Mattinen Miika, Hämäläinen Jani, Gao Feng, Jalkanen Pasi, Mizohata Kenichiro, Räisänen Jyrki, Puurunen Riikka L, Ritala Mikko, Leskelä Markku
Laboratory of Inorganic Chemistry, Department of Chemistry, University of Helsinki , P.O. Box 55, FI-00014 Helsinki, Finland.
VTT Technical Research Centre of Finland , P.O. Box 1000, FI-02044 Espoo, Finland.
Langmuir. 2016 Oct 18;32(41):10559-10569. doi: 10.1021/acs.langmuir.6b03007. Epub 2016 Oct 6.
Nucleation and conformality are important issues, when depositing thin films for demanding applications. In this study, iridium and iridium dioxide (IrO) films were deposited by atomic layer deposition (ALD), using five different processes. Different reactants, namely, O, air, consecutive O and H (O + H), and consecutive O and H (O + H) pulses were used with iridium acetylacetonate [Ir(acac)] to deposit Ir, while IrO was deposited using Ir(acac) and O. Nucleation was studied using a combination of methods for film thickness and morphology evaluation. In conformality studies, microscopic lateral high-aspect-ratio (LHAR) test structures, specifically designed for accurate and versatile conformality testing of ALD films, were used. The order of nucleation, from the fastest to the slowest, was O + H > air ≈ O > O > O + H, whereas the order of conformality, from the best to the worst, was O + H > O + H > O > O. In the O process, a change in film composition from IrO to metallic Ir was seen inside the LHAR structures. Compared to the previous reports on ALD of platinum-group metals, most of the studied processes showed good to excellent results.
在为高要求应用沉积薄膜时，成核和保形性是重要问题。在本研究中，使用五种不同工艺通过原子层沉积（ALD）沉积铱和二氧化铱（IrO）薄膜。使用不同的反应物，即O、空气、连续的O和H（O + H）以及连续的O和H（O + H）脉冲与乙酰丙酮铱[Ir(acac)]一起沉积Ir，而使用Ir(acac)和O沉积IrO。使用多种薄膜厚度和形态评估方法研究成核。在保形性研究中，使用了专门为ALD薄膜的精确和通用保形性测试而设计的微观横向高纵横比（LHAR）测试结构。成核顺序从最快到最慢为：O + H > 空气 ≈ O > O > O + H，而保形性顺序从最好到最差为：O + H > O + H > O > O。在O工艺中，在LHAR结构内部观察到薄膜成分从IrO变为金属Ir。与之前关于铂族金属ALD的报道相比，大多数研究的工艺显示出良好到优异的结果。
