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Lecture

Bulk Acoustic Wave Resonators in MEMS

In course

MICRO-621: MOOC: Micro and Nanofabrication (MEMS)

Micro- and nanofabrication can be taught to students and professionals by textbooks and ex-cathedra lectures, but the real learning comes from seeing the manufacturing steps as they happen. This MOOC will not only explain the basics of microfabrication but ...

Description

This lecture covers the design and fabrication of Bulk Acoustic Wave (BAW) resonators, focusing on their application in smartphones for RF front-end modules. It explains the structure of BAW resonators, the fabrication process, and the importance of precise thickness and good piezoelectric properties. The lecture also discusses the two types of BAW resonators, FBAR and SMR, and their role in telecom band selection. Key players in the industry and the widespread use of BAW filters in smartphones, such as the iPhone 6S, are highlighted.

In MOOC

Micro and Nanofabrication (MEMS)

Instructors (2)

Martinus Adela Maria Gijs

Martin A.M. Gijs received his degree in physics in 1981 from the Katholieke Universiteit Leuven, Belgium and his Ph.D. degree in physics at the same university in 1986. He joined the Philips Research Laboratories in Eindhoven, The Netherlands, in 1987. Subsequently, he has worked there on micro-and nano-fabrication processes of high critical temperature superconducting Josephson and tunnel junctions, the microfabrication of microstructures in magnetic multilayers showing the giant magnetoresistance effect, the design and realisation of miniaturised motors for hard disk applications and the design and realisation of planar transformers for miniaturised power applications. He joined EPFL in 1997. His present interests are in developing technologies for novel magnetic devices, new microfabrication technologies for microsystems fabrication in general and the development and use of microsystems technologies for microfluidic and biomedical applications in particular.

Jürgen Brugger

I am a Professor of Microengineering and co-affiliated to Materials Science. Before joining EPFL I was at the MESA Research Institute of Nanotechnology at the University of Twente in the Netherlands, at the IBM Zurich Research Laboratory, and at the Hitachi Central Research Laboratory, in Tokyo, Japan. I received a Master in Physical-Electronics and a PhD degree from Neuchâtel University, Switzerland. Research in my laboratory focuses on various aspects of MEMS and Nanotechnology. My group contributes to the field at the fundamental level as well as in technological development, as demonstrated by the start-ups that spun off from the lab. In our research, key competences are in micro/nanofabrication, additive micro-manufacturing, new materials for MEMS, increasingly for wearable and biomedical applications. Together with my students and colleagues we published over 200 peer-refereed papers and I had the pleasure to supervise over 25 PhD students. Former students and postdocs have been successful in receiving awards and starting their own scientific careers. I am honoured for the appointment in 2016 as Fellow of the IEEE “For contributions to micro and nano manufacturing technology”. In 2017 my lab was awarded an ERC AdvG in the field of advanced micro-manufacturing.

Official source

Related concepts (19)

Thin-film bulk acoustic resonator

A thin-film bulk acoustic resonator (FBAR or TFBAR) is a device consisting of a piezoelectric material manufactured by thin film methods between two conductive – typically metallic – electrodes and acoustically isolated from the surrounding medium. The operation is based on the piezoelectricity of the piezolayer between the electrodes. FBAR devices using piezoelectric films with thicknesses ranging from several micrometres down to tenths of micrometres resonate in the frequency range of 100 MHz to 20 GHz.

Crystal oscillator

A crystal oscillator is an electronic oscillator circuit that uses a piezoelectric crystal as a frequency-selective element. The oscillator frequency is often used to keep track of time, as in quartz wristwatches, to provide a stable clock signal for digital integrated circuits, and to stabilize frequencies for radio transmitters and receivers. The most common type of piezoelectric resonator used is a quartz crystal, so oscillator circuits incorporating them became known as crystal oscillators.

Filter (signal processing)

In signal processing, a filter is a device or process that removes some unwanted components or features from a signal. Filtering is a class of signal processing, the defining feature of filters being the complete or partial suppression of some aspect of the signal. Most often, this means removing some frequencies or frequency bands. However, filters do not exclusively act in the frequency domain; especially in the field of many other targets for filtering exist.

Semiconductor device fabrication

Semiconductor device fabrication is the process used to manufacture semiconductor devices, typically integrated circuits (ICs) such as computer processors, microcontrollers, and memory chips (such as NAND flash and DRAM) that are present in everyday electrical and electronic devices. It is a multiple-step photolithographic and physio-chemical process (with steps such as thermal oxidation, thin-film deposition, ion-implantation, etching) during which electronic circuits are gradually created on a wafer, typically made of pure single-crystal semiconducting material.

MEMS

MEMS (Microelectromechanical systems) is the technology of microscopic devices incorporating both electronic and moving parts. MEMS are made up of components between 1 and 100 micrometres in size (i.e., 0.001 to 0.1 mm), and MEMS devices generally range in size from 20 micrometres to a millimetre (i.e., 0.02 to 1.0 mm), although components arranged in arrays (e.g., digital micromirror devices) can be more than 1000 mm2.

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