Automated semiconductor processing systems

A semiconductor processing system for wafers or other semiconductor articles. The system uses an interface section at an end of the machine accessible from the clean room. A plurality of processing stations are arranged away from the clean room interface. A transfer subsystem removes wafers from supporting carriers, and positions both the wafers and carriers onto a carrousel which is used as an inventory storage. Wafers are shuttled between the inventory and processing stations by a robotic conveyor which is oriented to move toward and away from the interface end. The system processes the wafers without wafer carriers.

TECHNICAL FIELD

This invention relates to automated semiconductor wafer processing systems for performing liquid and gaseous processing of wafers. Such systems can be used to process semiconductor wafers, data disks, semiconductor substrates and similar articles requiring very low contaminant levels.

BACKGROUND OF THE INVENTION

The processing of semiconductor wafers has become of great economic significance due to the large volume of integrated circuits, data disks, and similar articles being produced.

The size of features used in integrated circuits and data disks have decreased significantly, thus providing greater integration and greater capacity. This has been possible due to improved lithography techniques and improved processing.

The reduction in feature size has been limited by contamination. This is true because various contaminating particles, crystals, metals and organics lead to defects in the resulting products. The limitations on feature size caused by contaminants have prevented fill utilization of the resolution capability of known lithography techniques.

Thus there remains an acute need for improved methods and systems for processing semiconductor wafers, data disks and similar articles requiring very low levels of contamination during processing.

During the fabrication of semiconductor components, various manufacturing steps involve the application of processing liquids and gases to the articles being processed. The application and removal of these processing fluids to and from the exposed surfaces of the wafers are enhanced by movement of the wafers within the processing chamber. Processing is also enhanced by centrifugal action of the semiconductor wafers which improves movement of fluids across the wafer surfaces, such as when liquids are sprayed upon the wafer and then move across the wafer surfaces due to centrifugal forces acting upon the liquids as the wafers spin.

As one example, after semiconductor wafers have been cleaned, they must be dried. This is not a trivial process because any water that remains on the surface of a semiconductor wafer has at least some potential of leaving some form of residue which may interfere with subsequent operations or cause defects in the resulting products. Centrifugal action aids in the removal of water and other processing liquids so that such residues are not as likely to occur because the fluid is applied to the surface and then moves outwardly and is removed from the surfaces. Drying is also benefitted because less liquid remains on the wafer surfaces, so drying speed is increased. This saves processing time and reduces the risk of residue or contamination due to particle adhesion.

In one type of prior art centrifugal processor, several wafer carriers are put in holders or carriers in a spaced substantially circular array around the axis of rotation. The rotor with loaded carriers of wafers is then rotated within a processing chamber which is typically enclosed within a processing bowl or vessel. In the center of the vessel and at other peripheral locations are fluid manifolds with spray nozzles or similar inlets that are connected to a source of deionized water, heated nitrogen, or other processing chemicals both liquids and gases. These or other processing fluids are thus applied to the wafers to effect washing, drying or other processing.

Other prior art spin rinser dryers have been built for drying batches of wafers held in a single wafer carrier. The wafer carrier and supported wafers are held within a rotor. The rotor has an opening for receiving the carrier with the wafers positioned in an array with the centerpoints of the wafers at or nearly aligned with the axis of rotation. Typically a small offset is used so that the wafers will seat into the wafer carriers as centrifugal forces are developed during rotation. The water, nitrogen or other processing fluids come into the chamber along the sides rather than through a manifold mounted at the center. The rinsing, other liquids application, or drying take place as the rotor spins with the carrier and wafers held therein. Stationary retainer bars are typically provided adjacent the open top side of the wafer carrier to prevent the wafers from being displaced if the rotor should stop in an upside-down position. The rotors are also typically controlled to stop in a right-side-up position. This type of spin rinser dryer is normally termed an axial or on-axis spin rinser dryer.

Additionally semiconductor processing machines of similar configuration are also used for centrifugal chemical etching or other chemical processing. In this regard, the required chemicals are pressurized or pumped to the processing chamber and valves control the supply of such chemicals into the chamber. The chemical processing can be following by associated rinsing and drying operations. The application of processing chemicals adds to the complexity of the processing because highly reactive chemicals may impinge upon the wafer surfaces at different angles, fluid velocities, with differing flow rates, and with other dynamically varying effects. This variability can cause different etch rates or other variations in chemical processing which is difficult to overcome.

Process uniformity within a batch and repeatability from batch to batch have been major considerations in semiconductor processing, and in particular centrifugal semiconductor processing. The issue is particularly of interest in the case of batch centrifugal processing because the wafers are held in closely spaced arrays using wafer carriers. In addition to inherent variations in the application of processing fluids to the wafers, there are also variations associated with how wafers are held within the carriers. The structural parts of the carriers necessarily restrict access of fluids to the wafer surfaces. This has almost invariably led to different processing results for wafers in different positions within a carrier, even though processing has occurred in the same batch. Although carriers have been designed to reduce their effects on processing fluid distribution within the processing chamber, it has been impossible to eliminate their effects on uniformity and repeatability of processing results.

While the apparatus and methods utilized heretofore have operated with varying degrees of success, they have also sometimes suffered problems with regard to contamination or particle additions which can occur during processing. As the features and geometries of the discrete components formed on the semiconductor devices have become smaller and more densely packed, the need for more stringent contamination control has become increasingly difficult.

Thus there has been a need in the art of semiconductor wafer and similar article processing for a centrifugal processing machine which provides improved uniformity of process results while minimizing the possibility of contamination. This must be done without substantial risk of damage to the semiconductor wafers.

A further area of significance in the processing of semiconductor articles includes the handling and coordination of wafer carriers commonly used to support semiconductor wafers in various stages of processing and translocation between processes. Wafer carriers are often susceptible to picking up undesirable contaminants. Carriers which have been contaminated can in some processing schemes be used to carry more than one batch of wafers. This increases the potential for spreading contamination amongst multiple wafers and batches.

These and other considerations have led to a novel semiconductor processing system as described herein, with various benefits and advantages which are described or inherent from the construction and description given herein.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Processing System Generally

FIGS. 1 and 2generally show a preferred processing system11constructed in accordance with the novel aspects of the inventions. The processing system includes a frame13which is connected with a housing12. The housing12and frame13rests upon a supporting surface (not shown). The housing is most preferably constructed to form an enclosure which is substantially or fully encloses the machine and defines a working space18within which the wafers80or other semiconductor articles are moved and processed in relative protection from dust and contamination.

FIG. 1does not show the full enclosure of housing12to improve the illustration. Specifically, the top or roof has been removed for purposes of illustration. The roof can advantageously be provided with a series of ultrafine filters (not shown) through which air, nitrogen or other work space gas is supplied to working space18.

FIG. 1shows that the processing system11includes an interface section14which includes mechanisms and features for inputting and outputting the wafers80or other semiconductor articles being processed. The interface section also includes mechanisms for transferring wafers from wafer carriers79and for inventorying both the wafers and carriers upon a carrousel720. Preferred forms of these mechanisms will be described in detail below after further introduction of some additional basic features of the processing system.

Processing Stations Generally

Processing system11also includes a processing section8. The processing section includes one or more individual processing stations19which can be of various constructions. Centrifugal or immersion type stations can be used. In a preferred form of the invention, the processing stations19are each centrifugal processing stations which include a processing vessel201which partially encloses a processing chamber defined therewithin. The processing vessels also preferably mate with a movable door202which can be moved between the closed positions generally shown and the retracted position shown at one station in FIG.2.

The processing stations19are mounted within processing station console203which have associated supporting fluid supplies for providing processing liquids and gases as needed for the particular processes being carried out at that station. Stations19can all be the same, each be different, or there can be more than one of a particular type coupled with one or more other associated stations within the same processing system.

As shown, the semiconductor articles are processed in batches. The wafers within a batch are arranged in a linear batch array in which the individual wafers or other articles are spaced, substantially parallel and aligned with central normal axes of the disk-shaped wafers aligned to form a longitudinal central batch axis (axis not illustrated). The size of the wafers can vary. The number of wafers can also vary, but at this time typically will include 25 or 50 wafers because industry standard wafer carriers79have such capacities.

Robotic Conveyor

FIGS. 1 and 2further show a robotic conveyor, which is generally indicated by the numeral15. Robotic conveyor15includes a mounting conveyor beam or rail7upon which a movable conveyor robot subassembly5is mounted and moves relative to the rail. The conveyor15conveys the semiconductor wafers or other articles80within the processing system, specifically between, to and from, the inventory carrousel720and the processing stations19.

The robotic device can be of various designs. One design is that available from Semitool, Inc. of Kalispell, Mont. as part of processing systems sold under the trademark MAGNUM. Further detailed description of suitable conveyor devices and other aspects of the processing system can also be implemented in a manner shown in described in U.S. Pat. Nos. 5,544,421; 5,660,517; and 5,678,320 which are hereby incorporated by reference in their entirety. Such forms of apparatus are also described in corresponding PCT Applications which were published by the World Intellectual Property Organization under PCT Publication Nos. WO 95/30238; WO 95/30240; WO 30239; all of which are incorporated by reference.

In the preferred robotic transfer device15the construction includes an articulated arm16.FIG. 5better illustrates that the preferred articulated arm includes an upper arm portion741, lower arm portion742, and hand portion743. Articulated arm16uses hand743and an attached engagement head which can be oriented into various planes of orientation and various positions. The conveyor robot has a distal end17which is used to mount an engagement implement which is preferably of the construction detailed below or equivalents thereto. The distal end17may move along assorted courses of travel to deliver the semiconductor articles to various individual or plural work stations19. Each of these various courses of travel will be discussed in greater detail, hereinafter. While the present invention is described as being useful in combination with a washing or chemical processing stations, it will be appreciated that the same device may find utility in other applications.

Input-Output Interface Section

FIGS. 1 and 2also show that processing system11preferably includes an input-output or interface section14. The current invention in-part focuses on the novel construction used for interface section14. Interface section14is constructed using the processor framework13and enclosure wall structure12. The interface section has a front end wall701which is advantageously arranged along a hall or gallery within a clean room. Front wall701includes an interface opening702. Interface opening702is provided with an interface door703which is preferably at least partially transparent to allow observation by a human operator. Door703is preferably operated by a suitable power door operator709which can be a linear screw drive or many other suitable mechanisms. The front wall701is also preferably provided with an operator control module or station704which is accessible from the clean room end of the system and can be of various constructions. As shown, operator module704includes a touch screen display and control panel705. Also appropriately included are a disk drive706for providing control programming information, and other manually depressible control buttons (such as emergency stop) not specifically shown, but generally referred to as707.

Interface section14also preferably includes a carrousel support framework710which is mounted in an elevated position within the interface section enclosure. Carrousel support framework710includes a central frame opening711(FIG. 1) which is used to mount an inventory carrousel which will be more fully described below. The specific form of the carrousel support framework can easily vary depending upon the specific form in which the carrousel or other inventory storage is constructed.

Inventory Carrousel

FIG. 5shows portions of the carrousel inventory mechanism used to support a plurality of wafers80or other semiconductor articles being processed. Carrousel assembly720includes a carrousel mounting plate721which is secured within opening711of the carrousel support framework710using fasteners729(FIG.6). Support plate721is connected to and carries a carrousel main housing722which is detachable for maintenance and other purposes. Carrousel main housing722has internal features which support and mount a carrousel drive motor747(shown in phantom in FIG.7). The output of the carrousel drive motor is in the form of a carrousel rotor shaft723. The lower end of shaft723has a suitable angular position encoder745coupled at its lower end by coupling746. An encoder support bracket744is attached to frame13or other suitable supporting structure to stabilize portions of the encoder against rotation with shaft723.

The carrousel assembly further includes a plurality of carrousel support arms725which extend outwardly and are arranged to provide four cantilevered beam portions which can be advantageously used to support wafers80and wafer carriers79. As shown, the carrousel support arms725connect in an overlapping square-shaped array to form a central square726which is overlaid with a carrousel central support panel727.

Each carrousel support arm725is preferably constructed so as to receive one or more support brackets728. Support brackets728can be mounted in any suitable fashion. As shown, support brackets728rest over arms725and are secured thereto by fasteners (not shown).

Each support bracket728includes an upper or first rest or support730, and a second or lower rest or support731. The upper rest730is preferably provided with a series of grooves or notches732(seeFIG. 6) along opposing inner, upper surfaces. Grooves732serve as supporting receivers into which are received individual wafers80. The lower, second supports731are used for receiving and supporting wafer carriers79. As shown, the lower supports731are constructed so as to form a semiconductor article carrier support. Article carrier support731is advantageously provided with constructional surface details (not shown) which serve to help retain the wafer carriers79against unintended movement after being placed upon supports731. This maintains the carriers in position when the carrousel rotor rotates to a desired angular position. The specific features used will vary in conformance with the particular carrier design used.

The interface section also preferably includes a mid-level deck750which extends and portions which extend beneath such deck. Deck750is preferably perforated using perforations or apertures (not shown) which allow clean air or other work space gas to pass downwardly from upper air supply and filtration units (not shown) which provide filtered air into upper reaches of the processing system enclosure. This arrangement tends to take any generated particles or contaminants downwardly in the stream of filtered air or other working space gas.

The preferred carrousel construction shown inFIGS. 5-7illustrates a system designed to accommodate approximately four hundred (400) wafers. Such wafers are typically supplied in wafer carriers79which have the capacity of twenty five (25) wafers each. Carrousel720thus is capable of supporting both the wafers and sixteen (16) associated wafer carriers in inventory positions upon the carrousel. The carrousel construction and arrangement shown allows the inventoried wafers and carriers to be properly accessed at four different angular positions of the carrousel. Access can occur using either a wafer transfer apparatus800or robotic conveyor15. This arrangement also allows the robotic conveyor to access one arm of the carrousel while another arm of the carrousel is being loaded or unloaded using the transfer subsystem800.

Article Transfer Subsystem

The semiconductor article transfer mechanism800is shown in greater detail in FIG.8. Mechanism800is advantageously supported by a subframe802which either forms part of machine framework13or is otherwise appropriately supported within the enclosure12. Subframe802can be of various constructions.FIG. 8shows that subframe802includes a lateral stage guide rail803which mounts a laterally moveable transfer main subassembly810.

Lateral motion is provided to horizontally move the main subassembly810back and forth using a suitable later stage drive. As shown, the lateral stage drive includes a lateral stage drive motor804which drives an associated screw actuator or other suitable drive assembly which moves the main subassembly810horizontally back and forth along support rail803. The Lateral stage drive operates directly upon the supporting frame guide803and a lateral stage follow812which forms a part of main subassembly810. A variety of lateral stage guide and drive constructions are suitable for use in this invention.

The article transfer main subassembly810also includes a main part811. Main part811is mounted for elevation change such as by mounting for vertical motion relative to the lateral stage follower812. The connection between lateral stage follower812and main piece811is actuated by a first elevator actuator823which is mounted within main part811.

The lateral stage812and main part811together form a transfer first carriage which is mounted to the frame for movement relative thereto. As shown, the first carriage is mounted for both horizontal and vertical motion. The first carriage preferably includes at least one feature for supporting at least one article carrier79on the first carriage. The carrier support features can be constructed according to a variety of alternative designs; however, a preferred construction will be detailed next.

The article transfer mechanism800further includes two upper decks831and832which form a part of the first carriage and are connected to the main part811. As shown, first deck831is connected to the main part in a fixed relationship, although a moveable mounting is alternatively possible. First deck831has two wafer carrier receptacles833formed therein. Receptacles833are shaped and sized so as to support bottom edge surfaces of wafer carriers79. Receptacles833also each have an open portion or receptacle opening within the receptacle which is open through deck831. These receptacle openings allows for the free passage of article lift heads821up through the receptacle and deck. The lift heads also pass up through an aperture formed in the bottom of carriers79in order to lift wafers80from the wafer carriers79.

As shown, the carrier support on the first carriage also includes a second or upper deck832. Second deck832also has receptacles833for receiving wafer carriers79and supporting the carriers thereon. Receptacles833in the second deck also have openings which allow the wafer lift heads821to extend therethrough when elevated as explained below. The lift heads821associated with the first deck can be considered a first set of lift heads, and those associated with the second deck can be considered a second set of lift heads. Although a plurality of lift heads is shown and preferred, it is alternatively possible to use a single lift head and a single deck, with resulting reduced capacity of the transfer mechanism.

First and second decks831and832are advantageously provided with a suitable number of carrier positioners846which facilitate easy placement of the carriers79into the receptacles833. Carrier detectors847are also advantageously included at receptacles833to allow detection of the carriers when placed in a proper position within the receptacles.

The first and second deck pieces831and832are advantageously constructed, mounted and arranged so as to facilitate their loading with wafer carriers and wafers held in the carriers. This loading is intended to occur through the interface opening702. The loading is advantageously done by bringing both decks into close proximity to the opening so that either a robotic or human operator can set the carriers loaded with wafers into receptacles833through opening702. To facilitate this, the construction shown includes a first deck831and second deck832which are both capable of being placed adjacent opening702. Deck831is in closest proximity without special modification or movement beyond that provided by the lateral stage in properly positioning the subassembly810toward the opening702. This is illustrated in FIG.9. AsFIG. 9further shows, the second deck832is slidably connected to the first deck831or other parts of the main part811.FIG. 8shows a preferred construction for accomplishing this which uses a guide rail840. Guide rail840slidably connects the two decks and allows linear motion in the direction substantially defined by the longitudinal axis of guide rail840. Second deck832is moved relative to first deck831using an upper deck actuating driver or motor842. The actuator advantageously includes a linear drive, such as a helical screw and ball bearing follower which slides the upper deck relative to the lower deck to assume positions as is illustrated in more complete detail inFIGS. 9-12. The position shown inFIG. 9is an overlapping position in which the upper deck is positioned adjacent to the loading and unloading opening702for easy access. The position shown inFIG. 12depicts the upper deck in a staggered relationship with the lower deck which allows both decks to support wafer carriers thereon.

The transfer subassembly810also includes at least one second carriage. As shown, the second carriage includes the wafer lift heads821described above. The lift heads serve as supports for wafers or other semiconductor articles being transferred. In the exemplary construction shown, the lift heads are supported upon upstanding lift head extension rods820. The lift heads and portions of the lifting rods extend through the openings in the receptacles833, such as shown in FIG.14.

In the preferred construction shown there are two second carriages. One of the second carriages include the first set of lift heads which extends through the first deck831. The other second carriage includes the second set of lift heads which extend through the second deck832. The second carriages are preferably operated in an independent manner using the construction which will now be described.

The second carriages also include transverse second carriage members813. The transverse second carriage members813form a connecting bar which supports the lift rods820near the ends of each connecting bar. The connecting bars, lift rods and lift heads move upwardly and downwardly as the parts of the second carriage assemblies. These second carriage assemblies are move by second carriage assembly operators. In the preferred construction, these operators include a suitable linear drive mechanism, such as a helical screw drive. The drive shown inFIG. 8includes a drive motor814which drives a screw member841. A screw drive follower842is nonrotatably supported within a guide channel843formed in the side of the main part811. The transverse members813are connected to the drive followers842by fasteners844. This construction provides vertically moveable second carriage assemblies which each move independently relative to the main piece811using second carriage elevator motors814.

It is further noteworthy that the wafer lift heads821are preferably provided with a series of wafer or other semiconductor article receiving grooves or other similar receiving features822which allow an array of wafers or other articles to be held therein.

Transfer of Wafers Between Carriers and Carrousel

FIGS. 9-21illustrate the preferred operation and methods according to the invention. The methods described in this section include loading the processor and those steps involved in transferring wafers80from carriers79to the carrousel array held by carrousel720.

FIG. 9shows an initial stage of the methods wherein the wafer transfer has been controlled by positioning the upper deck832of the transfer first carriage toward the opening702(not shown inFIG. 9see FIG.1). The illustrated carriers79and supported wafers80are awaiting loading onto the upper deck832. The carriers are then manipulated manually or by machine to perform loading of the carrier or carriers through the opening702and onto the upper deck. The loading is preferably performed so as to provide positioning of the carriers onto the deck and into the carrier support receptacles833, or other features used to properly position the carriers upon the transfer first carriage.

After the carriers have been positioned upon upper deck832, then operation preferably proceeds by retracting or otherwise moving the upper deck into the position shown in FIG.12. This retracting step allows access to the carrier receptacles833formed on the lower deck831. This causes a presenting of the second set of carrier receptacles in preparation for loading of carriers thereon in the same manner as just described above.FIG. 13shows the second set of carriers loaded onto the lower deck831. With this action the transfer mechanism is fully loaded with wafer carriers having wafers contained therein.

FIG. 14illustrates the step of separating the wafer80or other semiconductor articles from the carriers79. The separating of the articles from the carriers can be effected by raising or elevating the lifting heads822. The raising or extending step is preferably powered using the second carriage operators814which lift the heads relative to the first carriage of the transfer mechanism.

FIG. 15shows a further stage of the transfer process wherein the two carrier-loads over the upper deck832are moved to effect a positioning of the wafers over the wafer supports provided on the carrousel. To effect this step, the carrousel is adjusted as needed by moving the carrousel angularly into the aligned pre-loading position shown in that Fig. Thereafter the step of translating the lateral stage of the transfer mechanism toward the open wafer support brackets728receptacles or receivers is performed. The first set of wafers is first positioned over the wafer supports on brackets728at the desired positions.

FIG. 16then shows the upper deck lifting heads retracted downwardly after a retracting step has been performed upon the upper deck second carriage. This retracting step causes a downward lowering and transferring of the wafers from the receiving grooves822in the lifting heads821to the receiving grooves732formed in the carrousel wafer supports730.

FIG. 17shows that the wafer lifted from the lower deck831are similarly transferred to the carrousel wafer supports. It should be noted that more efficient use of space is accomplished by placing the second set of wafers into closer proximity with the first set of wafers, than is otherwise allowed due to the size and geometry of the wafer carriers. This is indicated by elimination of the medial gap850(FIG. 16) as indicated in FIG.17. The result is to form two parallel carrousel batch arrays each having fifty (50) or other suitable number of wafers, starting with twenty five (25) from each wafer carrier. Although this configuration is preferred it is alternatively possible to use less or more numbers of carriers to form a single carrousel batch array.

FIG. 18shows the wafer transfer subassembly fully retracted away from the carrousel and prepared to accept another group of four (4) loaded wafer carriers to load another arm of the carrousel. Prior to undertaking such loading and transferring, the carrousel is affected by moving the carrousel angularly as illustrated in FIG.19. This rotating of the carrousel also performs an aligning or positioning step so that the robotic wafer conveyer15can interact with the carrousel batch arrays.

FIG. 20shows the robotic conveyor15after positioning the conveyor into a carrousel engagement position. In this positioning step the wafer engagement implement140is extended under the wafers held on the carrousel. The conveyor then performs a lifting step which separates the wafers from their supported positions on brackets728. The conveyor then performs a series of conveying movements, such as illustrated in FIG.21. The moving or conveying step is performed to relocate the wafers into position for loading into the desired processing station19. More specific explanation about the loading (installing) and unloading of the wafers into the processing stations19will be given below after first considering the preferred construction of the engagement implements and corresponding rotors which can advantageously be employed in the invention.

First Processing Rotor and Transfer Implement

A first embodiment of preferred centrifugal processor rotor used in the present invention is generally indicated by the numeral10in FIG.23. The centrifugal processor rotor forms part of the larger machine or processing system11described above.

FIGS. 24-27show a first preferred embodiment of rotor10and article transfer implement140in different positions in order to illustrate the various features of each and their cooperation to perform the novel operational methods described herein.FIG. 22shows the transfer implement140alone.FIG. 23shows the rotor alone.

The centrifugal processor rotor10includes a rotor frame20. The rotor frame has a front portion or plate21which is defined by a peripheral edge22. The front portion21further defines a substantially centrally disposed opening or aperture23, and a pair of mounting apertures24. The front portion or plate21has a forwardly facing surface25, and an opposite rearward facing surface26. Mounted in suitable relationship, such as the substantially parallel spaced relationship relative to the front plate21, is a rear portion or second plate30. The rear portion30has a peripheral edge31, and further defines a major aperture32, and a minor aperture33. The minor aperture is disposed in substantially coaxial alignment relative to the axis of rotation of the rotor frame20.

The rear portion further defines a pair of mounting apertures34. The rear portion30has a main body35which is substantially planar, and circular in shape, and which has substantially the same diametrical dimensions as the front portion21. The main body35is further defined by an exterior facing surface36, and an opposite, interior facing surface37, respectively.

The individual front and rear portions21and30, respectively, are held together in a suitable construction, such as the illustrated substantially coaxial and parallel spaced relation by means of rotor frame members40which are spaced about the rotor. Each of the rotor frame members40have a first end41, which is fixed on the front portion21by utilizing conventional fastening methods, and an opposite, second or distal end42, which is mounted on the rear portion30by using the same techniques. The location of the first and second plates in the given orientation described above defines a processing cavity43therebetween.

As best seen by reference toFIG. 23, a pair of laterally disposed support members, or combs50are borne by the rotor frame20and are positioned in the cavity43. The combs50include a first comb51, and an opposite, second comb52which are individually affixed on the interior facing surfaces26and37of the first and second portions21, and30respectively. The first and second combs extend substantially normally outwardly relative to the surfaces26and37, as shown. The first and second combs51and52are disposed to hold the wafers or other semiconductor articles being processed. This can advantageously be in the form of the illustrated substantially parallel, spaced configuration shown.

Each of the first and second combs has a frame portion53, which is affixed on the front portion21, and the rear portion30, by using conventional fastening techniques. Further, each of the first and second combs has a comb portion54which is defined by an undulating peripheral edge55. The undulating peripheral edges55are positioned in inwardly facing relation, one to the other, and are operable to engage the semiconductor articles as will be discussed in further detail in the paragraphs which follow. The peripheral edge may be provided in various materials or with various surface coatings which will protect the semiconductor articles which come into contact with same. One preferred construction utilizes a tetrafluoroethylene polymer plastic material. Others materials and constructions are alternatively possible.

FIG. 23further shows a pair of base combs, identified hereinafter as first and second base combs61and62, respectively. These base combs are affixed by conventional fastening techniques on the front and rear portions21and30respectively. The pair of base combs are shown disposed in parallel spaced relationship, and are generally aligned with the rotational axis of the rotor. The first and second base combs, in combination with the first and second laterally disposed combs51and52, define an article receiving assembly or receiver63which is operable to hold, support or cradle the articles in desired processing positions. The receiver is also preferably constructed to otherwise orient the semiconductor articles in substantially coaxial alignment relative to the axis of rotation of the rotor frame20.

FIG. 25shows that the base combs define a gap64therebetween and which has a given cross-sectional dimension. The individual base combs61and62each have a frame portion65which is affixed on the surfaces26and37respectively. The individual base combs further include an undulating peripheral edge66having receiving grooves and interposed projections.

As best illustrated by reference toFIGS. 4 and 5, the centrifugal processor rotor10includes a pair of retainer assemblies80. The retainer assemblies80will be identified hereinafter as a first retainer assembly81, and a second retainer assembly82, respectively. As will be appreciated by a study of the drawings, the first and second retainer assemblies81, and82are substantially mirror images of each other, and therefore the features of only one of the retainer assemblies will described in detail hereinafter. Each retainer assembly80includes a pair of end pieces83. The end pieces are identified as a first or forward end piece84, and a second or rearward end piece85. The first end piece84has a main body90which has a first end91, and an opposite second end92. The main body is further defined by an interior facing surface93, and an opposite, exterior facing surface94. The main body90also has a substantially linear portion95, and a curved portion96.

As illustrated inFIG. 24, the main body90is substantially curvilinear in its overall shape. A centrally disposed aperture97is formed in the linear portion95. Further, an engagement member100extends normally outwardly relative to the exterior facing surface94. A biasing member or spring102is borne by the rotor frame20. The spring has a main body103, with a first end104which is fixed by a conventional fastener on the rear surface26of the front portion21; and a second end105, which is fixed in a predetermined location on the linear portion95of the main body90. The operation of the biasing member or spring102will be discussed in greater detail hereinafter. As will be recognized, from a study ofFIGS. 3 and 4, the main body90is mounted for rotational movement about a front pin (not shown) and which is received in the individual mounting apertures24. The mounting pin is further in mating relationship and received in the aperture97.

FIG. 25illustrates that the second end piece85, of the respective retainer assemblies80, has a main body110which includes a first end111, and an opposite, second end112. The main body110further is defined by an interior facing surface113; an opposite, exterior facing surface114; a linear portion115; and a curved portion116which is positioned at the first end111thereof A centrally disposed aperture117is formed in the linear portion115. A rear pin120is received in mating relation in the aperture34. The rear pin120is also received in the central aperture117thereby rendering the main body110rotatable about the rear pin120.

Fastened on the first end91and111of the first and second end pieces84and85respectively, is a first longitudinally disposed member121. Further, fixed on the second end92and112of the first and second end pieces84and85, respectively is a second, longitudinally disposed member122. The first and second longitudinally disposed members121, and122are suitably oriented, such as in the fixed substantially parallel spaced relationship shown. These members are also further oriented in substantially parallel relationship to the axis of rotation of the rotor frame20.

The first longitudinally disposed member121includes an inside facing peripheral edge123which is coated with a material that does not harm or contaminate the semiconductor articles which are being processed.

The respective retainer assemblies80move along predetermined paths of travel130between a first, or open position131(FIG.23), and a second, or closed position132(FIG.26). As will be recognized by a study ofFIG. 27, the respective retainer assemblies80, when disposed in the second position132, secure the individual semiconductor articles on the object receiving assembly63for centrifugal processing. Further, it should be understood that when the individual retainer assemblies80are positioned in the second position132(FIG.27), the second longitudinally disposed members122are operable, under the influence of centrifugal force imparted to the respective longitudinally disposed members122by the rotation of the rotor frame20, to exert radially inward forces on the semiconductor articles thereby securing them in substantially coaxial alignment relative to the rotor frame20.

The centrifugal processor rotor10of the present invention works in combination with a transfer implement which is designated generally by the numeral140in FIG.22. The transfer implement140includes a face plate141which is releasably secured on the distal end17of the arm16. The face plate has a main body142which is defined by a left portion143; a right portion144; and bridging portions145which connect the left and right portions143and144together. Further, the face plate141includes an inside facing surface150, and an outside facing surface151. The outside facing surface is releasably secured in juxtaposed relation relative to the distal end17of the robotic arm16.

A pair of apertures,152are individually formed in the face place141. In this embodiment, the individual apertures have a first end153; and an opposite, second end154. The respective apertures further have a vertically oriented portion155, and a substantially horizontally oriented portion156. As best seen by reference toFIG. 24, the individual apertures152are substantially curvilinear in shape.

The transfer implement140includes a pair of arms160which extend substantially normally, outwardly relative to the inside facing surface150of the main body142. In this regard, each of the arms includes a first arm161, and a second arm162of substantially identical dimensions. Each of the arms161and162has a generally upwardly oriented surface which has a number of repeating undulations or grooves163formed therein. The upwardly facing surface may be coated or treated with a material which protects and does not substantially contaminate the semiconductor articles while being transported.

As best seen by reference toFIGS. 2 and 7, a gap164is defined between the first and second arms161, and162. It should be recognized that the gap164is larger than the gap64which is defined between the first and second base combs61and62respectively.

The transfer implement140is moveable along a given course of travel170. The course of travel comprises a first component171, (FIG.24); a second component172(FIGS.5and6); and a third component173(FIG.27). The first and third components171, and173, are substantially parallel to each other, and the second component172is substantially transversely disposed relative to the first and second components. As will be recognized, the transfer implement140, while traveling along the first course of travel171, cooperates with the individual engagement members100at the end of the first course. Continued movement of the transfer implement140along the second component172, imparts force to the retainer assemblies, thereby effectively urging the retainer assemblies along their respective paths of travel130, from the first position131, to the second position132. Further, the movement of the transfer implement140along the second course172brings the semiconductor articles, here illustrated as a plurality of silicon wafers180into resting relation onto the object receiving assembly63.

FIG. 24shows that the transfer implement carries the individual wafers or other articles in spaced, substantially parallel relation in a batch array.

The transfer implement140while moving along the first course of travel171cooperates with the respective engagement members100by receiving the respective engagement members in the individual apertures152. As seen inFIG. 25, when the transfer implement140is located at the end of the first course171, and at the beginning of the second course172, the respective engagement members are located at the first end153of the individual apertures152. As best understood by a comparison ofFIGS. 5 and 6, movement of the transfer implement141along the second course172has the effect of urging the individual engagement members along the sides of the respective apertures152, from the first end153, to the second end154thereof. This movement of the engagement members100along the individual apertures152draws the engagement members100generally radially inwardly, thereby defining the paths of travel130which are substantially arcuate in shape (FIG.23). It is also noteworthy that the apertures152are shaped to allow installation over the engagement members100for the entire range of positions which the engagement members can assume.

The article or object receiving assembly63carries or cradles the individual silicon wafers180in substantially the same orientation as the transfer implement140.FIG. 27shows that the object receiving assembly63passes through the gap164which is defined between the first and second arms161and162as the transfer implement164moves along the second course of travel172. Once the plurality of wafers180are disposed in rested relation on the article receiving assembly63, the transfer implement140moves along the third course of travel173out of the cavity43. As will be seen by a study ofFIG. 27, the movement of the individual retainer assemblies80along the paths of travel130between the first position131and second the position132orients the first longitudinally disposed members121in tangential, force engaging relation relative to the peripheral edge181of wafers180. This effectively secures the individual wafers in substantially coaxial alignment relative to the axis of rotation of the rotor frame20.

Upon rotation of the rotor frame20, the second longitudinally disposed member122is acted upon by centrifugal force thereby further urging the first longitudinally member121into increased radially inward force transmitting relation relative to the wafers180.

In addition to the centrifugal biasing which occurs, the biasing member102is a spring or other member which operates when the retainer assemblies80are in their first, or open position131to bias and urge the retainer assemblies80. The retainers are biased in the direction of the first position131, and in the direction of the second position132. This accomplishes the desired conditions of either being held in the opened or closed retainer positions.

To remove the individual wafers180from the rotor frame20, the reverse of the process outlined above would be followed. In particular, the transfer implement140would move along the third course of travel173into the cavity43. At the end of the third course of travel173, the engagement members100would be received in the apertures152, and oriented at the second end154thereof. The transfer implement140would then travel along the second course of travel172, in the direction of the first course171. This movement of the transfer implement140effectively moves the engagement members along the path of travel130, from the second position132, to the first position131. As will be recognized, this movement causes the longitudinally disposed members121to move out of tangential force engaging relation relative to wafers180.

At the end of the second course, the engagement members100are oriented at the first end153of the respective apertures. Further, as the transfer implement140moves along the second course172, the individual arms160engage, and cradle the wafers180thereby lifting them out of engagement with the article receiving assembly63. The transfer implement then moves along the first course of travel171out of the cavity43and on to another work station.

Operational Description of First Rotor and Transfer Implement

The operation of the preferred embodiment of the present invention is believed to be readily apparent but is briefly summarized at this point.

The centrifugal processor rotor10is best seen by a reference to FIG.23. The centrifugal processor rotor10for treating semiconductor articles, such as silicon wafers180, includes a rotor frame20defining a cavity43. A retainer assembly80is borne by the rotor frame20and positioned in the cavity43. The retainer assembly80is moveable along a path of travel130from a first, open position131, to a second closed position132. An object receiving assembly63is borne by the rotor frame20and positioned in a given location in the cavity43. The object receiving assembly63supports the semiconductor articles in the cavity43for centrifugal processing.

Still another aspect of the present invention includes a centrifugal processor rotor10for treating semiconductor wafers180comprising a rotor frame20defining a cavity43and having a predetermined axis of rotation. A pair of retainer assemblies80are borne by the rotor frame. Each retainer assembly80is rotatable about a given axis, and has at least one member121which moves along a given path of travel130from a first position131to a second position132. An object receiving assembly63is borne by the rotor frame20and is located in the cavity43. The object receiving assembly positions the semiconductor wafers180in substantially coaxial alignment relative to the axis of rotation of the rotor frame20. A transfer implement140is moveable along a course of travel170into, and out of, the cavity43. The transfer implement140supports the plurality of silicon wafers180in a predetermined orientation. Upon movement of the transfer implement140along the course of travel170, the transfer implement140cooperates with the retainer assemblies80, and further movement of the transfer implement140along the course of travel170following mating cooperation with the retainer assemblies80, carries the semiconductor wafers180into resting relation onto the object receiving assembly63. This movement of the transfer implement140along the course of travel170simultaneously urges the longitudinally disposed members121of the respective retainer assemblies80along their individual paths of travel130from the first position131, to the second position132.

Still a further aspect of the present invention includes a method for centrifugally treating a plurality of semiconductor wafers180. The method for treating semiconductor wafers180comprises providing a rotor frame20which defines a cavity43; providing a movable retainer assembly80which is borne by the rotor frame20, and which moves along a given path of travel130; providing an object receiving assembly63which is borne by the rotor frame43; providing a transfer implement140which is moveable along a given course of travel170, and which carries the plurality of silicon wafers180in a predetermined orientation into the cavity43; urging the transfer implement140along the course of travel170, the transfer implement140while moving along the course of travel170cooperating with the retainer assembly80, and effectively imparting force to the retainer assembly80to urge the retainer assembly80along its respective path of travel130, while simultaneously carrying the individual wafers180into rested relation onto the object receiving assembly63. The retainer assembly80secures the individual semiconductor wafers180in fixed substantially coaxial orientation relative to the rotor frame20. The method further includes the step of imparting rotational movement to the rotor frame20thereby creating centrifugal force which acts upon the respective semiconductor wafers180by means of the retainer assembly80.

Therefore, the centrifugal processor rotor10of the present invention provides a convenient means by which semiconductor articles, such as a plurality of semiconductor wafers180, can be centrifugally processed in a manner which avoids the shortcomings identified with the prior art practices and other devices.

Description of Second Rotor and Transfer Implement Assembly

FIGS. 8-11show a further preferred rotor and transfer implement combination according to this invention. This combination includes a rotor assembly310which bears similarity to rotor10described above. Parts which are common to both rotor constructions and transfer implement constructions are similarly numbered with regard to the second embodiment using numbers in the 300's and 400's in lieu of numbers ranging from 10 up into the 100's. Corresponding parts with corresponding reference numbers are determined by adding 300 to the first embodiment reference numbers. Not all features have been numbered in both embodiments to simplify and clarify the illustrations. Description of the common features of both embodiments will not be repeated. Additional description is provided below in connection with changed or noteworthy aspects of the second embodiment.

FIG. 28shows the robotic transfer device15having first, second, and third arm portions501,502and503, respectively; which can also be thought of as upper arm501, forearm502and hand503. The second embodiment engagement implement440is mounted at the distal end of the mechanical arm assembly15.

The transfer implement has cantilevered arm members460which extend from the face plate441. The upper and inward surfaces of the arm members have array support features in the form of grooves463(FIG. 31) and intervening ridges or projections which act to space the wafers180into the spaced parallel batch array.

The face plate also serves as a retainer actuator in the form of two apertures452which are appropriately shaped to provide camming or similar displacement action when the implement is engaged and moved relative to lever arms521. Lever arms521are pivotally mounted in the front rotor plate321.

Apertures452form part of an article retainer operator which functions to pivot lever arms521.FIG. 29shows how the lever arms can be pivoted between upper or retracted open positions shown in solid lines, and lower or contracted closed positions shown in phantom lines. This is accomplished by lowering the transfer implement downwardly from the upper or loading and unloading position shown inFIG. 30to a lowered retracted position shown by phantom lines531in FIG.30. To function in this capacity the retainer operator apertures452are positioned over the lever arm end extensions522. The transfer implement is then raised to move the lever arms up and into the open positions. The transfer implement is lowered to move the lever arms down and into extended or closed positions.

FIG. 28further illustrates that the transfer implement440can be used to mount a visual sensing subsystem600. Visual sensing subsystem600is advantageously used to monitor the position of the transfer implement, and to monitor the condition of the rotor. The visual sensing subsystem utilizes a television camera or similar image detection device601. Image detector601can be a charge coupled device image detector similar to video cameras or other suitable sensors. The image detector601has a light gathering lens602which collects light beamed toward the lens over a viewing range which is only partially suggested by view lines605shown in FIG.28. The lens602is positioned adjacent to a viewing opening611(FIG. 30) formed in the transfer implement face plate441. The image detector601is advantageously mounted to the face plate441using a camera mounting bracket613which is adjustably secured thereto using suitable fasteners614which are received through slotted mounting apertures615which allow vertical adjustment. The camera can alternatively be mounted directly upon the robot or at other suitable locations using a variety of adjustable mounts. The output signals from the image detector601are communicated via a suitable signal cable620or other suitable image conveying conduit.

The image information from camera601is communicated to a computer which serves as the central control processor. The image information is utilized with supporting image analysis computer software which allows items of the machinery to be recognized and used to verify proper operating conditions. Such image analysis software is commercially available from several sources. The software is customized to recognize specific features such as the lever arm end extensions522, so that verification can be had that the lever arms are retracted upwardly and are not positioned downwardly such that installation of a batch of wafers would cause interference and breakage of the wafers as the batch is attempted to be installed within the rotor310. Other verifications can also be performed using the image detection subsystem, such as explained below.

FIG. 28shows the preferred second embodiment rotor310in side elevational detail. The front and back rotor parts321and330are joined by several longitudinal rotor frame members340which are spaced about the rotor at suitable radial positions. This provides an annular rotor frame or framework320.

The front part321of the rotor frame is provided with a receiving opening323. The receiving opening allows a batch of wafers to be installed within the rotor. In the preferred version shown the wafers180are not supported upon any carrier or other array supporting piece or pieces which stay in the processing chamber. Instead the wafer batch array is installed into the processing chamber in an array formation defined by the transfer implement, and then transferred to a receiver which is on the rotor.

The receiver is generally referred to by the reference number363. The receiver advantageously includes a receiving space or cavity343adjacent the receiving opening323. In the preferred construction shown, the receiving cavity is substantially encompassed along the sides and rear end within the rotor frame320. The rotor frame is left with numerous open spaces to allow fluid access to the batch array of wafers when held in the receiver.

The receiver assembly also preferably includes one or more receiver array supports350. As shown, array supports350are provided in the form of combs having receiving grooves and intervening ridges or projections. The edges of wafers are captured in the receiving grooves and spacing between adjacent wafers is maintained by the intervening projections. The receiver363includes four stationary supports350each being fitted with the support combs which directly contact the edges of the wafers.

The front piece321of the rotor frame includes the receiver opening323. The receiver opening is preferably provided with cutouts563which allow sufficient clearance for the transfer implement to move downwardly and transfer the edges of the wafers into supporting contact with the supports350. Sufficient clearance is also provided to allow the transfer implement to move downwardly to allow free travel clearance between the transfer implement supports on arms460and the adjacent portions of the wafers resting in the receiver supports350. This downward transfer and clearance is illustrated in FIG.30.

The rotor assembly310further includes a complementary pair of retainer assemblies380. The retainers380each include a longitudinal main retainer member390which is mounted for pivotal action by front and back retainer end pieces384and385. The front and back end pieces extend through apertures formed in the adjacent rotor frame pieces321and330, respectively. Bushings or other suitable bearings386are provided to improve pivotal support. The front end pieces384are connected to the lever arms521. Lever arms521and end extensions522serve as part of the retainer operators used to operate the retainers between open and closed positions.

The rear end pieces385are connected to a rear lever arm596. The rear lever arm has a ball (not shown) mounted at the distal end thereof. The ball engages with either or two detents (not shown) formed along the rear face of the rear rotor part330. This construction provides a restraint which maintains the retainers in either open or closed positions.

The retainers380also preferably include contacting bars which have undulating groove and projection faces similar to the stationary receiver members350. Biasing springs are not shown similar to spring102, but could be utilized to add additional biasing forces to the retainers into the open, closed or both positions.

The retainers380are preferably constructed so as provide automatic centrifugal motivation which urges the retainers into a closed position to engage and securely hold wafers or other articles being processed. This is preferably done by providing appropriate balance to the main retainer member390relative to the pivotal mounts at each end. When the rotor rotates the center of gravity of the retainer assemblies causes the retainer support members to pivot into a closed position wherein the support members are extending inward in a nearly radial orientation toward the rotational axis. It is even further preferred that the centrifugal forces and balance of the assemblies be designed to pivot the retainers slightly past a radial line in order to more securely hold the retainers in a closed position and keep it affirmatively in that position using the detent construction and mechanical engagement between the retainers and the wafers or other articles being retained in the rotor.

Operational Description of Second Rotor and Transfer Implement

The processing system preferably operates using certain methods for centrifugally processing batches of semiconductor articles, such as the illustrated wafers180. The novel methods can according to one aspect of this invention involve supporting plural semiconductor articles in a batch array upon a suitable transfer implement, such as the transfer implements140and440described herein. The batch of articles typically are relatively thin wafer shaped articles which can be circular disks or panels having other possible shapes. The supporting advantageously involves arranging the articles in a spaced parallel relationship to form the batch processing array. The articles are preferably spaced approximately equal amounts, although irregular spacings may bear some advantage in particular circumstances. The articles can be supported upon peripheral edges thereof to form the array. The supporting step is preferably done by inserting the peripheral edges of the articles within grooves or receptacles formed along supporting surfaces of the transfer implement, such as at grooves163or463. The supporting can also be defined to include abutting the marginal portions of the wafers or other articles against the intervening projections formed between the grooves to provide endwise support against displacement in the longitudinal directions.

The novel methods can in another aspect of the invention include moving the transfer implement and supported batch array to and into a processing station, such as processing stations19, which are adapted to receive and support the batch array which is formed without a carrier which remains in with the wafers throughout centrifugal processing. The moving step or steps include moving the batch array on the implement to the processing station and aligning the batch array with a processing vessel main opening, such as opening203(FIG.31). The aligning operation occurs by positioning and orienting the array on the implement so as to be approximately aligned with the receiver formed on the rotor, such as receiver463on rotor310.

The moving step can additionally be defined by inserting the batch array of articles through the main opening of the processing vessel. Such inserting step can be accomplished by positioning the transfer implement and supported batch array within the receiver, such as receiver463.

In order to minimize potential damage to the wafer or other articles held in the batch array, it is preferable to include a retainer open positioning step which causes positioning of the movable article retainers, such as retainers81and82, into retracted or open positions. In the retracted open positions the retainers are laterally withdrawn away from the receiver opening to allow clear access for insertion of the batch array and supporting transfer implement in through the receiver opening and into longitudinally aligned or appropriate stopping position within the receiver. The opening or positioning of the retainers is advantageously accomplished at the end of the prior cycle of processing when the transfer implement is moved upwardly, thus engaging the retainer actuators in the form of receptacles152with the ends of the retainers to effect a lifting operation of the retainers. This lifting causes the retainers to be actuated and repositioned into the open positions.

During the loading of the receiver, the methods further preferably include the step of engaging the batch array with the receiver to support the plural semiconductor articles using the receiver in a batch array upon the supporting features of the receiver. This is advantageously accomplished by lowering the transfer implement as indicated inFIG. 30in phantom lines531. The step of lowering or otherwise displacing the transfer implement and supported wafers laterally with respect to the longitudinal axis of the array and axis of rotation, causes a transferring to occur. This transferring results in transfer of the wafers from the transfer implement onto supporting surfaces and features of the batch receiver. This transferring is preferably done in a manner which involves longitudinally aligning corresponding grooves which are on the transfer implement with receiving grooves in the article receiver. This results in the individual semiconductor articles being supported in a manner the same or substantially similar to the supporting step described above in connection with supporting the articles in a batch array on the transfer implement, as explained above.

In another aspect the novel methods preferably include repositioning or otherwise moving at least one movable article retainer into a closed position. This effects a retainer closing operation. In such closing operation and associated closed position, the article retainer or retainers are in juxtaposition with the plural semiconductor articles held in the receiver. More preferably, the article retainers are in direct physical contact with the semiconductor articles, such as along peripheral edge surfaces thereof. The article retainer or retainers are repositioned in a retainer close positioning step. This retainer close positioning step is performed using the preferred embodiments shown, as a simultaneous operation or actuation associated with the engaging step described above, although simultaneous actuation may not be needed in some forms of the invention. This closing is effected in a manner which is the complement of the retainer opening operation or open positioning step described above.

The methods further include retracting or withdrawing the transfer implement from the processing chamber. This is advantageously done using the robotic transfer15and moving the transfer implement outwardly along a line of travel which is in the same approximate orientation as the travel into the processing chamber.

In the close positioning step the transfer implement moves downwardly or otherwise in a laterally displacing mode of action. This causes force to be transferred between the transfer implement retainer actuator openings, such as openings152and452, against the exposed ends or the retainer mechanisms (100and522), bringing about movement of the retainers81,82and381,382into the closed positions. In these closed positions the contacting surfaces of the retainers may either be slightly spaced or brought in direct physical engagement with the articles being processed so as to effect an initial or preliminary urging or biasing which involves forcing of the semiconductor articles. This preliminary forcing or urging helps to seat the articles within the receiver grooves and minimizes the chance of vibration or movement of the articles, particularly as the rotor increases in angular speed. Such movement can be problematic in some processing operations, and is more generally undesirable.

In other aspects of the invention, the methods further include closing the processing chamber opening using a movable processing chamber door to provide a substantially enclosed processing chamber. In the embodiment shown inFIG. 31this is accomplished by moving the processing chamber door202upwardly and across the opening203. Other configurations are alternatively possible.

The methods further include rotating the rotor and supported wafers or other semiconductor articles. The rotating step is preferably performed to provide better access to processing fluids supplied to the processing chamber. The supply of processing fluids can occur in the form of liquids sprayed into the processing chamber, or gases which are emitted into the processing chamber. The rotating action is further useful without fluid application to spin liquids from the surfaces of the articles being processed, and to aid in drying liquids from the exposed surfaces of the wafers. The centrifugal action provides improved gaseous contact to aid in drying or other gaseous processing phases.

The novel methods further include maintaining or biasing the articles into their desired processing positions during centrifugal processing. This is advantageously accomplished by providing automatic centrifugal biasing action using the article retainer operators. The article retainer operators respond to centrifugal forces developed during rotation of the rotor. The retainer operators preferably have a restraining means, such as the biasing spring member102or the detent restraint which help to lock the restraints into the closed position during rotation. The restraining action can also be accentuated by designing the balancing of the retainer operators such that the contacting surfaces of the retainers go past a radial orientation which is pointing directly at the central axis of rotation and positions the retainer operators beyond this point to produce an action which maintains the retainers in a fully closed position until they are affirmatively released by the retainer actuator provided in the form of the transfer implement and its opening operation described above.

The methods can also further include opening the processing chamber opening by retracting the movable processing chamber door. This is done in a manner complementary to the door closing step listed above.

The novel methods also preferably include verifying retainer positions before any insertion of the transfer implement is attempted. This helps to reduce the risk of possible damage to the machine or articles being processed. The verifying can be performed in anticipation of the unloading phase of the processing. Verifying can best be accomplished using the image sensor601which looks at the open processing chamber and recognizes either or both the lever arms521and ends522using image analysis software which is commercially available. If the lever arms are in a closed position, then it is appropriate for the transfer implement to proceed with insertion to progress in unloading the machine.

Verifying steps can also be used prior to unloading to verify that the retainer actuator lever arms are in the desired closed positions. Additional verifying can be performed after loading the articles into the rotor, to assure that the retainers are in closed positions before spinning the articles.

The novel methods also preferably include inserting an unloaded transfer implement into the processing chamber to unload the batch array from the rotor. The inserting step is best prefaced with a set of moving and related steps explained above in connection with the transfer implement when loaded with a batch of articles. In the case of inserting and moving the unloaded transfer implement the arms140and160are inserted in a complementary relationship avoiding the receiver supports63and463. The transfer implement is brought into the receiver opening in a relatively low condition associated with insertion to load and retraction after loading the wafers onto the rotor article receiver. The steps further include longitudinally aligning or stopping the transfer implement in a desired position in anticipation of lifting and transferring the articles onto the transfer implement. The axial aligning step brings corresponding grooves of the article supports into registration.

The novel methods in another aspect include lifting or otherwise laterally displacing the transfer implement to cause an engaging of the articles supported on the receiver article supports. This effects a transferring and brings the transfer implement into a supporting action for the articles.

The lateral displacing action of the transfer implement also preferably causes a simultaneous actuation of the article retainers on the rotor. This releases the wafers or other articles and allows upward or other appropriate lateral displacement so that the wafers are brought into a retractable orientation and position for removal of the articles from the processing station.

The methods also in another aspect include retracting the transfer implement and supported batch array of articles from the processing station.

In further aspects the retracted batch array can then be prepared and controlled for repeating some or all of the above processing steps at a second or subsequent processing station as the particular requirements may be.

Control System

FIG. 32shows a preferred control system used in processor11. The control system advantageously uses a modular design which incorporate commercially available computer modules, such as Intel 80486 or equivalent based computer or computer boards, to perform various functions.FIG. 32shows the human operator interaction station704The first such station704has an associated control processor1341of conventional design and an electrically attached display and control panel705. Control and display panel704is accessible from the front or clean room side of processor11. Additional control stations can alternatively be provided at central processing control rooms, at the grey room side of the processing system, or at other desired locations and connected to added input ports1360.

Control stations are connected using a standard network interface hub1350. Network hub1350is connected to a central controller, such as a computer file server1351. Hub1350can also be used to connect an outside control or monitoring station at ports1360for additional control capabilities, data acquisition, or monitoring of processing and control functions.

Hub1350is further connected to processor control modules1361-1363, which are also conventional computers without displays. Three processor station control modules1361-1363are each associated with processing stations19respectively. Similar, added modules are used as needed for the particular number and types of stations19used in system11. These station control modules allow independent processing routines to be run at the processing stations and for data to be recorded indicating the processing performed in each particular batch being run by each processing station.

Processing station control modules are connected to and interact with the processing station motors, plumbing, etc which are collectively identified with the processing station number19in FIG.32.

FIG. 32further shows an interface subsystem controller1381, which again is a computer. Interface subsystem controller381is electrically connected to various features of the interface subsystem to both control operation and receive confirmatory signals of movements and positions. The interface controller381is preferably connected to the interface section to receive signals through a number of optical fibers1386used to convey signals from positional encoders for the first and second carriages1382, limit switches1383which detect the limit of travel of the carriages and elevators, and wafer detectors1384which detect wafer carriers and wafers held in the interface section. The system is preferably constructed so that most or all sensed signals used in the control and operation of the interface are communicated by optical fiber to eliminate the risk of cross-talk between signal lines. The optical fiber transmitted signals are converted into electronic signals by an optical fiber signal converter1387which produces electronic signals which are communicated to computer1381.

FIG. 32still further shows a conveyor control module in the form of a computer1391without display which is electrically connected to various parts of the conveyor, such as the mechanical arm drive motors1256,1271and1301, encoder1220, and other components thereof not specifically illustrated.

The conveyor control module also preferably receives a number of signals through optical fibers1396. Optical fibers1396are used to convey signals from angular position encoders and motor encoders for the conveyor15which are for simplicity exemplified by encoder1220in FIG.32. Limit switches for the conveyor are exemplified by limit switch1278in FIG.32. Hall effect sensors1395are used in sensing operation of the motors of the conveyor. The system is preferably constructed so that all sensed signals used in the control and operation of the conveyor are communicated by optical fiber to eliminate the risk of cross-talk between signal lines and provide a smaller cable bundle which is moved in connection with tram motion up and down the track. The optical fiber transmitted signals are converted into electronic signals by an optical fiber signal converter1397which is connected to reconvey the signals to computer1391.

FIG. 33shows a preferred processing system1040according to this invention. Processing system1040includes a basic frame1041which provides structural support for related components. Processor1040has two fundamental sections, one of which is the interface section1043. The other fundamental section is the processing section1044.

The frame supports an enclosure envelope1045which inFIG. 33is shown partially removed adjacent the processing section for purposes of illustration. The enclosure envelope encloses a working space1046within portions of processor1040. Wafers1050are held and maneuvered within the enclosed working space. The wafers are moved between multiple processing stations1071-1073contained within the processing section1044. The working space can be supplied with a purge gas and operated at either slightly elevated or slightly reduced pressures relative to ambient atmospheric pressure.

The upper portions of processor1040are provided with an interface filter section1038and a processing filter section1039. These filter sections preferably employ HEPA type ultrafiltration filters. Air moving equipment forces air through the filters and downwardly into the working space to move contaminants downwardly and out through the back side of the processor.

The multi-station processor1040also preferably has a process station maintenance section1053which is separated from the work space1026by portions of the enclosure envelope1045. Processor1040also preferably has an instrumentation and control section1054mounted rearwardly from the interface section1043. Control section1054preferably includes various control equipment used in processor1040.

Maintenance section1053and control section1054are of potentially higher contamination levels due to the presence of various equipment components associated with the processing stations. The processor1040is advantageously mounted in a wafer fabrication facility with clean room access to the front of the processor along front panel1048. The maintenance and control sections are preferably accessed from the rear of processor1040through a gray room adjacent the clean room. Such gray rooms have fewer precautions against contamination than the clean room. This configuration reduces plant costs while allowing access to portions of the processor more typically needing maintenance.

The front of processor1040includes a front control panel1057allowing operator control from the clean room. Control panel1057is advantageously a touch screen cathode ray tube control display allowing finger contact to the display screen to effect various control functions. Control section1054also preferably includes a secondary control panel which faces rearwardly into the gray room so that operation can be affected from either front or back of the machine. All control functions and options are displayed upon the control panels to effect operation and set up of the processor.

As shown, wafers1050are supplied to and removed from the enclosed work space1046of processor1040using interface section1043. Wafers are supplied to the interface section in industry standard wafer carriers1051(detailed in FIG.37). The wafer carriers are preferably supplied in groups, such as a group of four carriers. The groups are placed upon a cantilevered shelf2101forming a part of a first carriage2100. Shelf2101extends through an interface port1056which is controllably opened and closed using a interface port door1059. Adjacent the interface port and control panel is a view window1058through which a human operator can see operation of processor1040.FIG. 33shows two wafer carriers1051positioned upon the cantilevered shelf2101. There are two additional positions available for two additional carriers which are left unloaded in FIG.33.

Wafer Tray

Refer toFIGS. 34 and 35which show the novel wafer tray1060in greater detail. Wafer tray1060includes an upper surface1061and a lower surface1062. The tray also has a first end1063and a second end1064. Sides1065extend between the first and second ends. Additional features of the tray surfaces will now be more fully detailed.

Upper surface1061has a series of wafer tray receivers1066. Wafer tray receivers1066each comprise a semicircular groove or channel having downwardly converging receiver sides1067. The converging receiver sides1067adjoin to a receiver bottom section1068which is a relatively narrow slot having substantially parallel slot walls. The slot section is sized to provide a width about 0-10% greater than the thickness of the wafers which are being received therein. The receiver bottom or slot section has bottom surfaces1069. The lower portions of the slot sections1068are formed so as to be intermittently closed at slot bottom surfaces1069and open along receiver drain apertures1070(FIG.35). The slot bottom surfaces1069exist along longitudinal foundation bars1075and side rail portions1076. The particular number of wafer tray receivers1066in any particular tray1060is variable. Typically, there will be 25 or 50 wafer receivers in order to correspond with the capacity of associated wafer carriers1051being used in other parts of the fabrication plant.

The upper surfaces of wafer tray1060also preferably include side land portions1079. The side land portions are formed to reduce overall height of the tray while maintaining the general semicircular receiver shape. The overall width of tray1060is appropriately sized so that more than approximately 50° of arc are seated, more preferably approximately 60°-80° of arc are encompassed for seating the wafers in receivers1066. Even more preferably the arc of the receiving channels is approximately 65°.

The wafer tray ends1063and1064are preferably planar and perpendicular relative to a longitudinal axis1080(FIG. 36) which extends perpendicular to the receiving grooves along the center point of the receiving groove arcs defined by bottom surfaces1069. Longitudinal axis1080also coincides with the centers of the wafers1050supported on the wafer tray. Tray ends1063and1064are advantageously provided with apertures1088for receiving a tool therein to allow handling of the trays with minimum contact, such as during cleaning.

Wafer tray1060has side rails1076which extend along both sides. The side rails have outer side surfaces1065which are advantageously formed to provide tray support features1080. As shown, tray support features1080include a tray side channel1081. Tray side channel1081has a downward facing bearing surface1082which bears upon supporting tools and equipment as explained more fully hereinbelow. Adjacent to surface1082, is an outwardly facing channel base surface1083. Bearing surface1082is preferably constructed to form an included angle of approximately 120° of arc relative to the channel base1083. Channel81further includes an upwardly facing third surface84which serves to complete the channel shape of the tray support features and provides increased structural engagement between the wafer tray and equipment which engages the tray using the tray side channels81.

The lower surface1062of tray1060is preferably formed with a downwardly facing contact or foot surface1086. As shown, foot surface1086defines a footprint with five longitudinal segments associated with side rails1076, longitudinal bars1075, and end panels1063and1064. The lower surface of the tray also is preferably constructed to have longitudinal base recesses1077between bars1075and side rails1076. Processing fluids drain from the wafers1050and wafer tray1060through the receiving slot openings1070and base recesses1077.

The novel wafer trays1060provide improved processing of wafers in processor1040. The improvements include improved access of processing fluids to the surfaces of wafers1050. The improved access of processing fluids occurs because there is less coverage of the wafers as compared to prior art carriers1051. Only relatively small marginal edge portions along the arc of the receivers is covered. Thus allowing almost full access to the faces of the wafers by processing fluids. The improved access to processing fluids in turn results in reduced processing times and greater uniformity and effectiveness of the processes upon the surfaces being treated. Wafer tray1060also results in a small combined size of the wafer batch within processor1040. This translates into a much smaller overall size of processor1040and reduced floor space requirements in clean rooms and adjacent gray rooms. Since the cost of floor space in these facilities is very high, the installed cost of the processing system40is kept relatively lower. These factors all attribute to better yields, improved quality and reduced costs of production.

Standard Wafer Carrier

Processor1040is designed to work in conjunction with a standard industry wafer carrier which is illustrated in FIG.37. Such carriers are available from a number of supplying manufacturers. Carrier1051has a holding trough1034with a series of edge receiving receptacles1035along side walls1036. End walls1037are typically provided with handles1038. The bottom of carrier1051is provided with a bottom opening (not shown) which is rectangular and defined between base rails1039.FIG. 37shows a wafer tray1060positioned beneath wafer carrier1051aligned to pass up through the bottom opening of the carrier. Wafer tray1060is sized to pass through the bottom opening.

Interface Section

The interface section1043takes the wafers from the wafer carriers and installs them onto the specially constructed wafer trays1060. The wafer trays provide improved processing of wafers1050. The interface section also preferably provides a holding or inventorying capability for both wafers awaiting processing and wafers which have been processed. Thus the interface section constructed as shown inFIG. 33functions as both an input subassembly, output subassembly and wafer holding station.

Interface1043is substantially enclosed by the enclosure envelope1045. Interface1043has open work spare portions connected to the portions of work space1046contained within the processing section1044. The interface includes a interface port1056formed through envelope1045. Interface port1056allows wafers to be loaded into and removed from processor1040. Interface port1056is preferably provided with a interface port closure in the form of a movable door1059. Movable door1059is powered and extends upwardly from below to close the port and is retracted downwardly to open the port. This construction allows the interface port door to be automatically controlled to the extent desired.

FIGS. 38-44show the principal operational portions of interface1043. These portions serve to provide a wafer transfer which transfers wafers from the industry standard wafer carriers1051and installs the wafers onto the novel wafer trays1060. Additionally, interface1043serves to hold wafer batches loaded onto the trays. These loaded tray batches are held for processing in the processor. Still further interface1043allows for the storage of unloaded wafer trays. As shown, interface1043also performs loading and unloading operations through interface port1056.

FIG. 38shows that the preferred interface1043has a base1099which is secured to frame1041. A first or lower carriage2100is mounted for movements, such as the preferred horizontal movement. A second or upper carriage2102is also mounted for horizontal movement. Interface1043also has four elevators1104which provide vertical movement.

Base1099in some respects acts as an extension of frame1041and further serves to separate the interface section compartment into an interface section portion of working space1046and a mechanical compartment1098(FIG. 33) which is below and subjacent to the working space and base1099. As shown, base1099is provided with four elevator openings2102which serve as apertures through which elevators2104extend.

Base1099also is provided with first carriage travel openings or clefts2106. Clefts2106receive portions of a first carriage support pedestal2107which extend downwardly from the first carriage beneath base1099. The pedestal extends down to a first carriage support track (not shown) which is below base1099in the mechanical compartment1098. Pedestal2107is connected to a first carriage operator (not shown) which is advantageously in the form of a rotatable linear screw drive operator similar to the operator described below in connection with second carriage2102.

FIG. 38also shows that interface1043includes two carriages2100and2102which are movable relative to elevators2104. Carriages2100and2102are preferably mounted for simple linear motion relative to the elevators. However, alternative configurations and movement patterns may be possible. Carriages2100and2102are independently operable or otherwise controllable to allow different relative horizontal positions and movements of the first and second carriages.

As shown, first carriage2100is positioned above base1099and below the second carriage2102. This preferred configuration results in the first carriage functioning as a lower carriage, and the second carriage functioning as an upper carriage. Elevators2104serve to move wafer batches between a first or upper carriage level associated with the first carriage and a second or lower carriage level associated with the second carriage.

First carriage2100includes an outer or forward portion forming a first section2111of the carriage. This outward section is in the form of a cantilevered shelf or carrier support projection2101. Carrier support projection2101serves to support wafer carriers1051thereon. First carriage2100is laterally movable to extend the carrier projection or overhang through interface port1056into the fully extended first carriage receiving position illustrated in FIG.33. The overhanging carriage shelf2101is provided with carrier support features which are advantageously in the form of carriage support ledges2109. The carrier support ledges are preferably recessed areas formed in the upper surface of shelf2101. The carrier support features are advantageously constructed to provide lateral support against unintended horizontal displacement in either X or Y directions (see FIG.33). The carrier support features also hold the carriers to prevent downward movement from a desired vertical or Z position, but allow vertical movement above the shelf for easy installation and removal of the wafer carriers.

The carrier support ledges2109or other carrier support features are preferably positioned adjacent or about first carriage transfer openings2110. The support ledges are most preferably peripheral recessed areas about the opening2110. Openings2110are provided to allow extension of the elevators2104therethrough. Extension of the elevators through openings2110is used in conjunction with the transfer of wafers between the wafer carriers1051and wafer trays1060in either incoming or outgoing directions.

First carriage2100also preferably includes a second or central section2112which includes a group of four first carriage pass-through openings2113. Pass-through openings2113extend through the deck of the first carriage to allow extension of the elevators therethrough. Pass-through openings2113also allow unloaded wafer trays1060to be passed upwardly and downwardly through the first carriage deck in a manner as explained more fully below.

First carriage2100is further provided with a third or rearward section2113. Rearward section2113includes an empty or unloaded wafer tray magazine or storage2115. The empty wafer tray storage is advantageously in the form of four arrays each having three receptacles to receive three wafer trays therein. The receptacles each include shoulder pairs which function as rests upon which the side rails1076of the wafer trays rest. The shoulder pairs are along arranged along opposing sides of an empty tray gallery2116which is common to all three receptacles of a single storage array2115. Galleries2116allow the heads of the elevators to extend upwardly to engage empty wafer trays and lift them for removal from the storage array. The empty tray gallery also extends through the deck of the first carriage, and is contiguous with and open to the adjoining pass-through openings2114.

The empty tray storage is also preferably provided with an empty tray storage roof panel2117which extends over and protects the empty wafer trays from downwardly drifting contaminating particles. The roof panels are supported by first carriage rear section support panels2118.

The first carriage is further advantageously provided with a second carriage pedestal inlet opening2119which allows a support pedestal of the second carriage to extend thereinto when the second carriage is moved forwardly.

Interface1043also includes the second or upper carriage2102. Upper carriage2102has an upper carriage deck2121which is supported by a second carriage support pedestal2122. Pedestal2122has a linear drive operator2123which is advantageously in the form of a rotatable screw drive2124which moves the second carriage forwardly and backwardly between retracted and extended positions.

The upper carriage is provided to function as a loaded tray holding or inventorying station. As shown, this function is accomplished by having the second carriage in a position above the first carriage, and provided with a series of loaded tray holders2125. Loaded tray holders2125are formed as receptacle ledges formed in the deck. The receptacle ledges are adjacent to second carriage elevator openings2126. Openings2126are preferably portal openings which have open entrances at the forward ends thereof. As shown, the upper carriage is configured to hold two groups, each group having four wafer trays in a four by two loaded wafer tray storage array.

Interface1043also includes elevators2104which have elevator rods or shafts2128and enlarged elevator heads2129. The elevator heads are constructed to engage the lower surface1062of wafer trays1060in a stable manner. Most preferably the upper contacting face15of elevator head2129is provided with four engagement projections2130at the front and back of the contacting face. The engagement projections are spaced and sized to fit within the longitudinal recesses1077of trays1060adjacent the end panels. This provides positive engagement against lateral displacement of the trays relative to the elevator head during automated handling of the wafer trays by the interface.

Interface1043is advantageously constructed to handle wafer carriers and wafer trays in groups or gangs of four at a time. Although this configuration is preferred, it is alternatively possible to have other gang sizes.

Operation of Interface Section

The operation of interface1043will now be described in connection with the series of drawings shown inFIGS. 39-44.FIG. 39shows the interface moved from the fully retracted positions ofFIG. 38into an initial loading position wherein the first carriage has been extended fully to position the overhanging carrier shelf2101through the interface port1056.FIG. 39also shows the carrier shelf loaded with four wafer carriers1051containing wafers1050. The carriers and wafers are positioned in the carrier support receptacle ledges2109over the wafer transfer openings2110. The second carriage2102is maintained in the fully retracted position.

After the wafer carriers have been loaded onto shelf2101, the first carriage is retracted. When sufficiently retracted, the interface port door1059is closed by extending the door upwardly. The first carriage continues to retract rearwardly until the elevator head2129is aligned with the stored trays held in empty wafer tray storage arrays2115. At this tray pick position, the first carriage is stopped and the elevators are aligned below the stored wafer trays. The elevators are then extended upwardly to engage and lift the lowest empty trays from the four storage arrays. The elevators are then stopped and held at a tray lift elevation position.

The first carriage is then retracted further to bring the passthrough openings2114into alignment with the elevators and elevated empty wafer trays positioned upon the heads of the elevators. At this pass-through position of the first carriage, the first carriage is stopped. The elevators2104are then retracted downwardly to pass the empty wafer trays through the deck of the first carriage. The empty trays are move downwardly until they are below and clear of the first carriage.

The first carriage is then moved rearwardly from the pass-through position into a transfer position. In the transfer position the first carriage is positioned so that the elevators and empty wafer trays held thereon are aligned with the bottom opening of the wafer carriers held in carrier holders2109.FIG. 41shows the first carriage in the first carriage transfer position.

FIG. 41further illustrates the transfer of wafers from the wafer carriers1051and their installation onto the wafer trays1060. InFIG. 41the elevators have been extended upwardly after the first carriage has assumed the transfer position. The transfer includes aligning the individual wafer receivers1066below the wafers1050held in carriers1051. As the elevators extend upwardly, the tray moves up, into and through the open bottom of carriers1051. The edges of the wafers1050are guided by the V-shaped receiver mouths having downwardly converging receiver side surfaces1067. The edges of wafers1050are guided by the receiver mouths into the relatively close fitting receiver slots or channels1068. The edges of the wafers bear against the wafer slot bottom surfaces1069. The bearing allows the wafers to further be lifted upwardly by the elevating trays1060.

FIG. 41shows the elevators fully extended with trays1060fully elevated and with wafers1050held in an aligned side-by-side array upon the trays. In this condition, interface1043has transferred the wafers and the loaded wafer trays are ready to be moved to the holding stations on second carriage2102. To accomplish this, the second carriage is extended outwardly and forwardly from the retracted position into an extended position, such as the fully extended position shown in FIG.42. In this position the second carriage has been moved forwardly so as to align the rearward gang of loaded tray holding receptacles2125with the elevated wafer trays. The elevators are then retracted downwardly to lower the loaded wafer trays into the receptacles2125. After the loaded trays have been received in receptacles2125, the second carriage can then be retracted rearwardly into a retracted holding position, such as shown in FIG.43.FIG. 43also shows the elevators2104fully retracted and the first carriage retracted with empty wafer carriers1051awaiting discharge from the interface section.

FIG. 44shows the first carriage repositioned into a fully extended carrier unload position. This position is also the initial load position shown in FIG.39. The empty wafer carriers are removed using a suitable means, such as manual removal by a human operator (not shown). Loaded Wafer are then loaded onto the overhanging shelf of the first carriage and the process illustrated byFIGS. 39-44is repeated for a second gang or group of carriers, wafers and trays. The second loading process differs only slightly from the process described above. One difference is that different trays are used from the empty tray storage magazines2115. Another difference is that the second gang of loaded trays are held in the outer or forward holding receptacles2125instead of the rearward tray holders used by the first gang of wafer trays.

Processing Section

The processing section1044of processor1040will now be described in greater detail. As shown, processing section1044includes three centrifugal processing stations1071-1073. Each processing station includes a processing chamber bowl2131which substantially encloses an internal processing chamber2132. A centrifugal processing enclosure door2134is mounted for controlled powered vertical motion between a closed upward position and a downwardly retracted open position. Preferred door constructions are shown in U.S. Pat. No. 5,302,120, which is hereby incorporated by reference.

Within each processing chamber is a suitable rotor for receiving loaded wafer trays, such as rotor2133detailed in FIG.50.FIG. 51shows a front view of rotor2133without a wafer tray loaded therein.FIG. 54shows a front view similar toFIG. 53with a loaded wafer tray positioned within the rotor. Rotor2133is specially constructed to receive and appropriately engage wafer tray1060using wafer tray engagement features as explained below. The resulting interlocking interengagement of the tray with the rotor substantially prevents dislodgement until appropriately removed.

Rotor2133includes three principal ring pieces2141-2143. The front ring2141has a beveled rotor opening2149. The front, central and rear rings are connected by connecting longitudinal bars2144and2145. Upper longitudinal bars2144are spaced from the wafer trays1060and are provided with inwardly directed longitudinal bumpers2146. Adjacent the wafer tray receptacle2136are three additional longitudinal bars2145. The inward edges of bars2145serve to guide and support wafer trays1060appropriately positioned within the wafer tray receptacle.

The wafer tray engagement features used in the wafer tray receptacle include a rotor tray receiving channel2136. The sides of receiving channel2136include rotor tray engagement projections2137. The rotor tray engagement projections are shaped and sized to complement and be received along the tray side channels1081. However, the tray side channels are substantially higher than the engagement projects because the trays are loaded using a tray engagement tool2180which inserts between the downward facing bearing surface1082of the tray and the upward surface of rotor engagement projections2137. Additionally, the clearance is preferably sufficient so that engagement tines2184can also pass through the available space during insertion into the rotor to retrieve a tray therefrom.

The wafer tray engagement features used in rotor tray receiving channel2136also include opposing side receiving flutes2138. Flutes2138receive the longitudinal side flanges1085of tray1060in relatively close fitting interengaging relationship. The bottom or foot surface1086of tray1060bears upon inwardly directed tray support surfaces2147on the longitudinal bars2145. This advantageously occurs between both outer support bars2145with both side rails1076of the tray, and along a central tray support bar2145and the center longitudinal foundation bar1075of the tray. Central longitudinal bar2145is advantageously provided with a bumper bar2148(FIG.51).

The processing stations are each independently driven by rotating assembly motors153and have other features of a centrifugal fluid processor as needed for the desired processing of that station. Additional details of a preferred construction of centrifugal processor are well-known.

The specific processing performed in processing stations1071-1073can each be different or of similar nature. Various liquid and gaseous processing steps can be used in various sequences. The processor is particularly advantageous in allowing a series of complex processes to be run serially in different processing chambers set up for very different chemical processing solutions. All the processing can be accomplished without human handling and in a highly controlled working space, thus reducing contamination and human operator handling time.

The processing section1044also includes a processing section portion of working space1046. This portion of the working space is frontward of processing stations1071-1073within the enclosure envelope1045. This processing section working space allows the tray conveyor described below to supply and remove loaded wafer trays to and from the processing stations.

Conveyor

Processor1040is advantageously provided with a mechanical wafer tray conveyor2140. Conveyor2140will be described initially with reference toFIGS. 45 and 46. The preferred conveyor includes a conveyor carriage or tram2156and a mechanical arm assembly2157which is mounted on the tram. The tram moves the mechanical arm assembly along a defined tram travel path. The mechanical arm assembly moves the wafer trays1060upwardly, downwardly, inwardly, outwardly, and adjusts the tilt within a range of available positions and orientations.

Tram2156has a base2160which connects with a base subassembly2165which forms part of the mechanical arm assembly. The complementary base parts2160and2165join to provide a combined base assembly which serves as a movable base for the mechanical arm assembly.

Tram2156moves along a guide track which defines the tram path along which the tram travels. The guide track is advantageously formed by upper and lower guide bars2158and2159which are mounted along the outward side of a track support member2161forming part of the frame. This construction allows the mechanical arm assembly to extend into cantilevered positions to reach processing stations1071-1073with good positional stability. The guide bars are engaged by track followers in the form of linear bearings2171which are secured to the inward face of the tram base2160. The linear bearings2171are advantageously provided with rod engaging rollers spaced at equal 120° arc positions about the guide bars2158and2159.

The tram is powered along the defined path guide track by a suitable tram driver, such as a track magnetic drive in the form of linear magnetic motor2163. Linear magnetic motor2163is most preferably a linear brushless direct current motor. Such a preferred tram driver uses a series of angled magnetic segments which magnetically interact with an electromagnet on the base of the robotic conveyor to propel the tram and attached mechanical arm up and down the defined path track.

The path position of the base2160along the guide track is precisely controlled using a positional indicating array (not shown) affixed to the front of the track support member adjacent to guide bars2158and2159. An optical emitter detector pair (not shown) are mounted upon base piece2160. The optical emitter detector pair serves as a track position sensor or indicator which reads the position of the tram base from the indicating array after proper calibration. The positional accuracy of the track position indicator is preferably in the range less than 0.003 inch (approximately less than 0.1 millimeter).

A forearm assembly is connected near the outer distal end of the upper arm assembly. The forearm assembly advantageously includes two forearms2172which are joined by a forearm connection member2174. The forearm assembly also uses opposing face panels2173(FIG. 47) to provide a strong and mechanically integrated forearm assembly which is resistant to twisting and provides a high degree of positional stability. The forearm assembly is connected to the upper arm assembly to allow relative pivotal movement about an elbow pivot axis2169.

The distal end portions of the forearm assembly support a hand assembly2176. Hand assembly2176is supported in a manner allowing pivotal movement about a wrist pivot axis2170. The hand assembly includes two complementary hand bars2177. Hand bars2177are joined together by a hand cross piece2178. The hand assembly also preferably includes a tray engagement tool2180which is mounted to the hand cross piece2178.

FIGS. 48 and 49show that the preferred tray engagement tool2180includes a complementary pair of hand extensions2181. Hand extensions2181are advantageously semi-cylindrical sections which form a cradle which engages the wafer tray1060. The hand extensions preferably engage the wafer tray along the side rails, such as along the outer side surfaces of the tray. More specifically, the hand extensions preferably are spaced to define a hand extension gap2182having parallel inside engagement edges2183. Tool engagement edges2183are received along the wafer tray side channels1081. The tool engagement edges are slid longitudinally along side channels81to position the tool for engagement with the wafer tray.

The ends of the hand extensions are preferably provided with end tines2184. When the hand extensions are lifted upwardly, the engagement edges bear upon the downward facing bearing surface1082of the wafer side channels. Simultaneously therewith, tines2184move upwardly to latch at the end of the wafer tray to prevent longitudinal slippage of the wafer tray upon the hand extensions. This latching places the tines along end surfaces of the wafer tray. The hand extensions can advantageously be provided with perforations2185to lighten the weight of the assembly.

FIG. 33Operation and Methods

The operation and methodology of processor1040have in part been explained above. Further description will now be given.

The invention further includes novel methods for processing semiconductor wafers and similar units requiring extremely low contamination. The methods can include providing a suitable processor, such as processor40described herein above and the associated subsystems thereof. Novel methods of processing such units preferably are performed by loading the wafers or other units to the system in carriers, such as wafer carriers1051. Such loading step is to a work space which is enclosed or substantially enclosed, such as working space1046. The loading step can include opening an enclosure door, such as door1059of the interface port to allow entry of the wafers. The loading preferably is done by opening the enclosure door and extending a loading shelf through an open interface opening, such as port1056. Positioning of the loading shelf can be accomplished by moving the first carriage outwardly into an extended loading position.

The loading is further advantageously accomplished by depositing the wafers held within wafer carriers onto an extended loading shelf which is positioned through the interface opening. The wafers held in the carriers are positioned by depositing the loaded wafer carriers onto the extended shelf. The first carriage is thereafter moved such as by retracting the first carriage and the extended cantilevered shelf. After retracting the shelf through the interface port the methods advantageously include closing the interface port door or other similar enclosure door.

The methods also preferably include transferring wafers to a wafer tray, such as tray1060. Such transferring preferably is done by transferring the wafer from a wafer carrier and simultaneously onto the wafer tray. This is done by lifting the wafers from the wafer carrier using the wafer tray. The transferring is advantageously accomplished by extending the wafer tray through an opening in the wafer carrier, for example elevating the wafer tray up through a bottom opening in the wafer carrier to lift the wafers. The transferring preferably is accomplished using an array of wafer receivers, such as receivers1066. The wafer receivers which receive the wafers are preferably spaced and parallel to allow the receivers of the tray to be extended to receive the wafers in an edgewise relationship. The receiving is most preferably done using receiving channels having converging side surfaces which perform a guiding function as the tray and wafers approach relative to one another. The receiving also advantageously includes positioning edges of the received wafers into receiver bottom sections1068which includes positioning the edges into slots having spaced approximately parallel receiving slots with surfaces along marginal edge portions which hold the wafers in a spaced substantially parallel array.

The transferring also preferably includes extending, such as by lifting, the wafers received upon the wafer trays so as to clear the wafer free of the wafer carriers. This clearing of the wafers installed upon the trays completes the transferring of the wafers to perform an installing of the wafers onto the wafer trays.

The transferring and installing operations can in the preferred embodiment be preceded by storing wafer trays in a wafer tray storage area or array. The wafer trays can be stored by slipping the wafer trays into storage receptacles, such as upon storage support ledges2109. The storing can occur by vertically arraying the unloaded wafer trays.

The wafer trays held within the storage receptacles are also preferably removed by unloading therefrom. This unloading can advantageously be done by elevating or otherwise by extending a tray support, such as head2129into proximity to and then engaging the head with the tray. The extending can function by lifting the engaged head and then moving to dislocate the lifted tray from the storage area. This dislocating can most easily be accomplished by moving the storage area, such as by moving the second carriage2102, most preferably by retracting the carriage.

The steps preceding the transferring step can also advantageously include passing the engaged wafer tray through a pass-through opening in the first carriage. The passing-through step can be accomplished by lowering or retracting the engaged wafer trays through the passthrough opening and thus placing the wafer tray in a position suitable for performing the transferring. The passing-through most preferably includes aligning the engaged wafer tray with the pass-through opening.

The steps preceding the transferring and installing process also preferably include relatively moving the engaged wafer trays relative to the wafer carriers to bring the engaged wafer trays into aligned position. This aligning step is most ideally done by retracting or otherwise moving the first carriage rearwardly until the wafer carrier opening and engaged wafer tray are aligned for transfer and installation.

After the transferring or other installing of the wafers onto the wafer trays, the loaded wafer trays are preferably inventoried, such as by holding upon the second carriage. This storing is in the preferred embodiments done by extending or otherwise moving the second carriage or other loaded tray storage relative to the loaded wafer trays. The loaded wafer trays can be stored by positioning them over a holding features such as holding receptacles2125. The positioning can be followed by lowering the wafer trays into the holders and then supporting the wafer trays by the wafer holders.

The loaded wafer trays can then be processed further by loading the wafer tray onto a wafer conveyor, such as conveyor2140. The loading onto the conveyor can be done by moving a wafer tray engagement tool into engagement with the tray. This engaging step is most preferably done by sliding portions of the wafer engagement tool along receiving features of the wafer tray, such as by sliding the engagement edges2183along receiving channels1083of the tray, most preferably along opposing sides of the wafer tray. The engaging can further be perfected by lifting or otherwise interengaging the wafer tray engagement tool with the wafer tray being moved. This is most preferably done by lifting the tool relative to the tray and thereby positioning a longitudinal engagement feature, such as tines2184, against a complementary surface of the tray so that longitudinal or other lateral displacement of the tray upon the tool does not occur due to movement.

The methods also preferably include moving the wafer trays to one or more processing stations. The moving can be done by tramming the loaded wafer tray along a defined guide track upon a movable tram. The moving or conveying step can also include horizontally positioning the wafer tray, and vertically positioning the wafer tray, and orienting the angular orientation of the wafer tray to enable the wafer tray to be positioned into a processing chamber. This functioning is preferably followed by loading the wafer tray into the processing chamber. This loading can be done by inserting the loaded wafer tray into a centrifugal wafer tray rotor. The inserting or other loading step can best be accomplished by sliding the loaded wafer tray into an engaged relationship with the rotor by receiving interengaging parts of the rotor and wafer tray.

The wafers which were inserted or otherwise installed into the processing chamber are then preferably further treated by processing with fluid processing materials, such as chemical processing fluids, liquid or gas; or heating, cooling or drying fluids, most typically gases.

The processing can also advantageous be centrifugal processing which involves rotating or otherwise spinning the wafers being processed, particularly when still installed upon the wafer trays. The spinning preferably occurs with the wafers positioned within a rotor which performs a restraining function keeping the wafers in an aligned array centered near the axis of rotation. The centrifugal processing can include a variety of spinning, spraying, rinsing and drying phases as desired for the particular articles being processed. Additional preferred processing parameters are included in the appendix hereto.

The processing can also include immersion processing, such as can be performed by the immersion processing station2414described above. Immersion station2414or other suitable station can perform processes which include positioning a dipper so as to allow installation of a loaded wafer tray thereon. As shown, this is down by raising the dipper arm upwardly and positioning the wafer holding basket with an open side forwardly. The mechanical arm can then function by inserting or otherwise installing or loading the basket with an open receiver for accepting the loaded wafer tray. After insertion and loading of the wafer tray onto the dipper movable assembly, then the dipper arm is used by moving the held wafers on the trays so as to process the wafers in the desired immersion tank. This dipping or immersing operation is preferably a submersing step which places the entire tray of wafers into the bath of processing chemical. Thereafter the wafers are processed by holding the wafers in the desired immersion position and conduction any monitoring desired while performing the bath processing.

The immersion processing methods can further include withdrawing the bathed wafers, such as by lifting the dipping arm upwardly. The wafer holding head is then preferably removed from the bath and is held in a draining condition to allow processing liquids to drain back into the bath from whence they were removed. The immersion processing can then be repeated for the second or other subsequent processing bath. After the bathing processes have been finished at any particular station then the mechanical arm is used by unloading the wafer trays from the dippers and the loaded wafer trays are moved to the next desired processing station.

The methods of this invention also include unloading the wafer trays from the processing stations, such as by engaging the loaded wafer trays with a tray engagement tool in processes similar to those discussed above. The engaged and loaded wafer tray is then preferably processed by relocating the wafer tray to a second processing station, such as by conveying by moving with the mechanical arm assembly. The relocating can include withdrawing the wafer tray from the processing chamber and moving to another processing chamber and installing the wafer tray therein. The processing can then be furthered using a processing sequence similar to that described or in other processing steps desired.

The wafer trays are also handled by conveying the wafer trays and supported wafers to a holding station and holding the wafers thereat. The holding awaits an interface unloading sequence which can be accomplished by transferring the wafer trays and supported wafers from the wafer trays back to wafer carriers. The transferring or retransferring step back to the wafer carriers is essentially a reverse of the transferring and installing steps described above. Such advantageously includes unloading the wafer trays from the holding area, such as by lifting loaded wafer trays from the holding receptacles. The lifting or other removing of the wafer trays from the holders is advantageously done by extending an elevator head through an aligned wafer carrier and elevating the wafer trays. The holders are then moved in a relative fashion from the lifted or otherwise supported wafer trays. This is advantageously done by moving the second wafer carriage, such as by retracting the wafer carriage rearwardly away from the supported wafer trays. The relative moving of the removed loaded wafer trays and holders allows the wafer trays to be lowered or otherwise retracted. The retracting is best performed by lowering the wafer tray downward after aligning the wafer tray with a wafer carrier. The lowering causes a transferring of wafers from the wafer trays onto the wafer carrier.

The methods also preferably include retracting the elevators downwardly and beneath the first carriage with the supported and now unloaded wafer trays thereon. The first carriage can then be moved into the pass-through position by aligning the empty wafer tray with the pass-through opening. The empty trays can then be extended, such as upwardly, through the pass-through opening.

The methods then preferably include moving the transferred wafers held in the wafer carriers into an extended unloading position through the interface port. This is advantageously done by moving the first carriage forwardly and extending the cantilevered shelf out through the interface port.

The moving of the first carriage forwardly to accomplish unloading, can also be used to perform a storing function for the empty wafer trays into the empty wafer storage array. This is preferably done by elevating the wafer trays into an aligned storage position, such as at a desired aligned storage elevation and then moving the first carriage and attached storage gallery toward the engaged empty wafer tray. Once installed the empty wafer tray can be lowered into a storage position. The empty wafer trays are preferably stored in a downwardly progressing fashion when the elevator is used.

The wafer carriers and associated processed wafers are taken from the processor by removing the loaded wafer carrier from the cantilevered shelf after such has been extended out through the interface port or other unloading passageway. This is typically done by manually grasping the wafer carrier with the processed wafers therein.