Semiconductor wafer processing apparatus

Abstract
A processor for processing articles, such as semiconductor wafers, in a substantially clean atmosphere is set forth. The processor includes an enclosure defining a substantially enclosed clean processing chamber and at least one processing station disposed in the processing chamber. An interface section is disposed adjacent an interface end of the enclosure. The interface section includes at least one interface port through which a pod containing articles for processing are loaded or unloaded to or from the processor. The interface section is hygienically separated from the processing chamber since the interface section is generally not as clean as the highly hygienic processing chamber. An article extraction mechanism adapted to seal with the pod is employed. The mechanism is disposed to allow extraction of the articles contained within the pod into the processing chamber without exposing the articles to ambient atmospheric conditions in the interface section. The article processor also preferably includes an article insertion mechanism that is adapted to seal with a pod disposed in the interface section. The article insertion mechanism is disposed to allow insertion of the articles into the pod after processing by the at least one processing station. The article insertion mechanism allows the insertion of the articles without exposing the articles to ambient atmospheric conditions in the interface section.
Description




The present invention relates to an automated semiconductor wafer processing apparatus that is used, for example, to execute liquid and gaseous processing of wafers. Such an apparatus can be used to process semiconductor wafers, data disks, semiconductor substrates and similar articles requiring very low contaminant levels. More particularly, the present invention relates to such an apparatus having an improved input/output wafer handling system.




The processing of semiconductor wafers and the like has become of great economic significance due to the large volume of integrated circuits, data disks, and similar articles being produced. In recent years, the features used in integrated circuits and data disks have decreased significantly in size, thus providing greater integration and greater capacity. In addition, the diameters of semiconductor wafers have increased over time, providing greater economies of scale with respect to each processed wafer.




While the apparatus and methods utilized heretofore for processing semiconductor wafers 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, and as the diameters of the semiconductor wafers have increased, the need for more stringent control over contamination and breakage has become more acute.




A constant challenge in the production of semiconductors is the culmination of particle contamination. With respect to all types of semiconductor processors, preventing contaminant particles from entering into the processor enclosure is of paramount importance. Such particles can affect the photographic processes used to transfer the integrated circuit layouts onto the wafers being processed by causing deterioration of the image being transferred onto the wafer. Contaminant particles may also result in the altering of the characteristics of the device that is being manufactured.




One of the greatest sources of contaminating particles is the presence of environmental dust carried in the air surrounding the semiconductor processors. To reduce the amount of environmental contamination, semiconductor integrated circuit manufacturers have taken extreme measures to provide working areas with relatively low amounts of environmental dust. These areas are called “clean rooms”. Such working areas are expensive to build and operate. It is therefore preferable to limit the number and size of the clean rooms used to manufacture a particular device.




Another problem associated with traditional semiconductor processors relates to the fact that toxic and corrosive processing fluids, such as acids, caustics, solvents and other processing fluids are used in the manufacturing process. Such processing fluids must be maintained within controlled processing chambers to avoid corrosion and other harmful effects to personnel and materials outside of the semiconductor processor enclosure. Of concern are both liquid and gaseous forms of processing fluids, both of which should be prevented from exiting the processor chamber and contacting machine parts susceptible to corrosion. Thus, there exists a need to provide semiconductor processing equipment that adequately seals processing fluids inside the processing chamber during manufacturing and prevents them from escaping and causing damage.




The present inventors have recognized the foregoing problems and have addressed solutions for them in the apparatus described herein. The apparatus provides an improved system for batch wafer handling in automated semiconductor process equipment. Further, the apparatus provides a processing system which permits use of standard wafer containers or pods. Still further, the apparatus provides a processing system for multiple wafer container loading wherein air infiltration during the loading operation is minimized while also allowing continuous automated processing of the wafers.




In accordance with a further feature of the present apparatus, the apparatus is provided with an improved door actuating and sealing assembly that provides a fluid tight seal which prevents contaminant particles from entering a processing chamber and prevents processing fluids and vapors from escaping from the chamber.




BRIEF SUMMARY OF THE INVENTION




A processor for processing articles, such as semiconductor wafers, in a substantially clean atmosphere is set forth. The processor includes an enclosure defining a substantially enclosed clean processing chamber and at least one processing station disposed in the processing chamber. An interface section is disposed adjacent an interface end of the enclosure. The interface section includes at least one interface port through which a pod containing articles for processing are loaded or unloaded to or from the processor. The interface section is hygienically separated from the processing chamber since the interface section is generally not as clean as the highly hygienic processing chamber. An article extraction mechanism adapted to seal with the pod is employed. The mechanism is disposed to allow extraction of the articles contained within the pod into the processing chamber without exposing the articles to ambient atmospheric conditions in the interface section. The article processor also preferably includes an article insertion mechanism that is adapted to seal with a pod disposed in the interface section. The article insertion mechanism is disposed to allow insertion of the articles into the pod after processing by the at least one processing station. The article insertion mechanism allows the insertion of the articles without exposing the articles to ambient atmospheric conditions in the interface section.











BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS





FIG. 1A

is a perspective view of a semiconductor processing system in accordance with one embodiment of the invention showing the various stations of the input/output section and the general components of the processing section.





FIG. 1B

is a front perspective view of a semiconductor processing system according to the present invention with portions broken away to better illustrate some of the principal components thereof.





FIG. 1C

is a top view of the semiconductor processing system of

FIG. 1A

illustrating flow of semiconductor wafers therethrough.





FIG. 2

is a rear perspective view of the semiconductor processing system with some portions removed to better illustrate certain components.





FIG. 3

is a perspective view of an input/output subassembly of the processing system illustrated in FIG.


1


.





FIG. 4

is a perspective view of a load plate used in the input/output subassembly.





FIG. 5



a


is a perspective view of a wafer container in conjunction with the load plate and the elevator plate of the input/output subassembly.





FIG. 5



b


is a top view illustrating the transfer of a wafer container from the elevator plate to the load plate.





FIG. 6

is a perspective view of a preferred semiconductor inventory subassembly forming part of the processing system illustrated in FIG.


1


.





FIG. 7

is a perspective view of a container transfer forming part of the docking assembly of the processing system illustrated in FIG.


1


.





FIG. 8

is a perspective view of a hatch interface forming part of the docking subassembly of the processing system illustrated in FIG.


1


.





FIG. 9



a


is a front perspective view of a wafer transfer comb forming part of the transfer subassembly of the processing system illustrated in FIG.


1


.





FIG. 9



b


is a rear perspective view of the wafer transfer comb illustrated in

FIG. 9



a.







FIG. 10

is a perspective view of the conveyor for the wafer comb illustrated in

FIGS. 9



a


and


b.







FIG. 11A

is a perspective view of a wafer bunching comb forming part of the processing system illustrated in FIG.


1


.





FIG. 11B

is a cross-sectional view illustrating a groove of the comb of FIG.


11


A.





FIG. 12

is a perspective view of a semiconductor processor forming a part of the processing system illustrated in FIG.


1


and employing a novel door actuation and sealing mechanism.





FIG. 13

is a perspective view of the processor door actuation assembly.





FIG. 14

is a cross-sectional side view of the processor door in an open position.





FIG. 15

is a cross-sectional side view of the processor door in a closed position.











DETAILED DESCRIPTION OF THE INVENTION





FIGS. 1A

,


1


B, and


2


generally illustrate a processing system


10


which includes a basic frame


12


defining the walls of the processing system


10


. Generally stated, the processing system


10


is divided into two principal sections—an interface section


14


for receiving and inventorying semiconductor articles, and a processing section


16


, which contains one or more processing stations


3


for processing the semiconductor articles using, for example, liquid and/or gaseous processing procedures.




As illustrated, the interface section


14


is preferably divided into a plurality of stations. In the disclosed embodiment, the interface section


14


is comprised of a container access station


5


, an inventory station


6


, a container docking station


7


, and a wafer transfer station


8


. In operation, wafer containers


51


are inserted into the processing system


10


through a door


32


at container access station


5


. Each container


51


is then stored at the inventory station


6


until such time as the container is accessed by the components of the container docking station


7


. A wall


11


effectively separates the stations


5


,


6


, and


7


, from the wafer transfer station


8


. To this end, wall


11


is provided with one or more doors against which each container


51


may seal and allow direct access of the wafers contained in the container


51


without contamination by the exterior surfaces of container


51


. As such, the wafers in any given container


51


may be inserted into the processing section


16


of the processing system


10


without exposure to potentially contaminating environments.




With reference to

FIGS. 1A and 1B

, the frame


12


is constructed to form an enclosure that substantially encloses the processing system components and defines a working space


20


. The semiconductor articles, such as semiconductor wafers, are held and maneuvered within the working space


20


in relative protection from dust and contamination. The working space


20


can be supplied with purge gas and/or operated at either slightly elevated pressures relative to ambient atmospheric pressure.




The upper portions of processing system


10


are sealed with respect to the ambient environment and may be provided with an interface filter above the interface section


14


and a processing filter above the processing section


16


to provide the requisite filtering of ambient air before it enters the processing area


20


. These filter sections preferably employ HEPA type ultrafiltration filters. Air moving equipment, such as fans or the like forces air through the filters and downwardly into the working space


20


.




The processing system


10


also has a process station maintenance section and an instrumentation and control section that are separated from the work space


20


by portions of the frame


12


. Since these sections potentially have higher contamination levels due to the presence and operation of various equipment components associated with the processing stations, it is preferable to separate these sections from work space


20


. The processing system


10


is preferably mounted in a wafer fabrication facility with clean room access to the front of the processor


15


and with gray room access to the maintenance section and the instrumentation and control section rearward of the work space


20


. Such gray rooms require fewer precautions against contamination than clean rooms and, as such, they are less costly to build and maintain. The foregoing configuration thus reduces plant costs while allowing ready access to portions of the process system


10


more typically needing maintenance.




A front control panel


22


is disposed proximate the interface section


14


and allows operator control. The control panel


22


is preferably a touch screen cathode ray tube control display allowing finger contact to the display screen to effect various control functions. A secondary control panel may be included in the control section and accessed from the gray room so that operation can be effected from either front or back of the machine. All user programmable control functions and options are preferably displayed upon the control panel to effect operation and set up of the processing system


10


by a user.




Semiconductor wafers


50


are supplied to and removed from the enclosed work space


20


of processing system


10


through interface section


14


. The wafers are supplied to the interface section in industry standard wafer containers or pods


51


. The wafer containers are available from various manufacturers such as Empak, which sells a wafer container under the trademark CAPSIL.




As best illustrated in

FIGS. 5



a


and


5




b


, the wafer container


51


has a cover


52


which, when removed, allows semiconductor wafers to be inserted into and removed from the wafer container. Typically, the cover


52


is translucent to allow visual detection and optical scanning of the wafers within the container


51


. The wafer container


51


also includes a window


54


to permit viewing and optical scanning of the wafers. On the side opposite the window


54


, the wafer container


51


is provided with features to facilitate handling of the wafer container


51


by automated equipment. These features include a set of inner circular slots


55


, and a set of outer circular slots


56


. The manner in which the disclosed embodiment of the processing system


10


interacts with these features will be explained in further detail hereafter. The wafer containers


51


are sealed and can be supplied with purge gas. The number of wafers positioned within the container


51


can vary, but at this time, the industry standard wafer containers typically have a capacity for 13 to 25 wafers having a diameter of 300 mm.




In the disclosed embodiment, the interface section


14


functions as both an input subassembly for receiving wafers to be processed, and an output subassembly for withdrawing processed wafers. Additionally, the interface section


14


can provide a holding or inventorying capability for both unprocessed and processed wafers. The interface section


14


includes an input/output subassembly, generally indicated by the numeral


30


, which allows the wafer containers to be loaded into and removed from the processing system


10


. The subassembly


30


is disposed in station


5


of the disclosed embodiment of the system


10


.




The input/output subassembly includes an entry port, which is controllably opened and closed by the entry port door


32


. The entry port door


32


may be pneumatically powered by an air cylinder


33


or the like to slide upwardly and downwardly on a guide track


34


to open and close the port. The components within the input/output subassembly


30


are preferably operated so that they will not move until the entry port door


32


is closed, thus enabling the port door to function as a safety mechanism for the operator.




When the entry port door


32


is opened, one or more wafer containers


51


may be loaded onto a loading elevator


40


within container access station


5


. The loading elevator includes a container lift plate


42


which is adapted to receive a wafer container


51


. In the disclosed embodiment, the container lift plate


42


is provided with coupling pins


44


, which are mounted on the lift plate so that they are aligned and can be received within the respective inner slots


55


(

FIG. 5



b


) provided on the industry standard wafer containers


51


. As shown, the portion of the lift plate


42


between the coupling pins


24


is cut out, forming an almost pie-shaped cut-out


45


. This cut-out portion


45


permits the wafer container


51


to be transferred to a loading plate


60


, as will be described in further detail below. To assist with the positioning of the wafer container inner slots


55


onto the coupug pins


44


of the lift plate


42


, the upper edge of the lift plate


42


is provided with at least one guide block


46


. The lift plate


42


is carried on a guide track


47


, and is raised to an overhead position and lowered to a loading/unloading position adjacent the entry port door


32


by operation of a pneumatic cylinder


48


.




The loading elevator


40


allows the wafer containers to be loaded into the processing system in different ways. When the lift plate


42


is in its lower position adjacent the entry port door


32


, the wafer container


51


can be loaded laterally onto the lift plate either via human loading or automated robot loading. When the lift plate


42


is raised to its overhead position, loading can be accomplished vertically through an access door disposed through the top of station


5


through use of an overhead transport system.




With the container lift plate


42


in its overhead position, a wafer container


51


can be loaded onto the loading plate


60


in the input/output subassembly. As show in

FIG. 4

, the loading plate


60


is provided with coupling pins


62


, similar to the coupling pins


44


of the lift plate


42


, except that the coupling pins


62


on the loading plate are aligned with and adapted to be received by the outer slots


56


(

FIG. 5



b


) on the wafer container. The loading plate


42


also includes at least one mounting block


64


to assist in the positioning of the wafer container onto the loading plate. At its leading edge


65


, the loading plate has a pie-shaped projection


66


that is slightly smaller than and complementary to the cut out portion


45


of the lifting plate. As best shown in

FIG. 5



b


, the cut-out portion


45


allows the loading plate


60


to translate through the lift plate


42


to transfer a wafer container from the lift plate to the load plate, or vice versa, as described in further detail below.




The loading plate


60


is mounted on a guide track


70


for transverse horizontal movement in the direction of arrows


71


relative to the entry port door


32


. The horizontal drive mechanism is preferably comprised of a motor drive and belt assembly


72


, although other drive arrangements may be utilized. A second mounting and drive arrangement


75


mounts the loading plate


60


and includes various mounting arrangements and drive arrangements for moving the loading plate both vertically and rotationally about a vertical axis. The mounting and drive arrangement


75


include a drive arm


78


which is coupled via a mounting plate arrangement to the loading plate


60


. The drive arm


78


is preferably driven vertically by a motor and lead screw drive arrangement


80


to raise and lower the loading plate


60


. A motor and harmonic drive assembly


82


is coupled to the loading plate


60


to provide the rotational drive about a vertical axis


83


. The motor and harmonic drive assembly


82


rotates the loading plate 90°, from a position in which the leading edge


65


of the loading plate is facing the entry port door


32


, to a position in which the leading edge


65


is facing the container inventory subassembly


90


(see FIG.


1


B). Each of the drive mechanisms preferably includes an incremental encoder to control the positioning of the loading plate


60


and an absolute encoder to determine the relative horizontal, vertical, and rotational position of the loading plate


60


. The drive mechanisms operate in combination to position the loading plate


60


at the container inventory subassembly


90


(illustrated in

FIG. 1B

) to permit the wafer containers


51


to be transferred to and from the container inventory subassembly


90


.




The loading plate


60


can either receive a wafer container


51


from an operator through the entry port, or can receive a wafer container that has been placed and temporarily stored on the lift plate


42


to facilitate both input and output operation of the container access station


5


. In order to transfer the wafer container from the lift plate


42


to the loading plate


60


, the lift plate


42


is lowered to its load/unload position, and the loading plate


60


is rotated so that its leading edge


65


is facing the entry port door


32


. In this position, the loading plate


60


is below the lifting plate


42


. The loading plate


60


may then be raised so that the pie-shaped projection


66


of the loading plate translates through the cut-out portion


45


of the lifting plate


42


. As best shown in

FIG. 5



b


, during this action, the coupling pins


62


on the loading plate engage the outer slots


56


on the wafer container


51


, while the coupling pins


44


on the lifting plate are removed from the inner slots


55


on the wafer container, thus accomplishing a complete transfer of the wafer container


51


to the loading plate


60


. The loading plate


60


can then be rotated 90° to transfer the wafer container


51


to the inventory subassembly


90


.




Referring to

FIG. 6

, the inventory subassembly


90


includes a central horizontal hub


92


with a plurality of arms


94


radially extending therefrom. In the present embodiment, the number of arms is six, although other numbers of arms can be employed. Mounted on the end of each arm is a container carrier


96


having an upper and a lower shelf


97


,


98


, respectively. A bearing and timing shaft arrangement


99


mounts each container carrier


96


to an arm


94


. The bearing and timing shaft arrangement


99


may be coupled with a timing belt to insure that the upper and lower shelves


97


,


98


of each container carrier


96


always remain horizontal regardless of the relative position of the arms about the central hub


92


. Mounted on each arm


94


is a tension pivot assembly


106


which functions to reduce any play in the timing system. The upper and lower shelves


97


,


98


of each container carrier


96


include coupling pins


102


which are positioned on each shelf so that they are aligned with the inner slots


55


on the standard wafer container


51


.




A drive arrangement in the form of an indexer


104


with twelve preset index positions rotates the arms


94


with their container carriers


96


around the axis of the hub


92


from a preset loading position adjacent the input/output subassembly to a preset container transfer position 180° opposite the loading position. An absolute encoder


108


is mounted on the central hub


92


to detect the relative positions of the arms


94


.




In normal operation, each of the shelves will have a wafer container mounted thereon (twelve altogether) to facilitate the continuous processing of a full complement of wafers without interruption. The inventory subassembly


90


can, however, handle fewer than twelve wafer containers


51


depending on the batch processing requirements of the system user.




Detectors, such as, for example, optical sensors, can be mounted in fixed relationship with the frame


12


and positioned to optically scan the semiconductors wafers within the wafer containers as the containers are rotated about the central hub


92


. Preferably, such detectors are placed at a location adjacent the interface between the input/output subassembly


30


and the container inventory subassembly


90


, and at a location adjacent the interface between the container inventory subassembly


90


and a container docking subassembly


110


. Such optical scanning allows the processing system


10


to keep track of all wafers as they are processed through the system.




In operation, the indexer


104


rotates the arms


94


until a shelf on one of the container carriers


96


reaches a preset loading position adjacent the input/output subassembly


30


. A wafer container


51


may then be transferred from the loading plate


60


to the respective container shelf by moving the loading plate


60


until it is positioned above the shelf, rotating the loading plate until the inner slots


55


on the wafer container


51


are aligned with the coupling pins


102


on the shelf, and lowering the loading plate


60


so that the inner slots


55


are received by the coupling pins


102


. The loading plate


60


may then be rotated slightly to clear it from the shelf and then withdrawn. To unload the wafer container


51


from the inventory subassembly


90


for processing, the arm and the container shelf holding the wafer container


51


can be rotated 180° about the hub so that the wafer container can be accessed by the container docking subassembly


110


disposed in the container docking station


6


.




As best illustrated in

FIG. 2

, the container docking subassembly


110


includes a robotic conveyor


111


comprising a robotic arm


112


mounted on a carriage


114


for linear movement along a guided track


115


. The robotic arm


112


of the disclosed embodiment has three jointed segments—a lower or first segment


116


mounted to the carriage


114


, a middle or second segment


117


linked to the first segment via a timing belt arrangement or the like, and an upper or third segment


118


linked to the second segment. This robotic arm construction enables the arm to move up, down and back and forth while occupying a minimum amount of space. The third segment


118


has a horseshoe shaped appearance and permits the robotic arm to lift and separate the wafer container


51


from a container shelf within the container inventory subassembly


90


. Coupling pins


122


positioned on the third segment are adapted so that they may contact and be received within the outer set of slots


56


on the wafer container


51


to complete the transfer to the robotic arm


112


.




The carriage


114


, together with the robotic arm


112


, slide along the guided track


115


to a position adjacent to a container transfer subassembly, generally indicated at numeral


150


. As illustrated in

FIG. 7

, the container transfer subassembly includes a docking plate


152


mounted on a linear slide


154


for movement in the direction of arrows


151


. Coupling pins


156


are positioned on the docking plate


152


so as to align with the inner slots


55


on the wafer container


51


. The docking plate


152


also includes an aperture


158


for receiving a latch hook


160


which is sized and adapted to latch into a groove or the like located on the door of the wafer container


51


. The latch hook


160


may be mounted on a pneumatic slide which permits the latch hook to move towards and away from the wafer container


51


to latch and unlatch the wafer container


51


. Roller guides


164


are provided on the latch hook


160


to facilitate contact and engagement of the latch hook with the wafer container. An overhead frame


166


, mounted to the docking plate


152


, houses sensors for detecting the presence of wafers within the wafer container. Another sensor, such as a fiber optic cable, may be used to detect the presence of a wafer container on the docking plate.




The linear slide arrangement


154


slides the docking plate


152


into a position adjacent a hatch interface, generally indicated by numeral


180


in

FIGS. 1B

,


8


A and


8


B. The hatch interface


180


is disposed in the wafer transfer station


8


. Referring now to

FIGS. 8A and 8B

, the hatch interface


180


includes a hatch cover


182


which supports an interface plate


184


that is sized and adapted for sealing engagement with the door of the wafer container


51


The interface plate supports a perimeter seal


186


which seals the interface plate


184


with the wafer container door.




Vacuum cups


188


fit through apertures


190


in the interface plate to make vacuum sealing contact with the wafer container door and secure the door to the interface plate. T-shaped locking keys also extend through apertures in the interface plate and insert into receptors in the wafer container door. A rotary actuator


194


turns the locking keys to lock the wafer container door into sealing engagement with the interface plate. In the event of a loss of vacuum through the vacuum cups


188


, the T-shaped keys help to retain the container door against the interface plate


184


. The hatch cover


182


and interface plate


184


are mounted to a pneumatic cylinder assembly


196


, comprised of cylinder assemblies


196




a


and


196




b


, which allow the hatch cover and interface plate to slide forward and backward, and up and down, relative to the wafer container.




In operation, vacuum is applied to the vacuum cups


188


so that the container door is held in vacuum sealing relationship with the interface plate


184


. The vacuum seat traps any contaminants that might be on the container door and prevents them from entering into the processing section. The actuator


194


turns the keys to lock the container door to the interface plate. The pneumatic cylinder assembly


196




a


slides the interface plate


184


and hatch cover


182


backwards (i.e. away from the container), causing the container door to move with the interface plate. This opens the container and exposes the interior of the container to the clean environment of the processing section. The pneumatic cylinder assemblies


196




a


and


196




b


then cooperate together to slide the interface plate


184


and the hatch cover


182


, together with the container door, downward, and then forward (i.e. toward the container) to move the door out of the way for handling and processing of the wafers.




In a preferred embodiment, the processing system is provided with two container transfer subassemblies


150


, and two hatch interfaces


180


, as generally illustrated in

FIG. 2

, that are disposed within and proximate to the container docking station


7


. This allows one container transfer subassembly


150


to handle wafer containers


51


holding unprocessed wafers, while the other subassembly


150


handles containers


51


holding processed wafers, thus permitting efficient handling of the wafers.




The wafers are removed from the container


51


by a wafer transfer subassembly


200


disposed in the wafer transfer station


9


. The wafer transfer subassembly


200


includes a wafer comb


202


(see

FIGS. 9



a


and


9




b


) mounted on a carriage assembly


230


. (See FIG.


10


). Referring now to

FIGS. 9



a


and


9




b


, the wafer comb


202


comprises an outer comb frame


204


having outwardly extending engagement arms


208


, each of which carries a set of teeth


210


at the outer end thereof. The middle portion of the outer comb frame also carries a middle set of teeth


212


. A complementary-shaped inner comb frame


214


has an outer set of teeth


220


mounted on the outer ends of each of its engagement arms


218


and a middle set of teeth


222


mounted on the middle portion of the frame. The inner comb frame is positioned adjacent the outer comb frame such that the middle set of teeth


212


on the outer comb frame extend through an opening


224


in the inner comb frame, and the outer and middle sets of teeth


220


,


222


, respectively on the inner comb frame are adjacent the corresponding sets of teeth on the outer comb frame.




The outer comb frame


204


is slideable vertically with respect to the inner comb frame


214


. The inner comb frame


214


is in fixed positional alignment with the carriage assembly


230


. When the outer comb frame is in its lowest position, the teeth on the outer comb frame are aligned with the teeth on the inner comb frame in an “open” wafer comb position. In this position, the wafer comb


202


can be inserted into the open wafer container until the teeth of the wafer comb are interleaved with the wafers in the container. The wafers are held within the wafer comb by slightly lifting the outer comb frame


204


to the “closed” wafer comb position illustrated in

FIGS. 9



a


and


9




b


. Various mechanisms, such as a lead screw driven by a stepper motor, can be used to actuate lifting of the outer comb frame


204


. In this closed position, the teeth on the outer comb frame are offset with respect to the teeth on the inner comb frame, causing the wafers to be cantilevered on the outer comb frame teeth. The wafer comb is designed such that the individual teeth are canted down at a slight angle from horizontal, such as a 10 mm, pitch, to insure that the wafers remain positioned within the wafer comb.




To insure proper positioning of the wafers within the wafer comb, it may be desirable to provide the wafer comb with sensors. In one embodiment, sensors


226


are provided at each tooth of the middle set of teeth


212


on the outer comb frame


204


.




The carriage assembly


230


which mounts the wafer comb


202


is itself mounted on a guide track


232


for linear movement toward and away from the open wafer container


51


. The carriage assembly


230


includes a rotary drive mechanism


234


, such as a rotary motor


236


and harmonic drive


238


, for rotating the wafer comb 90° about a horizontal axis, from a horizontal position, to a vertical position, best shown in FIG.


2


. The carriage assembly


230


also includes a vertical drive mechanism


240


for lifting the wafer comb so that the wafer comb can deposit the wafers onto a wafer support in the form of a wafer bunching comb


250


(see FIG.


2


).




Referring to

FIGS. 11A and B

, the wafer bunching comb


250


has an upper surface


252


on which is provided a series of wafer-receiving grooves


254


. Each of the grooves has downwardly converging receiver sides


256


which adjoin a relatively narrow slot section


258


. The slot section has substantially parallel side walls and is sized to provide a width about 0-10% greater than the thickness of the wafers being received therein. The receiver sides help to insure proper insertion of the wafers within the grooves while minimizing contact with the wafer surface. The upper surface


252


and the slot sections therein are dimensioned to form an arc that generally corresponds to a segment of the diameter of the wafer. The particular number of grooves in the wafer bunching comb may vary. Typically there will be 26 to 50 grooves in order to correspond with the capacity of two of the associated wafer containers being used, so that the wafers from two wafer containers can be processed at once. Sensors


260


are provided on the upper surface


252


to detect the proper positioning of the wafers within the grooves.




The wafer bunching comb


250


has a longitudinal slot


262


that is sized to permit the vertical drive assembly


240


(see

FIG. 10

) of the wafer comb to pass therethrough. The vertical drive assembly


240


can lift the wafer comb until it is slightly higher than the wafer bunching comb


250


, and the horizontal drive assembly can linearly move the wafer comb until the vertical drive assembly is positioned within the longitudinal slot and the wafers are aligned with the grooves in the wafer bunching comb


250


. The wafers can then be lowered in a controlled fashion into the grooves in the wafer bunching comb.




Once the wafers are in place in the wafer bunching comb


250


, the docking assembly steps can be reversed so that the container door can be replaced onto the wafer container, the wafer container can then be retracted from the interface plate, and placed back onto a wafer container shelf of the inventory subassembly. The entire docking and wafer transfer processes can then be repeated so that the wafers from two wafer containers are positioned on the wafer bunching comb


250


.





FIGS. 1B

,


1


C, and


2


show a robotic conveyor, generally indicated by the numeral


280


, for conveying the wafers within the processing system, specifically between, to and from the bunching comb


250


and one or more processing stations, such as processing stations


290


. The robotic conveyor


280


includes a mounting beam or rail


282


upon which a movable conveyor robot subassembly


284


is mounted and moves relative to the rail.




The robotic device can be of various designs. In one design, the robotic conveyor comprises an articulated arm having an upper arm portion


285


, a lower arm portion


286


, and a hand portion


287


. Mounted to the hand portion is an engagement toot


288


for engaging the semiconductor wafers and delivering them to various individual or plural work stations. Further details of suitable conveyor devices and other aspects of the processing system are described in U.S. Pat. No. 5,544,421, issued Aug. 13, 1996; U.S. Pat. No. 5,660,517 issued Aug. 26, 1997; and U.S. Pat. No. 5,664,337, issued Sep. 9, 1997, each of which is herein incorporated by reference.





FIG. 1C

illustrates flow of semiconductor wafers as they are processed by the processor


10


. As illustrated, the pods


51


are first place in the insertion station


5


. The components of the insertion station


5


rotate the pod


51


and place it on the inventory subassembly


90


of the inventory station


6


where they remain until such time as the wafers contained therein are to be processed. When the wafers of a pod


51


are to be processed, the respective pod


51


is removed from the inventory subassembly


90


by one of the docking assemblies


150


. The docking subassembly


150


transports the pod to the hatch interface where the wafers are removed from the pod without being exposed to the ambient atmospheric conditions of the interface section. Rather, the wafers are only exposed to the clean environment of the workspace area


20


. After extraction, the wafers are presented to the wafer conveying system


280


which transports them for processing in the appropriate processing station(s)


290


. After removal from the processing station(s), the wafers are returned to the same or different pod and the pod is sealed without exposing the wafers to the ambient atmospheric conditions of the interface section. The respective docking subassembly


150


then returns the pod containing the processed wafers to the inventory subassembly


90


where the pod is stored until such a time as the wafers therein are to undergo further processing within the work space


20


or until they are removed through station


5


by an operator as directed, for example, through control panel


22


.




The processing section of the processing system includes at least one and preferably a plurality of individual processing stations


290


which can be of various construction. Further details with respect to suitable processions stations, and more specific explanation about the loading (installing) and unloading of the wafers into the processing stations are described in U.S. Pat. No. 5,664,337, issued Sep. 9, 1997, which is herein incorporated by reference.




Referring to

FIGS. 12 through 15

, each processing station


290


includes a processing vessel


292


which partially encloses a processing bowl. The processing vessel also mates with a movable door


512


which can be moved between the closed position shown in

FIG. 12

, and a retracted position shown in phantom outline. The disclosed embodiment of the processing system


10


includes an improved door assembly


500


for the processing vessel.




Referring to

FIGS. 12 and 13

, the door assembly


500


is in fixed positional alignment with a front wall


502


of a processing vessel. The front wall


502


is provided with an access opening, defined here by a circular opening


506


of the front wall (best illustrated in FIG.


15


). When the front wall


502


is mounted to the remaining portions of the processor, the opening periphery


506


is positioned to be in alignment with an access opening


507


(See

FIG. 15

) formed in the front wall of the processor bowl


294


.




The door assembly


500


further includes a door support plate


510


which mounts a door


512


and a door extension and retraction operator


514


. The door


512


includes a stiffening plate


504


and a viewing window


508


that permits visual inspection of the processing chamber defined by the bowl


294


. The door extension and retraction operator


514


of the disclosed embodiment includes a stationary outer cylinder


516


coupled to the door support plate


510


, and an operative extension part


518


. The operative extension part


518


is concentrically positioned inside of the outer cylinder


516


for controllable extension and retraction relative to the outer cylinder. Additional features and the operation of the door extension and retraction operator


514


are discussed in greater detail below.




The door support plate


510


includes a viewing aperture


520


for providing visibility through the window


506


into the processing chamber contained within the bowl


294


of the processor. The door support plate


510


is coupled on each side to slideable guide brackets


522


using, for example, conventional fasteners. Each slideable guide bracket


522


is slideably mounted to a respective pneumatic band cylinder


524


. The band cylinders


524


are connected to the front wall


502


of the processing vessel via mounting plates


528


. The combination of the guide brackets


522


, the band cylinders


524


, and the mounting plates


528


provides a simplified and rigid door mounting construction that needs no additional guides or support blocks. The guide brackets


522


are mounted for substantially vertical movement so that the door assembly can be moved between an open or fully displaced position to allow access into the bowl of the processor, and a closed position wherein the door assembly is in substantially concentric alignment with the access opening. In the closed position, the door can be extended into the access opening and sealed against the bowl of the processor.




Referring to

FIGS. 14 and 15

, which show sectional views of the door assembly


500


, the movement of the extension part


518


relative to the outer cylinder


516


is explained in greater detail. To this end, an annular inner stationary cylinder


530


has an annular flange portion


532


and an axially extending ring portion


534


. The annular flange portion


532


is securely mounted on its outer side upon the door support plate


510


. At the point of mounting, the annular flange portion is bounded on its opposite side by the outer cylinder


516


. A plurality of fasteners secure the outer cylinder


516


and the annular flange portion


532


to the mounting plate


510


.




The extension part


518


is concentrically positioned between the inner cylinder ring


530


and the outer cylinder


516


, and includes a U-shaped portion


519


that defines an annular guide receptacle


520


. As illustrated in

FIG. 14

, the axially extending ring portion


534


fits within the annular guide receptacle


520


. The extension part


518


also includes an annular piston portion


540


. The annular piston portion


540


rides within an annular piston operation chamber


542


defined by the ring portion


534


and the outer cylinder


516


.




The piston


540


bifurcates the piston operation chamber


542


into two operative compartments: a retraction chamber compartment


543


and an extension chamber compartment


544


. Each piston chamber compartment is adapted to hold pneumatic or hydraulic fluid. Multiple annular seals


550


are positioned about the piston


540


and the extension part


518


to seal separate fluid within the chambers


543


and


544


.




Separate fluid supply conduits are preferably provided to the retraction chamber


543


and the extension chamber


544


to increase or decrease fluid pressure within the respective chambers and effectuate movement of the piston. As shown in

FIG. 15

, when hydraulic fluid is supplied under an increased pressure to the extension chamber


544


, a pressure differential is created on the piston


540


which will cause the extension part


518


to extend away from the door support plate. Movement of the extension part


518


and the integral piston


540


into the extended position shown in

FIG. 15

moves the door into sealing engagement with the access opening


506


formed in the front wall


502


of the processor bowl, thereby closing the semiconductor processor. Mounted on the periphery of the door


512


is an annular door seal


551


. Preferably, the door seal is formed of Teflon using known machining techniques. The door seal includes an axially extending shroud portion


552


and an annular tongue portion


554


. When the door is in the closed position shown in

FIG. 15

, the shroud portion


552


of the door seal lies in a plane that is within the front wall of the processor, and the tongue portion presses in sealing engagement against the outside rim of the processor bowl, thereby effectuating a seal between the door and the processor bowl. The door seal also preferably includes a flange portion


555


which acts as a stop for the door seal.




The combination of the piston


540


and the door seal


550


provides a highly reliable and effective door closing and sealing mechanism. Movement of the piston allows the extension part to move the door outwardly from the support plate equidistantly at all times without the need for peripheral adjustments to ensure equidistant movement. By seating against the outside rim of the processor bowl, the tongue portion provides an effective fluid tight seal and automatically compensates for any misalignment between the door and the processor.




Numerous modifications may be made to the foregoing system without departing from the basic teachings thereof. Although the present invention has been described in substantial detail with reference to one or more specific embodiments, those of skill in the art will recognize that changes made thereto without departing from the scope and spirit of the invention as set forth in the appended claims.



Claims
  • 1. A processing system for processing wafers provided with a container having a removable container door, comprising:a wall; a container holding position on a first side of the wall, for holding a container; a wafer transfer robot on a second side of the wall; an opening in the wall; a cover adapted to cover the opening in the wall; a container door holder associated with the cover for engaging and holding a container door; a cover actuator assembly, for moving the cover and a container door to and away from the opening in the wall; at least one centrifugal liquid spray process chamber; and one or more robotic conveyors for moving the wafers into and out of the centrifugal liquid spray process chamber.
  • 2. The system of claim 1 further comprising a docking plate at the container holding position, with the docking plate moveable toward and away from the wall to dock and undock a container.
  • 3. The system of claim 1 wherein the transfer robot comprises a comb having equally spaced apart fingers for handling a batch of horizontally oriented wafers.
  • 4. The system of claim 3 where the comb is moveable through the opening in the wall and into and out of the container, to move wafers into and out of the container and into the transfer station.
  • 5. A system for processing the wafers in a clean environment, comprising:an enclosure; a process section and a transfer section within the enclosure; a docking station adjacent to the transfer section, with the docking station including a wall having at least one opening; a cover for covering the opening in the wall; a cover actuator attached to the cover, for moving the cover to and away from the opening in the wall; a wafer transfer device within the enclosure and movable through the opening in the wall, when the cover is removed from the opening, for removing the wafers from the container, with the wafers in a horizontal orientation; at least one centrifugal liquid spray process chamber wherein the wafers are rotated about a vertical axis; and a robot moveable within the enclosure for moving the wafers into and out of the centrifugal liquid spray process chamber.
  • 6. The system of claim 5 further comprising an interface plate attached to the cover, and a key and a container door holder extending outwardly from the interface plate, to engage a container door.
  • 7. The system of claim 6 wherein the cover actuator is adapted to move the cover and a container door to a position vertically below the opening.
  • 8. A system for processing semiconductor wafers, comprising:an enclosure; a transfer section and a process section in the enclosure; a docking station separated from the transfer section by a wall having at least one opening, to allow movement of wafers from the docking station into the transfer section; a cover for covering the opening in the wall; at least one door release actuator associated with the cover for releasing and holding a door of a container; a cover actuator linked to the cover, with the cover actuator adapted for moving the cover and a container door from a first position, where the cover is over the opening, to a second position, below the opening; at least one centrifugal liquid spray process chamber within the chamber; and a robotic conveyor for moving the wafers into and out of the centrifugal liquid spray process chamber.
  • 9. The processing system of claim 8 further including an electronic controller for controlling the door release actuator, the cover actuator and the robot.
  • 10. The processing system of claim 9 further including at least one optical sensor for sensing wafers within the container, with the optical sensor connecting to the controller.
  • 11. A processing system for processing wafers provided with a container having a container door, comprising:a wall; a container position on a first side of the wall, for holding a container containing a batch of wafers in a horizontal orientation; an opening in the wall; a cover adapted to cover the opening in the wall; container door holding means for engaging and holding a container door; cover actuator means for moving the cover and a container door to and away from the opening in the wall; at least one centrifugal liquid spray process chamber; and robotic conveyor means for removing the wafers from the container, reorienting the wafers from a horizontal to a vertical position, and for placing the wafers into the centrifugal liquid spray process chamber.
  • 12. The system of claim 11 wherein the robotic conveyor means comprises a first robot having a comb moveable into a container, for picking up a batch of horizontal wafers, and a second robot for moving the wafers in a vertical position into the centrifugal liquid spray process chamber.
BACKGROUND OF THE INVENTION

This Application is a Division of U.S. patent application Ser. No. 10/180,793, filed Jun. 25, 2002 and now U.S. Pat. No. 6,599,075, which is a Division of U.S. patent application Ser. No. 08/994,737 filed Dec. 19, 1997, now U.S. Pat. No. 6,447,232, which is a Continuation-in-Part of U.S. patent application Ser. No. 08/851,480, filed May 5, 1997, now abandoned, which is a Continuation-in-Part of U.S. patent application Ser. No. 08/680,463, filed Jul. 15, 1996, now U.S. Pat. No. 5,664,337, which is a Continuation-in-Part of U.S. patent application Ser. No. 08/622,349, filed Mar. 26, 1996, now U.S. Pat. No. 5,784,797, which is a Continuation-in-Part of each of U.S. patent application Ser. No. 08/236,424, filed Apr. 28, 1994, and now U.S. Pat. No. 5,544,421; Ser. No. 08/415,927, filed Mar. 31, 1995, now U.S. Pat. No. 5,660,517; and Ser. No. 08/415,240, filed Apr. 3, 1995, now U.S. Pat. No. 5,678,320. U.S. patent application Ser. No. 08/851,480, and U.S. Pat. Nos. 5,784,797, 5,544,421 and 6,447,232 are incorporated herein by reference.

US Referenced Citations (30)
Number Name Date Kind
4568234 Lee et al. Feb 1986 A
4886412 Wooding et al. Dec 1989 A
5215420 Hughes et al. Jun 1993 A
5364219 Takahashi et al. Nov 1994 A
5451131 Hecht et al. Sep 1995 A
5544421 Thompson et al. Aug 1996 A
5562383 Iwai et al. Oct 1996 A
5613821 Muka et al. Mar 1997 A
5660517 Thompson et al. Aug 1997 A
5664337 Davis et al. Sep 1997 A
5674039 Walker et al. Oct 1997 A
5674123 Robertson, Jr. et al. Oct 1997 A
5678320 Thompson et al. Oct 1997 A
5772386 Mages et al. Jun 1998 A
5784797 Curtis et al. Jul 1998 A
5784802 Thompson et al. Jul 1998 A
5788448 Wakamori et al. Aug 1998 A
5836736 Thompson et al. Nov 1998 A
5944475 Bonora et al. Aug 1999 A
6009890 Kaneko et al. Jan 2000 A
6030208 Williams Feb 2000 A
6240933 Bergman Jun 2001 B1
6274059 Krusell et al. Aug 2001 B1
6274506 Christenson et al. Aug 2001 B1
6329299 Wu et al. Dec 2001 B1
6364593 Hofmeister et al. Apr 2002 B1
6387190 Aoki et al. May 2002 B1
6406551 Nelson et al. Jun 2002 B1
6446644 Dolechek Sep 2002 B1
6672820 Hanson et al. Jan 2004 B1
Continuation in Parts (6)
Number Date Country
Parent 08/851480 May 1997 US
Child 08/994737 US
Parent 08/680463 Jul 1996 US
Child 08/851480 US
Parent 08/622349 Mar 1996 US
Child 08/680463 US
Parent 08/236424 Apr 1994 US
Child 08/622349 US
Parent 08/415927 Mar 1995 US
Child 08/236424 US
Parent 08/415927 Apr 1995 US
Child 08/415927 US