| Summary: | 碩士 === 國立虎尾科技大學 === 材料科學與綠色能源工程研究所 === 102 === This paper describes the formation of Cu and Cu-Ag nanofilms using electrochemical atomic layer deposition (EC - ALD), which combine atomic layer deposition (ALD) with underpotential deposition (UPD). Ag materials and technigues may ultimately be need to address the low resistivity requirements of interconnection, which are project to have current density greater than 4.13 mA/cm2 by 2018, and super-filling Cu-Ag using the great gap filling of EC-ALD.
The Si (100) wafer coated with 10 nm Ru films by pHysical vapor deposition, and the substrate was cleaned by cyclic voltammetry in 10 mM HCLO4 at a scan rate of 5 mV/s to remove the oxide layer. Cu underpotential deposition was used to deposit the first Cu atomic layer on Ru substrate. Pb was chosen as the sacrificial layer as it forms atomic layers on Cu via underpotential deposition and then Cu2+ solution was flushed into the cell at open-circuit potential where the Pb atoms were exchanged for Cu by redox replacements. The Cu bulk layer formation was by repeating the above step several times and then deposited Ag atomic layer on Cu using underpotantial deposition. Cu-Ag samples were formed using the sequence by performing 50 periods, each consisting of 4 cycles Cu and 1cycle Ag. The deposition were grown using 0.1 and -0.05 V for Cu and Ag precursor solution.The resulting Cu-Ag films were characterized using X-ray diffraction (XRD), electrochemical chromatograpHy and four point probe (FPP).
The result indicates the average formed amount of Cu per replacement cycle was 0.51 ML, that the lowest resistivity 3.6 and 2.2 μΩ．cm for Cu thin film and Cu-Ag thin film. The XRD pattern for 500 cycles displays two left-shifted peak, (111) and (200) for Cu, its show that the Ag atom moved into Cu lattice. As results of the self-limiting reactions and electrochemical suface limited reaction, EC-ALD have the great ability-deposited of atomic-level control, fabricated nano-scale filling processes.
|
|---|
