Specific Process Knowledge/Thin film deposition/Temescal: Difference between revisions
No edit summary |
|||
| Line 137: | Line 137: | ||
The machine gives a rough number for the crystal lifetime simply based on how thick a layer it calculates has been deposited on it. If many layers have been deposited and there is stress in the layers (e.g., in Cr, Ni, or Ru layers), there may be partial delamination, which can make the thickness measurement inaccurate. In this case the lifetime estimate given by the machine will be inaccurate. If you think the crystal is not measuring correctly, please let us know. We exchange the crystals usually around 20 % lifetime use. | The machine gives a rough number for the crystal lifetime simply based on how thick a layer it calculates has been deposited on it. If many layers have been deposited and there is stress in the layers (e.g., in Cr, Ni, or Ru layers), there may be partial delamination, which can make the thickness measurement inaccurate. In this case the lifetime estimate given by the machine will be inaccurate. If you think the crystal is not measuring correctly, please let us know. We exchange the crystals usually around 20 % lifetime use. | ||
<br clear="all" /> | <br clear="all" /> | ||
== | == Heating during deposition == | ||
If the material you are depositing requires a lot of heat to evaporate, the substrates may get warm during the deposition. | |||
A temperature test of a 100 nm Al deposition at 10 Å/s showed that the back of the wafer stays below 37 <sup>o</sup>C. The same is true for 10 nm Ti/90 nm Au at 10 Å/s. In contrast deposition of 60 nm W at about 1 Å/s heated the substrate to above 120 <sup>o</sup>C. | |||
Al requires intermediate power (about 450 mA and 1000 V supplied to the filament that creates the e-beam) while W requires high power (about 600 mA at 1000 V supplied to the filament). | |||
Please ask us if you need to test the heating of the substrates before making a deposition with the metal you need (contact thinfilm@danchip.dtu.dk). | |||