High overtone acoustic resonator HBAR based on IDT's/c-tilted ZnO/Si for timing applications

Laidoudi, Farouk; Medjili, F.; Caliendo, Cinzia; Hamidullah, Muhammad; Kanouni, Fares; Boubenider, F.

doi:10.1109/ssd54932.2022.9955797

Cited by 4 publications

(1 citation statement)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The sputtering chamber was evacuated, and the pre-sputtering process was carried out for at least 15 min in Ar (20 standard cubic centimeters per minute (sccm), working pressure 3 × 10 −3 Torr) to clean the target surface and remove impurities. The ZnO layers were deposited onto fused silica substrates according to optimized sputtering parameters [10,11], which are listed in Table 1. ZnO films of different thickness (grown for different sputtering times) were deposited onto fused silica and silicon substrates in the same sputtering run.…”

Section: Zno Layer Depositionmentioning

confidence: 99%

UV Sensor Based on Surface Acoustic Waves in ZnO/Fused Silica

Caliendo

Benetti

Cannatà

et al. 2023

Sensors

Self Cite

View full text Add to dashboard Cite

Zinc oxide (ZnO) thin films have been grown by radio frequency sputtering technique on fused silica substrates. Optical and morphological characteristics of as-grown ZnO samples were measured by various techniques; an X-ray diffraction spectrum showed that the films exhibited hexagonal wurtzite structure and were c-axis-oriented normal to the substrate surface. Scanning electron microscopy images showed the dense columnar structure of the ZnO layers, and light absorption measurements allowed us to estimate the penetration depth of the optical radiation in the 200 to 480 nm wavelength range and the ZnO band-gap. ZnO layers were used as a basic material for surface acoustic wave (SAW) delay lines consisting of two Al interdigitated transducers (IDTs) photolithographically implemented on the surface of the piezoelectric layer. The Rayleigh wave propagation characteristics were tested in darkness and under incident UV light illumination from the top surface of the ZnO layer and from the fused silica/ZnO interface. The sensor response, i.e., the wave velocity shift due to the acoustoelectric interaction between the photogenerated charge carriers and the electric potential associated with the acoustic wave, was measured for different UV power densities. The reversibility and repeatability of the sensor responses were assessed. The time response of the UV sensor showed a rise time and a recovery time of about 10 and 13 s, respectively, and a sensitivity of about 318 and 341 ppm/(mW/cm2) for top and bottom illumination, respectively. The ZnO/fused silica-based SAW UV sensors can be interrogated across the fused silica substrate thanks to its optical transparency in the UV range. The backlighting interrogation can find applications in harsh environments, as it prevents the sensing photoconductive layer from aggressive environmental effects or from any damage caused by cleaning the surface from dust which could deteriorate the sensor’s performance. Moreover, since the SAW sensors, by their operating principle, are suitable for wireless reading via radio signals, the ZnO/fused-silica-based sensors have the potential to be the first choice for UV sensing in harsh environments.

show abstract

Section: Zno Layer Depositionmentioning

confidence: 99%