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oxides_system [2012/12/10 14:39] – torrenoxides_system [2013/02/27 09:09] (current) – boltje
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-==== YBCO growth ==== +[[oxide_YBCO]] 
-The most complex process is YBCO growth. That process is described here.+==== Change Sample ====
  
 === Switch off the pumps === === Switch off the pumps ===
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 === Open the chamber === === Open the chamber ===
-  - Vent the chamber by opening the N<sub>2</sub> chamber valve and turning the gas selector valve to N<sub>2</sub>+  - Vent the chamber  
 +    - open N<sub>2</sub> chamber valve  
 +    - turning the gas selector valve to N<sub>2</sub> 5.0
   - Close both valves when the pressure is 8e2 Torr.   - Close both valves when the pressure is 8e2 Torr.
   - Switch on the ''Lift'' main switch   - Switch on the ''Lift'' main switch
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   - Remove the heater shield   - Remove the heater shield
   - Remove samples, clean sideplates in HNO<sub>3</sub>   - Remove samples, clean sideplates in HNO<sub>3</sub>
-  - Clean the heater surface 1)with a razor, 2)with 400 grit sandpaper, 3) with 800 grit sandpaper, 4) with Scotchbrite. Clean with IPA. This step is crucial!+  - Clean the heater surface  
 +    - with a razor 
 +    - 400 grit sandpaper 
 +    - 800 grit sandpaper 
 +    - Scotchbrite 
 +    - Clean with IPA. This step is crucial!
   - Mount the sample with ''SPI silver paste plus II'' (should be kept in freezer, warm up before use) and squeeze the substrate against the heater with the glass tool (clean before use)   - Mount the sample with ''SPI silver paste plus II'' (should be kept in freezer, warm up before use) and squeeze the substrate against the heater with the glass tool (clean before use)
-  - Shine a halogene lamp on the substrate for 15 minutes 
   - Cut away glue around the substrate   - Cut away glue around the substrate
   - Mount side plates, push them flush against the substrate using a cotton tip.   - Mount side plates, push them flush against the substrate using a cotton tip.
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   - Pump overnight   - Pump overnight
  
-=== Deposition ===+ 
 +==== Deposition ====
 == Procedure start== == Procedure start==
-  - Pressure should be 1e-6 mbar +  - Pressure <1E-6 mbar 
-  - Position heater between 2 sources, opposite to YBCO +  - Position heater between 2 sources, opposite to Target 
-  - Open N<sub>2</sub> purge on the pump. Do not forget this! +  - Open **N<sub>2</sub> purge on the pump**. Do not forget this! 
-  - Open the O<sub>2</sub> valve at the front of the system. Do not touch the O<sub>2</sub> needle valve! Flow should be around 40. +  - Open the O<sub>2</sub> valve at the front of the system. (Do not touch the O<sub>2</sub> needle valve! Flow should be around 40.) 
-  - Open the YBCO shutter, keep other shutters closed (unless you make a multilayer of course) +  - Adjust Turbo speed to regulate pressure 
-  - Switch on the YBCO power supply, current regulation+  - Open the Target shutter, keep other shutters closed (unless you make a multilayer of course) 
 + 
 +=== RF === 
 +  - check cooling water 
 +  - Switch on power supply, power regulation 
 +  - Switch on matching power supply 
 +  - Check for no reflection when turning power up 
 +  - Let everything stabilize 
 + 
 +=== DC ===   
 +  - Switch on the target power supply, current regulation
   - Set the setpoint at 8 ma, display actual current and voltage   - Set the setpoint at 8 ma, display actual current and voltage
-  - Switch turbo to pressure control, setpoint 3.5 +  - when pressure is right, switch power supply to on. The plasma should ignite. Get help if it doesn't!
-  - Short after that, when the pressure is between 5e-2 and 1e-1 torr, switch power supply to on. The plasma should ignite. Get help if it doesn't!+
   - Let the pressure increase until the voltage gets below 350-380 V (the lower the better!)   - Let the pressure increase until the voltage gets below 350-380 V (the lower the better!)
   - The voltage keeps decreasing, keep it constant at 350-380 V by increasing current (it is critical that you follow this rate given by the O<sub>2</sub> backfill rate of the chamber and not faster!   - The voltage keeps decreasing, keep it constant at 350-380 V by increasing current (it is critical that you follow this rate given by the O<sub>2</sub> backfill rate of the chamber and not faster!
-  - The turbo pump is at 0 Hz now and starts to accelerate 
-  - At 100 Hz, set pressure setpoint to previous value from the logbook 
   - Keep increasing current, set current to 350 mA (never get above 390 V!)   - Keep increasing current, set current to 350 mA (never get above 390 V!)
-  - Use the Keithley to read O<sub>2</sub> pressure, fine adjust setpoint so that pressure is between 2.99 and 3.01 mbar (better: 2.995 - 3.005) 
-  - Let everything stabilize 
  
 == Presputtering == == Presputtering ==
   - You will see that the conditioning of the target takes quite a while, check that while conditioning the voltage goes down to about the previous value in the logbook.   - You will see that the conditioning of the target takes quite a while, check that while conditioning the voltage goes down to about the previous value in the logbook.
   - Presputter for >1 hour   - Presputter for >1 hour
-  - Program the heater in the meanwhile. There is a recipe for YBCO.+  - Program the heater in the meanwhile. 
  
 == Sputtering == == Sputtering ==
-  - Run the recipe +  - Run temperature the recipe 
-  - When the deposition substrate temperature is reached, the temperature will overshoot 2 or 3 degrees. Get ready to rotate the substrate above the YBCO source. +  - When temperature is reached, turn sample above target.  
-  - //Immediately// (absolutely do not wait) when the temperature is right (0-1 degree from the setpoint) rotate the target above the source. Check the symmetry of the plasma and the substrate position.  Start a timer.+  - Start a timer.
   - Time the epitaxial growth process   - Time the epitaxial growth process
  
-== Annealing == +== After Sputtering == 
-  - Turn the substrate away and press ''Skip segment'' on the Eurotherm control program +  - Turn off power supply 
-  - Turn off the power supply //and turn the setpoint back// +  - Cool down sample
-  - Set the chamber backfill selector to O<sub>2</sub> +
-  - Wait until the substrate reaches the annealing temperature + 10 degrees +
-  - Quickly close the gate valve and the O<sub>2</sub> valve +
-  - Close the gas valve under the chamber and exactly at the annealing temperature open the chamber backfill valve (you have to be quick here!) +
-  - Close the chamber backfill valve at 8e2 torr (reproduce this value!) +
-  - Set the chamber backfill gas selector to neutral+
  
 === End === === End ===
 +  - Close O<sub>2</sub>, if not done already
   - Let pump run for 20 minutes   - Let pump run for 20 minutes
   - Close N<sub>2</sub> purge on the pump.   - Close N<sub>2</sub> purge on the pump.
-  - The Eurotherm control program takes the sample trough the annealing temperature profile 
   - Wait until the sample temperature is <50 C   - Wait until the sample temperature is <50 C
   - Check whether **all** gas valves are closed   - Check whether **all** gas valves are closed
  
- +==== Recipes ====
  
 ====== Deposition rates ====== ====== Deposition rates ======
  
 ^ Material ^  Date     ^ Sample ID ^ Process parameters           ^ Measured with  ^ Result ^ Rate          ^ ^ Material ^  Date     ^ Sample ID ^ Process parameters           ^ Measured with  ^ Result ^ Rate          ^
-|  LCMO    | 20060918  |   L408    |   3 mbar, 350mA ,384V                   |     X-ray       |  45 nm  |   1.21 nm/min   | +|  LCMO    | 20060918  |   L408    |   3 mbar, 350mA ,384V                   |     X-ray       |  45 nm    | 1.21  nm/min   | 
-|  Pt      | 20120711  |   Pt-01   |   1 mbar, 35mA, 603V, 19W, 15min        |     X-ray       |  11.5 nm  |   0.766 nm/min   |+|  Pt      | 20120711  |   Pt-01   |   1 mbar, 35mA, 603V, 19W, 15min        |     X-ray       |  11.5 nm  | 0.766 nm/min   | 
 +|  LAO     | 20121210  | from Ishrad | DC 0.8 mbar, 30W                      |                 |           | ~0.18 nm/min   | 
 + 
 + 
 +====== Tech stuff ====== 
 +  * Targets: 2 inch OD, 0.125 inch thick 
 +  * Backingcup: 53mm OD, 6.3mm thick 
 + 
 + 
oxides_system.1355150360.txt.gz · Last modified: 2012/12/10 14:39 by torren
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