Etching characteristics of LaNiO3 thin films in BCl3/Ar gas chemistry

LaNiO3 (LNO) electrode was intensively studied as electrodes because LNO has a pseudocubic perovskite crystal structure with a lattice parameter of 3.84 A. But the etching process of LNO thin films must be developed in order to realize highly integrated ferroelectric random access memories. In this work, we investigated etching characteristics and mechanisms of LNO thin films using inductively coupled BCl3/Ar plasma (ICP) system. The maximum etch rate of LNO thin films was 41.1 nm/min at a BCl3(20)/Ar(80) gas mixing ratio. The positive ions and the ion energy distributions were measured with a quadrupole mass spectrometer (QMS). As rf power and dc bias voltage increased and working pressure decreased, the ion energy and etch rates of LNO thin films were increased. A chemically assisted physical etch of LNO was experimentally confirmed by ICP system and QMS measurements