Etch characteristics of magnetic tunnel junction stack with nanometer-sized patterns for magnetic random access memory

Etch characteristics of magnetic tunnel junction (MTJ) stack masked with TiN films were investigated using an inductively coupled plasma reactive ion etcher in Cl2/Ar and BCl3/Ar gases for magnetic random access memory. The effect of etch gas on the etch profile of MTJ stacks was examined. As Cl2 and BCl3 concentrations increased, the etch slope of etched MTJ stack became slanted and the dimensional shrinkage was observed. A high degree of anisotropic etching of MTJ stacks was achieved using Cl2/Ar gas at the optimized etch conditions.