MVT 643 Sputtering System
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The system consists of several major components:
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| Location of some major components |
The Load Lock and Chamber are located on the top of the system with the motion indicator panel running the width of the system directly below. The bottom half of the system consists of three electronic bays. On the right end of the system is the interconnection terminal blocks and on the rear is the AC breaker panel and the service connection panel.
The three electronics bays on the front contain the various support electronics. The left bay has the Diagnostic Maintenance Panel and at the bottom the DC power supply for the targets.
Between the left and center bays is a divider panel containing the front Emergency Stop switch and the Audible Alert. The audible alert routinely sounds for ½S as the RF, DC or heater power supplies are enabled. It will also beep when the Diagnostic Maintenance Panel is placed into 'no safety' mode.
The center panel contains the Granville-Phillips 303 Ion gauge controller. This is used for precise high vacuum pressure readings of both the Chamber and the Load Lock. Below that is a panel containing four gauges. The first is the Cryo Pump temperature indicator. This reads the temperature of the Cryo Pump and provides high and low set point indicators to the PLC. Next to that are three Convectron Gauges that provide pressure readings from atmospheric down to the milliTorr range. There are three gauges, one for the Load Lock, a second for the Chamber and the third for the Cryo. The remainder of the middle bay has a large panel with a single small control for the heating elements. This control is tied to a thermocouple located directly in front of the heating elements in the Chamber.
Between the center and right bays is a divider panel containing the front panel On/Off switch.
The right hand bay contains various support electronics for the RF tuning system and the RF power supply itself. It also has the 275-gas pressure regulator and the Baratron gas pressure sensor for controlling the trace gas flow during processing. There are four gas channels and the 275 and Baratron control their pressure as they are released to the Chamber thru the distribution manifold.
Located on the right end of the system behind the modesty panels is the 400 terminal block interconnection system. All of the PLC I/O are brought to this panel and connected out to the rest of the system. The PLC connections are all on the left side of the terminal blocks and the system connections are to the right.
On the rear of the system at the top left is the PLC itself and its control modules. There are two PLC base plates and the power supply's on each should both have three green indicators on at all times, PWR, OK, RUN. Additionally the 2, 3, 4, 5 and 6 LEDs on module #12 will be flickering rapidly as will be all the LEDs in the bottom half of module #10. Other LEDs will be on and off as the state of the system changes and the OK indicators on modules 2 thru 6 should all be steady on. All of these together indicate that the PLC is alive and well.The AC breaker panel contains the circuit breakers for the major sub-systems and is detailed in the appendix of this document.
The center rear of the system contains the Cryo pump and associated connections in the top half and the hydraulic pump and it's valving in the lower half. On the right rear is the service connection panel for connection of the mechanical pump, power for the Cryo and mechanical pumps, water flow controls and service connections for water and air.
There are three sputtering targets in the system and the RF etch station. For example the targets can be configured as:
| Target | RF/DC | Hot Swappable |
|---|---|---|
| T1 | RF | Yes |
| T2 | DC | No |
| T3 | DC | No |
| Etch | RF | No |
Additionally there is the RF etch/heat station. This water-cooled station is equipped for RF etching and radiant heating from IR quartz lamps. It may also be used for substrate pallet cooling by setting the RF etch power to zero.
The system has dual power On/Off switch stations (one on the front, one on the PS chassis) as well as front and rear mounted safety switches. The wiring of the system is such that the Off and Emergency Stop switches are on a single series string. Interruption of the string at any point will stop the motion systems. Restoration of an Emergency Stop switch WILL NOT automatically restart a motion process but PUMPS will be.
The Motion Indicator Panel shows the position of the substrate carrier and shutter within the vacuum Chamber as well as position indicator LED's for the Load Lock elevator, grippers, and RF etch/heater platform:
| Elevator | Grippers | Etch Platform | |
| Carrier Shutter | ||
| Motion Indicator Panel | |||
Startup/Shutdown
The MVT 643 is engineered for simple startup and shut down under normal operating conditions. Since it is designed to be controlled by a remote PC type computer system, operations are inhibited until the Host PC is properly connected and the software is running.J53, located on the right side of the system on the side of the power chassis is used to connect to the Host PC type computer. Position the Host PC computer conveniently to the sputtering system and connect the computers 9-pin COM1 port to J53 with the supplied cable. Details on the wiring of this cable are in the Lab Notes manual, drawing CMM311.
Insure that the system is connected to an adequate supply of clean, dry, compressed air at a minimum pressure of 80 PSIG.
Connect the system to a supply of chilled water capable of supplying a 5 GPM flow and ensure that the rear utility panel water valves are in the open position (as shown, right). Observe that the flow switch rotors are spinning.All of the AC breakers in the AC breaker panel (located on the right rear) should be in the ON position.
Initialize the system by pressing the ON button located on the front panel:
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| Primary On/Off control |
The system is wired so that it will go to safe standby with all valves closed when the Host PC computer is turned off or disconnected. Even if the host software program is not running, the PC should be left on if the system is running a long process. A reset of the PC will NOT reset/standby the PLC, nor will simply stopping and restarting the host software.
Manual Operation
The system has a manual Diagnostic Maintenance Panel that can be used to control the motion systems. There are five motion systems on the MVT 643, these are:- 5 Station Elevator
- 7 Station Carrier
- 3 Station Shutter
- 4, Two Position Grippers
- 2 Station Etch Platform
The Diagnostic Maintenance Panel has three modes of operation.
- Disabled (Manual Key in Disabled position)
Switches are inoperative except for GTG (Good to Go), indicators are active
— The Manual Key can only be removed in this position - Manual with safety (Manual Key to Enabled)
Switches and indicators active with safety interlocks enabled - Maintenance without safety (GTG pressed as Manual Key turned to Enabled position).
Switches and indicators active WITHOUT safety interlocks
WARNING! |
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| During Maintenance mode all Valve safety interlocks are DISABLED! USE WITH CAUTION!Motion Interlocks remain active at all times. |
The manual diagnostic system also allows manual start and run of the vacuum pump systems and adjustment of the RF tuning for RF sputtering/RF Etch targets.
The four targets, T1, T2, T3, Etch and none can be manually selected by pressing and holding the GTG switch while using the Man/Auto switch in the RF group to sequence thru the selections. The Man position will select the next target to the left (E-3-2-1-x-E) while the Auto position will select to the right (1-2-3-E-x-1). The selection advances when the switch is released. Both the RF and DC supplies are commanded off before the switching occurs.
This Diagnostic Maintenance Panel does NOT allow manual initiation of the automated motion sequences. These functions can only be accessed via the Host PC software. However the indicators on the panel allow you to confirm the state of the RF/DC system.
The red target selector indicators in the RF tuning area indicate the selected target. They do NOT, however, indicate that the RF/DC power is on; rather they just indicate which target has been selected. In order to confirm that a target is actually POWERED the shutter indicator associated with that target will blink whenever that target is selected and the RF or DC power supply's are ON. That the Etch Platform has RF on is indicated by blinking the Carrier 7 LED, Shutter 3/Etch LED, and the Platform Back LED located on the right end of the motion indicator. If the heaters are on, the Platform Fwd LED and the Shutter 1/Heat LED will blink instead.
Maintenance operation bypasses many of the interlocks associated with the automatic sequencing of the system and should be used only by highly knowledgeable personnel. Even in Manual mode, certain interlocks are honored to prevent major damage to the system. In any case, caution and forethought should always be used when operating a complex sputtering system in any manual mode.
The Diagnostic Maintenance Panel is laid out to facilitate error free operation and ease of operator training/use. It is divided into seven groups:
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| Diagnostic Maintenance Panel |
Motion Group
The Motion Group has controls for the operation of four of the major motion systems as well as a variety of indicators. The vacuum valves and pump status are shown in green, while the position indicators for the carrier and shutter are displayed in amber.The controls are physically arraigned around a functional diagram of the system with the control location approximating the actuator physical location on the system. Thus the RF etch control is on the right end of the diagram and the Load Lock elevator control is to the left. Additionally, the switch levers are orientated to imply the direction of motion during actuation.
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| Motion Group |
Elevator Forward/Back
Used to move the hydraulic elevator from the Load Lock station (position 5) thru the various 'lower' stations. There are five indicators on the left side of the motion indicator panel that show the actual position of the elevator.Note that the elevator may be mechanically prevented from motion depending on the vacuum state of the system. If the vacuum in the Chamber and Load Lock are greatly imbalanced the elevator may be unable to overcome the pressure forces.
The GTG switch acts as a 'multiplier' on the Elevator Forward/Back switch. If the GTG is held as the Elevator Forward/Back switch is activated, the elevator will automatically move to the next 'floor' instead of stopping when the Elevator Forward/Back switch is released.
When the system is under vacuum, the elevator will maintain a seal at the Load Lock position by monitoring the hydraulic pressure switch. This switch closes at approximately 1000 PSI and opens at 900 PSI. Whenever the pressure switch opens, the PLC will momentarily 'bump' the hydraulic system until the upper set point is reached.
Substrate Carrier
The substrate carrier is used to transfer the work pieces between the Load Lock and the various other stations. The substrate pallet is carried along on the substrate carrier and can be loaded and unloaded by the grippers.There are seven substrate carrier positions with associated indicators on the Diagnostic Maintenance Panel. These indicate the position of the substrate carrier within the system. Additionally, the motion indicator panel, along the front edge of the system, has a position indicator bar that is mechanically linked to the substrate carrier position internal to the Chamber.
You should not attempt to move the carrier station #1 or #2 (the left most two stations) when the elevator is not at station 1–4. You should not attempt to move to carrier station #6 or #7 when the etch platform is forward.
The GTG switch acts as a 'multiplier' on the Carrier Left/Right switch. If the GTG is held as the Carrier Left/Right switch is activated, the carrier will automatically move to the next station instead of stopping when the Carrier Left/Right switch is released.
Shutter
The shutter is used to cover unused targets during sputtering to prevent cross contamination between targets. It is also used to protect the IR quartz heat lamps during RF Etch. The shutter has three positions, A, B and C corresponding to targets 1, 2, and 3. Only the target associated with the particular position is exposed. The shutter is also used as a "etch collector" when using the RF etch station. During RF etch operations the shutter should be positioned at station C. For heating, the shutter should be at station A or B. The shutter should not be moved while the Load Lock elevator is in motion and should be positioned at station B or C prior to moving the Load Lock elevator. The shutter position indicator LED's also blink to show when the target at that station is powered.The GTG switch acts as a 'multiplier' on the Shutter Left/Right switch. If the GTG is held as the Shutter Left/Right switch is activated, the shutter will automatically move to the next station instead of stopping when the Shutter Left/Right switch is released.
RF Etch Platform
The RF Etch Platform has two positions, Forward and Back. The forward position is used only as part of the transfer operation where the substrate pallet is moved from the substrate carrier to the RF etch station. The back position is used for RF etching. There are a pair of amber LED indicators located along the right edge of the motion indicator panel that show the position of the RF Etch Platform. These indicators also blink when power is applied to the etch platform (Platform Back LED blinks) or when the heaters are on (Platform Fwd LED blinks).Indicators
There are four (4) different types of indicators within the Motion Group. These include the amber position indicators for both the carrier and shutters (discussed previously) as well as green LED indicators for the vacuum valves and pumps.The vacuum valve indicators show what valves are in which position at any given time. There should be a 1:1 correspondence between the last valve switch actuation and the associated indicator.
The pump indicators, however, operate in a somewhat different manner. There are three (3) pumps in the system:
- Mechanical Roughing Pump
- Load Lock Turbo Pump
- Chamber Cryo Pump
| Pump | RED Located in Pumps group |
GREEN Located in Motion group |
|---|---|---|
| Mech | Power Sensed | Power Sensed |
| Turbo | Commanded On | At Speed |
| Cryo | Power Sensed | Cold Temperature <20ºK 1 |
| Note: Most Diagnostic Maintenance Panel switches are inhibited for 30 Seconds after Mech Pump Start — 1 Set point adjustable on rear panel of CTI temperature controller in center electronics bay | ||
Note that the Power On indicators for the Mechanical and Cryo pumps reflects the actual presence of AC power applied to the pump and are NOT just hardwired to the switches. Thus if the rear panel AC breakers are tripped, the LED's will not come on even if the AC contactor to a pump is activated.
The pumps are interlocked so that turning off a pump will automatically close all valves associated with that pump to isolate it from the rest of the system. Additionally certain valves cannot be opened unless the associated pump is running (or not running in certain cases). This is so that the system acts at all times to preserve vacuum and to prevent damage to the system or any of its components.
The turbo pump controller indicator panel (right electronics bay) will have a red indicator and display "E005" when the turbo is not running. This is normal and not an actual error. This is the only 'allowed' error code. If the pump controller displays any other code, refer to the TCP 380 Electronic Drive Unit Operating Instructions Manual section 9.2 for a complete list of errors.
| TCP 380 Turbo Pump Controller | |
|---|---|
 Turbo Commanded OFF Display shows E005 |
 Turbo Commanded ON |
From the TCP 380 manual, p. 18  | |
Master Group
The Master Group has two controls. The Master Enable key switch and the GTG (Good To Go) push button. The Master Enable key switch must have the key inserted and be in the ENABLE position for any of the controls (except the GTG button) on the manual Diagnostic Maintenance Panel to be active. All of the indicators are active independently of the switch position. The key can only be removed from the switch in the MANUAL DISABLE position.The GTG button is a manual confirmation button used in combination with certain other controls to modify their basic operation or to provide an operator confirmation. Typically this is used in conjunction with the Load Lock door switch to indicate to the system that Load Lock pump down is desired. This prevents accidental sequence initiation in the event that the Load Lock door is accidentally closed.
Pump Control Group
The Pump Control Group has three (3) switches and indicators that are used to manually start/stop the mechanical, Cryo and turbo pumps within the system. The power indicators operate as previously discussed in the Motion Group.
RF Tuning Group
The RF group is used to tune the RF matching network for minimum VSWR. There are two meters, four indicators, four adjustment knobs and two switches in this group.There are four possible RF targets, T1, T2, T3 and the Etch station. However at the client's request RF is only provided on T1 and the Etch station. Each target and the etch station has an indicator and tuning knob. Target selection is normally via the Host PC software but the operator can manually sequence thru the four targets (T1, 2, 3 and Etch) by holding the GTG button down while using the MANUAL/AUTO switch to cycle thru the four targets and none selected. The MANUAL switch position cycles to the left, while the AUTO switch position cycles to the right.
As each target is selected the RF network should be tuned for minimum indication on the Reverse meter.
You can sequence thru the targets by using the Manual/Auto switch in conjunction with the GTG button. Holding the GTG button down while activating and releasing the Manual/Auto switch will cycle thru the four stations and no station selected. The Manual position selects the next position to the left while the Auto position will select the next station to the right.
Chamber Valve Group
All of the valves associated with the Chamber and Cryo pump are controlled by the switches in this group. The indicators for the valves are located in the Motion Group. The ordering of the switches is the same in both the Chamber Valve Group and in the Load Lock Group. They are also sequenced in the order they will most likely be used in going down from the top of the panel. Each switch is momentary and placed in the up position to open the valve and the down position to close. You should be able to hear the valves respond as each switch is actuated.Certain valves in both the Chamber Valve Group and the Load Lock Valve Group are interlocked and will close other valves prior to them opening. These interlocks can be bypassed by placing the system into maintenance mode.
Load Lock Valve Group
All of the valves associated with the Load Lock are controlled by the switches in this group. The indicators for the valves are located in the Motion Group. The ordering of the switches is the same in both the Chamber Valve Group and in the Load Lock Group. They are also sequenced in the order they will most likely be used in going down from the top of the panel. Each switch is momentary and placed in the up position to open the valve and the down position to close. You should be able to hear the valves respond as each switch is actuated.
The Cryo Regen and both the Load Lock Rough and Chamber Rough switches connect to the mechanical pump. Only one should be selected at a time. The valves are interlocked so that only one can be activated at any given time. Attempting to open another roughing valve will automatically close any previously opened valves. If the vent valves are open on the Load Lock or Chamber or the Cryo Purge valve is opened, opening the Load Lock Rough, Chamber Rough or Cryo Regen valves will close the associated vent/purge valve.
The Vent switches will vent the Chamber/Load Lock to atmosphere, albeit slowly. It may take several minutes for the system to vent sufficiently so that the Load Lock door opens.
Gripper Group
There are four pneumatic grippers in the system set up as two pair. One pair (the left) is used to grip/release a pallet in the elevator area. The other pair (the right) is used to grip/release a pallet in the etch platform area. Each gripper has an indicator on the motion indicator panel. The indicators are on when the grippers are open and NOT holding a pallet.
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| Gripper Indicators on Motion Panel |
On the host computer console's Service Tab the gripper state indicators have an additional icon to show when the grippers are holding a pallet. This icon appears in the center area of the other gripper icons on the left and right sides of the screen as appropriate.
NOTE!
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If the upper gripper does not raise when the lower gripper is activated, this is a signal that a pallet has been dropped internally to the system. DO NOT ATTEMPT TO CONTINUE OPERATIONS UNTIL THIS FAULT HAS BEEN CLEARED! |
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Releasing the pallet reverses the gripping operation. First the lower gripper is lowered allowing the upper gripper to sink back onto the carrier. Then the upper gripper is raised, releasing the pallet onto the carrier, elevator, or etch platform.
For safety, the left (elevator) grippers cannot be actuated if the elevator is not at stations 1 to 4.
The PLC interlocks will trip if there is a gripper failure. Generally, if the software reports a gripper error, this is an indication that the valve actuator has failed and a gripper has not reached a commanded position. Gripper errors will inhibit other systems as well. If the palette has not been dropped, most gripper errors can be fixed without having to open the Chamber.
If the either upper gripper is in the down position, down action of the corresponding lower gripper is blocked. This is normal and is a safety interlock.
RF Tuning
RF tuning is needed to maximize the power coupled into the target from the RF power supply. Maximizing input or forward power implies the need to minimize the reverse or reflected power.Power reflections are caused by the mismatch between the RF impedance of a target vs the ideal 50 ohm impedance that the power supply expects to see.
Due to the physical configuration of targets they generally are lousy 'antennas' from the RF power supply's standpoint.
In order to tame the wild impedances caused by the physical properties of the target, we have developed the RF tuning network that helps compensate for the typically poor RF properties of the target. This is accomplished by adding some capacitance to the impedance of the target to achieve a better (lower) VSWR (Vertical Standing Wave Ratio). However due to the power level's involved the mechanical system required to tune the capacitance is somewhat complex and has to be performed remotely.
Tuning is accomplished by using the Host PC software in conjunction with the manual Diagnostic Maintenance Panel. The target is selected and a low power is used for initial tuning. The target is tuned for a minimum on the Reverse power meter on the panel and then the power is increased and the process repeated. It may be necessary to perform several iterations to get the desired result at the final power level.
Motion Sequencing
By 'motion sequences' we refer to action sequences that are completely pre-programmed into the PLC. This allows the Host PC software to be greatly simplified and protects the system against accidental damage do to improper operator actions. There are currently four motion sequences set into the PLC:- Load Lock Pump Down and Load Lock Pallet Exchange
- Multiple Pass Target Scanning
- Etch Station pallet Exchange
- Heat Station
Initiating Sequences
The with the exception of the Load Lock Pump Down, motion sequences can be triggered manually only from the Host PC software (described in detail in the next section). However we will briefly summarize their operation here. For complete details on the functions of the Service Tab refer to the next section.Load Lock Pump Down
Load Lock Pump Down and pallet exchange cannot occur until the following conditions are met:- Mech Pump Running
- Elevator at Load Lock
- Load Lock Door open
- Completed Work pallet has been removed
- New Work pallet has been installed
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| Pallet Hanger Top View |
| Falling | Steady | Rising |
|---|---|---|
 Mint |
 Straw |
 Rose |
Load Lock Pallet Exchange
The Load Lock Pallet Exchange can only be started once the Load Lock Pump Down sequence is complete and the Load Lock pressure is comparable with the Chamber pressure (the pressure match does not have to be perfect).The Load Lock Pallet Exchange usually occurs automatically once the Load Lock Pump Down sequence is completed. The exchange sequence can also be initiated manually from the Service Tab by clicking on the Exchange icon. The exchange sequence cannot occur while other processes are active and other processes cannot begin until the elevator is fully up and the Load Lock isolated from the Chamber.
There are 19 steps in the kinematics of the Load Lock exchange and the step number will be shown on the Service Tab display. Some steps occur so rapidly that the display will appear to skip certain numbers in the sequence, this is normal and no cause for concern.
Multiple Pass Target Scanning
Once the software has specified the target, power level, number of repetitions, the Multiple Pass Target Scanning sequence can be started. The pallet carrier will always move to station #2 prior to the start of scanning. This is to insure that the scans are correctly counted and that the work is not exposed to a partial scan during sequence initialization.As each scan occurs the Repetitions and Remaining indicators will update. The Repetitions indicator will decrement and the Remaining indicator will increment. Adding both values together should always give the total number of scans specified for this step in the recipe.
Depending on the scan speed and number of repetitions this process can take anywhere from seconds to hours to complete. The limit on the number of repetitions is 1000 per recipe step. If you require more scanning passes than this you will have to create two steps in the recipe, both with the same basic settings.
Etch Station Pallet Exchange
The etch station pallet exchange is used to position the pallet for etching operators. The pallet is transferred from the carrier to the water cooled etch platform and the shutter moved to protect the heating elements. The pallet will remain at the etch station until either the Host PC signals that the time is up or until the operator intervenes by pressing the GTG button. This allows the operator to 'short cycle' the etching process when initially testing a recipe.Heat Setup
Pallet bake occurs at the etch station, carrier station #7, but the pallet remains on the carrier. The shutter moves out of the way (to shutter station A) and the heating cycle begins. As with the etch cycle, the heating operation will continue until signaled by the Host PC computer or by the operator via the GTG switch.There is a thermocouple installed between the heating elements and the pallet that can be used to establish a process set point for the heaters. However this set point is not monitored nor is it settable by the PLC or the Host PC.
WindowsTM GUI
In order to faciliate the operation of the system, A WindowsTM based GUI has been created to manage the system. Sequences of operations can be saved as recipes. These can be used to select the gasses, targets, power levels, number of repetitions and scan speed. The software has been installed such that it will automatically launch when the Host PC is started. However you can manually launch the program by clicking on the icon. Only one copy of the program can be active at a time.
As the program is initializing a dialog will be displayed similar to this:
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| Wait Dialog |
NOTE
If the Wait Dialog appears to stall,
check to make sure that the serial cable
is properly connected at the Host PC end.
Recipe Tab
The Recipe Tab is used to load and save recipes to disk. You cannot 'cook' with a recipe until it has been loaded and the chamber gate valve has been opened. Once the recipe is loaded it can be reviewed/modified on the Settings tab.Buttons on this panel allow you to:
The Recipe Tab also has the online reference manual pane. This leads the operator to this document where it can be reviewed at any time (except when actually running a process). Settings Tab
The Settings Tab is where a recipe is developed. For each step in the recipe various parameters can be set, these include:
![[Add this step to Recipe]](btnadd.gif){kind=small} button. You can modify a step of an existing recipe by clicking on that step in the grid.
Service Tab
The Service tab is used to monitor and control the state of the system while not running a recipe. All of the controls for this page should be active. You can select active targets as well as gasses and control the valves in the system. The layout of the Service tab and the manual Diagnostic Maintenance Panel is similar as are the functions of the switches and indicators. The LED's on the manual Diagnostic Maintenance Panel should reflect the same state as the Service tab.In addition to the various controls the Service tab also has indicators for the water flow sensors. Water flow is critical to the proper operation of the sputtering system. Without sufficient water flow, the targets and matching network would tend to overheat and would rapidly degrade. For this reason the flow interlocks are part of the 'safe to start' circuit and neither the RF nor the DC power supplies can be enabled, nor can targets be selected if the appropriate water flow interlocks are not met. There are two icons used to indicate the state of the water flow interlocks:
 One indicator, the right, shows when the pump is on (normally only as the elevator is in motion). The second indicator, the left, informs you that the hydraulic system is at operating pressure of 900-1000 PSIThe controls for the motion systems are grouped and function with interlocks on most operations. Due to the nature of the communications between the Host PC and hardware, there may be a several second delay in processing certain commands. DO NOT MULTIPLE CLICK ITEMS! The software will perform the action for EACH time that you clicked the control. This is almost never desirable. Give the screen time to refresh. The screen is currently updated once a second and may lag the hardware by several seconds as the systems maintain synchronization. The elevator position is indicated both as LED's on the Motion Indicator Panel and on the Host PC screen as a position bar. The actual position is highlighted in green. The carriage position and shutter position are also indicated in a similar manner:
In addition to the control buttons on the lower portion of the screen, the valve buttons are active on the pictorial upper portion. Each valve will be filled with green or red depending on if the valve is open or closed. Additionally the piping in the figure will change colors as the various pumps and valves interact. Most all of the valves require the mechanical pump to be active. Valves associated with a specific pump typically have a dependency on the state of the pump. The system is interlocked so that both manual and software actions are protected by interlock.
Once an exchange as been initiated, a small dialog will appear showing the step within the sequence that the PLC is currently executing. This is to give a visual confirmation of the progress of the exchange. The indicators for the carrier, elevator and grippers will all update as the exchange sequence runs. This is also true for the Etch Platform Swap.
The gas indicators can also be clicked on to operate the gas valves. The indicators will show filled/red  when active and open/clear  when off. The indicators will be black filled  when input is not available. This typically occurs during program restart and is used to confirm I/O activity.
The slider is used to set the process gas manifold pressure. The range on this control is from 0 to 100mT. The current value from the manifold gauge readout is shown in the label directly below the slider. There is normally a certain delay and variance in the setting of the slider and the value displayed. 
Under certain circumstances manual commands will not be acted upon by the PLC. This is caused by the PLC's safety interlocks overriding the operator command. In the event that this occurs, a message will be displayed and the Host PC will 'beep' once to alert the operator that their command has NOT been accepted.The PLC Status box is also a 'hidden' command button to re-initialize the PLC. This should only be used in emergencies and NOT as a part of 'normal' operations. Re-initializing the PLC will abort any sequences currently running and will close all valves. The pumps, however, will remain in their previous state. This is normally only used to recover from an aborted process or other Emergency Stop. 
Below the PLC Status box there is a green acknowledge button that is used to clear the PLC's internal error registers. All messages sent to the PLC Status box are also logged to the plclog.txt file for later review.
Configuration Tab
The Configuration Tab set the operating parameters for the system. These include target types, power and speed limits, etc. Additionally the RF and DC power supplies can be enabled and exercised from this screen. Care should be used when operating the power supplies manually as the outputs are potentially lethal.Access to this screen is password controlled. Initially when the software is installed the password is defaulted to MVT 643. This password can be changed at any time. Note that passwords are case sensitive and leading or trailing blanks can be used as well. The password dialog appears similar to:
In actual practice the parameters on this page require only infrequent adjustment and should not be changed as a normal course of operation. The configuration information is stored along with the recipe information and the software has been configured to not run a recipe if the configuration of the system is incorrect. This prevents errors but does imply that you should adjust your configuration initially and THEN develop any recipes using that given. Along the top of this Configuration Tab are four rows of settings, one for the RF Peak Power, one for DC Peak Power and two for the carriage speeds. The indicators on the other tabs are color coded by the settings on the configuration tab. While the power supplies can put out their full stated ratings, for a given process you may wish to caution the recipe developer against exceeding process dependent limits. The operator can specify the normal, caution, and danger limits for each of these four parameters by adjusting the sliders. There are three pressure set points. Once for the Turbo On Pressure, a second for the LL Rough Close Pressure and a third for the Ok to Exchange Pressure. These three parameters control the set points of the Load Lock Pump Down sequence in the PLC. They are read directly from the PLC and not stored in the .CAL file. The four process gasses and the three targets can be named. This allows the screens to display the actual name of the process gas and not just "Gas #1", etc. The PLC integrates the target power into a kWH value. This value is displayed on both the Service Tab and the Configuration Tab. The Reset button to the right of the cumulative kWH reading on the Configuration Tab is used to reset the counters to zero when the targets are replaced. There are two fields filled with asterisks that hold the password needed to access this screen. When changing the password the characters entered will be shown as asterisks and you should make sure that both fields contain the same information. The password entry is case sensitive. The Configuration Tab also has diagnostic controls for selecting as setting power levels to the targets. Use this with caution as potentially deadly voltages are present in the system and enabling the outputs while personnel are present could be lethal. When using the RF Power diagnostic you should select the target, set the power and THEN turn the output on. There is normally a several second delay when using the controls on this tab. The top slider sets the commanded RF or DC power level. The indicator directly below shows the commanded analog voltage and the tolerance limits as set by the bottom two sliders. The color coding on the indicators is dependent on the Caution Level and Danger Level controls at the top of the tab. The lower indicator of the pair directly below the level setting slider shows the feedback signal from the power supply. The indicator value should track the command level indicator with a several second lag. The feedback indicator will remain at zero if the power is not switched on. One unique feature of the MVT 643 Sputtering system is the HTML based 'twinkle board'. This allows the Host PC to be part of the customer's LAN and to have it generate a web browseable display page. In this manner several people may observe the state of the system remotely, making it an ideal tool for teaching and production situations. The remote monitor also allows multiple sputtering systems to run and be monitored from a central location using a web browser. 
This feature is enabled by specifying a update rate and clicking on the Twinkle Enable button:
Run Time Tab
The Run Time tab is updated as long as a recipe is actively processing. This is the only time that this tab can be used. The display of the valve and various system status items is the same as on the Service screen but there are no operator controls with the lone exception of an Emergency Stop safety icon.Note that this tab is not normally accessible unless a process is running, and when running, you may not select a different tab. Real time status display of the recipe step, time, and PLC health is on the bottom left Status panel. The Run Log shows the reverse chronological log of the system activities since the recipe began (most recent at the top). Actions such as target selection, gas selection, repetitions etc. are logged and date/time stamped. The user can scroll thru the list while the process is running to review the history of this recipe run. The data logged during the run is saved automatically when the Host PC software is stopped. This file has a .log extension and is simple ASCII text that can be read by any word processor or editor program. 
The large E Stop button is used to 'dump' a recipe and stop all preprogrammed actions. However Motion Sequences that are already in process cannot be stopped. Scanning can be aborted, but only at the completion of current scan. If the situation is a dire emergency, the front or rear Emergency Stop or either power switch should be used to quickly disable the sputtering system.
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Appendices
Lab Notes
The Lab Notes for the construction of the system are a separate Adobe Acrobat data file. The current Lab Notebook consists of over 300 pages of reference materials including drawings, wiring information, manufacturers spec sheets, manuals, photographs and other related materials.Click HERE!
PLC Source
For reference, the entire source code to the PLC is available as a related Adobe Acrobat data file. The current listing is over 100 pages of ladder diagrams. The PLC ladder diagrams and code are copyright 2004 by MAT-VAC Technology, Inc. and All Rights are Reserved despite the inclusion of the code here. The contents of the code are proprietary and not for dissemination to any 3rd party without the express written consent of MAT-VAC Technology, Inc.Click HERE!
Requirements
Breaker Panel
Refer to this diagram for the relative location and ratings of the rear circuit breakers:| Breaker | Ampere Rating |
Phase | Locator | Breaker | Ampere Rating |
Phase |
|---|---|---|---|---|---|---|
| L1 — IO PLC LED's on, but system otherwise unresponsive |
20A | 1 |  |
R1 — RF PS System will operate normally but unable to sputter on RF targets or etch |
20A | 3 |
| L2 — Service No effect on normal operation |
20A | 1 | ||||
| L3 — PLC System completely dead, no lights on PLC |
15A | 1 | R4 — Cryo Cryo Pump will not operate. Rest of system functional. |
15A | 2 | |
| L4 — Heater System will operate normally but unable to heat |
25A | 2 | R6 — Hyd Elevator will not move. Other linked operations may be inhibited depending on elevator position. |
10A | 3 | |
| L6 — Mech Since the other pumps are interlocked with this one, no pumps will start |
15A | 3 | R9 — Main System completely dead. No indicators anywhere |
100A | 3 | |
| L9 — DC PS System will operate normally but unable to sputter on DC targets |
45A | 3 |
The Diagnostic Maintenance Panel indicators for the Mech pump and the Cryo pumps reflect the actual presence of voltage at the pump power terminals. The contactors will actuate even if the associated circuit breaker is off, however the Diagnostic Maintenance Panel LED will not illuminate under these circumstances.
PS Chassis
Below the PLC is the Power System (PS) chassis. This is covered by a clear panel and contains no user serviceable components inside. However the left side of the panel (accessible from the right side of the system) contains the auxiliary On/Off switch and the system fuses. This panel also contains J53 which is used to connect the system to the Host PC.There are two groups of fuses on the left side of the PS chassis. The upper group F10, F11, F13 and F14 are above the auxiliary On/Off switches and seven fuses, F19, F20, F21, F23, F24, F25, F27. The fuse ratings and their function are listed in the table below:
| Fuse | Rating | Function | Layout |
|---|---|---|---|
| F10 | FNQ5 | Power to the RF Tuner subassembly via connection ACO2 on the right side of the PS chassis |  |
| F11/F13/F14 | FNM12 | Hyd Pump Power The Hyd pump is a three phase motor and each phase is fused Elevator will not move when any of these fuses are blown |
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| F19 | 2A | Power Interlock relay System will refuse to power on if this fuse is blown |
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| F20 | 1½A | Reference Supply for Convectron and Ion Gauges. Pressure readings will be unavailable to the PLC or Host PC if this fuse is blown. |
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| F21 | ½A | +110VDC supply for vacuum relays. The system will appear functional but unable to sputter on any target, RF or DC |
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| F23 | 8A | Carriage Motor Controller via ACO1 connector on right side of PS Chassis Carriage unable to move |
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| F24 | 2½A | +24V Input power No LED's will light on the Diagnostic Maintenance Panel nor on the PLC input modules. System will be completely dead. |
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| F25 | 10A | 110VAC Output power No relay will fire. No LED's will light on the PLC output modules. |
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| F27 | ½A | Host PC control relay The system will refuse to operate but all indicators will appear fine. |
| Connector | Function | Layout |
|---|---|---|
| ACO1 | Carrier Motor |  |
| HOLE 2 | PLC/Host PC serial cable
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| ACO3 | 110VAC Outputs | |
| DJ5 | Panel Switches | |
| ACO2 | RF Box Tune | |
| DJ6 | Panel Lights | |
| DJ7 | Interlocks | |
| TB8 | Power System Feedback and control Note: Terminal #1 is at the BOTTOM
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| TB9 |
I/O power and Hyd Pump contactor. Note: Terminal #1 is at the BOTTOM
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| TB10 | Cryo and Mech Pump Contactors Note: Terminal #1 is at the BOTTOM
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| HOLE 1 | Power Inlet from Breaker Panel |
- N2 Inlet (working gas)
- Process Gas 1 Inlet (usually Argon)
- Process Gas 2 Inlet (usually N2)
- Process Gas 3 Inlet (usually O2)
- Process Gas 4 Inlet
Etch Fault Recovery
Normally fault recovery is simple, however if you are in the middle of an etch process and have to emergency stop the system there is no automated recovery. When you emergency stop while etching you have a situation where the pallet is no longer on the carrier but the system is unaware of that. In order to recover, you must perform the following steps manually at the Diagnostic Maintenance Panel.- Position Carrier out of the way of the etch platform at station 4.
- Move Etch Platform Forward
- Drop Upper Right Gripper
- Raise Lower Right Gripper — Pallet is held by grippers...
- Move Etch Platform to Rear
- Position Carrier at station 7
- Drop Lower Right Gripper
- Raise Upper Right Gripper — Pallet is released onto carrier...
Manual Pallet Load/Unload
The system is designed to operate with two pallets and to have a pallet continuously in the machine. This speeds operation by reducing cycle time in production environments. However the software has no provision for automated load/unload of both pallets as this situation only occurs during the initial install of the system. For completeness, we have the manual procedure for loading and unloading pallets.The sequence of operations is somewhat complex to visualize so for the following discussion please refer to the Exchange Kinematics page of the Lab Notes manual.
The kinematic diagram has a series of states showing the position of the elevator, carrier and grippers at each step in the exchange sequence. The pallet unload is states 0 thru 8 while the pallet load is states 9 thru 17. Beneath the position reference diagram there are a series of position codes in the form E5/C3. These tell you that the kinematic position is (in this example) Elevator at position #5 (Load Lock) and Carrier at position #3. To move from one state to the other use the GTG button in conjunction with the Elevator and Carrier switches. This will make positioning more accurate and reduce the chance of a pallet drop.
Load
Load the Pallet into the system by referring to the kinematic diagram and starting with a pallet loaded on the front of the exchange carrier pump down the Load Lock. Once the Load Lock is ready begin at state 9 of the diagram:- Move Shutter to Station C — Far Right
- Move empty Carrier to Station 3
- Move Elevator to Station 2
- Lower the Upper Left Gripper
- Raise the Lower Left Gripper — Pallet is held...
- Move Elevator to Station 1
- Move Carrier to Station 1
- Lower the Lower Left Gripper
- Raise the Upper Left Gripper — Pallet is released onto carrier...
- Move loaded Carrier to Station 3
- Return Elevator to Station 5 — Load Lock
Unload
Remove the Pallet from the system by referring to the kinematic diagram and started with no pallets loaded on the exchange carrier and pump down the Load Lock. Once the Load Lock is ready begin at state 0 of the diagram:- Move Shutter to Station C — Far Right
- Move loaded Carrier to Station 3
- Move Elevator to Station 3
- Move Carrier to Station 1
- Lower the Upper Left Gripper
- Raise the Lower Left Gripper — Pallet is held...
- Move empty Carrier to Station 3
- Move Elevator to Station 4
- Lower the Lower Left Gripper
- Raise the Upper Left Gripper — Pallet is released onto elevator...
- Move Elevator to Station 5 — Load Lock
File Formats
The data file formats are intentionally simple. This is to facilitate manual editing and to clarify the file meaning. Each file is a standard ASCII text file editable with Notepad or Wordpad on any PC. Each line in the file represents the setting for one parameter. Generally the files are case insensitive.All calibration and recipe files (as well as the ERROR.TXT support file) are located in the program startup directory as set during installation. If the program is manually moved to a new location without performing an installation, the data files will have to be copied as well.
.CAL File
The .CAL is used to hold the settings of the Configuration Tab. This file is created any time that the settings have been changed and the operator clicks on the Update button. There is only one calibration file for the entire program. Changes to the Configuration Tab are generally only needed when some hardware component is replaced. A copy of the settings are stored in each recipe (.RCP) file and this is compared to the current .CAL when the recipe is loaded. If the settings do not match, an error occurs as the system concludes that the recipe does not apply to the current machine configuration.If no .CAL file is found, the system will default all parameters.
.CAL File Contents | |||
|---|---|---|---|
| Line # | Setting | Unit | Default |
| 1 | RF Peak | Watts | 2000 |
| 2 | RF Caution | ||
| 3 | RF Danger | ||
| 4 | DC Peak | Watts | 2000 |
| 5 | DC Caution | ||
| 6 | DC Danger | ||
| 7 | Carrier High | CPS | 20 |
| 8 | Carrier Caution | ||
| 9 | Carrier Danger | ||
| 10 | Carrier Caution Low | ||
| 11 | Carrier Danger Low | ||
| 12 | Gas #1 Name | Argon | |
| 13 | Gas #2 Name | N2 | |
| 14 | Gas #3 Name | O2 | |
| 15 | Gas #4 Name | Other | |
| 16 | Target #1 Name | Target #1 | |
| 17 | Target #1 Name | Target #2 | |
| 18 | Target #1 Name | Target #3 | |
.RCP File
Each distinct recipe created on the system has a unique file associated with it. All of these files have a .RCP file extension on them. All of the .RCP files will be listed on the Recipe Tab in the dropdown selector..RCP File Contents | ||
|---|---|---|
| Line # | Setting | |
| 1 | File Title | |
| 2 | Recipe Description | |
| 3-21 | Duplicate of .CAL file | |
| 22-30 | Step #1 | |
| 22 | Step Number | |
| 23 | Target Name | |
| 24 | RF/DC | |
| 25 | Power | |
| 26 | Scan Speed/Gear | |
| 27 | Reps | |
| 28 | Gasses | |
| 29 | Gas Pressure in mT | |
| 30 | Comment | |
| 31-32 | Step #2 — Duplicate of lines 22-30 for as many steps in the complete recipe | |
.LOG File
The system saves all messages logged on the Runtime Tab automatically when the program is halted. This file is ASCII text and has the same name as the program executable. The file is found in the programs startup directory and can be used to diagnose or review the process just completed. The .LOG file is overwritten every time the program exits and you should manually copy the files after a run if you wish to retain a copy for your records.ERRORS.TXT File
This file contains the narrative description of each of the possible PLC error codes. Each line contains the error code, an ASCII 'tab' (character code 9) and then a narrative description of the error. Although the errors are in numerical sequence in the file, this is just for convenience, the error codes and descriptions can be in any order.PLCLOG.TXT File
This file contains all messages from the PLC in chronological order with the most recent message at the end of the file. Each line has a date/time stamp on it as well as the error ID and narrative from the ERRORS.TXT file. Certain other messages may also be present in this file. This file is located in the program installation directory.This file is not limited in size and should be manually renamed occasionally. The Host PC performance will suffer somewhat as this file grows in size.
Fin