Specific Process Knowledge/Thin film deposition/Deposition of Zinc: Difference between revisions
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Beyond this, Zn cannot be deposited in systems with a cryo pump, as it will completely clog the cryo pumping system. The best solution is therefore a sputter system that is pumped by a turbo pump and where possible Zn contamination is not a problem for other users. | Beyond this, Zn cannot be deposited in systems with a cryo pump, as it will completely clog the cryo pumping system. The best solution is therefore a sputter system that is pumped by a turbo pump and where possible Zn contamination is not a problem for other users. | ||
In the lab at Danchip the only evaporation system with no cryo pump is the Lesker Thermal Evaporator, so this is the only system that is an option for Zn evaporation. We tested it and found that Zn coats every surface in the chamber and re-evaporates during subsequent evaporation of other materials, contaminating the growing film. After a thorough chamber cleaning, we no longer detect Zn in Al or Ag films made in the evaporator. However, this kind of cleaning takes a full working day and while the chamber is used for Zn no other materials can be deposited without contamination. '''We are therefore hesitant to use the evaporator for Zn again. If you wish to deposit Zn, please first explore other options than Danchip's systems | In the lab at Danchip the only evaporation system with no cryo pump is the Lesker Thermal Evaporator, so this is the only system that is an option for Zn evaporation. We tested it and found that Zn coats every surface in the chamber and re-evaporates during subsequent evaporation of other materials, contaminating the growing film. After a thorough chamber cleaning, we no longer detect Zn in Al or Ag films made in the evaporator. However, this kind of cleaning takes a full working day and while the chamber is used for Zn no other materials can be deposited without contamination. '''We are therefore hesitant to use the evaporator for Zn again. If you wish to deposit Zn, please first explore other options than Danchip's systems.''' | ||
Note that Zn will not adhere to an Si wafer (probably due to SiO2 on the surface). The same is true for a Ti-coated wafer - the Zn did not stick. We were able to deposit Zn on a Ti/Au coated dummy wafer. | Note that Zn will not adhere to an Si wafer (probably due to SiO2 on the surface). The same is true for a Ti-coated wafer - the Zn did not stick. We were able to deposit Zn on a Ti/Au coated dummy wafer. | ||