Wet Chemical Wafer Cleaning and Isotropic Thin Layer Etching
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The wet chemical processes are neccessary for all semiconductor research tasks of the Institute and include the following standard techniques:
| Standard silicon wafer cleaning |
RCA-1-(SC-1)-cleaning (NH4OH/H2O2/H2O)
RCA-2-(SC-2)-cleaning (HCl/H2O2/H2O) Piranha-(SPM)-cleaning (H2SO4/H2O2) |
| Specialized cleaning techniques | Hydrophilling of Si surfaces (e.g. for silicon wafer bonding) |
| Standard silicon oxide etching |
Diluted HF (DHF), (HF/H2O)
Buffered oxide etch (BOE), (HF/NH4F/H2O) |
| Slight isotropic silicon etch | HF/HNO3 solutions with well defined etch rates between 6 and 1000 nm/min |
| Standard silicon nitride etching | Hot H3PO4 |
| Metal contact layer etching |
H3PO4/HNO3/H2O and H3PO4/HNO3/H2O + TMAH
for Al-contact layer etching and Al/Si-contact layer etching respectively |
| Specialized etching techniques for: | Metals, glasses, poly-Si, etc. |
