88
W. C. Law and S. De W. Wong
Fig. 18 SEM image of TiN/CoFe/Ti on Si wafers a, b before etching, c, d Ar plasma etching,
e, f Cl 2 plasma etching, g, h subsequent H 2 plasma etching. [199] Adapted from and reprinted
with permission from T. Kim, Y. Kim, J. K.-C. Chen, and J. P. Chang, “Viable chemical approach
for patterning nanoscale magnetoresistive random access memory,” Journal of Vacuum Science &
Technology A: Vacuum, Surfaces, and Films, vol. 33, p. 021,308 (2015)
Magnetic Film Degradation and Recovery.
In recent development, RIE plasma with non-corrosive and organic chemistries, such
as CH 3 COOH/Ar [205, 206], CO/NH 3 [207], C 2 H 5 OH [208] and Me-OH/Ar [209,
210] have been explored for MTJ etching. Although the aforementioned chemistries
have displayed high selectivity between hard masks, such as Ti and Ta, and the MTJ
W. C. Law and S. De W. Wong
Fig. 18 SEM image of TiN/CoFe/Ti on Si wafers a, b before etching, c, d Ar plasma etching,
e, f Cl 2 plasma etching, g, h subsequent H 2 plasma etching. [199] Adapted from and reprinted
with permission from T. Kim, Y. Kim, J. K.-C. Chen, and J. P. Chang, “Viable chemical approach
for patterning nanoscale magnetoresistive random access memory,” Journal of Vacuum Science &
Technology A: Vacuum, Surfaces, and Films, vol. 33, p. 021,308 (2015)
Magnetic Film Degradation and Recovery.
In recent development, RIE plasma with non-corrosive and organic chemistries, such
as CH 3 COOH/Ar [205, 206], CO/NH 3 [207], C 2 H 5 OH [208] and Me-OH/Ar [209,
210] have been explored for MTJ etching. Although the aforementioned chemistries
have displayed high selectivity between hard masks, such as Ti and Ta, and the MTJ