Design, Materials Development and Fabrication of Capacitive Micromachined Ultrasonic Transducer (CMUT)

Project leaders

Luca Maiolo, Ravindra Mukhiya

Agreement

INDIA - CSIR-expired - Council of Scientific and Industrial Research

Call

CNR-CSIR 2016-2018

Department

Physical sciences and technologies of matter

Thematic area

Physical sciences and technologies of matter

Status of the project

New

Research proposal

Micro-Electro-Mechanical Systems (MEMS) based sensors/actuators are vastly attractive due to their low cost, small size, low power consumption and robust performance. A particular class of MEMS is devoted to the development of the Ultrasonic Transducer (UT). Ultrasounds are mechanical, non-ionizing waves which have frequencies beyond the human audible range (> 20 kHz). Broadly, the UT can be categorized based on the transduction mechanism such as piezoelectric ultrasonic transducer and capacitive ultrasonic transducer. So far, intensive research has been carried out towards the development of piezoelectric ultrasonic transducer. Recently, the development of capacitive ultrasonic transducer has attracted attention due to the less stringent requirements on the impedance matching, ease of integration, high sensitivity, wide bandwidth and high temperature operating range.
Capacitive micromachined ultrasonic transducer (CMUT) have wide applications in industry, medical, automotive and consumer electronics. In this context, the primary goal of the project is to design and develop a complementary metal oxide semiconductor (CMOS)-compatible CMUT process and technology. This project proposal focuses on the development of innovative CMUT to improve electronic design, materials and device operability. Additionally, a feasibility study on the manufacturing of CMUT on flexible substrates will be pursued, by using advanced laser technique.
The project research work includes design, simulation, technology and material selection, unit process characterization and standardization, and technology development to realize MEMS CMUT. In particular, the research activity of IMM will be devoted to the optimization of materials and to the definition of procedures to deposit dielectrics and sacrificial layers at low temperature (

Research goals

Specific objectives, towards the goal of design and development of CMUT, can be classified as:
- CMUT design: It includes technology selection, materials and methodology selection, geometry selection and dimension selection (CEERI-IMM)
- CMUT process design: It includes fabrication process design, mask layout generation and fabrication of mask (CEERI-IMM)
- CMUT process optimization: It mainly includes development of wafer bonding parameters for low temperature bonding, and optimization of RIE for uniform etching of structure layer (CEERI)
- CMUT process optimization: Development of the sacrificial layer for the CMUT transfer, and optimization of the best laser parameters for the device detachment (IMM)
- CMUT fabrication: It includes development of CMUT (CEERI-IMM)
- CMUT characterization: It includes electrical, mechanical and ultrasonic testing (IMM-CEERI)

Last update: 18/04/2024