TY - JOUR
T1 - Evaluation of electroless deposited Co(W,P) thin films as diffusion barriers for copper metallization
AU - Kohn, A.
AU - Eizenberg, M.
AU - Shacham-Diamand, Y.
AU - Israel, B.
AU - Sverdlov, Y.
N1 - Funding Information:
The work was supported by grant no. 8460-1-98 from the Israel Ministry of Science and Technology. The assistance of R. Brener, C. Cytermann and R. Kroeger is gratefully acknowledged.
PY - 2001/3
Y1 - 2001/3
N2 - Electroless deposited Co(W,P) thin films were evaluated as diffusion barriers for copper metallization. Capacitance versus time measurements of MOS structures as well as SIMS depth profiles indicate that 30-nm-thick films can function as effective barriers against copper diffusion after thermal treatments up to 500 °C. The improved barrier properties relative to sputtered cobalt are explained by the incorporation of phosphorus (8-10 at.%) and tungsten (approximately 2 at.%) which most probably enrich the grain boundaries of the nanocrystalline hcp cobalt grains, forming a `stuffed' barrier. The phosphorus and tungsten additions stabilize the hcp crystalline structure of the cobalt grains, delaying the transition to the fcc phase by more than 80 °C compared to bulk pure cobalt. An advantage of this material compared to alternative diffusion barriers for copper is its relatively low resistivity of 80 μΩ cm.
AB - Electroless deposited Co(W,P) thin films were evaluated as diffusion barriers for copper metallization. Capacitance versus time measurements of MOS structures as well as SIMS depth profiles indicate that 30-nm-thick films can function as effective barriers against copper diffusion after thermal treatments up to 500 °C. The improved barrier properties relative to sputtered cobalt are explained by the incorporation of phosphorus (8-10 at.%) and tungsten (approximately 2 at.%) which most probably enrich the grain boundaries of the nanocrystalline hcp cobalt grains, forming a `stuffed' barrier. The phosphorus and tungsten additions stabilize the hcp crystalline structure of the cobalt grains, delaying the transition to the fcc phase by more than 80 °C compared to bulk pure cobalt. An advantage of this material compared to alternative diffusion barriers for copper is its relatively low resistivity of 80 μΩ cm.
UR - http://www.scopus.com/inward/record.url?scp=0034830082&partnerID=8YFLogxK
U2 - 10.1016/S0167-9317(00)00460-3
DO - 10.1016/S0167-9317(00)00460-3
M3 - 文章
AN - SCOPUS:0034830082
SN - 0167-9317
VL - 55
SP - 297
EP - 303
JO - Microelectronic Engineering
JF - Microelectronic Engineering
IS - 1-4
ER -