Substrate temperature and electron fluence effects on metallic films created by electron beam induced deposition
Substrate temperature and electron fluence effects on metallic films created by electron beam induced deposition
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DOI：
10.1116/1.4751281
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发表时间：
2012-09-01
影响因子：
1.4
通讯作者：
Fairbrother, D. Howard
中科院分区：
文献类型：
--
作者：
Rosenberg, Samantha G.;Landheer, Kees;Fairbrother, D. Howard
使用三种不同的前驱体[MeCpPtMe3， Pt(PF3)4和W(CO)6]，采用超高真空表面科学方法确定并合理地确定衬底温度和电子影响对电子束诱导沉积（EBID）薄膜的化学成分和键合的影响。x射线光电子能谱数据表明，这两个工艺变量对薄膜性能的影响是由前驱体的分解机制决定的。对于像MeCpPtMe3这样在EBID过程中分解而不形成稳定中间体的前驱体，膜的化学组成与底物温度或电子影响无关。相比之下，对于Pt(PF3)4和W(CO)6， EBID中的初始电子刺激沉积事件分别产生表面结合的中间体Pt(PF3)3和部分脱碳的Wx(CO)y。这些中间体随后可以通过热反应或电子刺激反应。因此，由Pt(PF3)4或W(CO)6制备的EBID薄膜的化学成分受到衬底温度和电子影响。较高的底物温度分别促进Pt(PF3)3和Wx(CO)y中间体中完整的PF3和CO配体的析出，提高了薄膜的金属含量。然而，Pt(PF3)3和Wx(CO)y中间体与电子的反应涉及配体分解，增加了Pt(PF3)4薄膜中不可逆结合的磷含量和W(CO)6薄膜中钨的氧化程度。除了温度对化学成分的影响外，升高的衬底温度（约25℃）增加了MeCpPtMe3和Pt(PF3)4形成的EBID沉积层的金属特征程度。
Using three different precursors [MeCpPtMe3, Pt(PF3)4, and W(CO)6], an ultra-high vacuum surface science approach has been used to identify and rationalize the effects of substrate temperature and electron fluence on the chemical composition and bonding in films created by electron beam induced deposition (EBID). X-ray photoelectron spectroscopy data indicate that the influence of these two processing variables on film properties is determined by the decomposition mechanism of the precursor. For precursors such as MeCpPtMe3 that decompose during EBID without forming a stable intermediate, the film's chemical composition is independent of substrate temperature or electron fluence. In contrast, for Pt(PF3)4 and W(CO)6, the initial electron stimulated deposition event in EBID creates surface bound intermediates Pt(PF3)3 and partially decarbonylated Wx(CO)y species, respectively. These intermediates can react subsequently by either thermal or electron stimulated processes. Consequently, the chemical composition of EBID films created from either Pt(PF3)4 or W(CO)6 is influenced by both the substrate temperature and the electron fluence. Higher substrate temperatures promote the ejection of intact PF3 and CO ligands from Pt(PF3)3 and Wx(CO)y intermediates, respectively, improving the film's metal content. However, reactions of Pt(PF3)3 and Wx(CO)y intermediates with electrons involve ligand decomposition, increasing the irreversibly bound phosphorous content in films created from Pt(PF3)4 and the degree of tungsten oxidation in films created from W(CO)6. Independent of temperature effects on chemical composition, elevated substrate temperatures (> 25 degrees C) increased the degree of metallic character within EBID deposits created from MeCpPtMe3 and Pt(PF3)4.