Dependence of the etching characteristics of SBT thin films on the amount of BCl 3 added to a Cl 3/Ar inductively coupled plasma

Abstract

The etch characteristics of SBT films were investigated using Cl-2/Ar inductively coupled plasma with BCl3 added. A 10% addition of BCl3 into the Cl-2/Ar plasma caused an increase in the etch rate, but an addition of over 20% BCl3 caused a decrease in the etch rate. As the rf power and the dc bias were increased, the etch rate of SBT increased. At 800 W and -200 V, we obtained the maximum etch rate of 764 Angstrom/min. The etch rate change in SBT was studied by using a combination of optical emission spectroscopy (OES) and X-ray photoelectron spectroscopy (XPS). In the OES analysis, the volume densities of Cl radicals and BCl molecules were monitored. In the XPS analysis, SrCl and B-O bonds were detected on the surface of SBT treated with a BCl3/Cl-2/Ar plasma. The SrCl layer on the surface prohibits any possible chemical reaction or reduction of physical sputtering by positive ions.