Wafer Level Integration of Film Bulk Acoustic Resonator on 8 inch LNOI Substrate

In this work, A new process flow is proposed to fabricate Film bulk devices on thin LiNbO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> film directly bonded on SiO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</inf>/Si. Accessing the bottom electrode is achieved by through via and self-aligned process. With the proposed process flow, the roles of substrate supplier and device manufacturing are clearly separated and will be easier to be implemented in current Micro-Electro-Mechanical Systems foundries. Besides, this process was demonstrated on the 6"-on-8" LiNbO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> on insulator substrate in an 8-inch Micro-Electro-Mechanical Systems process line, proving the compatibility of this LiNbO<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</inf> Film bulk acoustic resonator with 8-inch level mass production.