The paper presents the design features of silicon microprobe with a cross-sectional size less than 100 μm, taking into account the number of electrodes, as well as the conditions of anisotropic wet etching. Analytical calculations were carried out for the probe structure, represented by n-regions of various widths, carrying up to 2n-1 electrodes. The dependences of bottom width of the trapezoidal section of the probe and width of related mask on the thickness and top width of the probe are obtained. The permissible dimension ranges for several cases of one- to four-level microprobes have been established. The correction value of the mask size was estimated, reflecting the effect of etching conditions on the geometry of the probe. Modeling was carried out in an anisotropic wet etching simulator taking into account the conditions of KOH etching (in 20-40% solution at 60-80°C). It allowed to refine the results of the analytical calculations, refine dimensions of the silicon microprobe structure, the geometry of related masks, as well as the extent undercutting effect. The obtained results could be used in development of silicon microprobes formed by anisotropic wet etching.
In recent years, aluminum oxide films have found application in surface acoustic wave sensors. The paper presents the mechanical and physical properties of aluminum oxide (Al2O3) films obtained by the sol-gel method and subsequent sintering by high-temperature annealing. The synthesis of an aluminum oxide film from inorganic sols using the sol-gel technology was carried out. The effect of high-temperature treatment on the geometric dimensions, surface morphology, and hardness of Al2O3 films has been investigated. It was found that due to high-temperature sintering, the average values of film thickness and surface roughness are reduced by about 2 times. The effect of sintering temperatures on hardness suggests that with increasing temperature hardness of aluminum oxide film increases, and at sintering temperature of 800°C was 11.7±1.2 GPa.
The article presents the results of designing, manufacturing, and studying the resonant properties of a square silicon membrane for use in a fiber-optic acoustic receiver. The dependences of resonant frequency on edge length (6-9 mm) and thickness of the membrane (30-50 μm) are obtained. The geometrical parameters of the membrane satisfying the values of resonant frequency (2-60 kHz), pressure (0.1-14 Pa), and deviation (10 nm) are determined: edge length is 8 mm and thickness is 40-50 μm (9.2-42.3 kHz). A series of square silicon membranes was fabricated by anisotropic wet etching. The amplitude-frequency characteristics of the membranes were experimentally measured using an adaptive holographic interferometer. For a square membrane of 8×8×0.044 m3, the experimentally measured resonant frequency was 10.1 kHz, which is consistent with the results of numerical simulation.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.