| abstract |
An object of the present invention is to provide a dry etching agent having a low global environmental load, and capable of anisotropic etching without using a special apparatus, and having a good processing shape, and a dry etching method using the same. The dry etchant of the present invention is represented by at least the formula CF 3 -C x H y F z O (x = 2 or 3, y = 1,2,3,4 or 5, z = 2x-1-y) And a hydrofluoroalkylene oxide having a three-membered ring structure containing an oxygen atom. In the dry etching method of the present invention, at least one selected from the group consisting of silicon dioxide, silicon nitride, polycrystalline silicon, amorphous silicon, and silicon carbide using a plasma gas obtained by plasmalizing the dry etchant. The silicon based material is selectively etched. |