JP7525169B2 - Hybrid system architecture for thin film deposition - Google Patents

Description

Related Technology
This application is a continuation-in-part of U.S. Application No. 16/583,165, filed September 25, 2019, the disclosure of which is incorporated herein by reference in its entirety. This application also claims the benefit of priority to U.S. Provisional Application No. 62/781,577, filed December 18, 2018, the disclosure of which is incorporated herein by reference in its entirety.
(Technical field)
TECHNICAL FIELD This disclosure relates generally to the field of substrate processing, such as thin film coating of substrates, particularly semiconductor wafers.

Vacuum processing of substrates is well known in the art and is sometimes referred to as thin film processing. Generally, thin film processing systems can be categorized into one of three architectures: batch processing, cluster systems, and in-line systems. The advantages and disadvantages of each of these architectures are well known in the art.

In some system architectures, particularly those used to manufacture microchips using semiconductor wafers, substrates are individually transported by a robotic arm into the processing chamber and placed on a stationary chuck or susceptor. In contrast, in other systems, such as those used to manufacture hard disk drives or solar cells, substrates are transported and processed while placed on a transportable substrate carrier.

There is a need in the art for improved system architectures that can be used to form thin films on a variety of substrate types. Additionally, there is a need in the art for apparatus that can form thin film coatings at high throughput and at commercially acceptable costs.

The following summary of the disclosure is included to provide a basic understanding of some aspects and embodiments of the invention. This summary is not an extensive overview of the invention, and thus is not intended to particularly identify key or critical elements of the invention or to delineate the scope of the invention. Its sole purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented below.

The disclosed embodiments provide a system specifically designed to produce improved thin film coatings in high volume and at acceptable commercial costs. The disclosed system is particularly useful for forming multiple thin films of different compositions on a semiconductor wafer, such as in the fabrication of magnetoresistive random-access memory (MRAM).

In an MRAM cell, data is stored by magnetic memory elements. Each element consists of two ferromagnetic plates separated by a thin insulating layer. One of the plates, called the reference layer, is a permanent magnet set to a specific polarity. The other plate is a free plate whose magnetization state can be changed to match an externally applied magnetization to store a memory bit. This configuration, known as a magnetic tunnel junction, is the simplest structure for an MRAM bit. An MRAM memory chip is built from a grid of such "cells." In reality, each ferromagnetic plate is made up of many thin layers of different material compositions, somewhat similar to the structure of a hard disk.

The disclosed embodiments address two key elements of a vacuum processing system suitable for rapid deposition of thin film layers: the vacuum system architecture and the wafer loading system architecture. The architecture is designed to solve various challenges associated with sputtering thin films of magnetic materials onto circular silicon wafers, including avoiding water vapor from reaching the layer, avoiding particle contamination, and avoiding wafer misalignment and breakage.

In the disclosed embodiment, the vacuum enclosure has a number of process chambers attached thereto. During processing, the carriers move continuously in unison within the vacuum enclosure and are processed by the process chambers. A load lock is attached to the vacuum enclosure and may have a load side and an unload side, which may share a vacuum environment or may have separate vacuum environments. A gate valve separates the load lock from the vacuum enclosure. A track exchanger is disposed within the vacuum enclosure. The track exchanger is movable between a first position, in which the carriers move continuously within the vacuum enclosure, and a second position for moving the carriers between the vacuum enclosure and the load lock.

According to a general aspect, a processing system is provided. The processing system includes a vacuum enclosure, a plurality of processing chambers attached to a side wall of the vacuum enclosure, a transfer chamber coupled to a loading end of the vacuum enclosure via a first gate valve and having a transfer track therein, a load lock coupled to the transfer chamber via a second gate valve, having a third gate valve at an entrance side and having a transfer track therein, a wafer holding module attached to a side wall of the load lock and having a wafer holder that holds a substrate in a vertical or near-vertical position in the load lock, a multi-joint robot arm having an end effector attached to a distal end of the multi-joint robot arm via a rotatable wrist, the multi-joint robot arm being positioned outside the load lock and reachable to horizontally remove a substrate from a FOUP, and rotating the substrate to a vertical or near-vertical position to place the substrate on the wafer holder, and a plurality of substrate carriers moving on the transfer track to exchange substrates with the wafer holding module.

The system may include a turntable having a linear track portion thereon. The turntable may be rotatable to transfer the substrate carrier from an unloading position to a loading position, or from one transfer track to another. The turntable may be located in a vacuum enclosure or a load lock, and may include motorized wheels.

The system may include a racetrack-shaped monorail disposed within the vacuum enclosure, an endless belt disposed within the vacuum enclosure and engaging each carrier that moves freely on the racetrack-shaped monorail, and a track exchanger disposed at one end of the racetrack-shaped monorail and transporting each carrier between the racetrack-shaped monorail and the transport track.

Each of the substrate carriers may include a wafer holder and/or an electrostatic chuck arranged in a substantially vertical position.

The system may include a turntable disposed at an end of the vacuum enclosure opposite the loading end, a racetrack-shaped monorail disposed within the vacuum enclosure, an endless belt disposed within the vacuum enclosure and engaging each carrier moving freely on the racetrack-shaped monorail, a track exchanger disposed at one end of the racetrack-shaped monorail and transporting each carrier between the racetrack-shaped monorail and the turntable, and at least one second processing system attached to the end of the vacuum enclosure. The endless belt may include a plurality of driving forks, and each of the substrate carriers may include a plurality of freely rotating wheels configured to engage the racetrack-shaped monorail and a drive pin configured to engage the driving fork. The turntable may include a linear track portion and a motorized wheel, and each of the substrate carriers may include a drive bar that engages the motorized wheel.

The system may further include a second transfer chamber coupled to the loading end of the vacuum enclosure and a second load lock coupled to the second transfer chamber. The system further transports the carrier from the second load lock to the load lock or from the second transfer chamber to the transfer chamber. The transport mechanism may include at least one track changer having a movable table, a linear monorail section disposed on the table, and a curved monorail section disposed on the table, and may further include a turntable having a linear track section thereon. The system may also include a monorail disposed within the vacuum enclosure, the monorail being configured with a first monorail section shaped like a racetrack and a second monorail section having two parallel linear monorail extensions, a motive element disposed on the first monorail section, and a plurality of motorized wheels disposed along the second monorail section, and the track changer may be adapted to transport each carrier between the first monorail section and the second monorail section. Each of the plurality of carriers may include a base, an engagement mechanism attached to the base and configured to engage with the motive element to move the carrier while it is on the first monorail section, and a drive bar attached to the base and configured to engage with a plurality of motorized wheels to move the carrier traveling on the second monorail section.

According to yet another aspect, a processing system is provided that includes a vacuum enclosure having a plurality of processing windows and a continuous track disposed therein, a plurality of processing chambers attached to a side wall of the vacuum enclosure, each of which corresponds to one of the processing windows, a load lock attached to one end of the vacuum enclosure and having a loading track disposed therein, at least one gate valve isolating the load lock from the vacuum enclosure, a plurality of substrate carriers configured to move on the continuous track and the loading track, and at least one track exchanger disposed inside the vacuum enclosure and movable between a first position for continuously moving the substrate carrier on the continuous track and a second position for transferring the substrate carrier between the continuous track and the loading track.

In yet another aspect,
a load lock portion having a first side and a second side opposite the first side;
an atmospheric section coupled to a first side of the load lock section;
a vacuum section attached to a second side of the load lock section and having a plurality of processing chambers attached thereto;
A carrier transport mechanism including the following (i) to (iv);
(i) a first monorail section having a racetrack configuration and disposed within the vacuum section; a second monorail section disposed within the load lock section and having two parallel straight monorails with extensions extending into the atmospheric section and the vacuum section; and a third monorail section disposed in the atmospheric section and having a curved configuration with one end corresponding to the extension of one of the straight monorails and the other end corresponding to the extension of the other of the straight monorails.
(ii) a motive element disposed on said race track;
(iii) a plurality of motorized wheels disposed along the second monorail section;
(iv) two track exchangers disposed at one end of the first monorail section, each including a movable table, a straight monorail section disposed on the table, and a curved monorail section disposed on the table; and a plurality of carriers having a plurality of wheels and configured to engage with the monorail so that the carriers move along the monorail.

In one embodiment, the system includes a load lock unit having a first side and a second side opposite to the first side, an atmospheric section attached to the first side of the load lock unit, a vacuum section attached to the second side of the load lock unit and having a plurality of processing chambers attached thereto, and a carrier transport mechanism including:
(i) a first monorail section having a racetrack configuration and disposed within the vacuum section; a second monorail section disposed within the load lock section and having two parallel straight monorails with extensions extending into the atmospheric section and the vacuum section; and a third monorail section disposed in the atmospheric section and having a curved configuration with one end corresponding to the extension of one of the straight monorails and the other end corresponding to the extension of the other of the straight monorails.
(ii) an endless belt disposed on the racetrack and having a plurality of drive forks attached thereto;
(iii) a driving wheel disposed in the atmospheric section and having a plurality of drive forks attached thereto;
(iv) a plurality of motorized wheels disposed along the second monorail section;
(v) two track exchangers disposed at one end of the first monorail section, each including a movable table, a linear monorail section disposed on the table, and a curved monorail section disposed on the table; a base, a plurality of wheels attached to the base and configured to engage with the monorail so that the carriers move freely on the monorail, a drive bar attached to the base and configured to engage with the plurality of motorized wheels to move the carriers traveling on the second monorail section, and a drive pin attached to the base and configured to engage with the driving fork to move the carriers on the first monorail section or the third monorail section, wherein when the track exchanger is in a first position, the curved monorail section is aligned with the first monorail section and the carriers are moved continuously along the first monorail section by the driving fork, and when the track exchanger is in a second position, the linear monorail section connects the first monorail section to the second monorail section, and the carriers are exchanged between the load lock section and the vacuum section.

Other aspects and features of the present invention will become apparent from the following detailed description taken in conjunction with the drawings. It should be understood that the detailed description and drawings provide non-limiting examples of various embodiments of the invention as defined by the appended claims.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain and illustrate the principles of the invention. The drawings are intended to diagrammatically illustrate major features of exemplary embodiments. The drawings are not intended to depict every feature of an actual embodiment, nor are they intended to depict relative dimensions of the illustrated elements or to draw them to scale.
1, 1A, and 1B illustrate an embodiment of a modular system for forming thin film coatings using a dual-motion carrier. FIG. 2A shows one embodiment of a dual-motion substrate carrier, and FIG. 2B shows a substrate holder for a circular substrate. 3A-3B show an embodiment of an architecture configured for processing semiconductor wafers, and FIG. 3C shows an embodiment for mounting a processing module at one end of the system.

Now, the embodiments of the system for producing thin film coatings and the wafer loading system thereof according to the present invention will be described with reference to the drawings. Various embodiments or combinations thereof can be used in various applications and to obtain various advantages. The various features disclosed herein can be used partially or to the fullest extent, alone or in combination with other features, and in a balance of advantages and requirements and limitations, depending on the results to be achieved. Thus, even if a particular advantage is emphasized with reference to various embodiments, the advantage is not limited to the disclosed embodiment. That is, each feature disclosed herein is not limited to the embodiment in which it is described, but may be "combined or aligned" with other features or incorporated into other embodiments.

The disclosed embodiments describe two key elements of a vacuum processing system suitable for rapid deposition of thin film layers: the vacuum system architecture and the wafer loading system architecture. The disclosure below begins with a description of the vacuum processing system and then moves to a description of the loading system.

The disclosed embodiments provide a system architecture that allows continuous processing of substrates in a continuous pass processor using a first mode of carrier motion, and a mechanism for transporting carriers out of the continuous pass processor using a second mode of carrier motion. In both carrier motion modes, the carriers move freely along the track, but the driving force applied to the carriers to move them along the track varies from carrier motion mode to carrier motion mode. All carriers move in unison within the continuous pass processor, but when exiting the continuous pass processor, each carrier may move independently.

The first embodiment will now be described with reference to FIG. 1 in conjunction with FIGS. 2A and 2B, with FIG. 2B being specific to the processing of semiconductor wafers. FIG. 1 is a top schematic view of the system, FIG. 2A shows the carrier, and FIG. 2B shows a replacement substrate holder for the carrier of FIG. 2A.

The system 100 of FIG. 1 is comprised of an atmospheric section 105, a load lock section 110, and a vacuum section 115. Each carrier is loaded or unloaded in the atmospheric section 105 and transferred between the atmospheric section 105 and the vacuum section 115 via the load lock section 110. The substrates are processed in the vacuum section 115 forming a continuous pass-through processing section. Although four processing chambers 120A-120D are shown in this example, any number of processing chambers can be provided, as further described below. The illustrated processing chambers 120A-120D can be etching chambers, sputtering chambers, ion implantation chambers, etc., and in this embodiment, each processing chamber is connected to a common vacuum atmosphere without providing a valve gate between them, allowing pass-through processing. In MRAM manufacturing, the chamber can be a magnetron sputtering chamber with targets of various materials, such as cobalt (Co), tantalum (Ta), platinum (Pt), ruthenium (Ru), and alloys such as cobalt-iron-boron (CoFeB), to form the magnetic layers.

Monorail segments 125 are provided in the three components 105, 110, and 115 to allow substrate carriers to traverse all three components. The monorail segments form a racetrack monorail 127 in the continuous pass processing section 115, linear tracks 128A and 128B that traverse the load lock section 110 and extend partially between the atmospheric section and the vacuum section, and a rotating track 129 that curves into a crescent shape in the atmospheric section 105. An endless belt 130 is provided from a rotating drum 131A to a rotating drum 131B in the continuous pass processing section 115, and a plurality of driving forks 132 are attached to the endless belt 130. A plurality of electrically conductive wheels 135 are provided adjacent to the linear track, and a rotating wheel 137 with a plurality of driving forks 132 is provided in the atmospheric section 105.

Two track exchangers 140 are provided in the continuous pass processing section 115, and are shown in an enlarged view in the callouts. The track exchanger includes a table 141 provided with a curved track segment 142 and a straight track segment 144. As shown by the double arrow in FIG. 1, the track exchanger is movable to one of two positions. In one position, the curved track segment completes the racetrack 127 so that the carriers in the vacuum section move continuously along the racetrack to continuously process the substrates through the chambers 120A-120D. Once processing of the substrates in the vacuum chambers is completed, the track exchanger moves to a second position, where the straight track forms a connection between the straight tracks 128A and 128B and the straight portion of the racetrack 127 so that the carriers in the vacuum chambers exit the load locks and the carriers in the load locks enter the vacuum section.

2A shows an embodiment of a substrate carrier 150. In this embodiment, the carrier 150 has a base 152 and a substrate holder 154. The substrate holder 154 is detachable from the base so that substrates of different shapes and numbers can be processed. For example, the holder 154 shown in FIG. 2A holds three tiers of square or rectangular substrates, while the holder 154' shown in FIG. 2B holds circular substrates such as semiconductor wafers. In one embodiment advantageous for MRAM manufacturing, the holder 154' includes an electrostatic chuck 157. Alternatively or additionally, the holder 154' may include optional support pins 159 that engage the periphery of the wafer. The plane of the holder is also inclined at an angle θ to the horizontal. In this example, the angle is 15 degrees.

As shown in FIG. 2A, the base 152 includes a roller mechanism 153 that engages and propels the monorail 125. The roller mechanism may be non-motorized and may include a number of freely rotating wheels that allow the base to freely propel on the monorail. Motive power may be provided by either the wheels 135 engaging the drive bar 156 or the forks 132 engaging the drive pins 158.

An example of a typical process performed by the system 100 is now described. An empty carrier is driven to the loading station 160, where the roller mechanism 153 engages the linear track 128A and the motorized wheels 135 engage the drive bar 156. A new substrate is then loaded onto the substrate holder 154. Meanwhile, a processed substrate can be removed from another carrier located at the unloading station 161. Once loading and unloading is complete, the inlet gate valve EN of the load lock in the loading section 160 opens. If appropriate, the outlet gate valve EX of the load lock in the unloading section 161 also opens. The outlet gate valve of the loading load lock remains closed. Also, when the outlet gate valve of the unloading section opens, its inlet gate valve closes. In some embodiments, the two load locks are independent, as illustrated by the dashed partition 170, so that each can maintain a vacuum independently of the other. In this configuration, a processed carrier can be loaded from the vacuum section into the unloading load lock 161 while a new carrier is being loaded into the loading load lock. Note that the inlet and outlet gate valves have the same structure and are identified by the direction of carrier travel. That is, if the direction of travel is reversed, the designations of the inlet and outlet valves are also reversed.

In this condition, the motorized wheels 135 are energized to transport the carriers in the loading station to their respective load locks, while the carriers in the other load locks can be moved to the atmospheric section 105 and/or the processed carriers can be moved to the unloading load lock. Note, however, that these operations do not necessarily have to be performed simultaneously. If desired, loading can be performed with a time lag, in which case the motorized wheels of the unloading section are not energized and only the inlet gate valve for the carrier with the new substrate is opened to move the carrier to the load lock. In other words, the motorized wheels of the linear track section can be energized independently, or can be energized collectively, with only some of the motorized wheels being energized. Also, if each load lock is independent, i.e. has an independent dedicated pump mechanism, the various gate valves can be energized independently, and therefore there is no need to synchronize loading and unloading. Of course, synchronous processing is beneficial in terms of work efficiency.

In embodiments in which the load locks maintain a common vacuum atmosphere and are commonly pumped, e.g., in embodiments without partition 170, the gate valves operate synchronously. For example, gate valve EN of the loading load lock operates together with gate valve EX of the unloading load lock, and gate valve EX of the loading load lock operates together with gate valve EN of the unloading load lock.

As the carrier enters the load lock, the inlet gate valve is closed and a vacuum is applied. When the processed carrier is removed from the exit load lock, it is also pumped to vacuum. Once the appropriate vacuum is reached, the loading load lock's exit gate valve EX opens and the appropriate motorized wheels are energized to move the carrier to the vacuum section 115. The track exchanger 140 then moves to a position where the straight track section 144 is aligned with the straight section of the racetrack monorail 127. The wheels are then energized to move the carrier to the vacuum section, causing the carrier to enter the racetrack circuit and one of the driving forks to engage the drive pin 158. The track exchanger 140 then moves to a position where the curved track section 142 is aligned with the straight section of the racetrack monorail 127. In this position, the carrier is moved by the endless belt 130 rather than the motorized wheels 135. In this state, as the endless belt rotates, the carrier moves along the racetrack as many times as necessary until it is ready to leave the processing section. Thus, the substrates on the carrier can be repeatedly processed by each of chambers 120A-120D as many times as necessary.

Once processing is complete, the unloading section's track exchanger 140 is moved to a position where the straight track section 144 is aligned with the straight section of the racetrack monorail 127. As the endless belt continues to rotate, the carrier moves into the track exchanger and disengages from the prime mover fork while the drive bar 156 engages the motorized wheel 135. The motorized wheel is then energized to move the carrier out of the racetrack circuit.

As can be seen, in the described embodiment, the carrier has two operating modes, engaging with motorized wheels within the linear track and with driving forks within the race track and the air return circuit ARC. The forks in the race track are attached to an endless belt, and the forks in the air return circuit are attached to a driving wheel. And the track exchanger is used to guide the carrier to and from the race track. With the track exchanger in the first position, the carrier can be driven infinitely around the race track, and with the track exchanger in the second position, the carrier can be guided to and from the race track.

As mentioned above, the system can be scaled to include any number of processing chambers as required. An example is shown in FIG. 1A. The example shown in FIG. 1A is similar to the example shown in FIG. 1, and like elements are numbered the same. The main difference is that this example includes six processing chambers 120A-120F. All other elements may be identical to those in FIG. 1, illustrating the versatility of the architecture.

Figure 1B shows an external view of an embodiment having six processing chambers, from which processing chambers 120A-120C are visible. In this configuration, the system still consists of three components: atmospheric section 105, load lock 110, and vacuum section 115, which includes vacuum enclosure 163 in which the processing chambers are mounted. This view shows service access windows 166, 167, and 168 open to allow visualization of the interior of the vacuum enclosure. For example, rotating drums 311A and 311B are visible through service access windows 166 and 168, respectively. A portion of racetrack monorail 127 and endless belt 130 can be seen through service access window 167.

In this example, chamber 120B is shown open to allow easy access to the interior of the process chamber and vacuum enclosure through process window 172. Specifically, in this example, process chambers 120A-120C are attached to vacuum enclosure 163 via rotatable hinges 170 (hidden in FIG. 1B but visible in FIG. 1A). When chamber 120B rotates on its hinge, the interior of vacuum enclosure 163 is exposed, revealing carrier 150 with four substrates.

The architecture disclosed thus far provides a processing system having an atmospheric section 105, a load lock section 110, and a vacuum section 115 to which a number of processing chambers 120 are attached. The carrier transport mechanism includes a first monorail section 127 arranged in the vacuum section in a racetrack configuration, a second monorail section arranged in the load lock section and having two parallel linear monorails 128A and 128B with extensions extending into the atmospheric section and the vacuum section, a curved third monorail section arranged in the atmospheric section and having a crescent-shaped rotating track 129 with one end corresponding to the extension of one of the linear monorails and the other end corresponding to the extension of the other of the linear monorails, and a carrier transport mechanism for the racetrack. The system includes an endless belt 130 arranged in the rack and having multiple drive forks 32 attached thereto, a driving wheel 137 arranged in the atmospheric section and having multiple drive forks 132 attached thereto, multiple motorized wheels 135 arranged along the second monorail section, and two track exchangers 140 arranged at one end of the first monorail section, each track exchanger 140 having a movable table 141, a straight monorail section 144 arranged on the table, and a curved monorail section 142 arranged on the table.

A plurality of carriers support substrates to be processed, each carrier having a base 152, a plurality of free-rotating wheels 153 attached to the base and configured to engage the monorail to move the carrier freely on the monorail, a plurality of drive bars 156 attached to the base and configured to engage the motorized wheels 135 to move the carrier while it is on the second monorail section, and a drive pin 158 attached to the base and configured to engage the driving fork 132 to move the carrier while it is on the first monorail section or the third monorail section.

When the track exchanger is in a first position, the curved monorail section is aligned with the first monorail section, and the driving fork moves the carrier continuously along the first monorail section, and when the track exchanger is in a second position, the straight monorail section connects the first monorail section to the second monorail section, and exchanges the carrier between the load lock section and the vacuum section.

A method for processing a substrate in a disclosed processing system may include loading the substrate onto a carrier, transporting the carrier to a load lock via a transport track, drawing a vacuum in the load lock, transporting the carrier on the transport track to a processing enclosure having a plurality of processing chambers attached thereto, manipulating a track exchanger to a first position, thereby forming a connection between the transport track and a processing track, moving the carrier on the track exchanger and from there to a processing track in the processing enclosure, manipulating the track exchanger to a second position, thereby isolating the processing track from the processing track, continuously moving the carrier on the processing track while energizing the processing chambers, and, after processing is completed, manipulating the track exchanger to the first position, thereby transporting the carrier from the processing track to the transport track. A method for continuously moving the carrier may include, for example, a method in which a plurality of carriers are connected to an endless belt and the plurality of carriers are moved simultaneously and continuously.

The general architecture of the system described thus far can be used to process a variety of substrates. However, for processing semiconductor wafers, such as for the manufacture of MRAM, it is desirable to reconfigure the system so that it can be easily adapted for use in a wafer fabrication facility, commonly referred to as a fab. In the fab, wafers are transported in Front Opening Universal Pods (FOUPs), specially designed enclosures for holding multiple wafers. The following disclosure provides mechanisms that allow wafers to be transported from the FOUP to the processing system described herein.

Figure 3A shows an embodiment configured for processing semiconductor wafers. This embodiment is particularly useful for creating magnetic layers for MRAM on silicon wafers, but may also be used to fabricate other devices on standard circular silicon wafers. It is worthwhile to specifically discuss three potential difficulties in creating thin layers on circular silicon wafers and how these difficulties are addressed by embodiments of the present disclosure.

The quality of the magnetic layer after manufacture is very sensitive to contamination, especially water vapor. Therefore, the disclosed embodiment is designed so that no part of the wafer transport mechanism in the system leaves the vacuum environment. This prevents the carrier from being contaminated by the air environment. Also, the formation of the magnetic layer requires sputtering, which is a concern for particle contamination, but the wafer moves in a substantially vertical position in the present system, reducing the possibility of particle contamination. Since the wafer is round and can only be held by its periphery, if the wafer is held in a vertical position in the present system, it is likely to come off the carrier, which is dangerous. Therefore, in the system according to the disclosed embodiment, the wafer is held in a carrier in a substantially vertical position. In the disclosed embodiment, a substantially vertical position refers to the wafer being held at an angle of 5 to 20 degrees from vertical, which reduces the possibility of contamination and also reduces the possibility of the wafer falling off the carrier.

In FIG. 3A, elements similar to those in FIGS. 1-1B are identified by the same numbers. Also, the continuous pass processor, designated Vac115, is similar to that in FIGS. 1-1B. However, the arrangement for loading wafers into the vacuum environment of the continuous pass processor 115 is different.

Thus, within the continuous pass processing section 115, the wafers move in a generally vertical position. However, the FOUPs within the fab house the wafers in a horizontal position. Therefore, in addition to introducing the wafer into the vacuum environment of the processing system, it is also necessary to rotate the wafer to a generally vertical position. These objectives are achieved as follows.

Wafers are removed from or replenished in the FOUP 300 by a robot 312. In the disclosed embodiment, the robot 312 is a Selective Compliance Assembly Robot Arm (SCARA) robot having an end effector 314 coupled to the robot arm via a rotating wrist 316. The rotating wrist 316 allows the end effector 314 to rotate the wafer from a horizontal to a vertical position. The term end effector is used herein in its commonly accepted sense, i.e., the last link of the robot arm that interacts with the workpiece, in this case the wafer. While conventional end effectors may be used, in the disclosed embodiment, the end effector can be contact (physically gripping the wafer by its periphery) or attraction (holding the wafer by applying a vacuum or magnetic/electrical attraction to the backside of the wafer).

The end effector then assumes a horizontal position to remove a wafer from the FOUP 300 to load a new wafer into the system. The SCARA robot rotates, rotating the wrist 316 so that the wafer assumes a vertical or near-vertical position, i.e., 0-20 degrees from vertical. When the gate valve IN is opened, the robot places the wafer on the wafer-holding module 302 in the load lock/exchange chamber LL/EX 305. The wafer is placed on the wafer holder 304 of the wafer-holding module 302 in a vertical or near-vertical position, i.e., 0-20 degrees from vertical. The robot 312 then retracts and the gate valve IN is closed. This allows the load lock/exchange chamber LL/EX 305 to be evacuated. Once evacuated, the transport carrier 150 moves to a loading position in the load lock/exchange chamber LL/EX 305, and the wafer moves from the wafer holder 304 onto the transport carrier 150.

As previously mentioned, in some embodiments, the carrier 150 has a substrate holder 154' that includes an electrostatic chuck 157. In such embodiments, the method proceeds by actuating the end effector such that the wafer is placed on the wafer holder 304 with the device side of the wafer facing the wafer holder 304 and the backside of the wafer facing away from the holder 304. The electrostatic chuck is then energized as the carrier enters the load lock 305, and the wafer is attracted to the substrate holder 154' on its backside.

In this embodiment, the wafer holding module 302 has a telescoping wafer holder 304 that moves horizontally between a first position and a second position, i.e., an extended position and a retracted position. One position is used to exchange wafers to and from the robot 312, and the other position is used to exchange wafers to and from the carrier 150. Also, one position is used to receive wafers (from the robot to load a new substrate or from the carrier to unload a processed substrate) and the other position is used to deliver wafers (to the carrier to load a new substrate or to the robot to unload a processed substrate).

The carrier 150 can be moved to the loading position in the load lock 305 from a variety of locations and in a variety of ways and routes, depending on the particular architecture used. In the example shown in FIG. 3A, the carrier 150 is moved to the loading position by rotation of the turntable 322. In another example, as will be described with respect to FIG. 3B, the transport carrier 150 is moved from the transfer chamber TR 310 to the loading position of the load lock/exchange chamber LL/EX 305. Conversely, in another example, the transport carrier 150 is moved to the loading position without the use of a turntable, as will be described with respect to FIG. 3C.

Turntable 322 includes linear track portion 321 to allow carriers to move on and off linear tracks 128A and 128B. Turntable 322 may also have motorized wheels similar to wheels 135 to provide efficient linear movement of carriers on linear track portion 321.

After the transport carrier 150 is loaded with a new wafer, the carrier 150 moves into the transfer chamber 310 and gate valve EN can be closed for another loading cycle. After gate valve EN is closed, gate valve EX can be opened and the transport carrier 150 enters the continuous pass processing section 115. Processing of the wafer then proceeds as described above for any of the disclosed embodiments, with the carrier entering the racetrack monorail and moving along the racetrack circuit until the required number of passes have been made.

Of course, unloading is the reverse operation. After the carrier with the processed wafer enters the transfer chamber 310, it moves to the unload position on the turntable 322, where the wafer is loaded onto the wafer holder 304. The empty carrier then moves to the loading position to receive a new wafer. Meanwhile, the SCARA robot is used to remove the wafer from the wafer holder 304 and place it in the FOUP 300.

Thus, a wafer loading system is disclosed that includes a robot arm with an end effector connected via a rotating wrist, a load lock chamber having a wafer holding module for actuating a wafer holder, a transfer chamber for cushioning the load lock chamber, a gate valve disposed between the load lock chamber and the transfer chamber, a track passing through the load lock chamber and the transfer chamber, and a wafer carrier configured to travel on the track and exchange a wafer between the wafer holder and the load lock chamber. The wafer loading system may also include a turntable, on which a track portion for receiving the carrier may be disposed. The turntable may further include a motorized wheel for moving the carrier on a linear track portion. The carrier may be configured to travel freely on the track or may be configured to be transported by the motorized wheel. The carrier may further include an electrostatic chuck.

To transfer the transport carrier from the unload position to the load position, the transport carrier can simply be returned from the unload position to the continuous pass processing section 115, and the endless belt 130 can be used to move the carrier along the racetrack and out to the loading station. However, in the disclosed embodiment, such a transfer process is avoided, for example, by using a turntable 322. In the embodiment of FIG. 3A, the turntable 322 is located in the load lock chamber. However, the turntable 322 may be located in other chambers in the system or eliminated entirely, as described below.

Figure 3B shows another embodiment configured for processing semiconductor wafers. The embodiment of Figure 3B is similar to the embodiment of Figure 3A, except that the turntable 322 is located outside the load lock chamber and the transfer chamber. In this example, the turntable is located between the transfer chamber 310 and the processing section 115, i.e., between the transfer chamber and the racetrack section. In another embodiment (not shown), the turntable 322 may be located, for example, within the transfer chamber TR310.

Thus, the wafer loading system may further include a turntable having a linear track portion. Alternatively, the process chamber may further include a turntable having a linear track portion. Still alternatively, the turntable having a linear track portion may be disposed between the process chamber and the wafer loading system.

Any of the embodiments described thus far can be combined with other processing chambers and/or systems, an example of which is shown in FIG. 3C. For clarity, the illustration in FIG. 3C omits a portion of the loading section, but any of the loading sections described in any of the embodiments detailed herein can be used to load a substrate into the system.

A turntable 323 is positioned over the racetrack at the opposite end from the loading side. The turntable 323 is configured to receive a transport carrier from the racetrack and transport the carrier to an attached processing chamber or processing system (e.g., a conventional large general-purpose processing system). In the illustration of FIG. 3C, any of the elements 326 may represent such a processing chamber or processing system, e.g., a large general-purpose device. A mechanism of the track exchanger 140A, similar to the mechanism of the track exchanger 140 on the opposite side, may be used to transfer the carrier 150 from the racetrack monorail 127 to the turntable 323. For example, the turntable 323 may include a linear track portion 321 for receiving the carrier and may include motorized wheels 135 for moving the carrier on the linear track portion 321.

3C also illustrates a different configuration of a turntable that may be used in any of the disclosed embodiments and may simply be referred to as a turntable. Specifically, turntable 327 is configured as a hub 328 having spokes 329. A linear track portion 331 is attached to the end of each spoke 329. Each linear track portion 331 is adapted to form a continuation of track 128.

3A-3C show an embodiment split into a loading mechanism and an unloading mechanism with a turntable for moving the carrier from the unloading side to the loading side. However, this configuration is not required and instead a single mechanism for loading and unloading can be used. If there is enough time in the processing sequence, a single loading/unloading mechanism can be used to unload the processed wafer and load a new wafer. An example is shown in FIG. 3D. After evacuation of the load lock 305 is completed, the gate valve EN is opened to allow the carrier 150 with the processed wafer waiting in the transfer chamber 310 to be moved to the load lock 305. The processed wafer is then moved from the carrier 150 to the wafer holder 304. The carrier can then be returned to the transfer chamber 310 and the gate valve EN is closed. The load lock is then brought to atmospheric pressure and the gate valve IN is opened to allow the robot 312 to remove the processed wafer from the holder 304 and place a new wafer in the holder 304. Gate valve IN is then closed and a vacuum is drawn in load lock 305. Gate valve EN is then opened and carrier 150 is returned to the load lock and loaded with a new wafer from wafer holder 304. The carrier is then returned to the transfer chamber and gate valve EN is closed. Gate valve EX is then opened to advance the carrier and transfer it to racetrack monorail 127 via track exchanger 140.

It should be understood that the processes and techniques described herein are not inherently apparatus specific and may be practiced in combination with any suitable components. Additionally, various types of general purpose equipment may be used in accordance with the teachings described herein. While the invention has been described with reference to specific examples, it is intended in all respects to be illustrative and not restrictive. Those skilled in the art will recognize that there are many different combinations that may be suitable for practicing the invention.

Additionally, other aspects of the present invention will be apparent to those of ordinary skill in the art from consideration of the specification and practice of the invention disclosed herein. Various aspects and/or components of the above-described embodiments may be used alone or in any combination. The specification and examples are considered as examples only, with the true scope and spirit of the invention being indicated by the following claims.

Claims (20)

A vacuum enclosure;
a plurality of processing chambers mounted on a sidewall of the vacuum enclosure;
a transfer chamber coupled to the loading end of the vacuum enclosure through a first gate valve and having a transfer track therein;
a load lock coupled to the transfer chamber via a second gate valve, the load lock having a third gate valve at an inlet side and a transfer track therein;
a wafer holding module having a wafer holder attached to a side wall of the load lock for holding a substrate in a vertical or near vertical position within the load lock;
an articulated robot arm having an end effector attached to its distal end via a rotatable wrist and positioned outside of the load lock and reachable to horizontally remove a substrate from a FOUP and rotate the substrate to a vertical or near vertical position to place the substrate on the wafer holder;
a plurality of substrate carriers that move on the transport track and exchange substrates with the wafer holding module. a turntable having a linear track portion ;
The system of claim 1 , wherein the turntable is located at an end of the vacuum enclosure, in the load lock, in the transfer chamber, or between the processing chamber and a substrate loading system. The system of claim 2, wherein the turntable is rotatable to transport the substrate carrier from an unloading position to a loading position. The system of claim 2, wherein the turntable is rotatable to transport the substrate carrier from one transport track to the other transport track. The system of claim 2, wherein the turntable is disposed within the vacuum enclosure. The system of claim 2, wherein the turntable is disposed within the load lock. The system of claim 2, wherein the turntable further includes a motorized wheel. a racetrack-shaped monorail disposed within the vacuum enclosure;
an endless belt disposed within said vacuum enclosure and engaging each carrier moving freely on said racetrack-shaped monorail;
3. The system of claim 2, further comprising a track exchanger disposed at one end of said racetrack-shaped monorail for transporting each substrate between said racetrack-shaped monorail and said transport track. The system of claim 1, wherein the substrate carriers each include an electrostatic chuck disposed in a substantially vertical orientation. The system of claim 1, wherein the substrate carriers include substrate holders each arranged in a substantially vertical orientation. a turntable disposed at an end of the vacuum enclosure opposite the loading end;
a racetrack-shaped monorail disposed within the vacuum enclosure;
an endless belt disposed within said vacuum enclosure and engaging each carrier moving freely on said racetrack-shaped monorail;
a track exchanger disposed at one end of the racetrack-shaped monorail for transporting carriers between the racetrack-shaped monorail and the turntable;
10. The system of claim 1, further comprising at least one second treatment system mounted at said end of said vacuum enclosure. The system of claim 11, wherein the endless belt includes a plurality of driving forks, and each of the substrate carriers includes a plurality of freely rotating wheels configured to engage the racetrack-shaped monorail and a driving pin configured to engage the driving forks. The system of claim 12, wherein the turntable includes a linear track and motorized wheels, and each of the substrate carriers includes a drive bar that engages the motorized wheels. a second transfer chamber coupled to a loading end of the vacuum enclosure;
10. The system of claim 1, further comprising: a second load lock coupled to the second transfer chamber. The system of claim 14 , further comprising a transport mechanism for transporting the substrate carrier from the second load lock to the load lock. The system of claim 14 , further comprising a transfer mechanism for transferring the substrate carrier from the second transfer chamber to the transfer chamber. a transport mechanism disposed within the vacuum enclosure;
10. The system of claim 1 , wherein the transport mechanism includes at least one track interchanger having a movable table, a linear monorail section disposed on the table, and a curved monorail section disposed on the table. 20. The system of claim 17, wherein the transport mechanism further comprises a turntable having a linear track portion thereon. a monorail disposed within the vacuum enclosure and comprising a first monorail section configured like a racetrack and a second monorail section having two parallel linear monorail extensions;
A driving element disposed on the first monorail section;
a plurality of motorized wheels disposed along the second monorail section;
20. The system of claim 17, wherein the track exchanger transfers each carrier between the first monorail section and the second monorail section. Each of the plurality of carriers comprises:
A substrate;
an engagement mechanism attached to the base and configured to engage the motive element to move the carrier on the first monorail section;
20. The system of claim 19, further comprising: a drive bar attached to the base, the drive bar configured to engage a plurality of motorized wheels to move the carrier along the second monorail section.

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