Evaluation and Comparison of Novel Precursors for Atomic Layer Deposition of Nb2O5 Thin Films

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• 作者：Timothee Blanquart ; Jaakko Niinist枚 ; Mikko Heikkil盲 ; Timo Sajavaara ; Kaupo Kukli ; Esa Puukilainen ; Chongying Xu ; William Hunks ; Mikko Ritala ; Markku Leskel盲
• 刊名：Chemistry of Materials
• 出版年：2012
• 出版时间：March 27, 2012
• 年：2012
• 卷：24
• 期：6
• 页码：975-980
• 全文大小：309K
• 年卷期：v.24,no.6(March 27, 2012)
• ISSN：1520-5002

文摘

Atomic layer deposition (ALD) of Nb₂O₅ thin films was studied using three novel precursors, namely, ^tBuN鈺怤b(NEt₂)₃, ^tBuN鈺怤b(NMeEt)₃, and ^tamylN鈺怤b(O^tBu)₃. These precursors are liquid at room temperature, present good volatility, and are reactive toward both water and ozone as the oxygen sources. The deposition temperature was varied from 150 to 375 掳C. ALD-type saturative growth modes were confirmed at 275 掳C for ^tBuN鈺怤b(NEt₂)₃ and ^tBuN鈺怤b(NMeEt)₃ together with both oxygen sources. Constant growth rate was observed between a temperature regions of 150 and 325 掳C. By contrast, amylN鈺怤b(O^tBu)₃ exhibited limited thermal stability and thus a saturative growth mode was not achieved. All films were amorphous in the as-deposited state and crystallized between 525鈥?75 掳C, regardless of the applied precursor and oxygen source. Time-of-flight elastic recoil detection analysis (TOF-ERDA) demonstrated the high purity of the films. Atomic force microscopy (AFM) revealed that the films were smooth and uniform. The films exhibited promising dielectric characteristics with permittivity values up to 60.

Keywords:

ALD; niobium oxide thin film; high-k; niobium imido-amido