Wet Chemical Wafer Cleaning and Isotropic Thin Layer Etching




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.