CMOS-compatible ruggedized high-temperature Lamb wave pressure sensor

Abstract

This paper describes the development of a novel ruggedized high-temperature pressure sensor operating in lateral field exited (LFE) Lamb wave mode. The comb-like structure electrodes on top of aluminum nitride (AlN) were used to generate the wave. A membrane was fabricated on SOI wafer with a 10 µm thick device layer. The sensor chip was mounted on a pressure test package and pressure was applied to the backside of the membrane, with a range of 20–100 psi. The temperature coefficient of frequency (TCF) was experimentally measured in the temperature range of −50 °C to 300 °C. By using the modified Butterworth–van Dyke model, coupling coefficients and quality factor were extracted. Temperature-dependent Young's modulus of composite structure was determined using resonance frequency and sensor interdigital transducer (IDT) wavelength which is mainly dominated by an AlN layer. Absolute sensor phase noise was measured at resonance to estimate the sensor pressure and temperature sensitivity. This paper demonstrates an AlN-based pressure sensor which can operate in harsh environment such as oil and gas exploration, automobile and aeronautic applications.

A CMOS-compatible lamb wave resonator for liquid properties sensing

“…A primary resonant peak is detected at 477.5 MHz with a high Q-factor of 1909. This Q-factor is much better than our previous work where it is only 284 [27]. Frequency shift therefore is easy to be determined and Frequency response to glycerol-water mixtures is shown in Fig.…”

“…Since the membrane is not infinite, propagating Lamb waves will be reflected back at the lateral extremities, giving rise to resonant modes. Such type of resonating is not strong enough and the quality factor is not satisfied in our previous work [27]. To enhance the quality factor and provide rugged signals, two Bragg reflectors are employed at each side of IDT electrodes.…”

Millimeter-wave band-pass filter based on complementary split ring and SIW resonators

“…They are seen in applications such as sensor systems, clock generations, and more. Compared with the surface acoustic wave resonators, Lamb wave resonators present a smaller size, lower fabrication cost, and much higher resonant frequency [1][2][3]. The advances in semiconductor fabrication technologies have aided the implementation of Lamb wave devices on silicon substrates, making the Lamb wave resonators attractive for System-on-Chip (SoC) applications.…”

“…1 [6]) improves the modeling accuracies by considering electrode resistance and dielectric loss. Notable extensions of the MBVD model with enhanced modeling accuracy have also been proposed [3][4][5]8,9,12]. Compared with the conventional resonators, Lamb wave resonators feature higher resonant frequencies, i.e.…”

“…Compared with the conventional resonators, Lamb wave resonators feature higher resonant frequencies, i.e. GHz, and smaller sizes [1][2][3][4][5]10]. However, as the resonant frequency escalates, several parasitic components manifest.…”