EFFECT OF RESIDUAL GASES ON RESIDUE FORMATION DURING TUNGSTEN TIN/TI ETCHING USING SF6 AND CL2 GAS CHEMISTRY/

Residual gas-induced polymeric residue formation was investigated duri ng multistep plasma etching of tungsten/TiN/Ti film using SF6 and Cl2 gas chemistries in the same reactor. Heavy polymeric residues were for med during TiN/Ti etching by the reaction of Ti and residual fluorine gases originating from previous SF6 Plasma and seemed to be TiF(x) res idues from the results of micro auger electron microscope (mu-AES) ana lysis and etch rate of polysilicon with residual gas-assisted Ar sputt ering. It is highly recommended that multistep etching processes using different gas chemistries be carried out in separate reactors.