反应磁控溅射制备氮化钽扩散阻挡层的研究

采用反应磁控溅射在硅衬底上制备了TaN薄膜,研究了氮分压、溅射功率及衬底温度对薄膜晶体结构、表面形貌和电学性能的影响。结果表明,晶体结构随工艺参数的改变发生变化,GIXRD图谱衍射峰强度随溅射功率和衬底温度的增加而增强,氮气分压的增加使择优取向向(111)晶面偏移;TaN薄膜的表面形貌与溅射功率和氮气分压密切相关,与衬底温度的关系不大,其粗糙度随溅射功率的增加而增大,随氮气分压的增加而减小;TaN薄膜的方块电阻随溅射功率的增加逐渐减小,随氮气分压的增加逐渐增大,温度对方块电阻的影响不大;对Cu/TaN/Si互联体系热处理后发现TaN薄膜具有优异的阻挡性能,在600℃时依然可有效阻止Cu向Si的扩散。

TaN Diffusion Barrier Layers Deposited by Reactive Magnetron Sputtering

The TaN diffusion barrier layers were deposited by reactive magnetron sputtering on silicon substrates.The influence of the growth conditions,including the N2 partial pressure,sputtering power,and Si substrate temperature on TaN properties was evaluated.The microstructures of the TaN films were characterized with grazing incidence X-ray diffraction(GIXRD),and atomic force microscopy.The results show that the sputtering power and N2 partial pressure strongly affect the surface morphologies of the TaN films.For example,the GIXRD peak intensity increased with the increases of puttering power and substrate temperature;a higher N2 partial pressure moved the preferential growth orientation towards TaN(111).The surface roughness increased with an increase of the sputtering power and a decrease of N2 partial pressure.An increase of sputtering power and a decrease of N2 partial pressure resulted in an increase of the sheet resistance.We found that the TaN films,inserted between Cu coating and SI substrate,effectively block the diffusion of Cu into Si at a temperature up to 600℃.