TY - JOUR
T1 - Robust ultra-thin RuMo alloy film as a seedless Cu diffusion barrier
AU - Hsu, Kuo Chung
AU - Perng, Dung Ching
AU - Wang, Yi Chun
N1 - Funding Information:
The authors would like to thank the CRD thin film group of United Microelectronic Co. for TEOS film deposition. The funding support of the National Science Council of Taiwan under contract no. NSC 99-2221-E-006-138 is acknowledged.
PY - 2012/3/5
Y1 - 2012/3/5
N2 - This study investigated the properties of 5 nm-thick RuMo film as a Cu diffusion barrier. The sheet resistance variation and X-ray diffraction patterns show that the RuMo alloy film has excellent barrier performance and that it is stable upon annealing at 725 °C against Cu. The transmission electron microscopy micrograph and diffraction patterns show that the RuMo film is an amorphous-like structure, whereas pure Ru film is a nano-crystalline structure. The elements' depth profiles, analyzed by X-ray photoelectron spectroscopy, indicate no inter-diffusion behavior between the Cu and Si layer, even annealing at 700 °C. Lower leakage current has been achieved from the Cu/barrier/insulator/Si test structure using RuMo film as the barrier layer. A 5 nm ultrathin RuMo film provided two orders of magnitude improvement in leakage current and also exhibited a 175 °C improvement in thermal stability than that of the pure Ru film. It is a potential candidate as a seedless Cu diffusion barrier for advanced Cu interconnects.
AB - This study investigated the properties of 5 nm-thick RuMo film as a Cu diffusion barrier. The sheet resistance variation and X-ray diffraction patterns show that the RuMo alloy film has excellent barrier performance and that it is stable upon annealing at 725 °C against Cu. The transmission electron microscopy micrograph and diffraction patterns show that the RuMo film is an amorphous-like structure, whereas pure Ru film is a nano-crystalline structure. The elements' depth profiles, analyzed by X-ray photoelectron spectroscopy, indicate no inter-diffusion behavior between the Cu and Si layer, even annealing at 700 °C. Lower leakage current has been achieved from the Cu/barrier/insulator/Si test structure using RuMo film as the barrier layer. A 5 nm ultrathin RuMo film provided two orders of magnitude improvement in leakage current and also exhibited a 175 °C improvement in thermal stability than that of the pure Ru film. It is a potential candidate as a seedless Cu diffusion barrier for advanced Cu interconnects.
UR - http://www.scopus.com/inward/record.url?scp=84855568018&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84855568018&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2011.11.144
DO - 10.1016/j.jallcom.2011.11.144
M3 - Article
AN - SCOPUS:84855568018
VL - 516
SP - 102
EP - 106
JO - Journal of the Less-Common Metals
JF - Journal of the Less-Common Metals
SN - 0925-8388
ER -