Tensile strength of zinc oxide films measured by a microbridge method

Abstract

Double-layered ZnO/silicon nitride microbridges were fabricated for microbridge tests. In a test, a load was applied to the center of the microbridge specimen by using a microwedge tip, where the displacement was recorded as a function of load until the specimen broke. The silicon nitride layer in the structure served to enhance the robustness of the specimen. By fitting the data to a theory, the elastic modulus, residual stress, and tensile strength of the ZnO film were found to be 137 ± 18 GPa, −0.041 ± 0.02 GPa, and 0.412 ± 0.05 GPa, respectively. The analysis required the elastic modulus, internal stress, and tensile strength of the silicon nitride layer. They were measured separately by microbridge tests on single-layered silicon nitride microbridges. The measured tensile strength of the ZnO films represents the maximum tolerable tensile stress that the films can sustain when they are used as the functional component in devices.

Strategy for Carrier Control in Carbon Nanotube Transistors

“…In particular, the CNT transistor has an advantage if used for flexible, stretchable, and transparent electronics. Compared to ZnO and indium tin oxide (ITO), which have 0.03 [117] and 1 % [118] flexibility, respectively, CNTs have a higher flexibility (16 %). [119] A drawback of network CNT transistors is the presence of metallic nanotubes in the sample.…”

Highly Bendable, Transparent Thin‐Film Transistors That Use Carbon‐Nanotube‐Based Conductors and Semiconductors with Elastomeric Dielectrics

“…[7][8][9] Although the electrical properties of these oxides can be good (mobilities and conductivities as high as 20 cm 2 V -1 s -1[10] and 4.8 × 10 3 X -1 cm -1 , [11] respectively), their mechanical characteristics are not optimally suited for use in flexible and mechanically robust devices. For example, the tensile fracture strains for ZnO and indium tin oxide (ITO) thin films are less than 0.03 % [12] and 1 %, [13] respectively.Aligned arrays [14] or random networks [15,16] of individual SWNTs represent alternative classes of transparent semiconducting and conducting materials. In networks with high coverages of SWNTs, especially when in the form of small bundles, the metallic tubes (normally present with semiconducting tubes in a 1:2 ratio) form a percolating network that behaves like a conducting "film".…”

Nano/Micro Patterning of Inorganic Thin Films

“…Various growth techniques have been applied to synthesize ceramic thin films. These techniques fall into at least two categories: vacuum-based methods such as chemical vapor deposition (CVD), 19 sputtering, 20 metal organic chemical vapor deposition (MOCVD), 21 atomic layer deposition (ALD), 22 and chemical solution methods including sol-gel, electrochemical deposition, and hydrothermal synthesis. 23,24 Vacuum-based techniques are an expensive investment, are limited to line-of-sight production, and usually require highvapor-pressure chemicals or high-purity targets as starting materials.…”