Liquid Phase Deposition of Single-Source Precursors

Recently, solution processing of silicon based electronic devices has attracted considerable attention. Especially the low costs and the possibility of large area depositions and patterning materials offer great advantage to similar processes. Recent studies demonstrated the principal feasibility of liquid phase deposition (LPD) and processing of silicon films of high quality.[1] Therefore, the aim of this work was the synthesis of different heteroelement substituted higher silicon hydrides, which contain one or more heteroatoms covalently linked to silicon. The resulting materials are then applied as single source precursors for the deposition of functional silicon films. Therefore, different oligomeric compounds were synthesized by UV-activated oligomerization of neopentasilane, 2-methyl-2-silyltrisilane and 1,1,1-trimethyl-2,2-disilyltrisilane. With the successfully synthesized polysilanes thin layer materials were produced. These thin films were obtained via spin-coating technique on glass substrates under nitrogen atmosphere. Deposition at 500 °C for 60 s was carried out for all materials after spin-coating. By varying parameters like temperature, revolutions per minute, as well as spin-coating time, different series of films were produced and analyzed via light microscopy, SEM and ellipsometry.

[1] a) T. Shimoda, Y. Matsuki, M. Furusawa, T. Aoki, I. Yudasaka, H. Tanaka, H. Iwasawa, D. Wang, M. Miyasaka, Y. Takeuchi, Nature 2006, 440, 783. b.) M. Haas, V. Christopoulos, J. Radebner, M. Holthausen, T. Lainer, L. Schuh, H. Fitzek, G. Kothleitner, A. Torvisco, R. Fischer, O. Wunnicke, H. Stueger, Angew. Chem. 2017, 129, 14259