High density plasma etching of (Ba, Sr)TiO 3 (BST) and LaNiO 3 (LNO) thin films was performed in two different plasma chemistries, Cl 2 /Ar and CH 4 /H 2 /Ar. While the latter chemistry produced extremely low etch rates (≤100 A min -1 ) under all conditions, the Cl 2 /Ar produced smooth anisotropic pattern transfer. The etching was still strongly ion-assisted, but maximum removal rates of ∼900 A min -1 for both materials were achieved with selectivities of ∼1 for BST and ∼7 for LNO over Si. A single layer of thick (∼7 μm) photoresist is an effective mask under these conditions.