WO2000036479A1

WO2000036479A1 - An equipment virtual controller

Info

Publication number: WO2000036479A1
Application number: PCT/US1999/029208
Authority: WO
Inventors: Randy Smith; Craig Alan Hier
Original assignee: Speedfam-Ipec Corporation
Priority date: 1998-12-16
Filing date: 1999-12-09
Publication date: 2000-06-22
Also published as: TW464796B

Abstract

A distributed control system comprises an equipment virtual controller which includes a processor configured to store and execute a data collection application, a data query application, a recipe management application, and an alarm management application, wherein the equipment virtual controller is configured to communicate with one or more tools having respective equipment interfaces and communication links. In this way, misprocessing is reduced through a recipe management application which provides secured and version-controlled process recipes. Misprocessing is further reduced through an alarm management application which precisely tracks preventative maintenance schedules. Furthermore, a data collection application used in conjunction with a data query application enhances process performance and assists in tool diagnostics.

Description

AN EQUIPMENT VIRTUAL CONTROLLER

BACKGROUND OF THE INVENTION

1. Technical Field The present invention relates, generally, to distributed data acquisition and equipment control systems and, more particularly, to methods and apparatus for a virtual controller configured to acquire, store, and analyze data from multiple tools while managing process recipes and tool alarms.

2. Background Information Modern industrial control systems increasingly involve multiple tools organized in functional work cells. In the semiconductor industry, for example, it is not unusual to utilize an array of chemical mechanical planarization (CMP) machines and related machinery in a consolidated wafer processing operation. While the various individual tools used in such a system typically include some level of data acquisition and control capabilities, the level of functionality may be inadequate (i.e., some data or control features are not included in the local software or hardware), or the data or communication formats might be incompatible with other tools used in a particular work cell arrangement. Indeed, even when multiple instances of the same or similar tool are used, it is a non-trivial task to ensure that the machines are coordinated with respect to recipes, calibration parameters, preventative maintenance, and the like. This lack of coordinated process control has a number of deleterious effects. First, it is not uncommon for a piece of equipment to misprocess a workpiece or workpieces due to recipe errors. That is, recipe data (i.e., the set of parameters and conditions that uniquely characterize a process) may be altered inadvertently or without proper documentation or version control.

Furthermore, preventive maintenance of a particular tool is not always performed in accordance with a well-defined schedule. Even in cases where such schedules exist, it is often difficult to determine and track the optimum timing of for maintenance. This is particularly true in the case of consumables (e.g., polishing pads, conditioning pads, and the like). Moreover, individual tools may not be configured to supply the desired diagnostic information related to the processes or the tools themselves. Lack of preventative maintenance tracking and inadequate diagnostics can undesirably increase tool down-time.

Known systems are also characterized by a lack of accountability with respect to individual users, processes, and tools. That is, when a batch of workpieces is misprocessed, significant time and effort is often required in order to determine the source of the error or errors.

Accordingly, systems and methods are needed in order to overcome these and other shortcomings in the prior art.

BRIEF SUMMARY OF THE INVENTION

In accordance with one aspect of the present invention, a distributed control system comprises an equipment virtual controller which includes a processor configured to store and execute a data collection application, a data query application, a recipe management application, and an alarm management application, wherein the equipment virtual controller is configured to communicate with one or more tools having respective equipment interfaces and communication links.

Misprocessing is reduced through the use of a recipe management application which provides secured and version-controlled process recipes, and an alarm management application which precisely tracks preventative maintenance schedules. Furthermore, a data collection application used in conjunction with a data query application enhances process performance and assists in tool diagnostics.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

The present invention will hereinafter be described in conjunction with the appended drawing figures, wherein like numerals generally denote like elements, and: FIG. 1 is a schematic overview of a distributed equipment control system comprising an equipment virtual controller in accordance with various aspects of the present invention;

FIG. 2 depicts an exemplary set of software modules for use in conjunction with an equipment virtual controller in accordance with the present invention; and

FIG. 3 shows a plan view of an exemplary chemical-mechanical polishing machine.

DETAILED DESCRIPTION OF PREFERRED EXEMPLARY EMBODIMENTS

An equipment virtual controller in accordance with the present invention provides systems and methods for, inter alia, reducing misprocessing and enhancing tool diagnostics. In this regard, the present invention may be described herein in terms of functional block components and various processing steps. It should be appreciated that such functional blocks may be realized by any number of hardware components configured to perform the specified functions. For example, the present invention may employ various integrated circuit components, e.g., memory elements, digital signal processing elements, look-up tables, and the like, which may carry out a variety of functions under the control of one or more microprocessors or other control devices. In addition, those skilled in the art will appreciate that the present invention may be practiced in any number of data communication contexts and that the various systems described herein are merely exemplary applications for the invention. Further, it should be noted that the present invention may employ any number of conventional techniques for data transmission, signal processing and conditioning, and the like. Such general techniques that are known to those skilled in the art are not described in detail herein.

Referring now to Figure 1, an exemplary distributed control system in accordance with various aspects of the present invention comprises an equipment virtual controller (EVC) 100 configured to communicate with one or more tools 108 through individual communication links 116. EVC 100 is further configured to communicate with a workstation 110, an external network 112, off-line mass storage 130, and a host 120.

EVC 100 suitably comprises various application software modules 104 and an associated database 102 for providing, as set forth in detail below, equipment control and data acquisition communications with tools 108. As will be appreciated by those skilled in the art, EVC 100 may be based on any number of computer hardware and operating system platforms, for example, an Intel Pentium processor running a Windows NT operating system. EVC 100 further comprises appropriate equipment drivers 106 for communicating with equipment interfaces 109 disposed within tools 108. Various convention drivers may be employed for this purpose, for example, any of the various TCP/IP or RS232 drivers known in the art.

Host 120 is configured to communicate with EVC 100, and preferably comprises a serial interface configured in accordance with the SEMI Equipment Communications Standard (SECS). SECS consists of a pair of standards, SEMI E4-91 and SEMI E5-95, which are often used in the semiconductor industry for generalized host/tool communication. These standards are hereby incorporated by reference. Host 120 may comprise any suitable collection of conventional hardware/software components known in the art. Referring now to Figure 2, application software 104 suitably comprises various functional modules intended to achieve the objects of the present invention: i.e, a data collection/archiving application 202 ("data collection application"), a data query, analysis and presentation application 204 ("data query application"), a recipe management application 206, and an alarm management application 208.

Briefly, data collection application 202 is used to collect data from tools 108 periodically and archive that data to local database 102. Data query application 204 provides statistical analysis, mathematical manipulation, and graphical presentation of the archived data. Recipe management application 206 provides the user with a means for editing individual or groups of recipes (i.e., operating parameters and settings associated with particular tools 108) which are stored within database 102. Alarm management application 208 provides users (e.g., engineers and technicians having access to workstation 110 or terminals distributed throughout network 112) with easy access to the alarms, alarm history, and operational status of tools 108.

In a preferred embodiment, host 120 is configured (via the appropriate hardware and software) such that it substantially conforms to the SEMI Equipment Communications Standards SEMI E4-91 and E5-95.

Tools 108 may comprise nearly any type of suitably-configured processing equipment amenable to external control and monitoring. For the purpose of understanding the nature and operation of the present invention, a particular type of tool 108 ~ i.e., a chemical-mechanical polishing machine — will now be described.

Exemplary CMP Tool

Referring now to Figure 3, an exemplary tool 108 comprises a CMP apparatus configured to perform CMP, cleaning, rinsing, and drying of semiconductor wafers. For a more detailed discussion of an exemplary tool configured to perform such processing of semiconductor wafers, see, for example, U.S. Patent Application Serial No. 08/926,700, entitled "Combined CMP and Wafer Cleaning Apparatus and Associated Methods," hereby incorporated by reference. It will be appreciated that the present invention may be applied in the context of any number of tools and that the embodiment shown and described herein is not intended to limit the scope of the present invention. The illustrated CMP tool 300 includes a load and unload station 312 configured to accommodate a plurality of wafer cassettes 313 to permit substantially continuous operation of the tool 300. A wafer mapping system is suitably distributed throughout the tool 300. The wafer mapping system includes a plurality of sensors and associated hardware necessary to track the location and status of multiple wafers within tool 300. Upon the loading of a cassette into the tool 300 at the load and unload station 312, the wafer mapping system initially determines which locations within a cassette 313 contain wafers, and the operator is presented with this information on a suitable display. The operator then loads wafer processing information into the tool by an appropriate data entry device such as a touch screen display, alphanumeric keyboard, or the like.

After the processing information is loaded into tool 300, wafer processing may begin. In the illustrated embodiment, a robot arm 314 individually selects wafers contained within a cassette 313, then removes a wafer from a cassette 313 and inserts the selected wafer through an air knife 316 into an index station 318. Within index station 318, the wafer is placed upon one of a plurality of load cups 320 residing on index table 322. Upon loading of a wafer on a load cup 320, index table 322 suitably rotates so that an empty load cup 320 is aligned with air knife 316. Once all load cups 320 contain wafers, the wafers are transported by a transport assembly (not shown) to the polishing station 324. The wafers are positioned above and in contact with a polishing table 326 then polished and planarized according to preset recipes. Upon completion of the polishing cycle, the transport assembly returns the wafers to index station 318 where the wafers are placed in unload cups 328. Once the wafers are placed in unload cups 328, flipper arm 330 removes the polished wafers from index station 318 and transfers them to a track in cleaning station 332. After the wafers are cleaned, they are stacked by robot arm 314 into a cassette 313. A plurality of sensors are suitably distributed within CMP tool 300 to track the processing status and location of each wafer. These sensors are preferably located at the robot arm, the load cups, the rinse stages, and the like. For a more detailed discussion of an exemplary location of such sensors in a machine suitably configured to perform CMP of semiconductor wafers, see, the aforementioned U.S. Patent Application Serial No. 08/926,700. CMP tool 300 may be controlled by a processor 350 which receives the plurality of sensor outputs and controls the operation of the tool as determined by operator input and preprogrammed software or hardware applications. This processor may be part of a larger controller or central processing unit. Additionally, processor 350 may include any number of suitable memory and processing elements adapted to perform the various processes and programs that may be realized in the form of software instructions and the like. Processor 350 is preferably connected to an equipment interface 109 for communication over communication link 1 16 to EVC 100 as shown in Figure 1. Equipment interface 109 preferably comprises a suitable SECS interface which converts the instructions and data from the processor 350 into the SEMI/SECS format (e.g., SEMI standards E4 and E5).

As mentioned above, EVC 100 is preferably configured to receive, store, and process, inter alia, wafer position and status information from the CMP tool 300, which may contain more than one-hundred wafers located throughout the tool. At the load and unload station 312, multiple wafers may be awaiting processing or may be awaiting removal from the tool 310. Additionally, a plurality of wafers may also be undergoing processing at any one of the numerous polishing or cleaning stations contained within CMP tool 300.

During normal operation, processor 350 continually receives information regarding the current status and position of wafers within CMP tool 300. Parameters routinely updated within the processor include the specific position of each wafer within the tool, the elapsed processing time for a particular operation of the tool upon a wafer, and the like. These parameters are utilized by processor 350 to control the operation of the tool and are provided to the EVC 100 on a continual basis. EVC 100 receives the parameters and updates and stores the wafer status and position information.

Processor 350 begins receiving wafer status information upon the insertion of a cassette containing a plurality of wafers into CMP tool 300. In accordance with one embodiment of the invention, the cassette nominally holds 25 wafers in 25 slots. Thus, the cassette name and slot identification information are utilized to track and record the position and status of each wafer. Upon the initial loading of a cassette containing wafers, the operator may assign a recipe to each wafer or to a particular batch of wafers. The recipe designates the processing the wafer is to receive from the tool. Additional status variables can be assigned to each wafer and updated as needed. These status variables may include, for example, the station identification (initially set to correspond to the slot identification), the state identification, run number, segment number, segment time, elapsed time, and carrier offset. Each of these variables may be periodically sent from the processor to EVC 100.

The station identification is preferably a three digit number ranging from 001 to 122. Each number designates a particular location within the tool. For example: 010 = Input Cassette 1 , Slot 10; 101 = Robot; 119 = unload flipper, and so forth. Thus, as the wafer is processed by the tool, the station identification is updated to reflect the wafer's current position.

Having thus described a distributed control system and an exemplary CMP tool useful in illustrating the functional aspects of the system, the various applications 202, 204, 206, and 208 will be now be described in detail. - are desired.

In accordance with the present invention, a microreplicated pad is suitably employed in a CMP process in lieu of cellular polishing pad. The microreplicated pad has a microreplicated surface featuring a regular array of precisely-shaped three-dimensional structures. Referring now to Figures 4(a)-4(d), such structures might, for example, include square-base pyramids (Figure 4(a)), triangle-base pyramids (Figure 4(b)), cones (Figure 4(c)), or "cube-corner" elements. A cube-corner element has the shape of a trihedral prism with three exposed faces, and is generally configured so that the apex of the prism is vertically aligned with the center of the base, but may also be configured such that the apex is aligned with a vertex of the base (Figure 4(d)). Referring now to Figures 5 and 6, a microreplicated surface in accordance with a preferred embodiment of the present invention suitably comprises an array of square-base regular pyramids 51. Each pyramid has a sharp distal point 53 a height h from its base. Height h and lateral dimensions α and b suitably ranges from 0.1 to 200 microns, depending on material used and desired effect. The standard deviation of h is suitably less than 5 microns. In a preferred embodiment, gradual and controlled dulling of the microreplicated structures is advantageously produced by using a three-dimensional shape whose cross-sectional area increases as it is worn away, for example, pyramids and cones rather than cubes or other parallelpipeds.

Techniques for manufacturing microreplicated surfaces are well known in the art, and typically involve molding the surface using suitable materials in conjunction with a production tool bearing an inverse array. Such production tools, which are generally metallic, can be fabricated by engraving or diamond turning. These processes are further described in Encyclopedia of Polymer Science and Technology, Vol. 8, John Wiley & Sons, Inc. (1968), p651-61, incorporated herein by reference. As the technology of microreplication continues to advance, finer arrays and smaller structures can be produced (see, for example, Martens, U.S. Patent No. 4,576,850, issued March, 1986; and Yu, et al., U.S. Patent No. 5,441,598, issued August, 1995, both incorporated herein by reference). In addition, modern silicon micromachining techniques offer a substantially more precise method of fabricating microreplicated structures. More particularly, anisotropic wet chemical etching of silicon (typically 100 and 111 orientation wafers) may be used in conjunction with standard photolithographic patterning to produce exceedingly small and regular indentations which can in turn be used as a molding form.

Referring now to Figures 7(a) and 7(b), substantially sharp distal points 35(a) of microreplicated structures 33 associated with the underside of pad 31 contact dielectric surface 18) wafer moves from aligner to load flipper;

19) wafer moves from load flipper to load cup;

20) wafer moves from load cup to carrier;

21 ) wafer moves from carrier to unload cup; 22) wafer moves from unload cup to scrubber;

23) wafer moves from scrubber to wafer track; and

24) wafer moves from wafer track to unload cassette.

CMP tool 300 is also preferably configured to store and transmit various calibration coefficients, for example, calibration downforce for the various polishing heads. CMP tool 300 may also record other variables, e.g.: index table motor velocity, index table motor position, carrier rotation velocity and position, pad conditioner motor position, load flipper motor position, unload flipper motor position, elevator motor position, paddle motor position, primary RPM, final RPM, slurry rates , pad conditioner actual downforce, pad conditioner setpoint downforce, backfill pressures for the carriers, actual downforce at the carriers, scrubber rotation velocity, scrubber pressure, commanded downforce of carriers.

Furthermore, CMP Tool 300 is preferably configured to store various counters, e.g.: wafer counts for each of the carriers (i.e., the number of wafers that have been polished), life time of the tool (not resetable), machine hours (resetable), pad usage time, conditioning ring usage time, wafer counts for pad (i.e., number of wafers that have been polished on the pad), conditioning arm up counter, scrubber wafer counts (i.e., number of wafers that have been scrubbed), as well as various programmable counters to record usage by particular users.

Process conditions collected by the system may include, for example, various parameters collected during main polish, final polish, carrier clean, pad condition, and wafer clean, as well as mode information (e.g., automatic/manual, processing/paused). As the volume of data may, in practice, become prohibitively large with respect to database

102, the collected data may be transferred to off-line mass storage 130 at suitable intervals.

Data Query. Analysis, and Graphical Presentation

Data query application 204 provides statistical analysis, mathematical manipulation, and graphical presentation of data records received from tools 108. That is, this application provides a suitable interface for extracting, from database 102 (or off-line mass storage), relevant portions of data generated by the tools 108, then analyzing, sorting, and presenting the data in a form useful for the operator or a post processing system (not shown).

As a preliminary matter, data query application 204 allows the operator to select subsets of data in accordance with user-entered criteria. This data may be passed to software modules for mathematic transformation, statistical analysis, or graphical visualization. In regard to mathematical transformation, data may be manipulated in accordance with arbitrarily complex functions and then stored as a separate data subset or combined with previously extracted data.

The data may be subjected to a variety of standard statistical methods well known in the art, for example, regression analysis, hypothesis testing, population statistics, factorial studies, and the like. Information regarding common statistical methods can be found in a variety of texts, for example, DOUGLAS C. MONTGOMERY, DESIGN AND ANALYSIS OF EXPERIMENTS, Third Edition (1991), and DOUGLAS C. MONTGOMERY AND ELIZABETH A. PECK, INTRODUCTION TO LINEAR REGRESSION ANALYSIS, Second Edition (1992), both of which are hereby incorporated by reference.

Graphical visualization may take a number of forms depending on the nature and context of the data, including, for example, two and three-dimensional scatter diagrams, response surface plots, spatial data visualization, and the like. The resulting graphical information may be displayed on a standard computer monitor, printed in any number of formats, or stored for later retrieval.

Application 204 is preferably configured to plot information by a number of variables, including, for example, customer material ID, cassette ID, customer wafer ID, and slot number.

The time base and signal scales presented in these plots are preferably adjustable by the operator.

Recipe Management

Recipe management application 206 provides users with a means for editing individual or groups of recipes (i.e., operating parameters and settings associated with particular tools 108) stored in database 102. For each processing run, the actual recipe used during the run is preferably stored. That is, it will be appreciated that the conditions under which an actual processing run takes place will vary from the target recipe due to natural variation in timing, temperatures, pressures, and the like. As a result, in order to provide more accurate projections for future runs, it is advantageous to archive these data records as well. In an exemplary CMP embodiment, data collection variables for capturing this recipe information including pad conditioning variables, main polish variables, final polish variables, carrier clean variables, and wafer scrub variables. Pad condition variables suitably include: Main Table Speed (rpm), Ring Oscillation Speed

(in/sec), Ring Oscillation Radius (in), Down Force Input (lbf), Down Force Output (lbf), Pump

1 Flow Rate Actual (ml/min), Pump 2 Flow Rate Actual (ml/min), Pump 3 Flow Rate Actual

(ml/min), Pump 4 Flow Rate Actual (ml/min), Pump 5 Flow Rate Actual (ml/min), Pump 6 Flow Rate Actual (ml/min).

Main polish variables suitably include: Main Table Speed Actual (rpm), Main Table Temperature Actual (deg C), Pump 1 Flow Rate Actual (ml/min), Pump 2 Flow Rate Actual (ml/min), Pump 3 Flow Rate Actual (ml/min), Pump 4 Flow Rate Actual (ml/min), Pump 5 Flow Rate Actual (ml/min), Pump 6 Flow Rate Actual (ml/min), Carrier Rotation Speed Actual for carriers 1-5 (rpm), Carrier Down Force Actual for carriers 1-5 (lbf), Carrier Oscillation Speed Actual for carriers 1-5 (in/sec), Carrier Oscillation Radius Actual for carriers 1-5 (in), Carrier Backfill Pressure Actual for carriers 1-5 (psi)

Final Polish Variables suitably include: Final Table Speed Actual (rpm), Pump Flow Rate Actual for pumps 1-6 (ml/min), Carrier Rotation Speed Actual for carriers l-5(rpm), Carrier Down Force Actual (lbf) for carriers 1-5, Carrier Radius Actual for carriers 1-5 (in), Carrier Backfill Pressure Actual for carriers 1-5 (psi).

Carrier Clean Variables suitably include Carrier Speed Actual for carriers 1 -5 (rpm), and Wafer Scrub variables suitably include Brush Speed Actual (rpm) and Brush Pressure Actual (psi).

Alarm Management

Alarm management application 208 archives data records related to the alarm history of tools 108 in database 102 and provides a user interface (e.g., a graphical user interface) for viewing alarm status, alarm history, and current operational status of each of the tools 108. In a preferred embodiment, the alarm history data comprises the following fields: tool ID, alarm ID, alarm time stamp, alarm severity code, user ID, and alarm acknowledgment time stamp. The alarm time stamp and alarm acknowledgment time stamp fields provide, with suitable precision, the time at which the alarm was received by EVC 100, and the time at which the alarm was acknowledged by the user responding to the alarm, if a response was made. If a response is made, a code or name indicating the responding user is stored in the user ID field. This acknowledgment might take the form of a reset or other remedial action, depending upon the severity of the alarm.

Alarm severity field is an arbitrary code ~ preferably user-configurable — which uniquely indicates the severity or priority of the alarm. The tool ID field is used to store an identifier corresponding to the particular tool 108 from which the alarm was received.

The user interface to alarm management application 208 preferably includes a display indicating the status of the various tools, including current alarm details and alarm history. Additionally, the user interface provides the user the ability to filter and sort the alarm data according to various field constraints, e.g., severity code, alarm ID, user ID, unacknowledged alarms, time range, tool ID, and the like.

In a preferred embodiment, the alarm data structure specified in the following table is used. With respect to the table headings: ALID is the Alarm ID; ALCD is the Alarm Severity Code, where the low-order 7-bits of ALCD specify the severity code, and the high-order bit (bit-8) shows the current alarm state (1=SET, 0=CLEAR); ALTX is the Alarm Text, i.e., the actual string sent the Host in the Alarm Report; ON CEID is the Collection Event that is signaled when the alarm state changes from CLEAR to SET ("going-on"); OFF CEID is the Collection Event that is signaled when the alarm state changes from SET to CLEAR ("going-off ').

It will be apparent to those skilled in the art that the various applications set forth above may be implemented using hardware, firmware, software, or any combination thereof. In the case of software implementation, a variety of known programming languages or software products would be suitable, for example, the Factory Suite software produced by Wonderware. During normal operation, EVC 100 — in conjunction with data collection application 202

— receives and stores a constant stream of data related to the status of the ongoing processes and the tools as detailed above. Users may configure alarms using alarm management application 208, receive real-time graphical representations of process data, download recipes from EVC 100 to tools 108 via recipe management application 206, or perform a variety of other tasks in accordance with resident applications 104.

User interaction might take place via an in-cell client workstation 110 or any number of access points available over network 112. That is, a user might choose to monitor operation of one or more of tools 108 using hardware appropriately configured for communication with EVC 100 over network 112. Such access hardware might include, for example, personal computers, workstations, terminals, personal data assistants (PDAs), and the like. Network 112 itself may comprise a variety of data communication modalities well known in the art. EVC 100 and or host 118 might also be configured, using appropriate software, to act as a World Wide Web host over the Internet and or local intranet. In this regard, EVC 100 may employ software modules based on Java applets, ActiveX controls, or the like, to provide distributed user interface capabilities over network 112.

In summary, an equipment virtual controller has been described which reduces misprocessing through recipe management, alarm management, and advanced preventative maintenance scheduling; enhances process performance and tool diagnostics via data acquisition and query applications; increases tool accountability through alarm management; and provides communication connectivity to a central database and virtual controller via any number of communication modalities. Although the present invention has been described in conjunction with the appended drawing figures, it will be appreciated that the invention is not so limited. Various additions, deletions, substitutions, and rearrangement of parts and processing steps may be made in the design and implementation of the equipment virtual controller without departing from the scope of the present invention, as set forth more particularly in the appended claims.

Claims

Claims:

1. A distributed control system comprising: an equipment virtual controller comprising a processor configured to store and execute a data collection application, a data query application, a recipe management application, and an alarm management application; at least one tool configured to communicate with said equipment virtual controller through a communication link, said tool configured to generate a plurality of data records associated with said tool and communicate said data records to said equipment virtual controller; said data collection application, recipe management application, and alarm management application being responsive to said plurality of data records.

2. The distributed control system of claim 1, wherein said tool and said equipment virtual controller are configured to communicate over said communication link in accordance with a SECS protocol.

3. The distributed control system of claim 1 , wherein said tool comprises a chemical- mechanical polishing apparatus.

4. The distributed control system of claim 1, further comprising a host configured to communicate with said equipment virtual controller.

5. The distributed control system of claim 1, wherein said equipment virtual controller is further configured to interface with an external network.

6. The distributed control system of claim 1 , wherein said recipe management application is operable to receive and store a subset of said plurality of data records, wherein said subset includes: a pad condition variable and a main polish variable.

7. The distributed control system of claim 1 , wherein said alarm management application is operable to receive and store a subset of said plurality of data records, wherein said subset includes alarm history data.

8. The distributed control system of claim 1, wherein said data collection application is operable to receive and store a subset of said plurality of data records, wherein said subset includes a plurality of process conditions.