CHA ELECTRON BEAM EVAPORATOR SYSTEM OPERATING MANUAL Version: 1.0 Jan 2012

Transcription

1 CHA ELECTRON BEAM EVAPORATOR SYSTEM OPERATING MANUAL Version: 1.0 Jan 2012 UNIVERSITY OF TEXAS AT ARLINGTON Nanofabrication Research and Teaching Facility

2 TABLE OF CONTENTS 1.0 DESCRIPTION SAFETY REQUIREMENTS/RESTRICTIONS STARTING THE CRYO PUMP LOADING A SAMPLE PROGRAMMING THE XTC THICKNESS MONITOR BRINGING UP THE ELECTRON BEAM FOR EVAPORATION SYSTEM SHUTDOWN

3 1.0 Description The CHA Industries Electron Beam Evaporator uses a four pocket carousel crucible selector. Users are allowed to evaporate/deposit Al, W, Ti, Ni, Ge, Au, Ag, Pt, Cr, Co, Fe and Cu. Any other materials will need NanoFab staff permission. Single or stack films can be evaporated on 1-6 diameter wafers, glass slides and small samples. 2.0 Safety This machine is connected to HIGH VOLTAGE. If any ARC FAULT, OVERLOAD, or SYSTEM FAULT lights come ON call NanoFab staff immediately. Be very careful and aware of electrical hazards. If you encounter any electrical malfunctions contact NanoFab staff immediately This machine uses HIGH VOLTAGE. DO NOT operate this machine with any cables disconnected, or component enclosures/panels open This machine uses HIGH VOLTAGE. DO NOT operate this machine with any cables disconnected, or component enclosures/panels open This machine has use water flow to prevent over heating the cryro pump, carousel source crucibles and quartz crystal.if you encounter any water flow malfunctions or leaks notify NanoFab staff immediately This machine has an EMO (Emergency Off) switch/button mounted on the top panel. The EMO switch should be pressed only in an emergency. An emergency would be fire, smoke, electrocution hazards, and an injury to anyone using this particular piece of equipment. If the EMO is pressed notify NanoFab staff immediately Use sunglasses when viewing the material heating/ evaporation process to prevent eye damage 3.0 Requirements/Restrictions You must be a qualified user on the CHA E-beam evaporator Users must supply their own deposition supplies on this system. See the Kurt J Lesker page below (Fig. A) for more details Substrate heating is limited to 500 o C maximum The evaporator can be used to deposit metal or oxide film on 1-4 diameter wafers, glass slides, and small samples by using the substrate holder clips. Extremely small pieces can be processed by using longer holder clips or bonding to larger carrier wafer (bond with drop silver paint, drop of baked photo resist, MUNG II paste or other approved bonding material) No substrate heating allowed if using bonding material. 3

4 3.1.6 If you are using the substrate heater be careful not to over heat your wafer/samples to prevent any wafer breakage, metal or any other material to flow If you are using the substrate heater make sure you wait until the substrate temperature is < 50C before venting the chamber. 4

5 4.0 Starting the Cryo Pump Set the ROTARY Switch to MANUAL (Fig 1). (Fig. 1) Check the CRYO PUMP CONTROLLER (Fig. 2) to see if the controller power is ON and if the cryo pump is at the proper operating temperature of < 18K. If the Cryo Pump Controller is currently ON and at the proper operating temperature then skip forward to Section 5.0. If the Cryo pump is OFF then proceed to the next step. (Fig 2) Read the CRYO ROUGHING PRESSURE (Fig. 3), if it is > 100 mtorr go to step If it 100 mtorr go to step (Fig. 3) 5

6 4.1.4 Turn the MECHANICAL PUMP breaker ON (Fig. 4). (Fig. 4) Open the FORE valve (See Fig. 1) and wait until the CRYO ROUGHING PRESSURE 100 mtorr (Fig. 5). Close the FORE valve and monitor the CRYO ROUGHING PRESSURE, if it rises to > 100mT open the FORE valve again and allow the pressure to drop to < 100mt. Repeat this cycle until the CRYO ROUGHING PRESSURE remains < 100mT when the FORE valve is closed. Leave the FORE valve closed and proceed to the next step. **Warning** Do not leave the system unattended with the FORE valve opened. Allowing the pressure to drop for extended periods of time to levels of < 100 mtorr can result in hydrocarbon oil backstreaming into the cryo and contamination of the system. If you must leave, then close the FORE valve before doing so. (Fig. 5) 6

7 4.1.6 Turn the CRYO-PUMP CONTROLLER power ON (Fig. 6). Write down in the logbook the cryo starting time. The cryo pump is not going to be operational until it reaches 18 ºK as displayed on the CRYO-PUMP CONTROLLER. This may take up to 2 hours. (Fig. 6) ***Note*** At this time you may load your samples and perform steps while you wait on the cryo pump to finish cooling to < 18 ºK. 5.0 Loading a Sample On the PRESSURE GAUGE CONTROLLER, (Fig. 7) press the POWER button. Open the VENT valve (See Fig. 1) and wait until the THERMO GAUGE pressure gets close to 1000 Torr. (Fig. 7) 7

8 5.1.2 Move the RAISE/LOWER button to the RAISE position to fully raise the Bell Jar. Once the Bell Jar has fully lifted and stops, move the RAISE/LOWER switch to its middle STOP position (Fig. 8) and close the VENT valve (Fig. 8). (Fig. 8) Load your sample(s) onto one of the Sample Plates (Fig. 9) and then you re your supplies for evaporation into the chamber. Change the microscope slides if necessary. While the chamber is opened inspect the chamber seal and base area for flakes. Clean all flakes from the seal areas. If there are too many flakes within the chamber, vacuum the chamber. You need to be careful around the high voltage electrodes and e-beam gun. Do not touch the vacuum nozzle to any wires or delicate components. If necessary ask a staff member to assist you. If flakes get in the wrong location arcing can occur. (Fig. 9) LOWER the Bell Jar by moving the RAISE/LOWER switch to the LOWER position (See Fig. 8). Once the Bell Jar has fully lowered and stops moving then move the RAISE/LOWER switch to the middle STOP position. 8

9 5.1.5 Open the ROUGH valve (See Fig 8). After the pressure in the chamber indicates < 100 mt as indicated on the Thermo Gauge (Fig 7 & 9) close the ROUGH valve. You must now wait until the cryo temperature is 18 ºK before proceeding to the next step. Fig Verify that the cryo pump temperature is 18 ºK as indicated on the CRYO PUMP CONTROLLER (See Fig. 6) once this temperature has been reached open the HIVAC valve (See Fig 8) Wait a few minutes, then go to the PRESSURE GAUGE CONTROLLER (See Fig. 7) and turn the RANGE switch to 4x10 -N and press the FILAMENT button to turn ON the Ionization Gauge Wait until the pressure in the Ionization Gauge reaches < 5x10-6 Torr before proceeding. 6.0 Programming the Inficon XTC Thickness Monitor Turn ON the THICKNESS FILM MONITOR (Fig. 8) and then press the STOP and then START button to clear any errors. (Fig. 8) Press the XTAL button to check the % of crystal life remaining. If the crystal life is > 15% then it must be changed before deposition Press the Pg button then the DOWN ARROW key until DENSITY is highlighted. 9

10 6.1.4 Enter the material density from the materials selection guide. Once the correct density has been entered continue by pressing the DOWN ARROW again until Z-Ratio is highlighted. Enter the correct Z-Ratio for the deposited material from the materials selection guide. ***Warning***- DO NOT PRESS THE UP ARROW AFTER ENTERING A NUMBER OR THE ENTRY WILL BE LOST Once completed press the Pg button again to save the entries and return to the main screen. 7.0 Bringing up the Electron Beam for Evaporation Turn the e-gun X - Y beam sweep controller ON (Fig. 10) by moving the toggle power switch to the ON position. (Fig. 9) Turn on the interlock key by turning the key from OFF to MAN, Do not put the key in AUTO or the system will not function properly. All the yellow interlock lights will turn on and the green READY light will be on. If all the lights are not on call NanoFab staff. (Fig. 10) Turn SOURCE 1 emission control knob on the front of the Interlock panel to 0 by turning knob CCW until it stops Turn the REMOTE BEAM CONTROLLER emission current to 0 by turning the EMISSION current potentiometer fully CCW until it 0. 10

11 7.1.6 Turn on MAINS power by moving switch/breaker to ON position (SEB-06 e-beam power supply). If any ARC FAULT, OVERLOAD, SYSTEM FAULT lights go on turn OFF MAINS switch/breaker and call NanoFab staff immediately. Only the MAINS ON and INTERLOCK lights should be on Turn on high voltage by pressing the white HV ON push-button switch (SEB-06). The HV ON light will turn on. If any ARC FAULT, OVERLOAD, SYSTEM FAULT lights go on press the green HV OFF push-button switch, turn OFF MAINS switch/breaker and call NanoFab staff immediately. Only the MAINS ON, INTERLOCK and HV ON lights should be on If necessary adjust the OUTPUT VOLTAGE to 9.0 KV by turning output voltage adjust potentiometer UP or DOWN until the display shows 9.0 KV While watching the X Y Beam sweep controller Green LED readouts, adjust both the amplitude and position potentiometers on the Remote Beam Controller to be centered (position pot) and approximately 3 to 5 LED s in width (Amplitude pot) Check to ensure the Remote Emission Controller emission current is at 0 by rotating emission potentiometer CCW until it Turn on the Remote Emission Controller by pressing the EMISSION ON pushbutton switch. The ON light will turn red Move the Source shutter switch to its OPEN position (Fig. 11). (Fig. 11) Slowly increase emission current by rotating EMISSION potentiometer CW to a setting of while looking through the source view port window to monitor the initial heating process (about 15 downward). If necessary use the filter lens when viewing the material heating/evaporation process to prevent eye damage. 11

12 While looking into the viewport window you should be able to see the blue e-beam spot or the material glowing hot near the center of the crucible. Make fine centering adjustments to the Horizontal and Lateral Position potentiometers On the Remote Beam Controller increase/decrease the Horizontal Amplitude potentiometer CW to generate an optimal e-beam sweep without encroaching on the crucible edge On the Remote Beam Controller increase/decrease the Lateral Amplitude potentiometer CW to generate an optimal e-beam sweep without encroaching on the crucible edge On the Remote Beam Controller increase/decrease the Horizontal and Lateral Frequency potentiometers CW to achieve an optimum sweep frequency/speed Very slowly increase emission current by rotating EMISSION potentiometer CW. When you have the desired evaporation rate (2-3A/sec is typical) then press the ZERO button on the Inficon XTC thickness monitor (See. Fig. 8) Open the Substrate shutter (Fig. 12) to begin the deposition. (Fig. 12) When you have deposited the desired thickness as shown on the Inficon XTC thickness monitor (See Fig. 8), quickly close both the SOURCE AND SUBSTRATE shutter s by moving both switches to their closed position s (See Fig. 12) Begin the emission current shut down by SLOWLY decreasing emission current by rotating EMISSION potentiometer CCW until it 0. This process should take a couple of minutes to allow the crucible and filament sufficient time to cool slowly Turn off the Remote Emission Controller by pressing the EMISSION OFF pushbutton switch. The OFF light will turn green. 12

13 Turn off high voltage by pressing the green HV OFF push-button switch (SEB-06) and then turn off the Mains power by moving the breaker to the OFF position Then turn off the X Y Beam sweep controller and turn the Interlock key to the OFF position. 8.0 System Shutdown If the substrate was heated then you must wait until the temperature displays < 50 deg before proceeding to the next step Close HIVAC valve (See Fig. 1) and wait 5 minutes before proceeding to the next step, this allows the crucible sufficient time to cool down Open the VENT valve (See Fig. 1) and allow the chamber pressure to rise to approximately 1000 mt as indicated on the THERMOGAUGE display (See Fig. 7) Press the RAISE button (See Fig. 1) to raise the bell jar. Once the bell jar has fully raised close the VENT valve Remove the Sample Carrier from the system, unload your sample(s) from the plate and then reinstall the empty sample plate into the system Press the LOWER button (See Fig. 1) to lower the bell jar until it stops moving. Move the Raise/Lower switch back to the middle position Move the open the ROUGH valve and pump the chamber to < 100 mt on the THERMOGAUGE display (See Fig. 7) Close the ROUGH valve and then turn the MECHANICAL PUMP switch off (See Fig. 3) If another user is going to use the CHA E-beam system after you then skip this step. If no other user will be running the CHA E-beam system then proceed. On the Cryo Pump Controller (See Fig. 5) turn the CRYO-PUMP power switch OFF Switch to the system controller from MANUAL to the OFF position (see Fig. 1) Pick up your belongings, clean and organize the table and complete your log entry in the system logbook. 13