Denton Vacuum E-beam Evaporator Denton Vacuum - Quality, Service, Value 1259 North Church St. Moorestown, NJ, USA 08057 856-439-9100 www.dentonvacuum.com Contact Information:   Faculty Contact:   Aaron Hawkins   Staff Contact:   Joe Bussio   Student Contact:   Weisheng Hu Maintenance Request for Denton Vacuum E-beam Evaporator SCHEDULER IS REQUIRED

NOTE:

• All depositions must be approved by Dr. Hawkins
• Do NOT deposit anything containing iron. The only materials that can be deposited are Ni, SiO₂, Al, Au, Cr, Ti, SnO₂, Ge
• Never operate the high vacuum (TURBO) pump without the roughing (MECH) pump being on

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1. General Information

   1. The Denton Vacuum E-beam Evaporator is primarily used to deposit metal on silicon wafers. For these depositions to occur, the wafer and material to be deposited must first be brought to a very low pressure (high vacuum). This vacuum is usually in the range of 1x10e-5 torr. The material to be deposited must be capable of vaporizing for the deposition to be successful. Once at a high vacuum, an electron beam is focused on the crucible containing the deposition material until the material begins to evaporate. As the material in the crucible evaporates, its vapor will begin to coat the inside surface of the chamber. The Inficon Deposition Meter utilizes a quartz crystal monitor to accurately display the thickness and rate of the deposition. Also, a shutter is used to block the electron beam from hitting the deposition material until everything is ready for the deposition.
      
      

2. Equipment Specifications

   1. LCD Touch-screen
      1. Click on image to see location on E-beam
         
   2. Inficon Deposition Monitor
      1. Click on image to see location on E-beam
         
   3. Sightglass and Mirror Stand
      1. Click on image to see location on E-beam
         
   4. Chiller
      1. Click on image to see location on E-beam
         
   5. Each crucible holder is dedicated to a specific material:
      1. Aluminum
      2. Tin Oxide
      3. Germanium
      4. Nickel
      5. Chrome
      6. Gold
   6. 
      
      

4. Operating Procedures

   1. Start-up
      1. Check the status of the machine
         1. This is what you should see--the power should be on and the computer program should be running.
            
      2. Check the vacuum
         1. The E-beam should be left at a vacuum when not in use, so it is likely you will have to vent the chamber before you can load your wafers. Go to the PUMPS menu on the LCD screen and press VENT to begin venting the chamber. Once the chamber pressure is at atmosphere, open the door and press VENT again to stop venting the chamber.
      3. Turn on the chiller
         1. The chiller must be on while the E-beam is in use. It is located under the table to the right of the E-beam. Be careful to make sure you have the correct chiller because the E-beam chiller is next to the chiller for the ICP Etcher. Turn on the Power by flipping the white switch up and pressing the black button that says start.
         2. Click on image to see location on E-beam
            
      4. Check the water flow
         1. Both the TURBO pump and Ion Source are on the same cooling water line. The Electron Gun is on a separate line. The flow rates for the cooling water should look like this and the LCD screen should look like this before you begin pumping down the chamber
   2. Prepare the Chamber
      1. Load wafers into planetary
         1. To rotate the planetary go to the E-GUN menu, in the rotate section of the screen check that the setting is on slow, then press the power button the color of the button will change from red to green.
         2. Use the vacuum wand to load your wafers into the planetary
            1. Click on image to see location on E-beam
               
            2. There is a button on the side of it that pushes through to turn the vacuum on. Align the vacuum side of the wand to the back of the wafer so that there is a good suction. Place the wafer in on of the planetary slots and then push the big button in the middle to temporarily turn off the vacuum. Secure the wafer in place with a piece of yellow vacuum tape that should be near by. If none of the vacuum tape can be found (it may be back by the thermal evaporator), scotch tape may be used as long as you ensure that it is all removed when you are done.
         3. Make sure to align the flats of the wafer away from the knobs on the planetary, or your wafers may fall out.
            1. Click on image to see location on E-beam
               
            2. Note: Some of the planetary slots are partially blocked by a portion of the chamber which would cause your wafer to not be completely covered by the evaporation. Check to make sure nothing is blocking it. If something is, then move it to another slot.
      2. Load crucible(s)
         1. Find a crucible with the material you would like to deposit
            1. Click on image to see location on E-beam
               
            2. Make sure there are not any large cracks or openings in the crucible or it will not disperse heat well or work for evaporation
         2. Load the crucible into the chamber
            1. Multiple crucibles may be used in a single evaporation, however, you may encounter difficulty using crucibles containing magnetic materials (i.e. nickel) as the crucible must pass beneath some very strong magnets as it rotates out of position. The magnetic material in the crucible could be pulled upward to the magnets and jam the rotation of the crucibles.
            2. Click on image to see location on E-beam
               
      3. Adjust mirror stand
         1. Adjust the mirror stand so that you can see the crucible through the sightglass during the deposition--this is important because it will be difficult to center the electron beam on the crucible if you can't see the crucible. Place a flashlight in the chamber shining on the crucible so that when you close the door you can see the crucible through the sightglass. Remove the flashlight before pumping down the chamber. Light from the electron beam will be sufficient to see the crucible during evaporation.
      4. Check status of crystal
         1. Check the life of the crystal by pressing the LIFE button on the deposition monitor. The crystal will typically fail once this reading reaches about 50%. If it does fail this is not a problem, you will just have adjust the current by sight.
   3. Deposition
      1. Close the door
         1. Close the door, under the PUMPS menu press the MECH button to turn on the Roughing pump, the button will change color from red to green
      2. Turn on the TURBO pump
         1. Once the vacuum in the chamber falls below 1e-2torr, press TURBO to turn on the Turbo pump. This may take as long as an hour.
      3. Program the deposition monitor
         1. Now is a good time to program the deposition monitor because it will take a few min for the chamber to pump down to HIGH VAC. To program the deposition monitor, you must know the following information about the material you will deposit:
            • Density
            • Z-ratio
            • Tooling Factor
         2. Click on image to see location on E-beam
            
      4. Turn on the Ion Gauge
         1. Once the vacuum in the chamber reads HIGH VAC, press ION GAUGE to turn on the chamber's ion gauge, the button color will change from red to green--the ion gauge gives a more accurate reading of the pressure in the chamber, wait until the ION GAUGE reads 5.5e-5torr before going to the next step.
         2. Click on image to see location on E-beam
            
      5. Turn on power to Electron Gun
         1. You must wait 2 minutes after turning on the main power to the electron gun before you can actually turn on the electron beam (see sequential diagram below)
         2. Click on image to see location on E-beam
            
      6. Start deposition monitor
         1. As soon as you turn on the power to the electron gun, press START on the deposition monitor to begin monitoring the deposition.
         2. Click on image to see location on E-beam
            
      7. Rotate the planetary
         1. You will most likely want the planetary to be rotating during your deposition. To rotate the planetary, press NAVIGATE and then press E-GUN. Now press POWER and the planetary will begin to rotate.
         2. Click on image to see location on E-beam
            
      8. Increase current
         1. SLOWLY turn up the current of the electron beam by turning the dial seen below. As the current increases, you will see a bright spot somewhere on/near the crucible--this is the electron beam. Center it in the middle of the crucible by using the alignment joystick
         2. Click on image to see location on E-beam
            
      9. DEPOSITION TIPS
         1. As you increase the current, your deposition material will begin to vaporize and deposit on your wafers. Here are some tips for to having a successful deposition
            • Keep a constant deposition rate
            • Keep a low deposition rate (7-10 Angstroms/second)
            • Keep the electron gun centered on the crucible
   4. Shut-down
      1. Close the EGUN Shutter
         1. Press the navigate button press the EGUN menu Press the SHUTTER button, the button color will change from green to red. This closes the shutter and prevents deposition
      2. Decrease the Current
         1. SLOWLY turn down the current of the electron beam by turning the dial counter clockwise seen below.
      3. Turn off the power to the Electron Gun
         1. Turn off the power to the Electron gun. You must wait 2 minutes and then turn off the main power.
      4. Turn off the deposition monitor
         1. Push the white button on the deposition monitor to turn it off
      5. Turn off the ION GAUGE
         1. Turn off the ION GUAGE the button will change color from green to red
      6. Turn off the TURBO pump
         1. Turn off the ION GUAGE the button will change color from green to red
      7. Turn off the MECH pump
         1. Turn off the MECH pump the button will change color from green to red
      8. Turn on the VENT
         1. Turn on the VENT the button will change color from red to green, it will take about 2 minutes for the chamber to vent typically at a pressure of 5-6e2torr
      9. Turn off VENT
         1. When the chamber has finished venting turn off the VENT the button will change color from green to red
      10. Turn off the Planetary rotation
          1. Press the navigate button, press the EGUN menu, press the POWER button in the rotation section
      11. Open the EGUN Shutter
          1. In the EGUN menu press the EGUN shutter button the color of the button will change from red to green, this will open the shutter
      12. Remove wafers
          1. Use the wand to remove your wafers from the planetary
      13. Remove Crucible
          1. Remove the crucible from the Evaporator
      14. Turn on the MECH pump
          1. Turn on the MECH pump to pump down the chamber, the chamber should always be left pumped down
      15. Turn off the Chiller
          1. Turn off the chiller by flipping down the white switch on the chiller

5. misc

   1. To begin, check the status of the machine. It should already be turned on and the computer program should be running. The E-beam should be left at a vacuum when not in use, so it is likely you will have to vent the chamber before you can load your wafers. Go to the PUMPS menu on the LCD screen and press VENT to begin venting the chamber. Once the pressure is above 6e2 torr, open the door and press VENT again to stop venting the chamber. The chiller is located, turn it on by flipping the power switch
   2. Make sure the chiller is on WHENEVER THE EVAPORATOR IS IN USE The chiller is located under a table to the right of the E-beam. If it is not turned on, flip the power switch to on and press the START button.
   3. Preparing the chamber
      1. Look on the LCD display screen--if the chamber is at a vacuum, press "Vent" under the "Pumps" menu and wait for the chamber to reach atmosphere.
      2. Once at atmosphere, open the chamber door and attach sample to planetary.
      3. Select the crucible you would like to use and load it into the crucible holder. Multiple crucibles may be used in a single evaporation, however, you may encounter difficulty using crucibles containing magnetic materials (i.e. nickel) as the crucible must pass beneath some very strong magnets as it rotates out of position. The magnetic material in the crucible could be pulled upward to the magnets and jam the rotation of the crucibles.
      4. Once the crucible(s) is loaded, make sure to align the mirror stand with the markings near the chamber door(see image). The mirror stand allows you to see the crucible clearly during the deposition. This is important because the Denton E-beam allows you to adjust the horizontal/vertical swing of the ion beam as it sweeps across the crucible. It is important to make sure that the beam does not sweep outside the limits of the crucible because you may begin to melt the copper plating surrounding the crucible. It could also junk up your wafer with copper.
      5. Now you are ready to close the chamber door and begin the vacuum. Go to the "Pumps" menu on the LCD screen(see image) and press "MECH". This will initialize the mechanical pump.
      6. Once the vacuum reaches 1e-2 torr, press the "TURBO" button. This will initialize the Turbo pump.
      7. Once the vacuum has "HIGH VAC", press the "ION GAUGE" button. This will initialize the Ion gauge which gives a more accurate reading of the pressure in the chamber.
      8. When the vacuum has reached 1e-5 torr, you may begin the deposition. Flip the power switch to "On" and wait 2 minutes. Now press the power button for the ion beam
      9. Increase the current SLOWLY and monitor the deposition on the deposition controller
      10. Once the deposition is complete, turn off the power to the ion beam and wait 2 min before turning off the main power.
      11. Turn off the MECH and TURBO pumps and press vent until chamber is vented

6. Quick Reference

   1. It is best to leave the chamber pumped down to a low pressure when not in use.
   2. Once you have vented and removed your wafers, close the door and turn on the MECH pump until the chamber is at a vacuum