| abstract |
An object of the present invention is to provide an etching method. In the present invention, the workpiece includes a first region formed of silicon oxide and a second region formed of silicon nitride. The second region extends so as to provide a recess, and has a bottom region on the lower side of the recess. The first area is set to cover the second area. In the etching method, a deposit of fluorocarbon is formed on the workpiece, and the workpiece is irradiated with ions of rare gas atoms to etch the first region. Next, hydrogen ions are supplied to the bottom region to form a modified region. Next, a fluorocarbon deposit is formed on the workpiece, and the workpiece is irradiated with ions of rare gas atoms to etch the modified region. |