摘要
ALD HfO2 films fabricated by a novel multi deposition multi annealing (MDMA) technique are inves- tigated, we have included samples both with and without a Ti scavenging layer. As compared to the reference gate stack treated by conventional one-time deposition and annealing (D&A), devices receiving MDMA show a signif- icant reduction in leakage current. Meanwhile, EOT growth is effectively controlled by the Ti scavenging layer. This improvement strongly correlates with the cycle number of D&A (while keeping the total annealing time and total dielectrics thickness the same). Transmission electron microscope and energy-dispersive X-ray spectroscopy analysis suggests that oxygen incorporation into both the high-k film and the interfacial layer is likely to be re- sponsible for the improvement of the device. This novel MDMA is promising for the development of gate stack technology in a gate last integration scheme.
ALD HfO2 films fabricated by a novel multi deposition multi annealing (MDMA) technique are inves- tigated, we have included samples both with and without a Ti scavenging layer. As compared to the reference gate stack treated by conventional one-time deposition and annealing (D&A), devices receiving MDMA show a signif- icant reduction in leakage current. Meanwhile, EOT growth is effectively controlled by the Ti scavenging layer. This improvement strongly correlates with the cycle number of D&A (while keeping the total annealing time and total dielectrics thickness the same). Transmission electron microscope and energy-dispersive X-ray spectroscopy analysis suggests that oxygen incorporation into both the high-k film and the interfacial layer is likely to be re- sponsible for the improvement of the device. This novel MDMA is promising for the development of gate stack technology in a gate last integration scheme.
基金
Project supported by the Integrated Circuit Advanced Process Center,Institute of Microelectronics of Chinese Academy of Sciences,and the Ministry of Technology,China