Process for manufacturing an optical microelectromechanical device having a tiltable structure with an antireflective surface

• Main Authors: Boni, Nicolo, Carminati, Marta, Seghizzi, Luca, Carminati, Roberto, Oggioni, Laura
• Format: Patent
• Language: English
• Published: 17.10.2023
• Subjects: MICROSTRUCTURAL DEVICES OR SYSTEMS, e.g. MICROMECHANICALDEVICES; MICROSTRUCTURAL TECHNOLOGY; PERFORMING OPERATIONS; PROCESSES OR APPARATUS SPECIALLY ADAPTED FOR THE MANUFACTUREOR TREATMENT OF MICROSTRUCTURAL DEVICES OR SYSTEMS; TRANSPORTING

For manufacturing an optical microelectromechanical device, a first wafer of semiconductor material having a first surface and a second surface is machined to form a suspended mirror structure, a fixed structure surrounding the suspended mirror structure, elastic supporting elements which extend between the fixed structure and the suspended mirror structure, and an actuation structure coupled to the suspended mirror structure. A second wafer is machined separately to form a chamber delimited by a bottom wall having a through opening. The second wafer is bonded to the first surface of the first wafer in such a way that the chamber overlies the actuation structure and the through opening is aligned to the suspended mirror structure. Furthermore, a third wafer is bonded to the second surface of the first wafer to form a composite wafer device. The composite wafer device is then diced to form an optical microelectromechanical device.