STUDY OF THE RELATION BETWEEN ION BEAM ETCHING AND CHEMICAL ETCHING OF ALUMINIUM THIN FILMS PREPARED AT DIFFERENT EXPERIMENTAL CONDITIONS.

Aluminium thin films (200 nm thick) were prepared at different contamination levels of oxygen (pressure ranged from 10** minus **5 to 5 multiplied by 10** minus **2 Pa) and substrate temperatures (T//s) from 25 to 250 degree C. The ratio between the rates of chemical and ion etching is nearly constant for films prepared at T//s equals 100 degree C and above. The ion etching rate increases with increasing T//s while it decreases with increasing oxygen contamination levels as in the case of chemical etching. The oxide phase in the film usually has a dendritic form. The grain boundaries resist ion etching better than the grains. Some samples show different types of pitting depend on T//s and P//o//x//y//g//e//n.