Atomic layer deposition of Ru thin film using N₂/H₂ plasma as a reactant

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• 作者：Tae Eun Hong ; Ki-Yeung Mun ; Sang-Kyung Choi ; Ji-Yoon Park ; Soo-Hyun Kim ; Taehoon Cheon ; Woo Kyoung Kim ; Byoung-Yong Lim ; Sunjung Kim
• 关键词：Ruthenium ; Atomic layer deposition ; Nitrogen/hydrogen plasma ; Copper metallization ; Seed layer ; N-incorporation ; Microstructure
• 刊名：Thin Solid Films
• 出版年：2012
• 出版时间：31 July, 2012
• 年：2012
• 卷：520
• 期：19
• 页码：6100-6105
• 全文大小：788 K

文摘

Ruthenium (Ru) thin films were grown by atomic layer deposition using IMBCHRu [(¦Ç6-1-Isopropyl-4-MethylBenzene)(¦Ç4-CycloHexa-1,3-diene)Ruthenium(0)] as a precursor and a nitrogen-hydrogen mixture (N₂/H₂) plasma as a reactant, at the substrate temperature of 270 ¡ãC. In the wide range of the ratios of N₂ and total gas flow rates (fN₂/N₂ + H₂) from 0.12 to 0.70, pure Ru films with negligible nitrogen incorporation of 0.5 at. % were obtained, with resistivities ranging from ~ 20 to ~ 30 ¦Ì¦¸ cm. A growth rate of 0.057 nm/cycle and negligible incubation cycle for the growth on SiO₂ was observed, indicating the fast nucleation of Ru. The Ru films formed polycrystalline and columnar grain structures with a hexagonal-close-packed phase. Its resistivity was dependent on the crystallinity, which could be controlled by varying the deposition parameters such as plasma power and pulsing time. Cu was electroplated on a 10-nm-thick Ru film. Interestingly, it was found that the nitrogen could be incorporated into Ru at a higher reactant gas ratio of 0.86. The N-incorporated Ru film (~ 20 at. % of N) formed a nanocrystalline and non-columnar grain structure with the resistivity of ~ 340 ¦Ì¦¸ cm.