HEWLETT- PAC KAFID
`
`-JULY ‘I935
`
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`© Copr. 1949-1998 Hawlafi-Packard Co.
`
`

`
`HEWLETT-PACKARD
`
`Q] @ U E} MAL
`
`Ari it;Ie5
`
`A Protocol Analyzer for EDP Centers and Field Service. by Aileen C. Appleyard.
`Roger W. Ruhnow, William Grant Groirenburg. and Wayne M. Ange-zine
`ll monitors
`serial data streams up to 256 Kbps and simulates up to 72 kbps.
`
`5 How Protocol Analysis can Help
`10 Protocol Analyzer Software Development
`
`1 2 Simple Architecture Provides High Performance for Protocol Analysis, by Stephen
`H. Witt and Roger W. Ruhnow A 68000 microprocessor controls the system. A trap
`machine provides powerful triggering capabilities.
`
`in Protocol Analyzer Power Supply Design
`is Protocol Analyzer Mechanical Design
`17 Making a Protocol Analyzer Producible and serviceable
`
`1 8 Serial Data Acquisition and Simulation tor a High-Speed Protocol Analyzer. by Mark
`D. Keisllngi, Dorothy J. Yackle, David B. Karlin, and Elizabeth Gates Moore The tront end
`is a dedicated processor that interfaces the line under test to the system processor.
`
`2 4 ALow-Cost, Portable Field Service Protocol Analyzer, by Vonn L. Black, Alan Delwiche.
`Chris L. Odell, and Stephen B. Tursich Special features include remote operation,
`Autoconflg.-.ire. and bit error rate testing.
`
`3 0 Remote Monitoring and Control of Semiconductor Processing, by Wesley H. Hlgaki
`This software module provides process engineers with both a window and a handle on
`the fab area.
`
`33 SECS
`
`3 5 Authors
`
`
`
`
`
`Ii Associate Eo-tor Keni-airs Shaw 0 Ass-siai-ifdiloi Nai-4:i,iF? ’ca=.e: I »'«i"-. Director Pnciogieoher Aruius Dani-3=sc="i I 5-JDDDFI Supetvisof S-..sariE W'g"-'-
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`I-‘iusseii M H Bell;
`
`2 HE.I,.‘I.LE1-l-_pACKARD JOUHNAL JULY ‘Q35
`
`*0 Hewielt-Packard Company I935 Pm-ileo in Li S A
`
`© Copr. 1949-1998 Hewlett-Packard Co.
`
`

`
`Remote Monitoring and Control of
`
`Semiconductor Processing
`
`This addition to l-lP's Semiconductor Productivity Network
`acts as a host computer to lC processing equipment,
`providing remote control and data gathering for i‘abn’cation
`personnel.
`
`by Wesley H. Higaki
`
`as a host computer system for processing equipment. PC-10
`provides the capability to rnonitorand control semiconduc-
`tor processing equipment remotely. Its greatest asset is that
`it provides the capability to store and download recipes to
`the appropriate system at the appropriate time. This feature
`alone increases equipment versatility and can reduce pr'n~
`cessing errors dramatically. From the PC-10 system. a user
`can request equipment status. store measurement data. re-
`motely control equipment. store and restore calibration
`data. and store and restore recipes. Equipmeltt-generated
`alarm conditions are recorded and reported.
`I-‘C-10 acts as the central node in the equipment network
`to gather all of the data from the equipment and feed it
`
` It Cost Accounting
`
`0 Financial Accounting
`
`Plaflnlng
`and
`F I nanciai
`
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`
`
`
`Manutacturlng
`3,",
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`Supervisory
`Monitoring
`and Control
`
`
`
`
`
`T HE INCREASING FABRICATION COMPLEXITY.
`
`shrinking device geometries. and larger chip sizes
`of VLSI circuits are requiring more and more automa-
`tion to provide acceptable yields and adequate control of
`process parameters. Automated process monitoring and
`control can provide exact duplication of processing steps.
`accurate measurements of the results. and precise adjust-
`ments to improve the process.
`Automation is common to some degree in modern
`semiconductor processltlg and measurement equipment.
`Microprocessors and minicomputers control the process
`steps in most wafer processing systems [diffusion furnaces.
`plasma etchers. ion implanters. ctc.] by using clqsed-loop
`feedback with stored “recipes" or process programs and
`loop coellicients. This reduces mechanical complexity
`(fewer switches. relays. etc.] and minimizes the need for
`human intervention during the process sequence. ii a suit-
`abie interface to an external computer system can be pro-
`vided, such process equipment can be controlled and mon-
`itored remotely.
`Defining. creating. and storing recipes and then applying
`them to computer control allows greater repeatability of a
`process step. Like a computer program. process programs
`yield greater control over the quality of the output once
`the programs have been qualified. A computer-controlled
`piece of equipment fed the same program over and over
`will yield almost exactly the same results each time; with
`manual control. the results can be unpredictable. Computer
`control also allows for easy monitoring and recording of
`the process. Since closed-loop feedback control relies on
`monitoring capabilities. storing and analyzing the moni-
`tored data becomes the next logical step.
`Equipment controllers are designed to monitor and con-
`trol a process stop. They have limited data storage and
`computing capabilities. They also have a very narrow view
`of the overall integrated circuit fabrication process. Indi-
`vidually. each piece of process equipment can optimize
`and control the process step for which it is responsible.
`but cannot correlate the data it collects with the data other
`pieces of equipment have collected. To do this. a host com-
`puter system is required.
`
`PC-10: Equipment Monitoring and Supervision
`P010 is a recent addition to HP's Semiconductor Produc-
`tivity Network [SPl\'. see Fig. 1]. This product (Fig. 2] acts
`
`30 HEWLETT-PACKARD JOUHNAL .su._v 1955
`
`Level 4:
`0 Production Planning
`0 Capacity Planning
`C lalaster Schedule
`0 Materials Planning
`
`Level 3:
`
`' WW’ Tfllflkiflg
`0 Inventory Control
`9 OH-Llf'l'E' ll'I8Ifl.|¢IlDI"|S
`" 55°F FTOOF
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`0 Bill oi Materials
`
`Level 2:
`' Efiuiprnentconlrol
`I Alarms
`I Recipe Control
`0 Tester Data
`Collection
`
`I
`
`-
`
`Level 1:
`
`0 Facility Sensors
`
`0 Equipment Management
`a Engine“-i,-,9 um
`collacfiflrl
`0 Engineering Analysis
`n Rework mg;-ggggrmm
`a workstation ,i\na|y3i3
`
`0 Automatic Data
`Collection
`0 Facilities Monitoring
`and Control
`I Salary Assurance
`‘__ ”S)‘8I2l'!1§__
`leaf’
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`I Processing Equipment
`
`Fig. 1. HP’s Semiconductor Producliwty Network is a collec-
`tion ol hardware and sofn-rare products designed to aid micro-
`electronic product
`iaoncation personnel
`in controlling.
`monitoring,
`improving, and managing many of me levels of
`the complex n1ani.ifacrori'ng process.
`
`® Capt‘. 1949-1995 Hewlett-Packard C0.
`
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`FBRHQTTED EOUIPfl£NT STATUS DISPLHY
`
`THERHCO TEHPERHTURE SYSTEH STHTUS
`
`F020
`‘I
`|‘1F1IH T12 SETPUINT
`1000,0000
`1000.0000
`1000.0000
`
`SPIKE TC SETPUIHT
`1001.1000
`1001.2000
`1001,1600
`
`PROFILE TC SETPOIHT
`1002.9000
`1002.B000
`1002.?000
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`SDUPCE TC SETPOIHT SPIKE TC SETPUIHT
`1U00.5000
`1002.0000
`1000.S000
`1002.0000
`1000.5000
`1002.2000
`
`PROFILE TC SETPUINT
`100l.5000
`1001,5000
`1001.4000
`
`1-“ “ ’-“C 1
`
`1
`
`9
`
`© Copr. 1949-1998 Hewlett-Packard Co.
`
`

`
`can monitor the progress of their processes and their equip-
`ment at remote SPN terminals. Through PC-10 they can
`also review all of the history information that has been
`collected from the equipment.
`
`Data Communications
`
`Data communications is a major part of PC-10 in two
`areas. PC-10 uses DSl3000-1000 to link the SPN HP 3000
`
`Computer System with HP 1000 Computers. which act as
`real-time network nodes. PC-10 also relies heavily on the
`SECS communications standard (see box on page 33] to
`link the HP 1000 Computers to the process equipment.
`The DSf300U-‘1000 link allows P010 to use the real-time
`
`capabilities of an HP 1000 to interface processing equip-
`ment. User transactions initiated on the HP 3000 through
`the SPN transaction handler are transmitted down the DS
`
`line to the HP ‘1000 for processing. This link is useful for
`functions such as automatically downloading a recipe
`when a tracked material lot arrives at different pieces of
`equipment.
`PC-10 has applications software on top of the process»to-
`process communications capabilities in DS/3000-1000.
`These applications have the intelligence to recover from
`any soft DS failures transparently to all of the users on the
`system. PC-10 also has the capability to link multiple HP
`1000 Computers to a single HP 3000 central node.
`Communication with the process equipment is the key
`to monitoring and supervision. To communicate with each
`of the different types of process equipment. PC-10 relies
`heavily on the use of the equipment manufacturing indus-
`try's communications standard. The implementation of this
`standard by process equipment manufacturers and PC-10
`has made connecting the equipment to a remote monitoring
`and control system a much simpler task.
`
`History of PC-10
`PC-10 has essentially two roots: the tightly integrated
`SPN family of software packages and the process control
`system [PCS] developed and used by HP Laboratories.‘
`PC-10 is designed to integrate with the rest of the SPN
`products such as IC-10. EN-10. and EA-10.
`[C-10 is the major tracking product of SPN. EC-‘l0 is based
`
`on the HP 3000 Computer using Image data bases. one for
`parameter data and one for production data. its data bases
`define the location-level
`tracking of material
`[wafers]
`through the process. A location is a general area in the
`fabrication area such as diffusion or photomasking. Since
`PC-10 addresses individual pieces of equipment and not
`general
`locations. operation-level
`tracking has been de-
`veloped to subdivide locations into discrete equipment op-
`erations. EN-10 is used to collect measurement data man-
`
`ually for analysis by EA-10.
`Between [C-10 and operation-level tracking, process en-
`gineers can completely define the flow of material through
`the fabrication area. When material is tracked through this
`process to a particular piece of equipment. which is linked
`via SECS to PC-10. the proper machine instructions can be
`loaded and the process can be monitored from any SPN
`terminal. Measurement data collected by PC-‘I0 from the
`equipment is stored in the SPN production data base for
`analysis by EA-10.
`PCS was developed by HP Laboratories’ Integrated Cir-
`cuit Processing Lab UCPL] to track material through oper-
`ations with the capability of transferring the machine in-
`structions to the processing equipment, specifically a
`Thermco diffusion furnace with minicomputer controllers.
`This system was based on an HP 1000 using an internally
`developed data base and communicating with the furnaces
`using a forerunner of SECS. Many HP IC facilities now use
`some version of PCS to operate a portion of their fabrication
`areas. The problems with PCS are that it does not provide
`the complete solution SPN does. it is unsupportabie as an
`external product. and it was designed for communicating
`with only the Thermco furnaces.
`To be successful in the marketplace. PC-10 had to address
`two major issues: integrate well with SPN and interface
`with many different kinds of semiconductor processing
`equipment.
`
`Interfacing Equipment
`To automate a complete IC fabrication area, PC-10 must
`be able to communicate with many different types of equip-
`ment built by many different manufacturers. Our goal has
`been to develop interfaces easily and quickly, which means
`
`PG-10
`Specifications
`
`Translator
`Text File
`
`
`
`Fig. 4. Transistor flow diagram
`New equipment :5 added easily to
`PC-10 by St!'l'l,t'3ly developing the
`appropriate host-to-equipment and
`EQUJDITIEDI-fO~hOSf rabies tor the
`associated SECS I.‘ data streams
`Examptes are shown tor stream 2
`function I4 and stream 2 function
`66 messages (:.e.. S2.‘ 14 and
`S2F66)
`
`Equipment
`
`
`
`
`
`
`Specifications
`
`
`
`EDIT ‘F000
`EEdI'tor}
`
`
`
`
`
`Translator
`«Iv Binary Data
`File
`
`2‘
`I
`
`_
`
`_ _-,
`
`4" . “ATE
`{T ranstatorp
`
`SPN
`PC-10
`
`Semiconductor
`Processing
`Equipment
`
`32 new-.e‘rr.pn.cwmo aouarea-. .:us.r «ass
`
`® Copr. 1949-1993 Hetltrtatt-Packtard Co.
`
`

`
`avoiding writing custom software to fit all of the idiosyn-
`crasies of individual processing systents. Instead. PC-10
`handles IC process equipment by separating it into general
`classes. SECS ll [see box below] is a rnandatory prerequisite
`of
`the equipment before an interface to PC-10 can be
`developed.
`HF's approach to interfacing is to survey a representative
`number of processing systems within a class to develop a
`generic model. A class is a group of equipment systems
`that operate similarly and perform the same general func-
`tions so that the communications requirements look the
`same to PC-10. The assumption is that each piece of equip-
`ment in an equipment class supports a subset of the SECS
`[I data streams and functions that PC-10 supports for that
`class. We also assume that the order of the messages. which
`is not defined by SECS II.
`is generally the same for all
`equipment
`in that class. To date we have encountered
`batch. rnetrology. serial. and material handling equipment.
`We expect that this list will grow as we begin to explore
`the use of PG-10 for remotely controlling and monitoring
`other types of equipment.
`Batch processing systems. such as diffusion furnaces.
`process waters in large quantities [batches]. The primary
`
`SECS
`
`The semiconductor process equipment manufacturers have
`identified the need for their equipment to communicate with a
`larger host computer system and developed the Semiconductor
`Equipment and Materials Institute (SEMI) Equipment Cornrnur1i~
`cations Standard {SECS}. SECS defines parts of all seven ISO
`open system interconnect (OSI) communications layers. SECS I
`incorporates the use of FIS-232-C cabling and pin definitions and
`a relatively simple line protocol. SECS ll defines messages to
`request and send status information. transfer recipe data. report
`alarm conditions. send remote equipment control commands.
`and handle material transfer.
`SECS I uses a simple END-Aclc handshake across an RS-232-C
`line with checksurns at the end of each message. SECS I also
`defines lime-out intervals between handshake responses. indi-
`vidual message characters. and message responses. Message
`headers are defined in SECS I to include equipment identiiiers.
`message identifiers. message block numbers. and other system
`information.
`SECS II defines message types. Iorrnat. content. and direc-
`tions. SECS streams are groups of messages assigned to a
`general set of equipment functionality. Within each stream, the
`individual messages are assigned function numbers. For exam-
`ple. SECS stream 1 function 5 [abbreviated S1F5l is a formatted
`equipment status request. and stream 1 function 6 is the reply
`with the status information. Similarly. stieam 7 function 5 is used
`to request the transfer of a process recipe and stream 7 function
`5 is used to transfer the recipe. SECS It also defines whether a
`reply is required or not. the message content and format (incred-
`ing data item definition headers}. and whether a message may
`be used from equipment-lo~host andror host—to-equipment.
`A maior limitation of the SECS standard is that it defines mes-
`sages and their content only: it does not define how the messages
`are used together to perform a function. Equipment manufac-
`turers are tell to decide what messages to use to perform func-
`tions that were parforrned manually before. This. of course. makes
`it difficult to develop translators for external systems to communi-
`cate with such equipment.
`
`characteristic is that once a batch has started processing.
`no more wafers can be added until the process sequence
`has run to completion. PC-10 will download only one retr-
`ipe to the batch station when the batch is tracked in and
`no other batches will be allowed in until the first batch is
`done.
`
`Metrology systems are classified separately because they
`provide certain measurement data to PG 1El.PC-10 supports
`SECS if stream 5 messages. which handle the transfer of
`measurement data to the host system for this class of equip-
`ment. Examples are line width. film thickness. and defect
`measuring devices. Wafers passing through these stations
`are not processed. but are merely measured to determine
`the effectiveness or accuracy of previous process steps.
`Serial processing handles wafers one at a time. Wafers
`from one lot may be entered into the equipment for process-
`ing before the preceding lot has been completed. Photo~
`lithography wafer track systems are a prime example of
`serial equipment. PC-10. to ensure that the proper recipe
`is executed for each lot. must check to see if the recipe
`already executing is the proper recipe for the next lot. If
`not. it must download the new correct recipe at the proper
`time for beginning processing of the new lot.
`Material handling requires an entirely different set of
`messages. since material handling systems are responsible
`only for transporting the wafers from one station to another.
`PG-10 instructs the material handling system to take a lot
`or a group of lots to a particular piece of equipment. Exam-
`ples of material handling systems include robots or tracks
`used to move the wafers through the fabrication area.
`The challenge we face when we address a new class of
`equipment to develop our models is to perform an adequate
`survey of such equipment on the market and develop an
`accurate. yet general model of how these pieces of equip-
`ment operate. This requires that we understand how the
`equipment works. what
`it
`is used for. and how PC-10
`should interact with it. In the past we have reviewed com-
`munications specifications from the vendors and received
`training on how to operate the equipment.
`Once our models have been developed. it becomes a
`matter of evaluating equipment to see if they fit the model.
`If a piece of equipment fits the model. than we must resolve
`any differences in the equipntent's SECS message format
`and content. PC-it] does this at the lowest level of its soft-
`
`ware-—the message translator.
`
`TI’fll18l810l'8
`
`The translators convert SECS messages as interpreted by
`the equipment into PC—1tJ interpretable messages. This in-
`cludes trauslating binary values into ASCII representations
`and vice versa. resolving data item length differences,
`masking off unneeded data items. and formatting data for
`displays or data base records.
`The translators are table-driven. Thus. to interface a new
`piece of equipment. all that must be done is to generate a
`new table and pass it to the translator program (Fig. 4). No
`new code is written. This technique greatly reduces the
`time needed to develop a new interface compared to having
`to custom-code the interface.
`
`The price we pay for this short development time is an
`interface that may not take advantage of all of the features
`
`JULY 1985 HE\l'I'LETT—Pi°.CKAflD JOURNAL 33
`
`© Capt’. 1949-1993 Hewlett-PackagI'd Co.
`
`

`
`Byte ass
`
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`
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`Data Item
`Value
`
`data items. Each item is preceded by a format header that
`describes the item. This header is a 2—to-4-byte item de-
`scriptor. The first byte contains the data format (i.e.. ASCII
`or binary] and a 2-bit length byte count. The length byte
`count
`indicates the number [1 to 3) of following bytes
`that contain the length of the data item [Fig. 5b). The
`translator resolves the implementation and the equipment
`interpretation.
`The translator resolves differences in the PC-it) and
`
`equipment vendor's interpretations of SECS ll streams.
`functions. and data item formats by using a translator table
`for host-to-equipment messages and another table for
`equipment-to-host messages (Fig. 4]. Each tabla maps the
`appropriate equipment message stream and function to an
`equivalent PC-10 stream and function. This mapping is not
`necessarily one-to-one.
`A variant table is included to provide the capability for
`a one-to-many mapping of messages. The first item in the
`message is used to determine which stream. function. and
`message body format are used. The variant table entries
`contain data {either ASCII or binary] to be compared with
`the message data.
`If a match is made. then the mapping
`entry with the corresponding variant number is used to
`format the translated messages.
`Each table also maps. item by item. the data format and
`length to he sent. Each line in the host-to-equipment map
`defines the format and length of the individual data items
`from PC‘—10 to the translator and the formal and length to
`be used when the message is sent to the equipment. The
`equipment-to-host map contains the description of the data
`items as they will be passed to PG-10.
`The table entries have the ability to pass the data through
`the translator without reformatting. This is a feature PC-10
`uses to handle calibration and recipe data. since PC-10 will
`only store and deliver recipe data as the equipment pro»
`vides and expects it.
`The table entries can also mask off data items as neces-
`
`sary. This is useful when PC-10 provides data items that
`the equipment does not use or expect in its messages.
`
`Reference
`1. GR. Clare. "A Process Control Network." Hewlett-Por:kord' Jour-
`nal. Vol. 32. no. 8. lune 1981.
`
`Flg. 5. SECS H formats for raj messages and {bl data items.
`
`a piece of equipment has to offer or may make operating
`the equipment more awkward than if custom software were
`written. However. with only the translators changing for
`each different piece of equipment. the other software layers
`remain unchanged and so do not have to be updated
`whenever new equipment is added to a fabrication area.
`The first step in building a translator is to review the
`equipment vendor's SECS implementation specifications
`to see if the general interpretations match those of PC-10:
`that is. there is a message comparable to that of PC-10's for
`every critical message. Critical message sets differ from
`equipment to equipment. A measurement data report is
`critical to film thickness measuring devices. Recipe transfer
`messages are critical for furnaces, because that capability
`is what makes the interface useful.
`
`SECS ll defines a 1D-byte header and message bodies
`[see Fig. 5]. Within the ‘JD-byte header are the device ID
`[bytes 1 and 2]. message type {stream} and function {bytes
`3 and 4]. message block number [bytes 5 and 6}. and system
`bytes [bytes 7 through 10]. The translator is used to resolve
`the differences in the interpretation and usage of stream
`and function numbers between PC-1 D and the equipment.
`Within the SECS 11 message body. there can be several
`
`34 HE\i'|.'LE‘l'T-PACKARD JOURNAL JULY 1335
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`®.Co-pr. 1949-1993 Hewlet't-PackaI'd Co.