(Invited) Electrodeposition of Ferromagnetic Materials for Advanced Interconnect and MEMS

Abstract

Two relatively new processes for the electrodeposition of iron group metals and alloys, namely, self-terminated deposition and superconformal deposition will be detailed with an eye towards application in the seeding and filling of nanoscale patterned features. Self-terminated deposition derives from the interaction between metal deposition at the onset of water reduction where formation of a monolayer hydroxide blocks further metal deposition. Judicious choice of processing parameters enables the self-limiting deposition of conformal nanometer thick films of iron groups metal and alloy. The utility of microelectrodes and SECM to reveal new insights into the interaction between parasitic reactions and the metal deposition process will be detailed. Discussion will then pivot to the use of additives to obtain superconformal deposition of iron group metals in recessed surface features. A brief survey of feature filling results for Ni, NiFe, Co and CoFe and associated electrochemical measurements will be presented along with a discussion of important physical phenomena associated with filling.