove the air filters; install new air filters; inspect the newly installed air filters; retighten the screws and / or reinstall the lids and / or housings; and return the substrate carrier to production. Further details on the systems and methods for implementing the carrier repair station 18 will be described in connection with the Fig. 3 and Fig. 4 described in more detail.

[0018] The system 10 offers numerous advantages over existing semiconductor manufacturing systems. For example, the carrier rinsing station 14 enables automatic detection of damage in a substrate carrier. This automatic detection increases production output and reduces operational errors compared to visual inspection of the substrate carrier by an operator. Furthermore, the carrier repair station 18 enables automatic part replacement in a substrate carrier, which also increases production output and reduces operational errors compared to manual part replacement by an operator.

[0019] In Fig. 2, the carrier rinse station 14, which rinses a substrate carrier 22, is shown according to some embodiments. In the present embodiment, the substrate carrier 22 includes a body (or outer cover) 26 and grooves or other structures in the body 26 for holding a plurality of substrates (e.g., silicon wafers) 31. The substrate carrier 22 further includes a holder 28 for attaching the substrate carrier to the OHT 20. The substrate carrier 22 further includes a door (not shown) through which the substrate 31 is placed in or removed from the substrate carrier 22. The substrate carrier 22 has an inlet 30 with an air supply filter 32 mounted therein and an outlet 34 in which an exhaust filter 36 is mounted.In the inlet 30 and the outlet 34, the substrate carrier 22 may further include a filter housing (not shown) for holding the air filter, a cover (not shown) for securing the filter housing, and optionally an O-ring (not shown) between the filter housing and the respective air filter. In some embodiments, the substrate carrier 22 may have more than one inlet and more than one outlet. In one embodiment, the substrate carrier 22 may further include a sensor 60 in the housing 26. The sensor 60 may be a humidity sensor or an air pressure sensor.

[0020] Furthermore, Fig. 2, in the present embodiment, the carrier purge station 14 includes a table or base plate 40, an alignment sensor 42 for assisting in the alignment of the carrier purge station 14 to the OHT 20, guide pins 44 for aligning the carrier purge station 14 to the substrate carrier 22 (e.g., by fitting into guide holes in the substrate carrier 22), an inlet 46 for introducing a purge gas 50 into the inlet 30 of the substrate carrier 22, and an outlet 48 for discharging an exhaust gas 52 from the outlet 34 of the substrate carrier 22. The purge gas 50 may comprise nitrogen gas, ultrapure dry air, or other suitable inert gases. As in Fig. 2, the purge gas 50 expels some chemical residues or particles 33 from the substrate carrier 22 and drives them into the exhaust gas 52. Some chemical residues or particles 33 may be adsorbed by the exhaust filter 36.

[0021] As explained above, the same substrate carrier 22 may undergo numerous rinsing steps. After repeated use, the air filter 32 and / or the air filter 36 may become damaged. For example, a buildup of particles may clog the air filters 32 and 36, increasing their flow resistance and decreasing their filtering performance. In another example, the air filters 32 and 36 may lose their mechanical strength and tear over time. If the air filters 32 and 36 are torn, the substrate carrier 22 loses its effectiveness in protecting the substrates 31 from the environment. Therefore, timely detection of this damage (e.g., clogging or tearing) is important to ensure high-quality production.

[0022] In the present embodiment, the carrier purge station 14 further includes one or more humidity sensors 62, one or more gas flow sensors 64, and one or more particle sensors 66. The humidity sensor 62, the gas flow sensor 64, and the particle sensor 66 are mounted near the outlet 48 in the present embodiment. Furthermore, the sensors 62, 64, and 66 have direct contact with the exhaust gas 52 during purging. The humidity sensor 62 is operable to detect the humidity of the exhaust gas 52. The gas flow sensor 64 is operable to detect the flow rate of the exhaust gas 52. The carrier purge station 14 may also include another gas flow sensor (not shown) operable to detect the flow rate of the purge gas 50. In one embodiment, the particle sensor 66 is operable to detect the sizes of the particles in the exhaust gas 52.Alternatively or additionally, the particle sensor 66 is operable to detect the number of particles (or the particle count) in the exhaust gas 52, or it is operable to detect the density of particles in the exhaust gas 52. In various embodiments, the carrier purge station 14 may include only one particle sensor 66 for detecting the particle sizes, particle count, and particle density in the exhaust gas 52, or it may include separate particle sensors for respectively performing the aforementioned functions. Using the various sensors 60, 62, 64, and 66, the carrier purge station 14 may generate a condition indicator of the substrate carrier 22. In one embodiment, the condition indicator indicates whether or not the air filters 32 and 36 need to be replaced.

[0023] The carrier rinsing station 14 further includes a detection controller 68. In the present embodiment, the detection controller 68 is a computer-based device, such as a computer running software. The detection controller 68 may include, for example, a processor or microprocessor, an input device, a memory device, and a communication device interconnected by one or more buses, and may execute software instructions to perform various tasks of the carrier rinsing station 14. Some of these tasks are discussed below.

[0024] In one embodiment, the carrier purge station 14 generates the condition indicator based on a measurement of the air pressure in the substrate carrier 22. For example, the detection controller 68 may read the air pressure value measured by the sensor 60, for example, using a wired or wireless connection between the two. In another example, the detection controller 68 may detect the air pressure in the substrate carrier 22 without using the sensor 60. Instead, it may calculate the air pressure in the substrate carrier 22 based on the flow rate of the exhaust gas 52 (detected by the gas flow sensor 64) and, optionally, the flow rate of the purge gas 50. Other methods or mechanisms for detecting or measuring the air pressure in the substrate carrier 22 may also be used by the detection controller 68.If the air pressure value in the substrate carrier 22 is known, the detection controller 68 can then compare the value to an expected or predetermined air pressure range (which has an upper and a lower limit). If the measured or detected air pressure value is outside the predetermined air pressure range, the condition indicator is activated to indicate that the substrate carrier 22 needs to be repaired.

[0025] In one embodiment, the carrier purge station 14 generates the condition indicator based on a measurement of the humidity in the exhaust gas 52. For example, the detection controller 68 may read a humidity value of the exhaust gas 52 measured by the humidity sensor 62 and compare the measured humidity value to a predetermined humidity range (which has an upper and lower limit). If the measured humidity value is outside the predetermined humidity range, the condition indicator is activated to indicate that the substrate carrier 22 needs to be repaired.

[0026] In another embodiment, the carrier purge station 14 generates the condition indicator based on a measurement of the flow rate of the exhaust gas 52. For example, the detection controller 68 may read a flow rate value of the exhaust gas 52 measured by the gas flow sensor 64 and may compare the measured flow rate value to a predetermined flow rate range (which has an upper and a lower limit). If the measured flow rate value is outside the predetermined flow rate range, the condition indicator is activated to indicate that the substrate carrier 22 needs to be repaired. For example, a very low flow rate indicates that the air filter 32 and / or the air filter 36 may be clogged, and a very high flow rate indicates that the air filter 32 and / or the air filter 36 may be torn.

[0027] In yet another embodiment, the substrate purge station 14 generates the condition indicator based on a measurement of the particle sizes in the exhaust gas 52. For example, the detection controller 68 may read the maximum particle size detected by the particle sensor 66 and compare the value to a particle size threshold. If the detected particle size exceeds the particle size threshold, the condition indicator is activated to indicate that the substrate carrier 22 needs to be repaired. For example, the presence of large particles in the exhaust gas 52 indicates that the air filter 36 is no longer achieving its expected filtration performance.

[0028] In yet another embodiment, the substrate purge station 14 generates the condition indicator based on a measurement of the particle count in the exhaust gas 52. For example, the detection controller 68 may read the particle count determined by the particle sensor 66 and compare this value to a particle count threshold. If the detected particle count exceeds the particle count threshold, the condition indicator is activated to indicate that the substrate carrier 22 needs to be repaired. For example, the presence of too many particles in the exhaust gas 52 indicates that the air filter 32 and / or the air filter 36 are no longer achieving their expected filtration performance.

[0029] Fig. Figure 3 shows an embodiment of a carrier repair station 18 and the OHT 20 in a perspective view and the corresponding workflow, according to various aspects of the present invention. In Fig. 3, in the present embodiment, the carrier repair station 18 includes an input port 80 for receiving a substrate carrier 22 from the OHT 20 and an output port 82 for returning the substrate carrier 22 to the OHT 20 after repair. Between the input port 80 and the output port 82, the carrier repair station 18 further includes a first mechanism (e.g., a robotic arm) for removing screws, covers, and / or filter housings from the substrate carrier 22 in order to replace the air filters 32 and 36 ( Fig. 2); and a second mechanism (e.g., one or more robotic arms) for removing the old air filters from the substrate carrier 22 and installing new air filters in the substrate carrier 22. In one embodiment, the carrier repair station 18 further includes a third mechanism (e.g., a robotic arm) for retightening the screws and / or reinstalling the covers and / or filter housings in the substrate carrier 22. In another embodiment, the first and third mechanisms utilize the same device or robotic arm(s). The carrier repair station 18 further includes an automatic control mechanism (e.g., optical sensors) for controlling the newly installed air filters in the substrate carrier 22. The carrier repair station 18 further includes a controller 104 for coordinating the workflow in the station.

[0030] Fig. 4 shows a more detailed illustration of the carrier repair station 18 according to one embodiment. In Fig. 4, the input port 80 and the output port 82 may be designed to receive only one substrate carrier 22 at a time. Alternatively, they may be designed to receive multiple substrate carriers 22 at a time. Furthermore, the input port 80 and the output port 82 may be designed to receive different types of substrate carriers 22, for example, having different sizes and configurations. A carrier moving device 84 is operable to move the substrate carrier 22 from the input port 80 to other components of the carrier repair station 18, such as an opening / closing device 86, a rotating device 88, an assembling / disassembling device 90, and an assembly control device 94, upon receipt of a substrate carrier 22 through the input port 80. Fig. 4 shows several substrate carriers 22 being repaired in a streamlined manner by the carrier repair station 18.

[0031] In the present embodiment, the rotating device 88 is operable to rotate the substrate carrier 22 to a position such that various components of the carrier repair station 18, such as the opening / closing device 86, the mounting / dismounting device 90, and the mounting control device 94, can easily access the air filters and other parts of the substrate carrier 22. For example, with other types of substrate carriers (e.g., substrate carriers for FEOL, substrate carriers for BEOL, substrate carriers from other suppliers, etc.), the air filters may be installed at different positions on the respective substrate carriers. The rotating device 88 can be configured to rotate the substrate carriers 22 so that their air filters always appear in the same position relative to the opening / closing device 86, the mounting / dismounting device 90, and the mounting control device 94, regardless of the type of substrate carrier 22.

[0032] The opening / closing device 86 is operable to open a filter housing of the substrate carrier 22, e.g., by unscrewing a cover and pulling out the filter housing, and to close the filter housing, e.g., by reinserting the filter housing into the substrate carrier and screwing the cover back on. The assembly / disassembly device 90 is operable to remove old air filter parts, such as O-rings and air filters, and install corresponding new parts. The assembly control device 94 is operable to inspect newly installed parts, and in particular newly installed air filters. In one embodiment, the assembly control device 94 comprises a laser sensor and / or optical sensors for detecting the flatness of the air filter after its assembly in the substrate carrier 22.In another embodiment, the installation control device 94 includes a camera for capturing an image of the air filter, which image can be used by the controller 104 to determine the flatness of the air filter. In yet another embodiment, the installation control device 94 is operable to determine the orientation of the newly installed air filter relative to the inlet 30 and / or the outlet 34 (Fig. Fig. 2). After the substrate carrier 22 has passed the inspection by the assembly inspection device 94, the carrier moving device 84 can convey the substrate carrier 22 to the exit opening 82.

[0033] The carrier repair station 18 also includes various components for supplying new parts, such as new air filters and new O-rings, to the assembly / disassembly device 90. In the present embodiment, the carrier repair station 18 includes one or more parts containers 98 for receiving the new parts, a parts inspection device 96 for inspecting the new parts, a pusher device 92 for supplying the new parts that have passed the inspection to the assembly / disassembly device 90, a parts disposal device 100 for receiving old parts that have been removed from the substrate carrier 22, and a parts diagnostic container 102 for receiving new parts that have failed the inspection. In one embodiment, the parts inspection device 96 includes a camera (e.g., a CCD camera or a CMOS camera) for capturing an image of a new part (e.g.,a new air filter), and the control unit 104 can use the image to determine whether the new part is of good quality or not, for example, whether it has the expected size and shape and is free of bumps and holes.

[0034] It should be noted that in some embodiments, the carrier repair station 18 may include additional components not illustrated herein, and in some embodiments, some of the components discussed above may be omitted. Furthermore, some components discussed herein may be combined into a single component in embodiments of the carrier repair station 18.

[0035] Fig. 5 shows a flow diagram of a method 200 for rinsing a substrate carrier and for automatically detecting damage in the substrate carrier according to aspects of the present invention. For example, embodiments of the method 200 may be implemented by or with the carrier rinsing station 14. The method 200 is merely an example and is not intended to limit the present invention beyond what is expressly set forth in the claims. Further steps may be provided before, during, and after the method 200, and some of the described steps may be replaced, omitted, or shifted in further embodiments of the method. The order of the steps / processes is interchangeable. The method 200 is used in conjunction with the Fig. 1 and Fig. 2 described in more detail.

[0036] In step 202, in the method 200 ( Fig. 5) a carrier, such as the substrate carrier 22. The carrier accommodates several substrates. In Fig. 1, the carrier can be received by the carrier purge station 14 using the OHT 20 from one of the processing systems 12 or from the carrier exchange station 16. In one example, the plurality of substrates can be silicon wafers. The carrier has an inlet for receiving a purge gas and an outlet for discharging an exhaust gas. The carrier further has an air intake filter at the inlet and an exhaust filter at the outlet.

[0037] In step 204, in the method 200 ( Fig. 5) a purge gas is introduced into the carrier, e.g., via an inlet of the carrier. In some embodiments, the purge gas can be supplied at a flow rate of 1 to 15 liters per minute (l / min). The purge gas can comprise nitrogen gas, ultrapure dry air, or other suitable inert gases. In step 206, the exhaust gas is removed from the carrier, e.g., via the outlet of the carrier. Steps 204 and 206 can be performed concurrently. Furthermore, in some embodiments, steps 204 and 206 can be performed for approximately 10 to 650 s.

[0038] The procedure 200 ( Fig. 5) During the execution of steps 204 and 206, further comprises a step 208 in which the operating environment of the carrier is monitored. Step 208 may, for example, comprise one or more of steps 208a, 208b, 208c, 208d, 208e, and 208f. In step 208a, the air pressure in the carrier is measured. In step 208b, the humidity in the exhaust gas is measured. In step 208c, the flow rate of the exhaust gas is measured. In step 208d, the number of particles in the exhaust gas is measured. In step 208e, the particle sizes in the exhaust gas are measured. In step 208f, the flow rate of the purge gas is measured.

[0039] In step 210, in the method 200 ( Fig. 5) a carrier condition indicator is generated based on the carrier's operating environment. The condition indicator may be generated, for example, based on one or more of the following conditions: (a) whether the air pressure measured in step 208 is outside a predetermined air pressure range, (b) whether the humidity value measured in step 208b is outside a predetermined humidity range, (c) whether the exhaust flow rate measured in step 208c is outside a predetermined flow rate range, (d) whether the particle count measured in step 208d exceeds a particle count threshold, and (e) whether the particle size measured in step 208e exceeds a particle size threshold. If one or more of the aforementioned conditions are met, the condition indicator assumes a value indicating that the carrier is in poor condition.For the method 200, additional or alternatively further criteria may be used to generate the status indicator.

[0040] In step 212, in the method 200 ( Fig. 5) determines whether the carrier requires repair. In one embodiment, the carrier is ready for repair if the condition indicator indicates that the carrier is in poor condition. In another embodiment, method 200 may track the number of purge steps used for the same carrier. If the number exceeds a threshold, the carrier is ready for repair. For example, an air filter may have a maximum useful life (i.e., lifespan of the air filter), which may be set by the air filter supplier or the carrier supplier. After this limit is reached, the air filter has reached the end of its useful life and is considered unsafe for further use. In this case, method 200 may determine that the carrier requires repair regardless of whether the condition indicator indicates that the carrier is in poor condition.

[0041] If it is determined in step 212 that the carrier does not require repair, the method 200 proceeds to transfer the carrier to the next processing facility for further manufacturing processes in step 214. If it is determined in step 212 that the carrier requires repair, the method 200 proceeds to transfer the carrier to a carrier exchange station in step 216, where the substrates housed in the carrier can be removed from the carrier and placed in another carrier.

[0042] Fig. 6 shows a flowchart of a method 300 for exchanging a substrate carrier according to aspects of the present invention. For example, embodiments of the method 300 may be implemented by or with the carrier exchange station 16. The method 300 is merely an example and is not intended to limit the present invention beyond what is expressly set forth in the claims. Additional steps may be provided before, during, and after the method 300, and some of the described steps may be replaced, omitted, or shifted in further embodiments of the method.

[0043] In step 302, in the method 300 ( Fig. 6) a carrier with substrates accommodated in it. In Fig. 1, the carrier can be received by the carrier exchange station 16 by means of the OHT 20 from the carrier rinsing station 14. In step 304, in the method 300, the carrier is opened and the substrates are transported from the carrier to another carrier ("new carrier"). In step 306, in the method 300, the new carrier with the substrates accommodated therein is removed, for example, from the carrier rinsing station 14 ( Fig. 1). After rinsing, in the method 300, in step 308, the new carrier is returned to production, for example, by transporting it with the substrates accommodated therein to a processing system 12 ( Fig. 1). In step 310, the old carrier is sent to a carrier repair station, such as carrier repair station 18, for repair in method 300.

[0044] Fig. 7 shows a flowchart of a method 400 for repairing a substrate carrier according to aspects of the present invention. For example, embodiments of the method 400 may be implemented by or with the carrier repair station 18. The method 400 is merely an example and is not intended to limit the present invention beyond what is expressly set forth in the claims. Additional steps may be provided before, during, and after the method 400, and some of the described steps may be replaced, omitted, or shifted in further embodiments of the method.

[0045] In step 402, in the method 400 ( Fig. 7) a carrier is received. In the present embodiment, no substrates are accommodated in the carrier. In Fig. 1, the carrier can be received by the carrier repair station 18 by means of the OHT 20 from the carrier exchange station 16. In particular, the carrier can be received through the entrance opening 80 of the carrier repair station 18 ( Fig. 3 and Fig. 4) can be received.

[0046] In step 404, the method 400 ( Fig. 7) Covers on the inlet and outlet housings of the carrier are removed, for example, by unscrewing. In step 406, method 400 optionally rotates the carrier to allow easy access to the housing and the air filters located therein. In step 408, method 400 disassembles the inlet and outlet housings from the carrier to expose the air filters in the carrier. In step 410, method 400 optionally removes an O-ring from the carrier. In step 412, method 400 removes the supply and exhaust air filters from the carrier.

[0047] In step 414, the method 400 ( Fig. 7) New parts are provided to be installed in the carrier, such as new air filters and optionally new O-rings. In step 416, method 400 inspects the new parts to ensure they are free of defects. If defects are found in the new parts, method 400 repeats steps 414 and 416 until new, defect-free parts are found.

[0048] In step 418, the method 400 ( Fig. 7) the new parts, such as new supply and exhaust air filters, are installed in the carrier. In method 400, new O-rings can optionally be installed in the carrier if necessary. In step 420, in method 400, the inlet and outlet housings and the covers are reinstalled on the carrier. In step 422, in method 400, the newly installed parts are inspected. For example, optical sensors can be used to detect the surface flatness of the newly installed air filters. If the newly installed parts fail the inspection, method 400 returns to step 408 and repeats steps 408 to 422. If the newly installed parts pass the inspection, method 400 returns the carrier to production (step 424). In the Fig. 3 and Fig. 4, the carrier can be placed in the exit opening 82 and wait for transport by the OHT 20.

[0049] In one embodiment, one or more of the aforementioned steps of method 400 are implemented using computer-aided mechanical devices, such as robotic arms. This advantageously reduces downtime during manufacturing and increases the reliability and quality of the carrier.

[0050] One or more embodiments of the present invention, which are not intended to be limiting, provide numerous benefits for semiconductor manufacturing. For example, embodiments of the present invention automatically detect damage in a substrate carrier, thereby reducing manual labor and increasing production output. This also occurs more reliably and in a timely manner, thus reducing wafer defects. Furthermore, embodiments of the present invention automatically replace damaged air filters in the substrate carriers, thereby increasing production output and reducing operational errors.

[0051] In one exemplary aspect, the present invention is directed to a method. The method comprises the steps of: receiving a carrier having a plurality of wafers therein; supplying a purge gas to an inlet of the carrier; exhausting an exhaust gas from an outlet of the carrier; and generating a condition indicator of the carrier during supplying the purge gas and exhausting the exhaust gas.

[0052] In one embodiment of the method, generating the condition indicator is based on one or more of the following measurements: (a) a measurement of an air pressure in the carrier; (b) a measurement of a humidity of the exhaust gas; (c) a measurement of a flow rate of the exhaust gas; and (d) a measurement of particles in the exhaust gas.

[0053] In another embodiment of the method, generating the condition indicator comprises the following steps: reading an air pressure value measured with a pressure sensor installed in the carrier; comparing the air pressure value with a predetermined air pressure range; and indicating that the carrier needs to be repaired if the air pressure value is outside the predetermined air pressure range.

[0054] In a further embodiment of the method, generating the condition indicator comprises the following steps: reading a humidity value of the exhaust gas measured with a humidity sensor installed adjacent to the outlet of the carrier; comparing the humidity value with a predetermined humidity range; and indicating that the carrier needs to be repaired if the humidity value is outside the predetermined humidity range.

[0055] In a further embodiment of the method, generating the condition indicator comprises the following steps: measuring a flow rate of the exhaust gas; comparing the flow rate with a predetermined flow rate range; and indicating that the carrier needs to be repaired if the flow rate is outside the predetermined flow rate range.

[0056] In a further embodiment of the method, generating the condition indicator comprises the steps of: measuring the sizes of particles carried in the exhaust gas; comparing the sizes to a size threshold; and indicating that the carrier needs to be repaired if any of the sizes exceeds the size threshold.

[0057] In yet another embodiment of the method, generating the condition indicator comprises the steps of: measuring a number of particles carried in the exhaust gas; comparing the number to a threshold number; and indicating that the carrier needs to be repaired if the number exceeds the threshold number.

[0058] In one embodiment, the method further comprises, in the event that the condition indicator indicates that the carrier needs to be repaired: removing the plurality of wafers from the carrier; and conveying the carrier to a carrier repair station via an overhead transport (OHT). In another embodiment, the method comprises: receiving a carrier at the carrier repair station; replacing, by a first motor-driven device, an inlet filter at the inlet of the carrier with a new inlet filter; replacing, by a second motor-driven device, an outlet filter at the outlet of the carrier with a new outlet filter; and inspecting, by a third motor-driven device, the new inlet filter and the new outlet filter.In another embodiment, if both the new inlet filter and the new outlet filter pass the inspection, the method comprises conveying the carrier with the new inlet filter and the new outlet filter over the OHT to a processing facility. In another embodiment, if the new inlet filter or the new outlet filter fails the inspection, the method comprises replacing the new inlet filter or the new outlet filter with a replacement filter; and inspecting the replacement filter.

[0059] In one exemplary aspect, the present invention is directed to an apparatus for semiconductor manufacturing. The apparatus includes: an input port for receiving a carrier, the carrier comprising a carrier body, a housing mounted to the carrier body, and a filter installed between the carrier body and the housing; a first robotic arm for disassembling the housing from the carrier and mounting the housing into the carrier; one or more second robotic arms for removing the filter from the carrier and installing a new filter into the carrier; and an output port for returning the carrier to production.

[0060] In one embodiment, the one or more second robotic arms are further configured to insert and remove an O-ring between the filter and the housing. In one embodiment, the apparatus further comprises a first inspection mechanism for inspecting the new filter prior to its installation with the one or more second robotic arms. In one embodiment, the first inspection mechanism comprises a camera for capturing an image of the new filter; and an inspection device for determining the quality of the new filter based on the image.

[0061] In one embodiment, the device further comprises a second inspection mechanism for inspecting the new filter after its installation with the one or more second robot arms. In one embodiment, the second inspection mechanism comprises a laser mechanism for detecting the flatness of a surface of the new filter.

[0062] In another exemplary aspect, the present invention is directed to a system. The system includes: a plurality of semiconductor processing tools; a carrier purge station; a carrier repair station; and an overhead transport (OHT) loop for conveying one or more substrate carriers between the plurality of semiconductor processing tools, the carrier purge station, and the carrier repair station. The carrier purge station is configured to receive a substrate carrier from one of the plurality of semiconductor processing tools, purge the substrate carrier with an inert gas, and determine whether the substrate carrier needs repair. The carrier repair station is configured to receive a substrate carrier to be repaired and replace one or more parts in the substrate carrier.

[0063] In one embodiment, the system further comprises a carrier changing station configured to receive a substrate carrier with substrates, remove the substrates from the substrate carrier, and place the substrates into another substrate carrier.

[0064] In another embodiment of the system, the carrier purge station is configured to determine whether the substrate carrier needs to be repaired based on at least one of the following factors: whether the one or more parts in the substrate carrier have reached their respective lifetimes; a measurement of an air pressure in the substrate carrier while the substrate carrier is being purged; a measurement of an exhaust gas humidity while the substrate carrier is being purged; a measurement of an exhaust gas flow rate while the substrate carrier is being purged; and a measurement of particulates in the exhaust gas while the substrate carrier is being purged.

[0065] In one embodiment of the system, the one or more parts comprise an air filter in the substrate carrier. In another embodiment of the system, the substrate carrier is configured to support multiple wafers.

[0066] In another exemplary aspect, the present invention is directed to a method. The method includes purging a wafer carrier to produce an exhaust gas; and determining whether the wafer carrier requires repair based on one or more of the following factors: whether an air pressure in the wafer carrier is within a predetermined air pressure range; whether a humidity of the exhaust gas is within a predetermined humidity range; whether a flow rate of the exhaust gas is within a predetermined flow rate range; whether sizes of particles in the exhaust gas are smaller than a size threshold; whether a number of particles in the exhaust gas is smaller than a number threshold; and whether a filter in the wafer carrier has reached the end of its service life.

[0067] In one embodiment, if the determining determines that the wafer carrier requires repair, the method further comprises transporting the wafer carrier to a carrier repair station using an overhead transport (OHT) loop; and replacing one or more parts of the wafer carrier in the carrier repair station. In another embodiment, replacing the one or more parts comprises: receiving the wafer carrier using the OHT loop; removing the one or more parts from the wafer carrier with at least one robotic arm; installing one or more replacement parts in the wafer carrier with at least one further robotic arm; and inspecting the one or more replacement parts with at least one optical device.In another embodiment, if the one or more spare parts pass the inspection, the method further comprises returning the wafer carrier to a semiconductor processing tool using the OHT loop.

[0068] In another exemplary aspect, the present invention is directed to an apparatus. The apparatus includes: an input port for receiving a wafer carrier; a reservoir for holding a plurality of new air filters; a first mechanism for removing an air filter from the wafer carrier; a second mechanism for receiving a new air filter from the reservoir; a third mechanism for installing the new air filter in the wafer carrier; and an output port for returning the wafer carrier after the new air filter has been installed.

[0069] In one embodiment, the apparatus further comprises a rotating device for rotating the wafer carrier. In another embodiment, the apparatus further comprises a fourth mechanism for removing the housing from the wafer carrier to expose the air filter, wherein the fourth mechanism is configured to reinstall the housing after the new air filter has been installed.

[0070] In one embodiment, the apparatus further comprises a first inspection mechanism for inspecting the new air filter prior to its installation in the wafer carrier. In one embodiment, the apparatus further comprises a disposal container for receiving the air filter after its removal from the wafer carrier. In yet another embodiment, the apparatus further comprises a second inspection mechanism for inspecting the new air filter after its installation in the wafer carrier.

[0071] In yet another exemplary aspect, the present invention is directed to a system. The system includes: a plurality of semiconductor processing tools; a wafer carrier; a wafer carrier rinsing station; a wafer carrier exchange station; a wafer carrier repair station; and an overhead transfer (OHT) system for transporting the wafer carrier between the semiconductor processing tools, the wafer carrier rinsing station, the wafer carrier exchange station, and the wafer carrier repair station.

[0072] In one embodiment of the system, one of the plurality of semiconductor processing tools is configured to receive the wafer carrier having a plurality of wafers using the OHT system; process the plurality of wafers to produce a plurality of processed wafers; and, using the OHT system, transfer the plurality of processed wafers to the wafer carrier to be sent to the wafer carrier rinse station.

[0073] In another embodiment, the wafer carrier purge station is configured to receive the wafer carrier having multiple wafers using the OHT system; introduce a purge gas into the wafer carrier; and monitor an exhaust gas from the wafer carrier. In a further embodiment, the wafer carrier purge station is configured to monitor the exhaust gas to determine at least one of the following factors: humidity of the exhaust gas; gas flow rate of the exhaust gas; particle number in the exhaust gas; and particle sizes in the exhaust gas. In a further embodiment, the wafer carrier purge station is further configured to monitor an air pressure within the wafer carrier. In yet another embodiment, the wafer carrier purge station is further configured to determine whether the wafer carrier requires repair.

[0074] In one embodiment of the system, the wafer carrier exchange station is configured to receive the wafer carrier with multiple wafers using the OHT system; place the multiple wafers from the wafer carrier into another wafer carrier; and transfer the wafer carrier without a wafer to the wafer carrier repair station using the OHT system. In another embodiment, the wafer carrier repair station is configured to receive the wafer carrier without a wafer using the OHT system; remove a housing from the wafer carrier to expose an air filter; replace the air filter with a new air filter; reinstall the housing in the wafer carrier; and return the wafer carrier with the new air filter using the OHT system.

Claims

[1] Procedure with the following steps: Receiving (202) a carrier (22) having a plurality of wafers therein; Supplying (204) a purge gas to an inlet (46) of the carrier (22); Discharging (206) an exhaust gas from an outlet (48) of the carrier (22); and generating (210) a condition indicator of the carrier (22) during the supply of the purge gas and the discharge of the exhaust gas, wherein the carrier has at least one air filter (32, 26) and the condition indicator indicates whether the air filter needs to be replaced; wherein the method further comprises, in the event that the condition indicator indicates that the air filter needs to be replaced: Receiving the carrier (22) by a carrier repair station (18); and Automatic replacement of the air filter with a new air filter. [2] The method of claim 1, wherein generating the condition indicator is based on one or more of the following measurements: (a) a measurement of an air pressure in the carrier (22); (b) a measurement of a humidity of the exhaust gas; (c) a measurement of a flow rate of the exhaust gas; and (d) a measurement of particulates in the exhaust gas. [3] The method of claim 1 or 2, wherein generating the status indicator comprises: Reading an air pressure value measured by a pressure sensor installed in the carrier (22); Comparing the air pressure value with a specified air pressure range; and Indicate that the carrier (22) needs to be repaired if the air pressure value is outside the specified air pressure range. [4] A method according to any one of the preceding claims, wherein generating the status indicator comprises: Reading a humidity value of the exhaust gas measured by a humidity sensor (62) installed adjacent to the outlet of the carrier (22); Comparing the humidity value with a specified humidity range; and Indicate that the carrier (22) needs to be repaired if the humidity value is outside the specified humidity range. [5] A method according to any one of the preceding claims, wherein generating the condition indicator comprises; Measuring the exhaust gas flow rate; Comparing the throughput with a predetermined throughput range; and indicating that the carrier (22) needs to be repaired if the throughput is outside the predetermined throughput range. [6] A method according to any one of the preceding claims, wherein generating the status indicator comprises: Measuring sizes of particles carried in the exhaust gas; Comparing the sizes with a size threshold; and Indicating that the carrier (22) needs to be repaired if one of the sizes exceeds the size threshold. [7] A method according to any one of the preceding claims, wherein generating the status indicator comprises: Measuring a number of particles carried in the exhaust gas; Comparing the number with a number threshold; and Indicate that the carrier (22) needs to be repaired if the number exceeds the number threshold. [8] A method according to any one of claims 3 to 7, wherein, in the event that the condition indicator indicates that the carrier (22) needs to be repaired, the method further comprises: Removing the plurality of wafers from the carrier (22); and Transporting the carrier (22) to the carrier repair station by means of an overhead transport device. [9] The method of claim 8, further comprising: replacing, by means of a first motor-driven device, an inlet filter (32) at the inlet of the carrier (22) with a new inlet filter; Replacing, by means of a second motor-driven device, an outlet filter (36) at the outlet of the carrier (22) with a new outlet filter; and Checking the new inlet filter and the new outlet filter using a third motor-driven device. [10] The method of claim 9, further comprising, if both the new inlet filter and the new outlet filter pass the inspection, conveying the carrier (22) with the new inlet filter and the new outlet filter via the overhead conveyor to a processing facility. [11] A method according to claim 9 or 10, further comprising, in the event that the new inlet filter or the new outlet filter fails the inspection: Replacing the new inlet filter or the new outlet filter with a replacement filter; and Check the replacement filter. [12] Apparatus for semiconductor production comprising: an inlet opening (80) for receiving a carrier (22), the carrier comprising a carrier body, a housing mounted on the carrier body, and a filter installed between the carrier body and the housing; a first robot arm (86) for disassembling the housing from the carrier (22) and for mounting the housing into the carrier (22); one or more second robot arms (90) for removing the filter from the carrier (22) and for installing a new filter in the carrier (22); and an exit opening (82) for returning the carrier (22) to production. [13] The apparatus of claim 12, wherein the one or more second robotic arms (90) are further configured to insert and remove an O-ring between the filter and the housing. [14] The apparatus of claim 12 or 13, further comprising a first control mechanism for controlling the new filter prior to its installation with the one or more second robot arms. [15] The apparatus of claim 14, wherein the first control mechanism comprises: a camera for taking an image of the new filter; and a control device to determine the quality of the new filter based on the image. [16] Apparatus according to any one of claims 12 to 15, further comprising a second control mechanism for controlling the new filter after its installation with the one or more second robot arms (90). [17] The apparatus of claim 16, wherein the second control mechanism comprises a laser mechanism for detecting the flatness of a surface of the new filter. [18] System with: several semiconductor processing plants (12); a carrier rinsing station (14); a carrier repair station (18); and an overhead transport loop (20) for transporting one or more substrate carriers (22) between the plurality of semiconductor processing systems (12), the carrier rinsing station (14) and the carrier repair station (18), where the carrier purge station (14) is configured to receive a substrate carrier (22) from one of the plurality of semiconductor processing systems (12), purge the substrate carrier (22) with an inert gas, and determine whether the substrate carrier (22) needs to be repaired, and the carrier repair station (18) is configured to receive a substrate carrier (22) to be repaired and to replace one or more parts in the substrate carrier (22). [19] The system of claim 18, further comprising a carrier changing station (16) configured to receive a substrate carrier (22) with substrates, remove the substrates from the substrate carrier (22), and place the substrates into another substrate carrier. [20] The system of claim 18 or 19, wherein the carrier rinsing station (14) is configured to determine whether the substrate carrier (22) needs to be repaired based on at least one of the following factors: whether the one or more parts in the substrate carrier (22) have reached their respective service life; measuring an air pressure in the substrate carrier (22) while the substrate carrier is being rinsed; a measurement of an exhaust gas humidity while the substrate carrier (22) is being rinsed; a measurement of an exhaust gas flow rate while the substrate carrier (22) is being purged; and measuring particles in the exhaust gas while the substrate carrier (22) is purged.

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