Plasma chemistries for dry etching of SrBi2Ta2O9 thin films

Abstract

SrBi2Ta2O9 (SBT) thin films were etched in a planar type inductively coupled plasma (ICP) etcher with different chemistries of Cl-2/Ar, Cl-2/NF3/Ar, and Cl-2/NF3/O-2/Ar. The etch rate was a strong function of gas concentration, ICP source power, and rf chuck power. Cl-2/NF3/Ar and Cl-2/NF3/O-2/Ar plasmas showed maximum etch rates of similar to 1600 Angstrom /min at 5 mTorr, 700 W ICP power, and 150 W rf chuck power. Electrical properties of the SBT films were dependent on the plasma chemistry employed; Cl-2/NF3/O-2/Ar showed the least damage in the films and resulted in the best overall P-E hysteresis loops compared to other chemistries. (C) 2001 The Electrochemical Society.