Spraying spin coating silanization at room temperature of a SiO2 surface for silicon-based integrated light emitters

A new silanization method for SiO2 surfaces has been developed for Si-based light emitters which are intended to serve as light sources in smart biosensors relying on fluorescence analysis. This method uses a special silanization chamber and is based on spraying and spin coating (SSC) in nitrogen atmosphere at room temperature for 10 min. It avoids processes like sonication and the use of certain chemicals being harmful to integrated light emitters. The surface of a SiO2 layer serving as a passivation layer for the light emitters was hydrolyzed to silanols using an in situ-hybridization chamber and catalyzed with MES (2-(N-morpholino)ethanesulfone acid hydrate) buffer solution. Subsequently, the substrates were silanized with the SSC method using two coupling agents as (3-Aminopropyl)trimethoxysilane (APMS), and N′-(3-(trimethoxysilyl)-propyl)-diethylenetriamine (triamino-APMS).The structure of the SiO2 surface, the APMS and the triamino-APMS layers was controlled and characterized by Infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The results show a covalent binding of the silane coupling agents on the surface. Atomic force microscopy was used to investigate the roughness of the surface. The silanized samples exhibit smooth and densely covered surfaces. Finally, the suitability of the SSC method was verified on real light emitters.

Graphical abstractA new silanization method for SiO2 surfaces has been developed for Si-based light emitters which are intended to serve as light sources in smart biosensors relying on fluorescence analysis.Figure optionsDownload full-size imageDownload as PowerPoint slide