REACTIVE ION ETCHING OF SPUTTER DEPOSITED TANTALUM OXIDE AND ITS ETCH SELECTIVITY TO TANTALUM

Reactive ion etching of the sputter deposited tantalum oxide has been studied. Process parameters that affect the etch rate, such as the power, pressure, and temperature, were investigated in a wide range of conditions. Etch selectivities between tantalum and tantalum oxide in various processes have been examined. By exchanging one F atom in the CF4 molecule or one Cl atom in the CF3Cl molecule with one H atom, we can reverse the etch selectivity. Structures of the etched surfaces were characterized with the electron spectroscope for chemical analysis. Comparisons of chemical structures of the etched and unetched surfaces were carried out. Etch mechanisms of different plasma processes have been suggested from these comparisons.