A neutral beam etching process has been developed that achieves damage- free (chemically and physically) etching. Recently, it was found that transition metals could be etched using neutral beam etching through metallic complex reactions. In this process, a neutral beam is extracted from a plasma generation region into a reaction chamber. Complex reactant gases are injected into a reaction chamber which is screened from the plasma during neutral beam etching. In this paper, etching of Pt and CoFeB, candidate materials for MRAM structures by a neutral beam system is described. It was found that etch rate enhancement of Pt/CoFeB surfaces resulted from their exposure to a neutral beam from Ar/O₂ plasma with simultaneous injection of EtOH /acetic acid into the reaction chamber. Etching damage was also evaluated and no magnetic hysteresis degradation has been observed. Neutral beam etching technology has the capability to make breakthrough for fabricating MRAM device.

Date Published: 17 March 2015
PDF: 6 pages
Proc. SPIE 9428, Advanced Etch Technology for Nanopatterning IV, 94280N (17 March 2015); doi: 10.1117/12.2178327

Published in SPIE Proceedings Vol. 9428:
Advanced Etch Technology for Nanopatterning IV
Qinghuang Lin; Sebastian U. Engelmann; Ying Zhang, Editor(s)