Vacuum gauges. Chapter 9

Transcription

1 Chapter 9 Vacuum gauges Two thermocouple (TC) gauges, one convectorr gauge and two inverted magnetron (IM) gauges are used to measure wafer chamber vacuum. The gun and isolation chamber ion pumps, which also act as gauges, measure pressure in the gun and isolation chambers. A gauge controller the Multigauge reads pressure from the TC, convectorr and IM gauges and sends the readings to the IVS 230 system controller. For the ion pumps, the ion pump controller (MultiVac) sends the pressure readings to the system controller (see Chapter 7 for ion pumps.) The Multigauge also allows you to calibrate the thermocouple and convectorr gauges. Readings can be checked from the Multigauge front panel as well although this data can also be read right from the IVS 230 monitor. This chapter covers: Thermocouple gauges Inverted magnetron gauges Ion pump gauges Convectorr gauge Vacuum gauge controller (Multigauge) 9 For more information about how the gauges monitor pressure during pumpdown and operation to ensure proper system functioning see "The pumpdown sequence when a wafer is loaded" in Chapter 4. IVS 230 Maintenance Manual 97

2 Vacuum gauges Overview Gauge locations As shown in Figure 9-, an inverted magnetron gauge is located in the passageway between the turbo valve and turbo pump for each pump stack. The thermocouple gauge for the chamber is located on the same pipe as the pressure relief valve, shown in Figure 9-. The other two thermocouple gauges are located in the roughing pump lines between the roughing valve and the roughing pumps. See Figure 9-2 for an outline drawing of gauge locations. Roughing valve Inverted magnetron gauge (IM) Convectorr for chamber (TC5) Turbo valve Pressure relief valve Figure 9-. TC5, IM and Convectorr gauge locations 98 IVS 230 Maintenance Manual

3 Vacuum gauges Overview Intermediate chamber 20 l/sec ion pump (in back of gun column) Inverted magnetron gauges IM=A IM2=B Turbo valve A 470 l/sec turbo pump (pump B toward rear) B Foreline valve B Roughing valve B Thermocouple gauge (TC3) Wafer chamber TC5 Gun chamber 20 l/sec ion pump Gun valve Intermediate chamber isolation valve A Foreline valve A Thermocouple gauge (TC2) Roughing valve A 765 l/min mechanical roughing pumps Chamber vacuum indicator Chamber door Turbo valve A 470 l/sec turbo pump (pump A toward front) 9 Figure 9-2. Outline drawing showing vacuum gauges (view is from front of measurement module) Thermocouple and convectorr gauges Measure rough vacuum from atmosphere down to x 0-3 Torr. Inverted magnetron gauges Measure high vacuum from x 0-3 to x 0- Torr. Ion pumps (as gauges) The ion pumps function as cold cathode gauges at the same time as they pump the gun and intermediate chambers. They read pressure in the gun and intermediate chambers. Ion pumps and their controller are covered in Chapter 7. IVS 230 Maintenance Manual 99

4 Vacuum gauges Inverted magnetron gauge Inverted magnetron gauge The inverted magnetron (IM) is a cold cathode gauge with a controlled magnetic field in the ion chamber. It is capable of reading from 0-3 Torr down to 0 - Torr. A high voltage supply (3kV) is connected to the gauge. Metering is in series with the high voltage supply. Both the high voltage supply and metering are provided by a card in the Multigauge controller. Gauge model The gauge is a Varian model NW40 (with NW40 flange and coaxial connector, see Figure 9-3.) 5kV Coaxial Connector Gauge NW40 Flange Electrometer connection Cylindrical magnet High voltage connection Anode Cross sectional view Figure 9-3. Inverted magnetron gauge 200 IVS 230 Maintenance Manual

5 Vacuum gauges Inverted magnetron gauge How the gauge works The IM gauge operates on the same principle as a regular cold cathode except the anode is now at a positive potential and the cathode is at ground. The high potential (+3 kv) and linear magnetic field provide the ability to see lower pressure at reduced sensitivity. When the gauge tube is subjected to a total pressure below approximately 0-2 Torr, an electron is removed from the anode by the strong electrostatic field (see Figure 9-4.) It finds itself in an orbit around the anode perpendicular to the magnetic field. The electron will then collide with gas molecules that are present and ionize them. Positively charged ions and free electrons are produced. The resulting free electrons also travel in orbits within the anode. They ionize other gas molecules present. Once this "avalanche" effect starts, it takes milliseconds to arrive at a final current value (dependent upon pressure.) The positive ions are collected by the anode and the resultant current is proportional to the pressure. 9 Pressure measurement current meter Feedthru Anode (+3 kv) N Magnets N S S S S N magnetic field lines N Cathode to Ground Figure 9-4. Operation of the Inverted Magnetron gauge IVS 230 Maintenance Manual 20

6 Vacuum gauges Inverted magnetron gauge The gauge will typically operate in this way up to the 0-2 Torr range. At pressures above this, the gauge will draw too much current, so current limiting must be used to keep maximum current at ma. Current limiting results in an upper pressure reading capability typically in the 0-3 Torr range. The control board provides the gauge with a pulsating DC current, allowing it to operate. Once off, the gauge requires a minimum DC voltage to fire. This threshold voltage is dependent upon pressure and reduces in value as the pressure rises. 202 IVS 230 Maintenance Manual

7 Vacuum gauges Inverted magnetron gauge Starting an inverted magnetron gauge at low pressure When the gauge has been off for a period of time with a system pressure of 0-7 Torr or lower, delayed starting may occur. This "no-strike" condition is caused by the lower probability of ionizing enough atoms and/or molecules to obtain the starting glow discharge condition. When the gauge is started by pressing EMIS on the Multigauge, high voltage is applied. The Multigauge will display a valid measurement value as soon as it is available. If the current measurement is zero, the Multigauge will first assume that the pressure is near the underpressure limit and that there is difficulty starting the gauge. Hyphens [- - -] will be displayed for approximately 30 seconds while the Multigauge attempts to fire the gauge. If no gauge current is sensed, the display will show an error code (E3 insufficient signal) and shut off. Note that this could indicate an open cable instead of a gauge start underpressure problem. The gauge can be started again at the keyboard using the Manual menus or at the controller by pressing EMIS. If the "no-strike" condition persists, the gauge can be started by increasing the pressure in the pump stack. To start the gauge in this situation, you would have to raise the pressure in the pump stack where the gauge is located. To do so, see "Venting a pump stack" in Chapter 6 Turbomolecular Pumps. 9 WARNING Only personnel trained in IVS 230 maintenance and operation at Schlumberger should work on the system. Venting a pump stack requires that you work in sequential steps. You can cause severe damage to a turbo pump, valves or even the gun by improperly venting the system. Whenever working on the vacuum system, proceed cautiously to prevent component damage due to the rapid inrush of air into the pumps or chamber. IVS 230 Maintenance Manual 203

8 Vacuum gauges Inverted magnetron gauge Removing and installing an inverted magnetron gauge The gauge can be quickly removed from its fitting on the chamber. To remove gauge from chamber:. The pump stack you will remove the gauge from must be vented before removing the gauge. To vent a pump stack, see "Venting a pump stack" in Chapter 6. WARNING If you try to remove the gauge without properly venting the stack, you can destroy the turbo pump and possibly damage other components. Venting a pump stack requires that you work in sequential steps. Only personnel trained by Schlumberger to work on the IVS 230 should carry out this procedure. 2. Ensure that power to the gauge is off. Press CHAN on the Multigauge until the IM gauge being removed is displayed (IM or IM2.) Press EMIS to turn the gauge off, then remove the gauges' electrical cable (a BNC twist off connection.) WARNING Deadly voltage (3kV) is supplied to the gauge. Ensure that power to the gauge from the Multigauge controller is off before attempting to remove the gauge. Use extreme caution when working with the gauge and controller. Proper grounding of the Multigauge unit and the gauge are necessary. Do not operate the Multigauge with the cover off. 204 IVS 230 Maintenance Manual

9 Vacuum gauges Inverted magnetron gauge 3. Unscrew the handle on the quick clamp that holds the gauge to its chamber fitting. Hold the gauge while doing so to prevent any chance of it falling off its fitting once loose. Unscrew the clamp until it is loose enough to be disengaged from both NW 40 flanges (gauge flange and chamber fitting flange.) 4. Pull gauge away from its chamber flange. To install gauge on turbo stack:. Place O-ring on centering ring and place centering ring between NW 40 mounting flanges. Place quick clamp over ring and flanges. Tighten down quick clamp. 2. Twist on the electrical BNC connector. 3. Press the CHAN button on the Multigauge to select IM or IM2 (the gauge being installed.) 4. Press the EMIS button on the Multigauge to turn the gauge on. 5. When all service work is completed, place the pump stack back in service. To do so, see "Venting a pump stack" in Chapter 6. 9 K25 Flange fitting Reducer Centering ring Flange clamp K40 Flange fitting O-ring Figure 9-5. KF 40 coupling assembly used with IM gauge IVS 230 Maintenance Manual 205

10 Vacuum gauges Inverted magnetron gauge IM gauge maintenance There is no maintenance required for the IM gauges. However, should an IM gauge be removed and placed back into the system, or replaced by a new gauge, the following procedures should be observed:. Place the gauge back into the system in the same way it was removed and connect the electrical cable. 2. Turn the gauge on by pressing CHAN on the multigauge until the IM gauge that was removed (IM or IM2) is displayed in blue on the left side of the multigauge display. Hit EMIS to turn the gauge on. 3. The gauge must be tested on the system before putting the system back in service. For best results, make sure the pump stack is working correctly. Typical low pressure for the stack should be.0 x 0-6 to.0 x 0-7 Torr. Pump down the stack and observe pressure readings. Allow time for the gauge to warm up and pump out any impurities accumulated at atmosphere. Monitor gauge for at least 5 minutes. Note: A data sheet is supplied in this section to record these values. Copies of this chart should be made and pressure values recorded at regular intervals for the system. This allows you to track system performance and catch problems before they cause a system shutdown. The data will also help in setting up preventive maintenance schedules. 4. The gauge on the system should be leak checked using the appropriate IVS 230 leak check port. If no leaks are found, this completes maintenance of the IM gauges WARNING Severe damage to pumps or other components will result if leak check connections are not made properly. Follow all procedures carefully. Only personnel trained at Schlumberger should work on the IVS IVS 230 Maintenance Manual

11 Vacuum gauges IM GAUGE TEST DATA SHEET Tester: Date: IM gauge no. System no. Reason for test: Installed new gauge Scheduled data collection Other Length of time required for turn on Pressure reading Time Pressure reading Time Pressure reading Time Pressure reading Time Pressure reading Time Pressure reading Time Pressure reading Time Pressure reading Time Pressure reading Time Pressure reading Time Pressure reading Time 9 Comments IVS 230 Maintenance Manual 207

12 Vacuum gauges Thermocouple gauge Thermocouple and Convectorr gauges Thermocouple and convectorr gauges can only accurately measure vacuum down to x 0-3 Torr. There are three thermocouple gauges on the IVS 230. Chamber TC gauge (TC5): It is on the same pipe with the pressure relief valve located at the top front of the chamber over turbo pump B. This gauge tells the system when to switch from rough pumping to the turbos during a pumpdown. When the chamber goes down to 200 mt, the turbo valves open. Foreline TC gauge (TC2): It is in the "A" roughing line between the roughing pump and back end of the turbo pump. This gauge monitors the back of the turbo pumps to ensure that pressures do not go too high. The turbos must exhaust to a vacuum. They will not work properly if they are forced to exhaust to atmosphere. The trip point value for this TC gauge is 200 mt. If pressure rises higher than this, turbo A will shut down and the Iso valve will close. Foreline TC gauge (TC3): It is in the "B" roughing line between the roughing pump and back end of the turbo pump. The trip point value for this TC gauge is 200 mt. If pressure rises higher than this, turbo B will shut down and the Iso valve will close. Thermocouple gauge model The thermocouple gauge is Varian model 53 with NW6 flange. Convectorr gauge model The convectorr gauge is Varian model L with NW6 KF flange. 208 IVS 230 Maintenance Manual

13 Vacuum gauges Thermocouple gauge How the thermocouple gauge works A thermocouple gauge operates on the principle that at sufficiently low pressures, the thermal conductivity of the gas decreases with a decrease in pressure. In a thermocouple gauge, the thermocouple is attached to a heater wire in which the temperature is raised to approximately 350 C by passing current through it. When constant power is maintained through the heater wire, the temperature measured by the thermocouple will change with pressure. This change is directly related to the heat conducted away by the gas in the environment. The electromotive force (emf) measured from the thermocouple is read on a scale that has been calibrated for pressure. At higher pressures, much heat will be conducted away from the wire. At lower pressures, less heat is conducted away from the wire and the wire is hotter. The relationship between wire temperature and pressure is not linear. The gauge stops responding at about mtorr ( x 0-3 ) Torr because the heat loss through radiation becomes the largest factor in heat loss. The gauge no longer responds linearly below this point. 9 To vacuum system TC gauge tube Filament Multigauge Thermocouple Figure 9-6. Thermocouple gauge operation IVS 230 Maintenance Manual 209

14 Vacuum gauges Thermocouple gauge Removing and installing a thermocouple gauge Any one of the three thermocouple gauges on the system can be removed easily. The appropriate pump stack (or chamber) must be properly vented before attempting to remove a thermocouple gauge or severe damage to the system can occur. WARNING Removing the gauge without properly venting the pump stack or chamber (for the chamber thermocouple gauge) may destroy the turbo pumps or damage the gun or other components. To remove a thermocouple gauge:. The pump stack you will remove the gauge from must be vented before removing the gauge. To vent a pump stack, see "Venting a pump stack" in Chapter 6 "Turbomolecular pumps." For the chamber TC gauge, the chamber must be vented. 2. Ensure that power to the gauge is off. Press CHAN on the Multigauge until the thermocouple gauge you will remove is displayed (TC5, TC2, or TC3.) Press EMIS to turn the gauge off. 3. Remove the gauge electrical cable by grabbing the connector part of the gauge and pulling it straight out. The connector is a four plug connector with a key in the center for plug alignment. NW6 flange Key Figure 9-7. Thermocouple gauge 20 IVS 230 Maintenance Manual

15 Vacuum gauges Thermocouple gauge 4. Unscrew the handle on the NW 6 quick clamp that holds the gauge to its chamber fitting. Hold the gauge while doing so to prevent any chance of it falling off its fitting once loose. Unscrew the clamp until it is loose enough to be disengaged from both flanges (gauge flange and chamber fitting flange.) 5. Pull gauge away from its chamber flange. To install gauge:. Place O-ring on centering ring and place centering ring between mounting flanges (same as coupling assembly procedure for IM gauge, see Figure 9-5.) Place quick clamp over ring and flanges. Tighten down quick clamp. 2. Push the electrical connector on its socket on the gauge, making sure the key is aligned correctly. 3. Press the CHAN button on the Multigauge to select the gauge that was installed (TC5, TC2, or TC3.) 4. Press the EMIS button to supply current to the gauge. 5. When all service work is completed, put the pump stack back in service. To do so, see "Venting a pump stack" in Chapter 6. 9 IVS 230 Maintenance Manual 2

16 Vacuum gauges Thermocouple gauge Calibrating thermocouple gauges Thermocouple gauges drift with time and need occasional calibration. A good time to calibrate the gauges is whenever the system is down for maintenance. Calibration is an easy procedure to perform. It consists of setting the gauge reading at atmosphere to 7.6 x 0-2 Torr and setting the gauge reading at low pressure to x 0-3 Torr, which is the lowest pressure the gauge can read. There are two procedures below one to calibrate the chamber TC gauge (TC5) and one for the foreline TC gauges (TC2 and TC3.) Note: You can incorporate the following calibration procedures into the procedure for venting a pump stack. This way, you can take care of TC calibration while a pump stack is down for service, and you won't have to vent a stack just to calibrate a TC gauge. To vent a pump stack, see "Venting a pump stack" in Chapter 6 Turbomolecular pumps. WARNING Do not calibrate thermocouple gauges unless you are certain of the vacuum pressure. Incorrect setting could damage equipment or add unnecessary pump down time. 22 IVS 230 Maintenance Manual

17 Vacuum gauges Thermocouple gauge Calibrating the chamber TC gauge (TC5) This procedure requires using the roughing pumps and the turbo pumps to pump down the chamber. Pumps and valves can be operated from the Manual/Column menu with the system in protect mode. The system does not have to be placed in service mode for this procedure. To calibrate the chamber gauge:. First, select the chamber TC gauge on the Multigauge controller. To do so: Press the CHAN key on the Multigauge keypad until TC5 is displayed at the upper left corner inside the bar wheel readout. Gauge pressure is now displayed for TC5 on the bar graph and in the LCD display. If the gauge was replaced and is powered off, press the EMIS key to supply current to the gauge. 2. If necessary, vent the chamber to atmosphere. You can use the Manual menus to do so ( Manual/Column/Valves.) Select <5> (Vent Valve Auto) from the Valve menu. The appropriate valves will close and the chamber will vent to atmosphere. 3. At atmosphere, the ideal TC5 pressure read from the Multigauge should be 760 Torr (atmospheric pressure.) If pressure reads differently, press the ATM button on the Multigauge once. Press again if necessary to display the correct value (760 Torr.) This sets the gauge to atmosphere. 4. Next, pump down the system and check the reading of the IM gauge for the pump stack being used. A pressure reading below 9 x 0-4 is acceptable. 5. You now need to set the display to read Press the VAC key on the Multigauge. The left-most digit will flash. Use the and arrow keys to change the digit to "." Then use the F key to move to the next digit and use the arrow keys to change its value. Continue in this way to change all digits so the display shows Press the F key again and the display goes back to reading pressure. This completes chamber gauge calibration. 9 IVS 230 Maintenance Manual 23

18 Vacuum gauges Thermocouple gauge Calibrating the foreline TC gauges (TC2 and TC3) Calibrating the foreline TC gauges requires using the roughing pump and turbo pump to pump down the pump stack for the gauge you are calibrating. To calibrate a foreline TC gauge (TC2 or TC3.). First, select the chamber TC gauge on the Multigauge controller. To do so: Press the CHAN key on the Multigauge keypad until the gauge being calibrated (TC2 or TC3) is displayed at the upper left corner inside the bar wheel readout. Gauge pressure is now displayed for the gauge on the bar graph and in the LCD display. Note: TC2 is in pump stack A. TC3 is in pump stack B. If you replaced the gauge and it's off, press the EMIS key to supply current to the gauge. 2. Vent the foreline of the pump stack for the gauge being calibrated. To vent a pump stack, see "Venting a pump stack" in Chapter 6 Turbomolecular pumps. WARNING Venting must be down properly. Improperly venting a pump stack may destroy the turbo pumps or damage the gun or other components. Only qualified personnel trained in IVS 230 maintenance at Schlumberger should work on the system. 3. The ideal TC pressure read from the Multigauge should be 760 Torr (atmospheric pressure.) If pressure reads differently, press the ATM button on the Multigauge once. Press again if necessary to display the correct value (760 Torr.) This sets the gauge to atmosphere. 24 IVS 230 Maintenance Manual

19 Vacuum gauges Thermocouple gauge 4. Pump down the foreline and start the turbo pump. Note: See "Venting a pump stack" in Chapter 6 Turbomolecular pumps for the steps to pump down a pump stack after venting. 5. Allow the system to pump down for 0 minutes. This is to ensure that pressures are stable and there are no leaks. 6. Press the VAC button on the Multigauge. Use the and arrow keys to correct the display to read x 0-3 Torr. The F key can be used to move between digits. The display will revert back to reading pressure after a few seconds, or use the F key to fast forward to the end. Calibration of a foreline TC gauge is now completed. Note: The x 0-3 Torr setting, which is the bottom of the TC gauge's measuring range (not necessarily the actual pressure at the foreline), tells the system this is the lowest pressure the gauge will see. The Multigauge uses this value to trip setpoints. A large change in the TC gauge reading (for example, a pressure rise from x 0-3 to x 0-2 Torr) is a good indication of a leak, a prob em with the turbo pump, a foreline valve that's closed, or a mechanical pump problem. 9 IVS 230 Maintenance Manual 25

20 Vacuum gauges Thermocouple gauge Thermocouple gauge maintenance There is no scheduled maintenance on TC gauges. Cleaning is impractical. If a gauge does not work, the best thing to do is to replace it. Always remember to calibrate a new gauge. 26 IVS 230 Maintenance Manual

21 Vacuum gauges Multigauge controller Multigauge controller for IM and TC gauges The Multigauge controller contains the boards that operate the inverted magnetron gauges and thermocouple gauges. It communicates with the IVS 230 system controller through the RS-232 port on its back panel. The Multigauge contains two inverted magnetron boards (one for each gauge), a thermocouple board which handles all three thermocouple gauges, a convector card, and a communications board (RS-232) for communications with the system controller. A setpoint board relays setpoint data to the logic driver module. The logic driver uses this information to close various valves and stop measurement operation when setpoints are exceeded. To see setpoint values for the gauges and how they govern chamber pumpdown, see "The pumpdown sequence when a wafer is loaded" in Chapter 4. Setpoints are programmed into the system software. 9 Video support module power supply HV BNC connectors for IM gauges Fuse Setpoint board connector Convector card connectors 20/240 Vac plug ON/OFF switch Recorder outputs Multi-cable with one connector to TC gauges RS-232 connector to system controller Figure 9-8. Multigauge controller back panel IVS 230 Maintenance Manual 27

22 Vacuum gauges Multigauge controller block diagram Multigauge controller block diagram Inverted magnetron board Inverted magnetron board Convector board TC gauge board Setpoint connector RS-232 Logic driver IM gauge 2 on pump stack B IM gauge on pump stack A communications with system controller Multi-port serial interface board in system controller (slot 5) P6 Figure 9-9. Multigauge controller block diagram 28 IVS 230 Maintenance Manual

23 Vacuum gauges Multigauge front panel Using the Multigauge front panel keypad You do not need to use the Multigauge front panel for operating the system. Pressure readings for each gauge are shown in the Vacuum Status Window. It can be displayed in the lower right corner of the screen when you press F4. Use the controller keypad:. When calibrating a thermocouple gauge. 2. To turn the gauges on or off. 3. To check gauge pressure readings at the Multigauge for convenience instead of looking at the monitor. For instance, it may be more convenient to read pressure from the Multigauge when working nearby. This section covers only the keys needed to turn gauges on or off and check readings. That's all you really need to do using the Multigauge keypad. Thermocouple gauge calibration is covered earlier in this chapter. 9 IVS 230 Maintenance Manual 29

24 Vacuum gauges Multigauge front panel Example of a Multigauge display The Multigauge front panel is shown in Figure 9-0. In this display, the pressure for TC gauge 5 is shown on the bar graph display in Torr. The bar graph reads down to.00 Torr ( x 0-3 T ) which is the end of the linear range for a thermocouple gauge. Pressure for IM gauge no. 2 is shown in the LCD display (.4-6 Torr.) You know IM gauge 2 is displayed because "IM" and "2" are shown in the boxes at bottom right of the display. EMIS means that the gauge has power (emission current.) The setpoint indicator at lower left is lit because setpoints are used. Five setpoints (3 thru 7) are used for the IVS 230. If pressure is lower than the setpoint, the setpoint box is lit. Bar graph display for TC gauges. Gauge no. displayed is shown to left of bar graph. LCD pressure reading display Turns a TC or IM gauge on or off. Key used to select gauges ATM.0 TC SET PT.0.00 EMIS TORR IM CHAN EMIS DEGAS SET PT SENS EMIS MA VAC UNITS GAS CORR AUTO ON DIGIT ATM F KBAUD Indicates IM gauge is on (has emission current) These boxes are lit when setpoints are tripped (only 3, 4, 5, 6, 7 are used). Setpoint box at left indicates setpoints have been programmed. Indicates IM gauge 2 is selected. Pressure in LCD display is for this gauge Figure 9-0. Multigauge front panel 220 IVS 230 Maintenance Manual

25 Vacuum gauges Multigauge front panel Changing channels To select a TC or IM gauge to see its pressure reading: Press the CHAN key. You can scroll through all five gauges. For IM gauges, the gauge displayed will be indicated by the IM or IM2 designations at lower right of the display as shown in Figure 9-0 (example shows IM2 being displayed.) For TC gauges, TC 2, 3, or 5 will be displayed in the upper right next to the bar graph display. When no IM indicator is lit, you will see the pressure reading for the TC gauge indicated in the LCD display as well as in the bar graph display. Note that you will see the designation "TC 4" displayed for a TC gauge as you scroll channels. TC 4 is not used. You will also see the designation "UHV" displayed in place of IM as you scroll. This indication is for a UHV board which is not installed. Just scroll past it. You can use the arrow keys to switch between TC gauges while keeping the pressure reading for IM gauges or 2 displayed in the LCD display. 9 Turning a gauge on or off You can only turn inverted magnetron gauges on or off. Using the procedure below for a thermocouple gauge will have no effect. To turn an inverted magnetron gauge on or off:. Select the gauge using the CHAN key. 2. To turn the gauge on, press the EMIS key. The EMIS indicator will light in the display for the gauge. To turn the gauge off, press the EMIS key. The gauge will be off and the EMIS indicator on the display will go off. "OFF" will be displayed. IVS 230 Maintenance Manual 22

26 Vacuum gauges Multigauge front panel IM gauges can also be turned on or off by using the Manual Menus by calling up the Device Control Menu (Manual/ Column/Device Control.) You must be logged in at a maintenance level or above to use this menu. Choices and 2 on the menu are "Turbo A Gauge" and "Turbo B Gauge." If you toggle one of these choices, you will be asked if you really want to change the state of the gauge. For example, if on, you will be asked if you want to turn it off. Answer "yes" and the gauge will turn off. A third choice on the Device Control Menu affects the Multigauge. Choice 3 Reset Multigauge will reset the Multigauge by re-initializing it; that is, by reloading all programmed setpoints. This is not something you would normally do. It would only be necessary if the setpoint board was suspected to be faulty or if it was changed. Setpoints The numbers at the bottom row of the display (3 thru 7 in Figure 9-9) show the setpoints channels. The setpoint board has eight SPDT relays. The IVS 230 uses five of the eight available setpoints on the board. Setpoint channels, 2, and 8 are not used. Here are the setpoint designations: Setpoint 3 IM turbo A Setpoint 4 IM2 turbo B Setpoint 5 TC2 foreline A Setpoint 6 TC3 foreline B Setpoint 7 TC5 chamber When pressure is below the setpoint, the setpoint number will be lit. 222 IVS 230 Maintenance Manual

27 Vacuum gauges Multigauge controller board Multigauge controller board specifications Listed in this section are specifications and other information about the three boards in the Multigauge controller. The three boards are the thermocouple board, cold cathode board and setpoint board. Table 9-. Thermocouple board specifications Pressure range Two Torr to x 0-3 Torr TC heater current 65 ma ± 0% Recorder output 0 to 0V nonlinear. See Varian Multigauge Controller manual for recorder connections Fault detection No cable or open TC circuit (E03) TC power supply fault (E) 9 Table 9-2 Inverted magnetron board specifications Electrometer 0-6 Torr ±5% of ion current reading accuracy (ion current 5 µa) Overpressure Automatic gauge tube turnoff when pressure protection equals or exceeds 2 x 0-2 Torr. Recorder output V/decade log-linear output (two-conductor Micro Jax connector plug supplied with board. See Varian Multigauge Controller manual for more about recorder connections Fault detection No ion current (E03) Power supply error (E) overcurrent/cable short (E04) overtemperature shutdown gauge power shuts off when internal temperature reaches 65 C. (E07) Table 9-3. Setpoint board specifications Setpoints Eight, floating SPDT relays with NO, NC, and C terminals available Contact rating 3 amps at 24 VDC/250VAC, gold-flashed IVS 230 Maintenance Manual 223

28 Vacuum gauges Multigauge error codes Multigauge error codes Listed below are error codes that may be displayed on the Multigauge if a gauge or the unit malfunctions. E0 E02 E03 E04 E05 E06 E07 E08 E09 E E2 E3 E4 E5 Indicates an illegal board combination (no gauge boards, too many gauge boards, or a board developed after the software in use was developed.) Pressure burst caused by a sudden rise in pressure No current or measurement signal (bad or missing collector cable connection, bad electrometer) Filament overcurrent (shorted filament circuit) Filament undercurrent (open filament, cable not connected); bad control board Grid voltage low (grounded grid, bad grid supply, bad EB degas supply) overtemperature (temperature inside unit over 65 C) Board logic failure Overpressure, indicated pressure above high pressure limit of the ion gauge being used Plug-in board power supply failure Underpressure Insufficient current Invalid keypad function (keypad is locked out) Negative CDG input, beyond VAC range 224 IVS 230 Maintenance Manual

29 Vacuum gauges Multigauge software revision Checking software revision number on Multigauge Push the F key to see the software revision number. It is displayed in the format PX.Y (example: P3.4 for an IVS 230) The F key also lights all segments on the front panel display for test purposes. 9 IVS 230 Maintenance Manual 225

30 Chapter 2 System Logic The system logic prevents the operator from performing improper actions that could damage the system. It checks various pressure setpoints and the status of valves and pumps, and then controls the sequence in which the valves and pumps are allowed to operate. The logic also prevents wafer damage by ensuring that a wafer is properly loaded and the chamber door is closed before pumping begins. In addition, the logic monitors house air pressure, house vacuum and nitrogen pressure. If a problem develops in any one of these lines, the system logic would stop operation and put the chamber in a safe state with all valves controlling chamber openings closed. Examples of some disallowed actions are: trying to open a turbo valve with the chamber at atmosphere, trying to pump down with the chamber door open, and trying to open the Iso valve with the chamber at atmosphere. 2 NOTICE The system logic is the IVS 230's built-in safety system, and is its default "protect mode". Be aware that if the person using the system tries to carry out an action such as opening or closing a certain valve, and they are not allowed to do so, the logic is telling them that they are trying to operate the system out of sequence or in some other improper manner. IVS 230 Maintenance Manual 267

31 System logic Service mode Service mode overrides system logic Putting the system into service mode overrides the system logic controls. In service mode, you can use the Manual Service Menu in the Manual menus to open or close any valve without system protection or interference. Always use extreme caution when using these menus in service mode, because improperly opening a valve may cause damage to the turbo pumps, gun or other components. Service mode should only be entered when a maintenance task requires that system logic be overridden. For instance, to change an Iso valve, Service mode would have to be used because you need to open the Iso valve with the chamber at atmosphere. To vent a pump stack, you need to be in service mode because you can't open the foreline valve with the turbo pump off in protect mode. The system is placed in Service mode by inserting the Service mode mating connector (it has a jumper wire on it) into the D-sub connector on the front panel of the logic control board (marked LCB.) When you are in service mode, the word "service" will be visible in the upper left of the Vacuum Status Display. Only personnel with a service level password can operate the system in service mode. See Chapter for more about passwords. You should not attempt to work on the system in service mode unless you have been trained in system operation and maintenance. NOTICE You must be very careful when working in service mode, as the system will not automatically protect itself from damage. Only personnel trained in IVS 230 operation and maintenance at Schlumberger ATE should perform maintenance work on the IVS IVS 230 Maintenance Manual

32 System logic Logic Overview Logic overview The logic hardware consists of a logic driver module, which contains the logic driver board, and the logic control board. Communication with the system controller is through the control interface receiver in the eurocard cage to system controller's control interface transmitter board. The logic driver module is located at the left of the system between the eurocard cage and the multigauge display, while the logic control board is in the second board from the left in the eurocard cage (See Figure 2-.) These components are described in this chapter. 2 Figure 2-. Front of system showing, at left from top down, the multigauge display, the logic driver module, and the eurocard cage IVS 230 Maintenance Manual 269

33 System logic Logic driver module Logic driver module Located at the left of the system between the eurocard cage and the multigauge display, this module contains the logic driver board. The board contains the circuitry that controls all valves, turbo pumps, and the video signal module (VSM) high voltage enable. Besides containing the circuitry to turn valves or pumps on or off, it acts as a big terminal block for many other lines and passes their signals through to the logic control board. For instance, it reports setpoints from the MultiVac (ion pump controller) and Multigauge (inverted magnetron and thermocouple gauge) controller to the logic control module. This setpoint information is passed directly through to the logic control board. Also, indicator status signals for valves or pumps are passed directly through to the LCB. In each case, the valve or gauge pulls the line from the LCB (through the driver board) low to indicate the valve condition or that the trip point has been reached. The logic driver board is stored inside a pullout shelf assembly called the logic driver module. 270 IVS 230 Maintenance Manual

34 System logic Logic control board Logic control board Located in the card cage below the logic driver module, this board is the brains of the operation for controlling valves and pumps. It contains three PAL's (programmable logic chips) which interpret commands from the system controller and send them to the logic driver. The LCB also contains registers which store on/off information about pumps and valves. Each time a command to open a valve comes from the system controller, a PAL checks the registers to get the status of all components in the vacuum system, then decides whether to go ahead and issue the "open" or "close" command to the logic driver board. If the PAL logic determines the command cannot be issued due to an out of sequence condition (such as opening the Iso valve with the chamber vented, it sends a message back to the system controller (for instance, "valve move failed".) This is how the LCB protects the system from damage that could be caused by improper operator commands. In service mode, the LCB does not safety check the vacuum system before issuing the command to the logic driver board to open or close a valve. This is why components in service mode can be damaged if commands are issued to open a valve at the wrong time. 2 IVS 230 Maintenance Manual 27

35 System logic Control interface receiver/transmitter Control interface receiver and control interface transmitter The control interface receiver board in the Euro card cage communicates with the logic control board and all the other boards in the card cage through the card cage common bus. It talks to the Control Interface Transmitter in the system controller. 272 IVS 230 Maintenance Manual

36 System logic Logic driver board Working with the logic driver board Troubleshooting the system logic requires some knowledge of the output connections at the logic driver board to the various valves, pumps, and controllers and an understanding of how the circuitry on the logic driver board works to turn components on or off. This section contains a table of the logic driver board pinouts, showing the voltages you can check to see if the proper signal has been given to a pump or valve. It also contains circuit diagrams of drive circuits on the logic driver which show how the drive circuit works. It also describes loop back circuits and board test points. The logic structure is principally based on an active low signal. That means that drive signals for valves go low to open a valve and go high to close a valve. Pressure setpoint trip signals also work this way. The trip signal is low when the setpoint is reached. Use this section to troubleshoot a component problem. Remember that you can't always rely on system error messages to pinpoint a problem. For instance, failure to open a valve may be because the logical conditions that must be met before the board will turn it on have not been met, rather than because there is a problem with the valve. Logical conditions relating to the logic driver board will be discussed later in this chapter. 2 IVS 230 Maintenance Manual 273

37 System logic Logic driver pinouts Terminal Block # Turbo pump A control GND J6- Logical condition Status indicator Turbo pump A START J6-2 +5V OFF, ground ON Front panel LCD display Turbo pump B control GND J6-3 Turbo pump B START J6-4 +5V OFF, ground ON Front panel LCD display VSM HV enable J6-8 +5V ON, ground OFF Stage bias enable J6-0 +5V ON, ground OFF Pins J6-5, J6-7, and J6-9 at +5V Scan drive relay + J V OFF, GND ON LED inside power box Scan drive relay - J7-4 GND Bake cool valve drive J7-8 Not used Foreline valve A drive J7-0 OV OPEN, +24V CLOSED Signal loop back, valve body tip Foreline valve B drive J7-2 OV OPEN, +24V CLOSED Signal loop back, valve body tip Door valve drive (open) J7-4 OV OPEN, +24V CLOSED Door valve flag switch Door valve drive (closed) J7-6 OV CLOSED, +24V OPEN Door valve flag switch Shroud vent drive J7-8 OV OPEN, +24V CLOSED Fast chamber vent drive J7-20 OV OPEN, +24V CLOSED Vacuum status window, signal loop back Vacuum status window, signal loop back Pins J7- through J7-9 odd all at +24V ISO valve drive J8-2 OV OPEN, +24V CLOSED Iso valve flag switch Gun valve drive J8-4 OV OPEN, +24V CLOSED Vacuum status window, signal loop back Rough valve A drive J8-6 OV OPEN, +24V CLOSED Signal loop back, valve body tip Rough valve B drive J8-8 OV OPEN, +24V CLOSED Signal loop back, valve body tip Spare 2 drive J8-0 Not used Turbo valve A drive J8-4 OV OPEN, +24V CLOSED Turbo valve flag switch Turbo valve B drive J8-6 OV OPEN, +24V CLOSED Turbo valve flag switch Chamber vent drive J8-8 OV OPEN, +24V CLOSED Signal loop back, valve body tip Sublimate drive J8-20 OV ON, +24V OFF Pins J8- through J8-9 odd all at +24V Signal loop back, pilot lamp on supply. Table 2-. Logic driver pinouts 274 IVS 230 Maintenance Manual

38 System logic Logic driver pinouts Terminal Block # Logical condition Status indicator Multivac gun ion pump setpoint J9- Low=tripped, high=ok Vacuum status window Multivac iso ion pump setpoint J9-3 Low=tripped, high=ok Vacuum status window Multigauge turbo A setpoint J9-5 Low=tripped, high=ok Vacuum status window Multigauge turbo B setpoint J9-7 Low=tripped, high=ok Vacuum status window Multigauge foreline A setpoint J9-9 Low=tripped, high=ok Vacuum status window Multigauge foreline B setpoint J9- Low=tripped, high=ok Vacuum status window Multigauge chamber setpoint J9-3 Low=tripped, high=ok Vacuum status window Foreline valve A open J9-5 Low=open Vacuum status window Foreline valve A closed J9-7 Low=closed Vacuum status window Rough valve A open J9-9 Low=open Vacuum status window Pins J9-2 through J9-20 even are GND Rough valve A closed J0- Low=closed Vacuum status window Turbo valve B open flag J0-3 Low=open Vacuum status window Turbo valve B closed flag J0-5 Low=closed Vacuum status window Turbo valve A open flag J0-7 Low=open Vacuum status window Turbo valve A closed flag J0-9 Low=closed Vacuum status window Foreline valve B open J0- Low=open Vacuum status window Foreline valve B closed J0-3 Low=closed Vacuum status window Rough valve B open J0-5 Low=open Vacuum status window Rough valve B closed J0-7 Low=closed Vacuum status window Chamber vent open J0-9 Low=open Vacuum status window Pins J0-2 through J0-20 even are GND Gun valve open flag J-2 Low=open Vacuum status window Gun valve closed flag J-5 Low=closed Vacuum status window iso valve open flag J-8 Low=open Vacuum status window iso valve closed flag J- Low=closed Vacuum status window Bake cool valve open flag J-3 Not used Chamber door open flag J-5 Low=open Vacuum status window Chamber door closed flag J-7 Low=closed Vacuum status window Bake cool valve closed flag J-9 Not used Pins J-, 4, 7, 0 all at +5V; J-3, 6, 9, 2, 4, 6, 8, 20 at GND 2 Table 2-. (cont.) Logic driver pinouts IVS 230 Maintenance Manual 275

39 System logic Logic driver pinouts Terminal Block # Logical condition Chamber vent closed J2- Low=closed Shroud vent open J2-3 Low=open Shroud vent closed J2-5 Low=closed Fast chamber vent open J2-7 Low=open Fast chamber vent closed J2-9 Not used Service door A J2- Not used Service door B J2-3 Low=closed Cassette door sense open=down J2-5 Low=open Cassette door sense closed=up J2-7 Low=closed Status indicator Pins J2-2 through J2-20 even are GND Turbo pump A status J3-3 +5=OFF, GND=ON Vacuum status window Turbo pump B status J3-5 +5=OFF, GND=ON Vacuum status window Multivac gun pump status J3-7 LOW=ON Vacuum status window Multivac iso pump status J3-9 LOW=ON Vacuum status window Pins J0-4 through J0-0 even are GND Vacuum status window Table 2-. (cont.) Logic driver pinouts 276 IVS 230 Maintenance Manual

40 System logic Logic driver test points Logic driver board test points The test points on the logic driver board (TP -TP0) are used to adjust the vacuum, air, nitrogen, and water flow sensor signals so they accurately indicate that vacuum, air, and nitrogen is present and that water flow to the turbo is functioning. Here's how to adjust the sensors using these test points.. Make sure water flow is on and that the gauges on the Utilities Distribution box for nitrogen, air, and vacuum show the correct values required for the system. (See Chapter 0 Vacuum Valves for recommended values.) 2. Confirm that the water flow sensor switch is tripped. If not, adjust switch before proceeding. To do so, see "Checking trip signal for low water cutoff" in Chapter 6. (Note that the last part of that procedure is the same as step 3 below.) 3. Check test points 7 through 0 one at a time to see if voltages are as indicated in Table 2-2. Measure between the test point and ground. A good ground to use on the board is the black lead at J5 (the chassis power connector.) If the voltages are not as shown below, adjust the specified potentiometer until you see the voltage listed. The LED's will be on. These voltages are the trip point for the sensors monitoring the utility lines. If voltage drops below these values, the logic will indicate that the utility line being monitored has dropped below specification. 2 Water flow sensor Nitrogen sensor Air supply sensor Vacuum Transfer pedestal INPUT FROM SENSOR I nput TP 8 (5.0) I nput TP 9 (.7 for 5 psi) I nput TP 0 (.7 for 80 psi) I nput TP 7 (5.0 for 22 in Hg) Input TP 6 OUTPUT TP FOR LED TRIP POINT ONLY adjust R35 TP 3 L ED J30 (ADJ 4.5 V) adjust R36 TP 4 L ED J3 (ADJ 0.7 V) adjust R37 TP 5 L ED J32 (ADJ.7 V) adjust R34 TP 2 L ED J29 (ADJ 3.0 V) adjust R33 TP LED J33 Table 2-2. Logic driver board sensor adjust values IVS 230 Maintenance Manual 277

41 System logic Logic driver jumpers Jumpers for loop back signals Jumpers on the logic driver board are used to loop back a valve drive signal in order to let the logic control board know that the drive signal to open the valve has been issued. This method is used because some valves do not have built-in flag circuits. The loop back of the drive signal lets the logic control board know that the drive command has indeed been issued. Here's an example of how the loop back circuit works using foreline valve A. The drive signal to open the valve a low at J7-0 is also looped back through jumper JP4 to J9.5. This signal is sent out to the logic control board at J.45. The LCB now knows a command to open the valve has been sent. There is no actual feedback from the valve itself as with, say, the turbo valve. Valves which have their drive signals looped back to the logic driver board are shown in Figure 2-3. The gun valve and iso valves have their own built in flag circuits (see Table 2-.) 278 IVS 230 Maintenance Manual

42 System logic Logic driver jumpers J9.9, J.38!ROUGH_VALVE_A_OPEN J0., J3.40 3!ROUGH_VALVE_A_CLOSED 2 JP* J8.6!ROUGH_VALVE_A_DRIVE J0., J.44!FORELINE_VALVE_B_OPEN J0.3, J3.25 3!FORELINE_VALVE_B_CLOSED 2 JP6* J7.2!ROUGH_VALVE_B_DRIVE LOOP BACK ROUGH VALVE A LOOP BACK FORELINE VALVE B J.3, J.39!TURBO_VALVE_B_OPEN J.5, J3.6 3!TURBO_VALVE_B_CLOSED 2 JP2 J8.6!TURBO_VALVE_B_DRIVE J0.5, J.37!ROUGH_VALVE_B_OPEN J0.7, J3.38 3!ROUGH_VALVE_B_CLOSED 2 JP7* J8.8!ROUGH_VALVE_B_DRIVE LOOP BACK TURBO VALVE B J0.7, J.42!TURBO_VALVE_A_OPEN JP3 J8.4 2!TURBO_VALVE_A_DRIVE J0.9, J3.44 3!TURBO_VALVE_A_CLOSED LOOP BACK TURBO VALVE A LOOP BACK ROUGH VALVE B J.9, J3.24!CHAMBER_VENT_OPEN JP8* J8.8 2!CHAMBER_VENT_DRIVE J2., J3.45 3!CHAMBER_VENT_CLOSED LOOP BACK CHAMBER VENT 2 J9.5, J.45!FORELINE_VALVE_A_OPEN J9.7, J3.37 3!FORELINE_VALVE_A_CLOSED JP4* J7.0 2!FORELINE_VALVE_A_DRIVE J2.3, J3.3!SHROUD_VENT_OPEN J2.5, J3. 3!SHROUD_VENT_CLOSED 2 JP9* J7.8!SHROUD_VENT_DRIVE LOOP BACK FORELINE VALVE A LOOP BACK SHROUD VENT J.3, J3.7!BAKE_COOL_VALVE_OPEN J.9, J3.6 3!BAKE_COOL_VALVE_CLOSED JP5* J7.8 2!BAKE_COOL_VALVE_DRIVE J.5, J3.33!DOOR_VALVE_OPEN J.7, J3.30!DOOR_VALVE_CLOSED 3 2 JP J7.4!DOOR_VALVE_DRIVE LOOP BACK BAKE COOL VALVE LOOP BACK DOOR VALVE J2.7, J3.39!FAST_CHAMBER_VENT_OPEN J2.9, J3.48 3!FAST_CHAMBER_VENT_CLOSED JP3* J7.20 2!FAST_CHAMBER_VENT_DRIVE LOOP BACK FAST CHAMBER VENT Figure 2-2. Jumper block connections on logic driver. A * indicates jumper installed between pins and 2. JP0 and JP2 not used. IVS 230 Maintenance Manual 279

43 System logic Drive schematics Valve and pump drive schematics The schematics in this section show the drive circuits for these valves and pumps: Rough valves Chamber vent Shroud vent Iso valve Gun valve Turbo valves Door valve Foreline valves Turbo pumps Stored drive signals for some valves and pumps The drive signals for the door valve, foreline valves and turbo pumps are latched (stored in a flip flop) so that these components will remain open or in their present state even with power off at the logic control board. The foreline valves and turbo circuits are latched so you can turn off power to the card cage containing the logic control board and keep the turbos running (turbos need forelines open to run.) This way, you don't have to go through the step of turning off and restarting turbos when removing power to the card cage for troubleshooting or repair procedures. The door valve circuit is latched for a different reason. It is latched in the state it is in, either open or closed, with power to the card cage off. This is done for safety reasons, so the door will not unexpectedly close on somebody's hand. 280 IVS 230 Maintenance Manual