Methods of patterning a target material layer are provided herein. The method includes steps of positioning a semiconductor wafer having the target material layer thereon in an etch chamber and of providing a flow of etch gases into the etch chamber, the flow of etch gases etchant gas comprising a plurality of gases. The semiconductor wafer has a patterned hardmask feature formed from a compound on the target material layer. The method also includes steps of etching the target material layer using the patterned hardmask feature as a mask feature, wherein one of the gases chemically alters the patterned hardmask feature and at least one of the gases chemically repairs the patterned hardmask feature so that the patterned hardmask feature retains its dimensions during the etching. Associated semiconductor wafer are also provided herein.