Plasma-Enhanced Atomic Layer Deposition of Cobalt Films Using Co(EtCp)2 as a Metal Precursor

Nanoscale Research Letters

  ^{1    1    1    1    1    2} 

[1] 0000 0001 0125 2443, grid.8547.e, School of Microelectronics, Fudan University, 200433, Shanghai, China;0000 0001 0125 2443, grid.8547.e, School of Microelectronics, Fudan University, 200433, Shanghai, China;0000 0001 0125 2443, grid.8547.e, Department of Materials Science, Fudan University, 200433, Shanghai, People’s Republic of China;

关键词: Co films;    Atomic layer deposition;    Low resistivity;    Low deposition temperature;   

DOI  :  10.1186/s11671-019-2913-2

来源: publisher

【 摘 要 】

For advanced Cu interconnect technology, Co films have been widely investigated to serve as the liner and seed layer replacement because of a better wettability to Cu than Ta. In this article, the Co films are grown by plasma-enhanced atomic layer deposition using Co(EtCp)2 as a precursor, and the influences of process parameters on the characteristics of the Co films are elaborately investigated. The results indicate that the process window is 125–225 °C with a growth rate of ~ 0.073 Å/cycle. That is to say, the connection of Et group to Cp ligand can enable a stable film growth at 125 °C, while the corresponding temperature must be higher than 200 °C in terms of Co(Cp)2 and Co(MeCp)2. The deposited films contain N and O elements besides dominant Co and C. Furthermore, the prolongation of the NH3 pulse time significantly enhances the conductivity of the Co film and a low resistivity of 117 μΩ cm can be achieved with a NH3 pulse time of 40 s. The root mean square roughness shows a smaller variation with the deposition temperature and maintains a low value of ~ 0.3 nm, indicative of a flat Co film.

【 授权许可】

CC BY