Ion-enhanced chemical etching of ZrO2 in a chlorine discharge

Lin Sha, Byeong-Ok Cho, Jane P. Chang
2002 Journal of Vacuum Science & Technology. A. Vacuum, Surfaces, and Films  
Chlorine plasma is found to chemically etch ZrO 2 thin films in an electron cyclotron resonance reactor, and the etch rate scaled linearly with the square root of ion energy at high ion energies with a threshold energy between 12-20 eV. The etching rate decreased monotonically with increasing chamber pressures, which corresponds to reduced electron temperatures. Optical emission spectroscopy and quadrupole mass spectrometry were used to identify the reaction etching products. No Zr, O, or ZrCl
more » ... No Zr, O, or ZrCl were detected as etching products, but highly chlorinated zirconium compounds ͑ZrCl 2 , ZrCl 3, and ZrCl 4 ͒ and ClO were found to be the dominant etching products. ZrCl 3 was the dominant etching products at low ion energies, while ZrCl 4 became dominant at higher ion energies. This is consistent with greater momentum transfer and enhanced surface chlorination, as determined by x-ray photoelectron spectroscopy, at increased ion energies. Several ion-enhanced chemical reactions are proposed to contribute to the ZrO 2 etching.
doi:10.1116/1.1491267 fatcat:6zczlhgjrra35hnrr4waed52te