Effect of surface treatment on adhesion strength between magnetron sputtered copper thin films and alumina substrate

Sputter Deposition of Titanium on Poly(Methyl Methacrylate) Enhances Corneal Biocompatibility

“…Magnetron sputtered Ti film on PMMA has been explored previously, 36 and it was shown that the plasma treatment significantly improved the bond strength between the sputtered film and underlying substrate. 42 Our data show that the adhesion between a Ti sputtered film and plasma-treated PMMA (10.9 ± 1.1 MPa) is significantly higher than for non-treated PMMA (7.4 ± 1.1; P = 0.00002). For context, reported mean eyelid pressures based on three models of whole cell, imprint width, and Marx's line are 0.00051 ± 0.00001 MPa, 0.0011 ± 0.0004 MPa, and 0.0073 ± 0.0035 MPa, respectively, which are three to four orders of magnitude less than the adhesion strength of Ti-(p)PMMA.…”

“…For context, reported mean eyelid pressures based on three models of whole cell, imprint width, and Marx's line are 0.00051 ± 0.00001 MPa, 0.0011 ± 0.0004 MPa, and 0.0073 ± 0.0035 MPa, respectively, which are three to four orders of magnitude less than the adhesion strength of Ti-(p)PMMA. 43 The increase in adhesion strength likely stems from (1) removal of organic and inorganic surface contaminants 42 ; (2) removal of the so-called weak boundary layer made of oligomers present on the surface of polymer; (3) chemical modification of the surface, including oxidation of the surface and generation of carboxylic acid, along with generation of creation of surface dangling bonds, the latter being more reactive toward the incoming metal atoms 44 ; (4) increased surface energy of the polymer to approach those of the sputtered metal; and (5) increased interface surface area. 45 Mechanical evaluations also indicate that adhesion between the Ti film and underlying PMMA is not disrupted after incubation of Ti sputtered (p)PMMA in cell culture media, suggesting the stability of the coating under physiological conditions.…”

Joining Ti6Al4V to Alumina by Diffusion Bonding Using Titanium Interlayers

“…The Ti thin film is highlighted in light grey, and its total thickness is close to 1 µm, as desired. The adhesion pull-off test shows an average adhesion strength of 8 MPa, slightly below the 10 MPa referred to in the literature [48]. However, the thin films were not detached from the alumina substrate at the end of the experiments; only the interface glue/film was broken, which suggests that the adhesion strength is sufficient.…”

Highly-Conductive and Well-Adhered Cu Thin Film Fabricated on Quartz Glass by Heat Treatment of a Precursor Film Obtained Via Spray-Coating of an Aqueous Solution Involving Cu(II) Complexes

“…In our previous work, the thin film prepared from the precursor solution had an adhesion strength of 36 MPa whereas another film prepared using ion-beam assisted deposition attained an adhesion strength of 1.7 MPa [10]. There are various techniques utilized to modify the surface of substrates in order to promote excellent adhesion strength of thin films and a thin film of copper with an adhesion strength of 34 MPa onto an alumina substrate was fabricated via magnetron sputtering but only after pre-treatment of the substrate with an Ar gas plasma [28]. However, in techniques such as physical vapor deposition (PVD), it has been established that a good adhesion can be obtained as a result of the formation of a transition layer between the substrate and thin film [29].…”