Patent ID: 8920666
Filing Date: 2014-12-30
Classification: G03F,H01L

Abstract:
1. A dry etching method for a work layer as a lower layer formed over a substrate, comprising the steps of: forming a hard mask layer as an upper layer over the work layer formed over the substrate, forming a resist pattern over the hard mask layer, transferring the resist pattern to the hard mask layer by first dry etching conducted using the resist pattern, and patterning the work layer by second dry etching conducted using a hard mask pattern obtained upon the transfer to the hard mask layer, wherein the hard mask layer is a layer of a silicon-based material which consists of oxygen and/or nitrogen, silicon, and at least one transition metal selected from the group consisting of titanium, vanadium, cobalt, nickel, zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten; and the work layer is a layer of a silicon-based material which consists of silicon and at least one transition metal selected from the group consisting of titanium, vanadium, cobalt, nickel, zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten or a layer of a silicon-based material which consists of oxygen and/or nitrogen, silicon, and at least one transition metal selected from the group consisting of titanium, vanadium, cobalt, nickel, zirconium, niobium, molybdenum, hafnium, tantalum, and tungsten and which is lower than the hard mask layer in total mole percent of oxygen and nitrogen, and after the hard mask layer is patterned by the first dry etching in an etching apparatus, the patterning of the work layer by the second dry etching is continuously conducted with the first dry etching through changing the concentration of an oxygen gas as an auxiliary ingredient of a dry etching gas, without changing a chlorine-based gas as a main ingredient of the dry etching gas, in the same etching apparatus in which the first dry etching has been conducted.