title: Degradation of bare and silanized silicon wafer surfaces by constituents of biological fluids.
abstract: The 24 h stability of bare silicon wafers as such or silanized with CH(3)O-(CH(2)-CH(2)-O)(n)-C(3)H(6)-trichlorosilane (n=6-9) was investigated in water, NaCl, phosphate and carbonate solutions, and in phosphate buffered saline (PBS) at 37 °C (close to biological conditions regarding temperature, high ionic strength, and pH). The resulting surfaces were analyzed using ellipsometry, X-ray Reflectometry (XRR), X-ray Photoelectron Spectroscopy (XPS), and Atomic Force Microscopy (AFM). Incubation of the silanized wafers in phosphate solution and PBS provokes a detachment of the silane layer. This is due to a hydrolysis of Si-O bonds which is favored by the action of phosphate, also responsible for a corrosion of non-silanized wafers. The surface alteration (detachment of silane layer and corrosion of the non-silanized wafer) is also important with carbonate solution, due to a higher pH (8.3). The protection of the silicon oxide layer brought by silane against the action of the salts is noticeable for phosphate but not for carbonate.
authors.affiliation: Université catholique de Louvain, Institute of Condensed Matter and Nanosciences, Louvain-la-Neuve, Belgium.
authors.forename: C M
authors.initials: CM
authors.lastname: Dekeyser
authors.forename: C C
authors.initials: CC
authors.lastname: Buron
authors.forename: S R
authors.initials: SR
authors.lastname: Derclaye
authors.forename: A M
authors.initials: AM
authors.lastname: Jonas
authors.forename: J
authors.initials: J
authors.lastname: Marchand-Brynaert
authors.forename: P G
authors.initials: PG
authors.lastname: Rouxhet
mesh_terms: D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry*; D002021:Buffers; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010710:Phosphates / Q000737:chemistry*; D012825:Silicon / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*
chemical_list: D002021:Buffers; D010710:Phosphates; D012965:Sodium Chloride; D017438:Bisphenol A-Glycidyl Methacrylate; C033930:Silar (3M); D012825:Silicon