CHARACTERIZATION OF TITANIUM ETCHING IN CL-2 N-2 PLASMAS/

The effects of etch time, nitrogen and chlorine gas flows, radio frequ ency power, pressure, and temperature on the etch rate of sputtered ti tanium films in chlorine-nitrogen plasmas were investigated in this wo rk. The radio frequency power was found to have the greatest effect on the etch rate, followed fd by the reaction pressure. The increase in Ti etch rate with radio frequency power can be attributed to increased ionization of the gases and increase in ion and electron energies in the plasma. The increase in pressure led to a decline in the etch rate , probably due to loss of chlorine through recombination reactions. It was observed that the etch rate increased with increase in chlorine f or gas flows below 100 seem. Addition of nitrogen increased the etch r ate to a flow of 10 seem due to generation of free chlorine radicals, but led to a decrease in etch rate for nitrogen flows beyond 25 seem d ue to dilution effect. There was only slight dependence of etch rate o n the temperature within the range of this investigation.