High-density plasma etching of CoFeSiB magnetic films with hard mask

Multi-step ion beam etching of sub-30 nm magnetic tunnel junctions for reducing leakage and MgO barrier damage

“…However, due to thermal stability issues, the layer thickness cannot be reduced at will, resulting in a MTJ structure that resembles pillars as the cell sizes are reduced to sub 100 nm scales. Chlorine compound 5,6 and methanol 7 based reactive ion etching [8][9][10] have been used with Ta hard masks for the fabrication of sub 50 nm MTJ pillars. 11 Although they showed good etching characteristics, after-corrosion and oxidation issues exist and at sub 30 nm scales the effects could become amplified.…”