Studies on aluminium corrosion during and after HF vapour treatment

The behaviour of aluminium during anhydrous hydrofluoric acid (HF) vapour etching of silicon dioxide films deposited by different methods was studied. Silicon dioxide films were grown by plasma-enhanced chemical vapour deposition (PECVD), low-pressure chemical vapour deposition (LPCVD), and a thermally oxidizing method. The etch rate of different oxides varies a lot. Etching of PECVD oxide causes residues on the aluminium surface as LPCVD and thermal oxide do not. The origin of the residues and different preventative methods are proposed.