Currently I'm fabricating Nb/Au/Te thin film devices and I was wondering if anyone had any suggestions on how to keep the Te surface clean and if any of the current steps could damage the Te structure?

Material: Nb/Au/Te all layers grown epitaxially in-situ with Te being around 3-5nm thick

Resist: A4 PMMA, pumped in chamber rather than baked to avoid damaging sample via heat.

Current Process: Soak in heated acetone at 55C after etching or lift-off overnight, rinsing using acetone bottle first. IPA rinse and dry with N2 next day.

Constraints:

- Can't use O2 plasma as it would heavily oxidize the Te

- Sonication could damage the Te structure due to cavitation bubbles

- Tried using pg-remover once, but the Nb lost its superconductivity for some reason

Additional Questions:

- Could soaking in acetone at 55C damage the Te via temperature?

- How does soak time and acetone temperature effect pmma removal? Would I need to increase the soak time if I decreased the temperature?

- Is Ar plasma viable? Two concerns that I have for this option is surface roughness and temperature.