Patent Application
20220051918
Embodiments of the present disclosure generally relate to an apparatus and method of processing substrates in a sub-atmospheric pressure environment, and more particularly, an integrated monolith buffer station for pre-processing substrates.
Conventional cluster tools are configured to perform one or more processes during substrate processing. For example, a cluster tool can include a physical vapor deposition (PVD) chamber, an atomic layer deposition (ALD) chamber, a chemical vapor deposition (CVD) chamber, and/or one or more other processing chambers for performing one or more other processes on a substrate. Many thin film deposition and etch processes employ pre-processes such as cleaning, de-gassing, cooling-down, and annealing in dedicated chambers that are attached to a cluster tool, prior to processing in a processing chamber. The time required to load and unload a substrate from one chamber to another using a robot and pump down each chamber adds overhead time to the total time required to process a substrate in a cluster tool, decreases throughput, and increases cost of ownership (CoO).
Therefore, there is the need in the art for methods and apparatus for performing pre-processing of substrates that increases mechanical throughput and decreases CoO.
Embodiments described herein provide a transfer chamber in a substrate processing system. The transfer chamber includes a monolithic chamber body, a transfer robot configured to pass substrates between a factory interface and a processing module in a substrate processing system, a load lock chamber station, a shutter station, a pre-clean chamber station, and a process chamber station integrated within the monolithic chamber body, and a plurality of slit valves integrated within the monolithic chamber body. The plurality of slit valves are configured to open and close the load lock chamber station, the pre-clean chamber station, and the process chamber station each from the shutter station such that the load lock chamber station, the pre-clean chamber station, and the process chamber station maintain respective vacuum pressures.
Embodiments described herein provide a substrate processing system. A substrate processing system includes a processing module comprising one or more processing chambers, a factory interface comprising one or more front opening unified pods, a transfer chamber coupled between the factory interface and the processing module. The transfer chamber includes a monolithic chamber body, a transfer robot configured to pass substrates between a factory interface and a processing module in a substrate processing system, a load lock chamber station, a shutter station, a pre-clean chamber station, and a process chamber station integrated within the monolithic chamber body, and a plurality of slit valves integrated within the monolithic chamber body. The plurality of slit valves are configured to open and close the load lock chamber station, the pre-clean chamber station, and the process chamber station each from the shutter station such that the load lock chamber station, the pre-clean chamber station, and the process chamber station maintain respective vacuum pressures.
So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.
To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.
Embodiments described herein provide a transfer chamber (also referred to as a “buffer station”) attached to a main frame in a substrate processing system. The transfer chamber includes load lock chamber stations, pre-clean/degas chamber station, and an optional process chamber station integrated in a monolithic chamber body, in which pre-processes such as cleaning, de-gassing, cooling-down, and annealing can be performed. The necessity to load and unload a substrate from one chamber to another using a robot and pump down each chamber for such pre-processes in a conventional cluster tool is removed, and thus the total time required to process a substrate in the substrate processing system is decreased, leading to an increased throughput. The transfer chamber further includes a plurality of slit valves integrated within the monolithic chamber body. The plurality of slit valves are configured to open and close the load lock chamber station, the pre-clean chamber station, and the process chamber station each from the shutter station such that the load lock chamber station, the pre-clean chamber station, and the process chamber station maintain respective vacuum pressures.
In the example shown in
The factory interface 104 is connected to the transfer chamber 106 through a load lock chamber valve 126 at one side thereof to the factory interface 104. The factory interface 104 is an atmospheric or ambient pressure substrate input and output handling station in which substrates are safely secured and stored as the substrates are moved between different machines. In some embodiments, the factory interface 104 may be maintained in a positive-pressure non-reactive gas environment (using, e.g., nitrogen as the non-reactive gas) with minimum 4 torr above atmospheric pressure using a purging apparatus (e.g., a gas supply line, a gas source, a vacuum pump, a valve, or the like, not shown) located within and/or coupled to the processing system 100. This non-reactive gas environment prevents substrates from exposure to air, in particular oxygen, and moisture, which may adversely affect substrate properties and substrate processing due to oxidation.
In some embodiments, the factory interface 104 includes at least one docking station 116 and at least one factory interface robot 118 to facilitate the transfer of a substrate. The docking station 116 is configured to accept one or more front opening unified pod (FOUP). Four FOUPs, such as 120A, 120B, 120C, and 120D (collectively labeled as 120) are shown in the embodiment of
The system controller 122 controls activities and operating parameters of the automated components found in the processing system 100. In general, the bulk of the movement of a substrate through the processing system is performed using the various automated devices disclosed herein by use of commands sent by the system controller 122. The system controller 122 is a general use computer that is used to control one or more components found in the processing system 100. The system controller 122 is generally designed to facilitate the control and automation of one or more of the processing sequences disclosed herein and typically includes a central processing unit (CPU) (not shown), memory (not shown), and support circuits (or I/O) (not shown). Software instructions and data can be coded and stored within the memory (e.g., non-transitory computer readable medium) for instructing the CPU. A program (or computer instructions) readable by the processing unit within the system controller determines which tasks are performable in the processing system. For example, the non-transitory computer readable medium includes a program which when executed by the processing unit are configured to perform one or more of the methods described herein. Preferably, the program includes code to perform tasks relating to monitoring, execution and control of the movement, support, and/or positioning of a substrate along with the various process recipe tasks and various processing module process recipe steps being performed.
The load lock chamber stations 204A, 204B are connected through the load lock chamber valve 126 (shown in
The interior volume of the transfer chamber 106 is evacuated by one or more vacuum pumps 212 connected to an exhaust duct (not shown) of the transfer chamber 106 to reduce the pressure within the transfer chamber 106 to a sub-atmospheric pressure of between about 10−5 torr and about 10−8 torr, for example, about 10−7 torr. The vacuum pumps 212 may be a turbopump, cryopump, roughing pump or other useful device that is able to maintain a desired pressure within the interior volume of the transfer chamber 106. When the load lock chamber valve 126 is open, the interior of the transfer chamber 106 is exposed to atmospheric or ambient pressure conditions.
The transfer chamber 106 includes integrated slit valves 214, 216A, 216B, 218 to control the load lock chamber stations 204A, 204B, the preclean/degas chamber stations 208A, 208B, and the process chamber station 210 at different vacuum pressures for use of various different processing gases without the concern of contaminating among different stations within the transfer chamber 106. In one example, the process chamber station 210 is maintained at a pressure of between about 10−4 torr and about 10−8 torr, for example, 10−5 torr. The integrated slit valve 214 is configured to close the load lock chamber stations 204A, 204B, from the shutter station 206. The integrated slit valve 216A, 216B are configured to close the preclean/degas chamber stations 208A, 208B, respectively, from the shutter station 206. The integrated slit valve 218 is configured to close the process chamber station 210 from the shutter station 206. In some embodiments, the transfer chamber 106 includes a wafer station (not shown) located therewithin to accommodate a wafer that is either to be pre-processed or has been pre-processed and ready to be passed to process chamber station 210.
During operation, a substrate transferred from the factory interface 104 into one of the load lock chamber stations 204A, 204B may be moved to one of the preclean/degas chamber stations 208A, 208B or the process chamber station 210 through the shutter station 206 within the transfer chamber 106 by the transfer robot 108. Alternatively, a substrate processed within the processing module 102 and transferred into the process chamber station 210 of the transfer chamber 106 may be moved back to one of the load lock chamber stations 204A, 204B through the shutter station 206 within the transfer chamber 106 and subsequently out to the factory interface 104.
In the preclean/degas chamber stations 208A, 208B, a substrate is pre-cleaned prior to being transferred into the processing module 102 for substrate processing. The pre-cleaning process may include heating the substrate to volatilize any adsorbed moisture or other volatilizable materials therefrom. The pre-cleaning process may be subjecting the substrate to a plasma etch process whereby residual contaminant materials thereon are removed. In some embodiments, the preclean/degas chamber stations 208A, 208B pre-clean two substrates simultaneously. For example, one substrate is transferred from the load lock chamber station 204A to the preclean/degas chamber 208A and another substrate is transferred from the load lock chamber station 204B to the preclean/degas 208B, and the both substrates are pre-cleaned independently and simultaneously in their respective preclean/degas chambers 208A, 208B. Because the preclean/degas chambers 208A, 208B are isolated from the shutter station 206 by the integrated slit valves 216A, 216B, respectively, passages of different substrates can be undertaken from the factory interface 104 to the processing module 102 without interfering with the pre-cleaning of the substrate in the respective preclean/degas chambers 208A, 208B.
A substrate may be moved into the process chamber station 210 from the preclean/degas chamber stations 208A, 208B, for example, after the substrate has been pre-cleaned in the preclean/degas chamber stations 208A, 208B, or from the load lock chamber stations 204A, 204B, for example, when the substrate requires no pre-cleaning, through the shutter station 206 within the transfer chamber 106 by the transfer robot 108. The process chamber station 210 may be adapted to perform thermal process (e.g., rapid thermal processing (RTP), annealing, cooling down, thermal management control).
Each of the forks 310, 320 of the first and second end effectors 302, 304 can extend a maximum distance from the central axis 306 when the arms (first arm 312 and first hub arm 314, or second arm 322 and second hub arm 324) thereof are co-aligned, i.e., when they together form a straight line path. In this orientation of the arms, one of the first and second fork 310 or 320 is at the load or unload position to receive or leave a substrate with respect to a substrate support. From this position, by virtue of arcuate movement of an upper or lower hub about central axis 306 and one of the first or the second arms 312, 322 about the corresponding first wrist axis 318 or second wrist axis 328, the corresponding fork 310 or 320 is retracted toward the central hub 308. By locating the transfer robot 108 within the transfer chamber 106 and locating central axis 306 over the shutter station 206, the forks 310, 320 are operable to access any substrate support at any of the load lock chamber stations 204A, 204B, the preclean/degas chamber stations 208A, 208B, and the process chamber station 210, and independently of one another only through the shutter station 206.
In the example embodiments described herein, a transfer chamber attached to a main frame in a substrate processing system is shown. The transfer chamber includes load lock chamber stations, pre-clean/degas chamber station, and an optional process chamber station integrated in a monolithic chamber body, in which pre-processes such as cleaning, de-gassing, cooling-down, and annealing down can be performed. The necessity to load and unload a substrate from one chamber to another using a robot and pump down each chamber for such pre-processes in a conventional cluster tool is removed and thus the total time required to process a substrate in the substrate processing system is decreased, leading to an increased throughput. The transfer chamber further includes a plurality of slit valves integrated within the monolithic chamber body. The plurality of slit valves are configured to open and close the load lock chamber station, the pre-clean chamber station, and the process chamber station each from the shutter station such that the load lock chamber station, the pre-clean chamber station, and the process chamber station maintain respective vacuum pressures.
While the foregoing is directed to various examples of the present disclosure, other and further examples may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.
