Modeling and characterization of piezoelectric beams based on an aluminum nitride thin‐film layer

Abstract

This paper presents a method to determine the mechanical properties of piezoelectric thin films. The vibrational behavior of microcantilevers and clamped–clamped beams actuated by aluminum nitride (AlN) piezoelectric films were analyzed in order to investigate the suitability of these devices as characterization tools. Different geometries of resonators composed of a free‐standing structure made up of a TiPt/AlN/TiPt piezoelectric stack were tested. The out‐of‐plane motion of the resonators was assessed by laser Doppler vibrometry. An AlN Young's modulus of about 200 GPa was extracted from resonance‐frequency measurements by means of Comsol software simulations that allow taking into account AlN underetching. This value of Young's modulus was compared to the one measured by a nanoindentation technique. The quality of crystallinity was also assessed using X‐ray diffraction (XRD) measurements. We then estimated the residual stress (about 200 MPa) using an interferometry measurement.

Attenuated Glial Reactivity on Topographically Functionalized Poly(3,4‐Ethylenedioxythiophene):P‐Toluene Sulfonate (PEDOT:PTS) Neuroelectrodes Fabricated by Microimprint Lithography

“…A range of techniques have been explored to create defined microstructures on electrode surfaces, including laser ablation, focused ion beam, sputter etching, reactive ion etching, deep reactive ion etching, hot embossing, and electron beam lithography . Complementary to these techniques, imprint lithography is an especially attractive approach due to its simplicity, nondestructive character, and feasibility of patterning large areas with features down to 10 nm using elevated temperature and/or pressure processes to transfer a pattern into typically thermoplastic materials .…”

Characterization of Elastic Modulus Across the (Al1–<italic>x</italic>Sc<italic>x</italic>)N System Using DFT and Substrate-Effect-Corrected Nanoindentation

“…Various techniques are utilized to determine elastic modulus from thin films. The elastic modulus can be extracted from the resonance frequency of cantilever beams that are fabricated out of the thin film of interest [20]- [23], but this technique requires multiple film deposition, etching, and lithography procedures and optimization thereof. In contrast, instrumented indentation presents a nearly preparation-free testing method for thin films deposited on a substrate [18], [24]- [27], making it more suitable for rapid evaluation of elastic modulus in films fabricated via combinatorial deposition in order to cover a large composition range over a single sample library.…”

Screening of spherical moulds manufactured isotropically in plasma etching conditions

“…[4][5][6][7][8] Researchers have actively worked on anisotropic etching chemistry, explaining the etching parameters' effect on the profile. [4,[9][10][11] Many dry etching techniques result in anisotropic etching profiles, [12] but some can produce isotropic silicon etching, such as techniques based on chemistries: xenon difluoride (XeF 2 ), [13,14] sulfur hexafluoride (SF 6 ) plasma, [15][16][17][18] and/or wet etching by using an aqueous solution [19,20] such as Hydrofluoric acid-nitric acid-acetic acid HNA composed of hydrogen fluoride (HF*), nitric acid (HNO 3 ), and acetic acid (CH 3 COOH). [21][22][23] The latter produces the smoothest spherical cavities than the XeF 2 or SF 6 .…”