| AVS 63rd International Symposium & Exhibition | |
| Thin Film | Thursday Sessions |
| Session TF-ThP |
| Session: | Thin Films Poster Session |
| Presenter: | Shaista Babar, University of Illinois at Urbana Champaign |
| Authors: | E. Mohimi, University of Illinois at Urbana Champaign B. Trinh, University of Illinois at Urbana Champaign S. Babar, University of Illinois at Urbana Champaign G.S. Girolami, University of Illinois at Urbana Champaign J.R. Abelson, University of Illinois at Urbana Champaign |
| Correspondent: | Click to Email |
Manganese nitride can be synthesized in numerous phases whose solid-state properties are attractive for spintronic, magnetic or microelectronic applications. It is desirable to develop chemical vapor deposition (CVD) routes for manganese nitride films compared to physical vapor deposition (PVD) paths, since CVD can conformally coat high aspect ratio (deep) features, which are increasingly used in the architecture of nanoscale devices. However, lack of suitable precursors for deposition of manganese nitride hindered its development in novel applications where a conformal thin film is required.
Here, we report CVD growth of amorphous manganese nitride films, from a novel and practical precursor, bis(2,2,6,6 tetramethylpiperidido)Manganese (II) Mn(tmp)2 and ammonia as co-reactant. Growths are done in a high vacuum chamber at substrate temperature of 50-350 °C. Precursor container is heated at 60 °C and Ar carrier gas passes through the container at flow rates of 5-40 sccm to deliver precursor to the chamber. Ammonia is delivered through a separate line at pressures from 0-13 mTorr.
XPS reveals a bulk Mn:N ratio of 2.6:1 to 2.8:1 for films grown in the temperature range examined, with no carbon contamination within the detection limits of instrument. All films show a nodular microstructure in cross-section SEM, with rms roughness of 0.4 and 0.5 nm for films grown at 50 and 150 °C, respectively. We propose a transamination reaction between precursor and ammonia to be responsible for the nitride growth, as no reaction is observed in the absence of ammonia. Films are conformal in micro-trenches of aspect ratio 3, while having a directional growth component which led to higher thickness at the opening of the features. Copper diffusion barrier properties of a 12nm manganese nitride film is investigated by deposition on 300 nm thermal silicon oxide/Si substrate, and e-beam evaporation of 200 nm copper on top of manganese nitride film, followed by annealing at 500 °C under Ar for 1 hour. Samples were analyzed by Auger electron spectroscopy for depth profile composition, and compared with a reference sample of no diffusion barrier. Results show that manganese nitride performs well as copper diffusion barrier for microelectronic applications.