The etch characteristics of HfO2 by atomic-layer etching (ALET) were investigated using a BCl3/Ar neutral beam. The effect of ALET on surface modification and etch-depth control was also examined. Self-limited etching of HfO2 could be obtained using BCl3 ALET. This was attributed to the absorption of BCl3 by the Langmuir isotherm during the absorption stage and the vaporization of hafnium-chlorides/boron oxychlorides formed on the surface during the desorption stage. In addition, the surface composition of HfO2 was not altered by etching during ALET. (C) 2008 The Electrochemical Society.