MoC掺杂钌基合金无籽晶阻挡层微结构及热稳定性研究  

Microstructure and Thermal Stability of MoC Doped Ru-Based Alloy Films as Seedless Diffusion Barrier

作　　者：邹建雄[1] 刘波[1] 林黎蔚[1] 任丁[1] 焦国华[2] 鲁远甫[2] 徐可为[3] 

机构地区：[1]四川大学原子核科学技术研究所教育部辐射物理及技术重点实验室,成都610064 [2]中国科学院深圳先进技术研究院,深圳518055 [3]西安交通大学金属材料强度国家重点实验室,西安710049

出　　处：《金属学报》2017年第1期31-37,共7页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目Nos.11075112和11605116;深圳市科技计划项目Nos.JCYJ20150925163313898和JCYJ-20140417113130693;深圳市工程实验室项目No.2012-1127~~

摘　　要：采用磁控共溅射Ru和MoC靶制备非晶RuMoC薄膜。用四探针仪(FPPT)、X射线光电子能谱仪(XPS)、高分辨率透射电镜(HRTEM)和小角掠射X射线衍射仪(GIXRD)表征不同掺杂组分RuMoC薄膜和不同温度退火态Cu/RuMoC/p-SiOC∶H/Si多层膜系的方块电阻、成分和微观结构。结果表明,通过调控Ru膜中掺入Mo和C元素的含量能够实现RuMoC合金薄膜微结构设计及抑制膜体残余氧含量,且当MoC和Ru靶的溅射功率比为0.5时获得的RuMoCII薄膜综合性能最佳;500℃退火态RuMoC II薄膜中C-Mo和C-Ru化学键均未出现大量断裂,两者协同作用抑制了RuMoC薄膜再结晶和膜体氧含量升高,是Cu/RuMoCII/p-SiOC∶H/Si多层膜系具有高温热稳定性和优异电学性能的主要机制。Cu has been adopted to replace AI for conduction lines and contact structures in very large-scale integrated circuits due to its low resistivity. However, Cu could rapidly react with the SiO2- based dielectric under 300℃ and form deep level impurities which are strong sink for carriers, leading to the dielectric degradation of the devices. Therefore, it is important to insert a stable barrier between the Cu wiring and SiO2-based dielectric for suppressing Cu diffusion and improving the adhesive strength. The prediction of international technology roadmap for semiconductors that the thickness of diffusion bar- rier would be further reduced to 3 nm for 22 nm technology node indicates the widely being used Ta/TaN barrier would be incompetent in the future, since TarraN barrier at the limited thickness exhibits a high re- sistivity and a columnar grain structure which provides lots of vertical grain boundaries for Cu diffusion. Therefore a directly platable amorphous single barrier with low resistivity is highly desired. In this work, MoC are chosen as impurity to expect for amorphous Ru-based films. The RuMoC films with different components were deposited by RF magnetron co-sputtering with different deposition power ratios of MoC versus Ru targets. The sheet resistances, microstructures and components of the RuMoC films in Ru- MoC/Si and Cu/RuMoC/p-SiOC： H/Si structures were studied. The sheet resistances, residual oxygen contents and microstructures of the RuMoC films have close correlation with the doping contents of Mo and C elements which can be easily controlled by tuning the deposition power on MoC target. When the deposition power ratio of MoC versus Ru targets was 0.5, amorphous RuMoC II film with low sheet resis- tance and residual oxygen content was obtained. After annealing at 500 ℃ the Mo-C and Ru-C bonds were well-preserved and co-suppressed the recrystallization of the film and the increasing of the oxygen content, contributing to excellent thermal stability and electrical properties of Cu/RuMoC

关 键 词：非晶RuMoC 无籽晶阻挡层 热稳定性 铜互连 

分 类 号：TN406[电子电信—微电子学与固体电子学] TN04