Combination load lock for handling workpieces

A combination load lock apparatus is provided, wherein a chamber is coupled to two or more valves in selective fluid communication with two or more respective volumes. A support member for supporting a workpiece is disposed within an interior portion of the chamber, wherein a translation apparatus is operably coupled thereto. The translation apparatus is operable to rotate and/or translate the workpiece on the support member about and/or along a first axis, wherein a detection apparatus associated with the chamber is operable to detect one or more characteristics of the workpiece during the rotation and/or translation thereof. The workpiece may be further rotated in a predetermined manner based on the one or more detected characteristics. A recess is further defined in the interior portion of the chamber, wherein the translation apparatus is operable to translate the workpiece into and out of the recess to reduce particulate contamination thereon.

FIELD OF THE INVENTION

The present invention relates generally to workpiece handling systems and methods for handling workpieces, and more specifically to a combination load lock chamber for handling and characterizing workpieces.

BACKGROUND OF THE INVENTION

In the semiconductor manufacturing industry, a semiconductor wafer is typically processed in various differing processing environments in order to achieve desired electrical characteristics on the wafer. Conventionally, the wafer is transported between processing environments through one or more load lock chambers, wherein the load lock chambers substantially isolate the different processing environments from one another by substantially evacuating the load lock chambers of processing gases once the wafer is inserted therein. Such isolation of the processing environments via the load lock chambers helps to minimize cross-contamination between the processing environments.

Conventionally, a load lock chamber is coupled to a process chamber, such as a process chamber for an ion implantation system.FIG. 1illustrates an exemplary conventional processing system10, wherein a load lock chamber15is coupled to a process chamber20via a first gate valve25. The first gate valve25selectively isolates a process environment30within the process chamber20from a load lock environment35within the load lock chamber15. A second gate valve40is disposed opposite the first gate valve25, wherein the second gate valve selectively isolates the load lock environment35from an external environment45(e.g., atmosphere). Typically, the load lock chamber further comprises one or more ports50that selectively permit an evacuation or venting of the load lock environment35, depending on whether a wafer55is being transferred between the external environment45and the load lock environment35, or between the load lock environment and the process environment30.

One problem with the conventional load lock chamber15is that contamination particles60may be present within the load lock environment35, wherein upon evacuation or venting through the one or more ports50, the contamination particles may be moved onto a surface65of the wafer55. Such contamination particles60on the surface65of the wafer55can have deleterious effects on the subsequent processing of the wafer, thus leading to potential production losses. For example, the location of the one or more ports50and wafer55may lead to turbulent flows within the load lock environment35, thus dispersing the contaminant particles60about the surface65of the wafer55.

Further, various pre-processing procedures are typically performed prior to the wafer55being transferred into the process environment30. Such pre-processing procedures may comprise a notch alignment procedure, wherein the wafer55is aligned in a predetermined manner, an identification of the wafer by reading of a barcode (not shown) on a backside70of the wafer, or various other pre-processing such as a heating or cooling of the wafer prior to, or after, the wafer is transferred into or out of the process environment30. Typically, each pre-processing procedure on the wafer55is performed in a respective pre-processing station75, wherein the wafer is transferred from one pre-processing station to another, and then into the load lock chamber15. Such conventional pre-processing of the wafer55can take a significant amount of time, as identifying and/or positioning of the wafer, as well as transferring the wafer between each pre-processing station typically occurs prior to the wafer entering the load lock chamber15.

Therefore, it is desirable to provide an improved load lock apparatus, wherein contamination to the wafer is significantly decreased, while also allowing various pre-processing procedures to be performed from within the load lock apparatus, thus increasing overall production efficiencies.

SUMMARY OF THE INVENTION

The present invention overcomes the limitations of the prior art by providing a combination load lock apparatus, wherein contamination is minimized, and wherein various processes can be performed on a workpiece within the load lock apparatus. Accordingly, the following presents a simplified summary of the invention in order to provide a basic understanding of some aspects of the invention. This summary is not an extensive overview of the invention. It is intended to neither identify key or critical elements of the invention nor delineate the scope of the invention. Its purpose is to present some concepts of the invention in a simplified form as a prelude to the more detailed description that is presented later.

The present invention is directed generally toward a combination lock apparatus for a workpiece, wherein, in addition to changing atmospheric conditions between processing operations, the combination load lock apparatus is further operable to advantageously detect one or more characteristics of the workpiece, wherein the detected characteristics can be utilized in handling the workpiece. In accordance with one exemplary aspect of the invention, the combination load lock apparatus comprises a chamber having an interior portion, wherein a central region and a recess are further defined therein. A support member is further disposed within the interior portion of the chamber, wherein the support member is operable to support the workpiece, and wherein a translation apparatus is operably coupled to the support member. The translation apparatus, in one example, is operable to rotate the support member about a first axis, and also to linearly translate the support member along the first axis between the central region and the recess within the interior portion of the chamber. A detection apparatus associated with the chamber is further operable to detect one or more characteristics of the workpiece during the rotation and/or translation of the workpiece.

In accordance with one exemplary aspect, the workpiece comprises an indicia associated therewith, and wherein the detection apparatus comprises a sensor operable to detect the indicia. The indicia may be a notch in the workpiece, a barcode on a backside of the workpiece, or other type of identifying characteristic associated with the workpiece. Accordingly, the detection apparatus may comprise a proximity sensor, camera, bar code scanner, or other apparatus operable to detect the indicia. The detection apparatus, in one example, is operably coupled to the chamber, wherein the detection apparatus is operable to detect the one or more characteristics of the workpiece when the workpiece is positioned within the recess. For example, when the workpiece is positioned within the recess, the workpiece is rotated via the translation apparatus, wherein the detection apparatus detects the indicia and sends a signal to a controller, and wherein the controller further controls a handling of the workpiece based on the signal from the detection apparatus. The controller, for example, can provide a further control of the translation apparatus, such that the workpiece is rotated so as to position the workpiece in a predetermined manner based on the sensed notch or other indicia.

According to another exemplary aspect of the invention, two or more valves, such as gate valves, are further operably coupled to the chamber, wherein the two or more valves are operable to selectively permit a fluid communication between two or more respective volumes and the interior portion of the chamber. A pump port and a vent port may be further associated with the chamber, wherein the pump port is in selective fluid communication with a vacuum environment and the interior portion of the chamber, and wherein the pump port is operable to selectively expose the interior portion of the chamber to the vacuum environment. The vent port is accordingly in selective fluid communication with a pressurized environment and the interior portion of the chamber, wherein the vent port is operable to selectively expose the interior portion of the chamber to the pressurized environment, such as an atmospheric environment or process gas environment.

According to one exemplary aspect, the pump port is associated with a bottom portion of the chamber, and the vent port is associated with the recess in the chamber, wherein when the workpiece is positioned within the recess by the translation apparatus, substantially laminar flow can be attained proximate to the workpiece, such that contamination from turbulent flows within the chamber is substantially minimized. A high efficiency filter may be in further fluid communication with the vent port, wherein the filter is operable to substantially filter particles associated with the pressurized environment. Additionally, a temperature control apparatus may be associated with the chamber, wherein the temperature control apparatus is operable to provide one or more of a heating and cooling of the workpiece within the chamber.

DETAILED DESCRIPTION OF THE INVENTION

The present invention is directed generally toward a combination load lock apparatus and a method for using a load lock apparatus, wherein various efficiencies can be achieved. Accordingly, the present invention will now be described with reference to the drawings, wherein like reference numerals may be used to refer to like elements throughout. It should be understood that the description of these aspects are merely illustrative and that they should not be interpreted in a limiting sense. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be evident to one skilled in the art, however, that the present invention may be practiced without these specific details.

Referring now to the figures,FIG. 2illustrates a cross-sectional view of an exemplary combination load lock apparatus100in accordance with several aspects of the present invention. The load lock apparatus100, for example, comprises a chamber102, wherein an interior portion104of the chamber is generally defined between a top wall106and a bottom wall108of the chamber. A first valve110and a second valve112are further operably coupled to the chamber102, wherein the first valve is associated with a first volume114, and the second valve is associated with a second volume116. The first valve110and second valve112are operable to selectively permit a fluid communication between the interior portion104of the chamber and the respective first volume114and second volume116.

The first volume114, for example, may comprise an atmospheric environment118, and the second volume116may comprise a process environment120associated with a process chamber122. The process environment120, for example, may be a vacuum environment124, wherein the process environment is at a significantly lower pressure than the atmospheric environment118. The first valve110and second valve112may each further comprise gate valves126, wherein the gate valves are operable to selectively isolate each of the respective first and second volumes114and116from the interior portion104of the chamber102. It should be noted that any number of additional volumes (not shown) may be operably coupled to the chamber102, wherein the additional volumes may be further selectively isolated from the chamber by additional valves (not shown) similar to the first and second valves12, as will be appreciated by one of ordinary skill in the art.

In accordance with one exemplary aspect of the invention, the combination load lock apparatus100comprises a support member128generally disposed within the interior portion104of the chamber102, wherein the support member is operable to support a workpiece130thereon. The workpiece130, for example, is further operable to be transferred into and out of the chamber102though the first valve110and second valve112by a workpiece handling system (not shown), wherein the workpiece handling system is operable to place the workpiece with respect to the support member128. The support member128, for example, may comprise a platter or chuck132, wherein the chuck is operably to substantially hold or restrain the workpiece130from moving with respect to the support member. The chuck132, for example, may comprise an electrostatic chuck operable to selectively electrostatically attract the workpiece130thereto, therein substantially limiting a movement of the workpiece with respect to the support member128. Alternatively, the support member128may comprise any mechanism operable to substantially limit a movement of the workpiece130with respect to the support member. In another alternative, the support member128comprises one or more surfaces134on which the workpiece130is generally held by gravity. Accordingly, the support member128may comprise any structure on which the workpiece130may reside within the chamber102.

The combination load lock apparatus100of the present invention further comprises a translation apparatus136operably coupled to the support member128, wherein the translation apparatus is operable to move the workpiece130in one or more directions. For example, the translation apparatus136is operable to rotate the support member128about a first axis138. The translation apparatus136, in another example, is further operable to linearly translate the support member128along the first axis138within the interior portion104of the chamber102, such as between a central region140of the interior portion of the chamber and a recess142defined in the top wall106of the chamber. The translation apparatus136may be operably coupled to one or more actuators144, such as one or more of an electro-mechanical actuator, rotary actuator, servo motor, or a pneumatic actuator such as a piston and cylinder assembly, wherein the one or more actuators are operable to rotate and/or linearly translate the support member128about and/or along the first axis138.

FIG. 3illustrates another exemplary aspect of the invention, wherein a cross section146of the combination load lock apparatus100ofFIG. 2is shown. The combination load lock apparatus100ofFIG. 3, for example, illustrates side walls148of the chamber, and again illustrates the first valve110and second valve112coupling the chamber102to the respective first and second volumes114and116. The recess142in the top wall106is further illustrated, wherein a shape of the recess generally conforms to a shape of the workpiece130. For example, the recess142is generally circular in shape, and slightly larger in diameter than the workpiece130. Accordingly, the translation apparatus136is operable to generally translate workpiece130along the first axis138into the recess142. The recess142, for example can advantageously limit particulate contamination of the workpiece during an evacuation of the chamber102, as will be discussed infra.

Referring again toFIG. 2, in accordance with another exemplary aspect of the present invention, the combination load lock apparatus100further comprises a detection apparatus150associated with the chamber102. The detection apparatus150is operable to detect one or more characteristics152associated with the workpiece130. The one or more characteristics152, as illustrated inFIG. 3for example, may comprise one or more of a notch154defined in the workpiece130and one or more indicia156associated with the workpiece, such as a barcode158or other identifying characteristic. In one example, the detection apparatus150illustrated inFIG. 2comprises sensors160A and160B operably coupled to respective control electronics162A and162B, wherein the sensors are operable to detect the one or more characteristics152(e.g., the notch154and the indicia156ofFIG. 3). The control electronics162A and162B, for example, are further operable to provide signals164A and164B to a controller166indicative of the one or more characteristics. The controller166may then further provide a control signal168based on the signals164A and164B to the one or more actuators144, such that the workpiece130is accordingly rotated170and/or translated172, as will be discussed hereafter. It should also be noted that the control electronics162A and162B may be further integrated into the controller166.

In accordance with one exemplary aspect, wherein the indicia156comprises the barcode158or other image associated with the workpiece130, the sensor164B may comprise a bar code scanner or other appropriate imaging device operable to detect the barcode or image, as will be appreciated by one of ordinary skill in the art. Further, the exemplary sensor160A for detecting the notch154may comprise a proximity sensor or other appropriate detection device operable to detect the presence or absence of the notch154, as will be appreciated by one of ordinary skill in the art. According to another example, the detection apparatus150is operably coupled to the top wall106or bottom wall108of the chamber102, wherein the detection apparatus is operable to detect the one or more characteristics152associated with the workpiece130when the workpiece is positioned within the recess142. For example, the detection apparatus150(e.g., the sensor160A) is operable to detect the notch154during the rotation170of the workpiece130about the first axis138via the translation apparatus136, wherein the notch may be aligned with respect to the chamber102in a predetermined manner via the control signal168to the one or more actuators144, as will be discussed infra.

In accordance with another aspect of the present invention, the combination load lock apparatus100illustrated inFIG. 2further comprises a pump port174and a vent port176associated with the chamber102. The pump port174, for example, is in fluid communication with a vacuum environment178(e.g., a vacuum pump) and the interior portion104of the chamber102, wherein the pump port is operable to selectively expose the interior portion of the chamber to the vacuum environment. The vent port176, for example, is in fluid communication with a pressurized environment180(e.g., an inert gas source) and the interior portion104of the chamber102, wherein the vent port is operable to selectively expose the interior portion of the chamber to the pressurized environment. In one example, the pump port174is associated with the bottom wall108of the chamber102, and the vent port176is associated with the recess142in the chamber. Accordingly, when the workpiece130is positioned within the recess142, gas flow (illustrated by arrows182) is believed to be substantially laminar within the recess, such that contamination to the workpiece130is substantially mitigated.

According to another example, the combination load lock apparatus100further comprises a filter184(e.g., a high efficiency particle filter) in fluid communication with the vent port176, wherein the filter is operable to substantially filter particles (not shown) associated with the pressurized environment180. Thus, the filter184, in conjunction with the laminar flow within the recess142when the workpiece130is positioned therein, further mitigates potential contamination of the workpiece during “pump down”, which is when the chamber102is substantially evacuated through the pump port174, and/or when the vent port provides filtered gas into the interior portion104of the chamber.

In accordance with another exemplary aspect of the invention, a temperature control apparatus186is further associated with the chamber102, wherein the temperature control apparatus is operable to provide one or more of a heating and cooling of the workpiece130positioned within the chamber. For example, the temperature control apparatus186is operable to heat and/or cool gases provided by the pressurized environment180, thus heating and/or cooling the workpiece130via the vent port176. Alternatively, the temperature control apparatus186may heat and/or cool the chamber102, such as by heating and/or cooling one or more of the top wall106and bottom wall108of the chamber.

In accordance with still another aspect of the present invention, a method200for handing a workpiece is provided inFIG. 4. While exemplary methods are illustrated and described herein as a series of acts or events, it will be appreciated that the present invention is not limited by the illustrated ordering of such acts or events, as some steps may occur in different orders and/or concurrently with other steps apart from that shown and described herein, in accordance with the invention. In addition, not all illustrated steps may be required to implement a methodology in accordance with the present invention. Moreover, it will be appreciated that the methods may be implemented in association with the systems illustrated and described herein as well as in association with other systems not illustrated.

As illustrated inFIG. 4, the method200begins with providing a combination load lock apparatus in act205. For example,FIG. 5Aillustrates an exemplary combination load lock apparatus300being provided in act205. The combination load lock apparatus300, for example, comprises a chamber302having an interior portion304, a support member306positioned within the interior portion, a detection apparatus308associated with the interior portion, a first valve310, and a second valve312. The first valve310, for example, is in selective fluid communication with a first volume314(e.g., atmosphere) and the interior portion304of the chamber, while the second valve312is in selective fluid communication with a second volume316(e.g., a process chamber) and the interior portion of the chamber.

In act210ofFIG. 4, a workpiece is generally translated through the first valve from the first volume into the interior portion of the chamber when the first valve is in an open position and the second valve is in a closed position, wherein the workpiece is generally placed onto the support member within the chamber. As illustrated inFIG. 5A, the first valve310is opened and a first transfer arm318(e.g., a robotic arm or holder) having a workpiece320disposed thereon is generally translated from the first volume314through the first valve and into the interior portion304of the chamber302. The support member306, for example, is in a lowered position322when the workpiece320is translated into the chamber302. As illustrated inFIG. 5B, the support member306, for example, is raised from the lowered position322ofFIG. 5Ato a raised position324within the interior region304of the chamber302, therein generally lifting the workpiece320from the first transfer arm318, wherein the first transfer arm may be retracted from the chamber. In accordance with one example, the support member306further translates the workpiece320into a recess326defined in the interior region304of the chamber302in act210ofFIG. 4.

In act215ofFIG. 4, the first valve is generally closed, and in act220, the interior portion of the chamber is generally evacuated. As illustrated inFIG. 5C, the interior region304of the chamber302is generally evacuated through a pump port328associated with the chamber. As illustrated, the workpiece320is positioned within the recess326, thus generally permitting a laminar flow330(indicated by arrows) along a surface332of the workpiece during the evacuation, thus generally limiting contamination to the surface from contaminants (not shown) residing within the interior region304of the chamber302.

In act225ofFIG. 4, the support member is rotated about the first axis, wherein the workpiece is consequently rotated within the chamber. During the rotation of the workpiece in act225, one or more characteristics of the workpiece are detected in act230, such as a detection of a bar code or other indicia or characteristic of the workpiece (e.g., a notch in the workpiece). For example,FIG. 5Cillustrates the workpiece320being rotated (indicated by arrow334), wherein the detection apparatus308generally detects a notch or other indicia (not shown) associated with the workpiece during the rotation thereof. The workpiece320may then be rotated in a predetermined manner based on the detection of the notch or other indicia, wherein, for example, the notch is generally aligned with respect to the chamber302or other component(s). Such an alignment of the notch within the combination load lock apparatus300eliminates a workpiece handling step that is conventionally performed once the workpiece is removed from a conventional load lock chamber, and such an elimination of a handling step advantageously increases workpiece throughput. For example, by allowing for the parallel operation of notch alignment during load lock pump down, the present invention advantageously decreases time spent between workpiece processing operations.

In act235ofFIG. 4, the second valve is opened, and the workpiece is subsequently translated from the chamber through the second valve and into the second volume in act240. The support member306ofFIG. 5C, for example, is lowered from the raised position324to the lowered position322ofFIG. 5D, wherein the workpiece320is lowered onto a second transfer arm336that generally extends through the second valve312from the second volume316. The second transfer arm336and workpiece320are then translated through the second valve312and into the second volume316.

In accordance with one example, a second workpiece338is transferred from the second volume316and onto the support member306within the chamber302, and the second workpiece is again raised into the recess326, as illustrated inFIG. 5E. While the second workpiece338is positioned within the recess326a pressurized gas (e.g., an inert gas or atmospheric gases indicated by arrow340) may be introduced into the chamber302via a vent port342, wherein the pressurized gas is further filtered via a high efficiency filter344prior to entering the interior portion304of the chamber302. Again, since the second workpiece338is generally positioned within the recess326, substantially laminar flow is believed to occur, thus mitigating potential contamination seen in conventional load lock chambers, wherein turbulent flow is typically experienced by workpieces.

Accordingly, the present invention provides an efficient combination load lock chamber, wherein productivity and efficiency is advantageously increased over the prior art by combining alignment and/or other workpiece detection processes with pump-down operations performed by the load lock chamber. It should be noted that although the invention has been shown and described with respect to a certain preferred embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described components (assemblies, devices, circuits, etc.), the terms (including a reference to a “means”) used to describe such components are intended to correspond, unless otherwise indicated, to any component which performs the specified function of the described component (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiments of the invention. In addition, while a particular feature of the invention may have been disclosed with respect to only one of several embodiments, such feature may be combined with one or more other features of the other embodiments as may be desired and advantageous for any given or particular application.