Specific Process Knowledge/Thin film deposition/Deposition of Zinc: Difference between revisions

← Older edit Newer edit →

VisualWikitext

@@ Line 9: / Line 9: @@
 '''The best solution is therefore a sputter system that is pumped by a turbo pump in a chamber where Zn contamination is not a problem for other users.'''
-Unfortunately, in the lab at Danchip the only physical vapor deposition 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.'''
+Unfortunately, in the lab at Nanolab the only physical vapor deposition 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 Nanolab'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. We were able to deposit Zn on a Ti/Au coated dummy wafer. A user was able to deposit on InGaP and InP.
@@ Line 16: / Line 16: @@
 ''Measurements made in June/July 2018.''
-XPS was done at Danchip with 50 eV and 50 ms dwell per scan. The number of scans per element varied as shown below in the figure captions. We can clearly see that the Zn amount in the Al film decreased and became indetectable after cleaning the chamber. Of course we cannot guarantee that there is no Zn contamination at all, since there is a detection limit for the XPS even with many scans per level.
+XPS was done at Nanolab with 50 eV and 50 ms dwell per scan. The number of scans per element varied as shown below in the figure captions. We can clearly see that the Zn amount in the Al film decreased and became indetectable after cleaning the chamber. Of course we cannot guarantee that there is no Zn contamination at all, since there is a detection limit for the XPS even with many scans per level.
 [[File:Al w Zn from 20-06-2018.png|400px|left|thumb|XPS of Al film made before chamber was cleaned after Zn deposition. 10 scans per level. Zn peaks are obvious. The Zn content was up to 10 % in some layers.]]