Abstract
We report the formation of silicide by annealing of a SiOx surface, with low coverage of Eu doped Gd2O3 nanoparticles. The annealing temperature required for removal of native oxide from the Si substrate decreases with close to 200 °C in presence of the nanoparticles. X-ray photoemission electron microscopy, low-energy electron microscopy and mirror electron microscopy are used to monitor the silicide formation and SiOx removal. Fragmentation of the nanoparticles is observed, and the SiOx layer is gradually removed. Eu migrates to clean Si areas during the annealing process, while Gd is found in areas where oxide is still present. This annealing process is clearly facilitated in the presence of rare-earth based nanoparticles, where nanoparticles are suggested to function as reaction sites to catalyze the oxygen removal and simultaneously form Eu based silicide. Reduction of the annealing temperature of SiOx substrates is also observed in presence of pure Eu3+ and Gd3+ ions. Simultaneous oxygen removal and EuSi formation enable this new rare-earth catalyzed annealing and silicide formation to find applications both within optoelectronics and processing microelectronic industry.
Highlights
Rare-earth elements are attractive for applications ranging from Light Emitting Diodes (LEDs) [1,2,3] to contrast agents in magnetic resonance imaging (MRI). [4,5,6,7,8,9,10] Depending on the rare-earth element chosen, both magnetic and fluorescent properties can be achieved
Rare-earth silicides are commonly produced through epitaxial growth where the rare-earth material is deposited on a pure Si substrate followed by annealing in vacuum at relatively low temperatures. [13,18,19,20] Deposition of sub-monolayer Eu, and subsequent Eu silicide formation has been studied
The native oxide removal is regularly performed through annealing of the substrate where an inhomogeneous decomposition and void formation in the oxide layer is commonly observed at about 900–1050°C. [21,22] A reduction in this temperature is highly appreciable for the electronics industry as this would result in a less time consuming, more efficient process with a lower energy consumption
Summary
Rare-earth elements are attractive for applications ranging from Light Emitting Diodes (LEDs) [1,2,3] to contrast agents in magnetic resonance imaging (MRI). [4,5,6,7,8,9,10] Depending on the rare-earth element chosen, both magnetic and fluorescent properties can be achieved. Rare-earth silicides are commonly produced through epitaxial growth where the rare-earth material is deposited on a pure Si substrate followed by annealing in vacuum at relatively low temperatures (about 500 °C). [23,24,25,26,27,28,29,30,31,32,33] In this study, these techniques are utilized to investigate rare-earth elements (Gd and Eu) and their step by step interaction with a silicon substrate. The rare-earth – silicon interactions are studied in relation to the material forms (i.e. ions or nanoparticles) and their potential as reaction centers for native oxide removal and heat induced rare-earth silicide formation.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
