Minjauw Matthias M, Feng Ji-Yu, Sajavaara Timo, Detavernier Christophe, Dendooven Jolien
Department of Solid State Sciences, COCOON Research Group, Ghent University, Krijgslaan 281/S1, 9000 Ghent, Belgium.
Physics Department, University of Jyväskylä, Finland.
Dalton Trans. 2022 Jul 19;51(28):10721-10727. doi: 10.1039/d1dt03543f.
In this work, the use of ruthenium tetroxide (RuO) as a co-reactant for atomic layer deposition (ALD) is reported. The role of RuO as a co-reactant is twofold: it acts both as an oxidizing agent and as a Ru source. It is demonstrated that ALD of a ternary Ru-containing metal oxide ( a metal ruthenate) can be achieved by combining a metalorganic precursor with RuO in a two-step process. RuO is proposed to combust the organic ligands of the adsorbed precursor molecules while also binding RuO to the surface. As a proof of concept two metal ruthenate processes are developed: one for aluminum ruthenate, by combining trimethylaluminum (TMA) with RuO; and one for platinum ruthenate, by combining MeCpPtMe with RuO. Both processes exhibit self-limiting surface reactions and linear growth as a function of the number of ALD cycles. The observed saturated growth rates are relatively high compared to what is usually the case for ALD. At 100 °C sample temperature, growth rates of 0.86 nm per cycle and 0.52 nm per cycle are observed for the aluminum and platinum ruthenate processes, respectively. The TMA/RuO process results in a 1 : 1 Al to Ru ratio, while the MeCpPtMe/RuO process yields a highly Ru-rich composition with respect to Pt. Carbon, hydrogen and fluorine impurities are present in the thin films with different relative amounts for the two investigated processes. For both processes, the as-deposited films are amorphous.
在本工作中，报道了使用四氧化钌（RuO）作为原子层沉积（ALD）的共反应物。RuO作为共反应物的作用是双重的：它既作为氧化剂又作为Ru源。结果表明，通过在两步过程中将金属有机前驱体与RuO相结合，可以实现含Ru三元金属氧化物（金属钌酸盐）的ALD。有人提出RuO可燃烧吸附的前驱体分子的有机配体，同时将RuO结合到表面。作为概念验证，开发了两种金属钌酸盐工艺：一种是通过将三甲基铝（TMA）与RuO结合制备铝钌酸盐；另一种是通过将甲基环戊二烯基铂（MeCpPtMe）与RuO结合制备铂钌酸盐。这两种工艺都表现出自限性表面反应以及随ALD循环次数呈线性生长。与ALD通常的情况相比，观察到的饱和生长速率相对较高。在100℃的样品温度下，铝钌酸盐工艺和铂钌酸盐工艺的生长速率分别为每循环0.86nm和每循环0.52nm。TMA/RuO工艺得到的Al与Ru的比例为1:1，而MeCpPtMe/RuO工艺得到的相对于Pt富含Ru的成分。在两种研究工艺中，薄膜中存在不同相对含量的碳、氢和氟杂质。对于这两种工艺，沉积后的薄膜都是非晶态的。
