Experimental Study on the Thickness-Dependent Hardness of SiO2 Thin Films Using Nanoindentation

Abstract

SiO2 thin films are widely used in micro-electro-mechanical systems, integrated circuits and optical thin film devices. Tremendous efforts have been devoted to studying the preparation technology and optical properties of SiO2 thin films, but little attention has been paid to their mechanical properties. Herein, the surface morphology of the 500-nm-thick, 1000-nm-thick and 2000-nm-thick SiO2 thin films on the Si substrates was observed by atomic force microscopy. The hardnesses of the three SiO2 thin films with different thicknesses were investigated by nanoindentation technique, and the dependence of the hardness of the SiO2 thin film with its thickness was analyzed. The results showed that the average grain size of SiO2 thin film increased with increasing film thickness. For the three SiO2 thin films with different thicknesses, the same relative penetration depth range of ~0.4–0.5 existed, above which the intrinsic hardness without substrate influence can be determined. The average intrinsic hardness of the SiO2 thin film decreased with the increasing film thickness and average grain size, which showed the similar trend with the Hall-Petch type relationship.

Study of High Transmittance of SiO2/Nb2O5 Multilayer Thin Films Deposited by Plasma-Assisted Reactive Magnetron Sputtering

“…The hardness of the SiO 2 and Nb 2 O 5 single-layer thin films was 10.73 GPa and 6.3 GPa, respectively. Previous works on the hardness of SiO 2 and Nb 2 O 5 thin films reported a hardness in the ranges of 10.4~11.9 GPa and 6.5~6.8 GPa, respectively [33,36]. The hardness (6.6 GPa) of the SiO 2 /Nb 2 O 5 multilayer thin films on B33 substrates showed a value that was more than 30% greater than the hardness (4.4 GPa) of the SiO 2 /Nb 2 O 5 multilayer thin film on D263 substrates.…”

“…Hardness (P max /A p 2 ) can be explained as the maximum indentation load P max divided by the projected contact area A p . The projected contact area A p can be estimated from this relationship (A p = C o × h c 2 ), where C o is 24.6 for the Berkovich indenter and h c is the contact depth [33]. The hardness properties of a thin film can be measured by using a nano indenter equipped with a modified Berkovich indenter.…”

Gelatin- and Papaya-Based Biodegradable and Edible Packaging Films to Counter Plastic Waste Generation

“…The surface roughness values of these films were found to be 0.14 µm and 0.49 µm, respectively. Furthermore, according to Kadhim et al [ 51 ], surface roughness and surface nano-hardness are negatively linked with each other; a smooth surface may yield a harder surface [ 51 , 54 ].…”

Fabrication of and corrosion prevention mechanisms of tin oxide (SnO2) decorated reduced graphene oxide (rGO) for anodic protection of Zn metal surfaces

“…The FTIR spectra of rGO-SnO2 nanocomposites showed these peaks, confirming that rGO was present in the composites. In addition, the rGO-SnO2 nanocomposite exhibited higher absorption band at 1620 cm -1 (C=C stretching) compared to GO, suggesting that the graphene network was restored and the GO was likely converted to rGO [17]. The symmetric and anti-symmetric O-Sn-O stretching were also ascribed to the usual peaks at 489 cm -1 and 671 cm -1 in SnO2, suggesting the well-interfacial combination of SnO2 nanostructures and rGO.…”