It is important to quantitatively measure the adhesion strength at the interface in a small area of electronics devices to ensure their reliability. In this study, a simple technique for measuring the adhesion using the nanoindentation method by considering the energy balance during the indentation process was proposed and applied to measure the adhesion of three kinds of UV-cured SiOC films with a thickness of 500 nm on a Si substrate.
The discontinuous points of approximately 300 nm in depth appeared in all the indentation curves with a high reproducibility, and it was confirmed that these points reflect the occurrence of an interfacial delamination. The total dissipated energies calculated from the load vs. indentation depth curves indicate a good correlation with the indentation load. The delamination energies can be estimated using this relationship. The energy release rates at the interface of the UV-cured SiOC films calculated from the energy balance increases with the increasing UV curing time.
From these result, we can confirm the technique proposed in this study is quite useful to simply and quantitatively measure the adhesion, especially against a thin film or the small area, even if the film is ductile.