通过多次淀积多次退火与Ti吸氧技术相结合来改善后栅工艺中高k金属栅的性能

本文的原子层淀积（ALD） HfO2薄膜采用新颖的多次淀积多次退火（MDMA）技术进行制备，并在有Ti吸氧层和没有Ti吸氧层两种情况下分别进行性能研究。 与传统的一次淀积一次退火相比，采用多次淀积多次退火后的器件漏电明显减小，同时，等效氧化层厚度（EOT）也被Ti吸氧层有效控制。器件性能的提升与淀积和退火次数密切相关（在保持总介质层厚度相同的情况下）。透射电子显微镜（TEM）和能量色散X射线光谱（EDX）分析表明，氧同时注入高k（HK）薄膜和中间层（IL）很可能是导致器件性能提升的主要原因。因此在后栅工艺中MDMA技术是一种改善栅极特性的有效方法。

Combining a multi deposition multi annealing technique with a scavenging (Ti) to improve the high-k/metal gate stack performance for a gate-last process

ALD HfO₂ films fabricated by a novel multi deposition multi annealing (MDMA) technique are investigated, 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 significant 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 responsible for the improvement of the device. This novel MDMA is promising for the development of gate stack technology in a gate last integration scheme.