文献类型：期刊文献

英文题名：Photolytic deposition of tungsten hexacarbonyl: CVD of W-based films with the assistant of UV beam in ultra-high vacuum condition

作者：Xiao, Changyong[1]; Liu, Boping[2]; He, Xuelian[1]

机构：[1] Shanghai Key Laboratory of Multiphase Material Chemical Engineering, East China University of Science and Technology, Shanghai, 200237, China; [2] College of Materials and Energy, South China Agricultural University, Guangzhou, 510642, China

年份：2019

卷号：6

期号：8

外文期刊名：Materials Research Express

收录：EI(收录号：20193007225486)

语种：英文

外文关键词：Chemical bonds - Corrosion - Morphology - Oxide films - Oxides - Silicon compounds - Silicon wafers - X ray diffraction - X ray photoelectron spectroscopy

摘要：Short-wave ultraviolet rays (UVC) at 254 nm was applied innovatively to deposit tungsten (W) oxide films on Si (111) wafer substrate from tungsten hexacarbonyls (W(CO)6) by low-pressure chemical vapor deposition (LPCVD) in an ultra-high vacuum (UHV)-compatible reactor. The advantages of adopting UV LPCVD process are as follows: decomposition of W(CO)6 at room temperature, no destruction to the substrate, no contaminant from the ambience and no corrosion for the processing facilities. The Si (111) substrate was coated for 1 h, 3 h, 5 h and 7 h respectively. The morphological evolution, thickness, crystallographic phase and composition analysis were conducted by SEM, XRD and XPS. An ultra-smooth and compact film with average diameter under 25 nm was observed by SEM and the time dependence of W oxide suggested that the reaction proceed via the three regimes of nucleation, growth and aggregation. The XRD shows the film mainly consists of WO2 and WO3 and W intends to be a more stable oxide state of WO3 as time increases. The XPS indicates that W6+, W5+ and W4+ composed the W-containing films and W5+ was transformed into W6+ or W4+ as time increases. The cross-sectional morphology shows the strong bonding strength between the films and substrate. ? 2019 IOP Publishing Ltd.