====== cha ======

{{ map-cha.svg|NanoLab map showing cha location}}

[[https://docs.google.com/document/d/1RAwxAD7kOLh9HgNd_HICKrMTNw4xvVO0Y-zNleuDcHE/edit?usp=sharing|NanoLab cha manual]]

cha is a multi-material e-beam evaporator. It holds three wafers (or chips) at once in a rotating planetary mount. We often use it to deposit chromium and gold. This is the standard evaporator for the NanoLab. A good backup is ebeam1, which has extremely similar capabilities (save cha's fancy but optional automatic deposition rate controller).

{{cha.jpg?0x200 |picture of cha tool}}

===== Process Notes =====

^ Date ^ Person ^ Data ^
| 22 Oct 2020 | Daniel | Tool power supply is replaced and is more powerful; processes should be recalibrated. |
| 21 May 2021 | Daniel | Cr evaporates at about 25mA (45% LOW beam power). Au evaporates at about 40mA (60% LOW beam power). |
| 12 Jul 2021 | Daniel | Ti evaporates at about 65mA (36% MID beam power). Pt evaporates at about 170mA (51% MID beam power). Both are extremely bright and heat the wafer significantly. |
| 12 Jul 2021 | Daniel | 11nm Ti + 70nm Pt on standard 2um MiR701 makes photoresist start to flake/reticulate; more causes cracking. Liftoff works but barely. |