Simple and Efficient AlN-Based Piezoelectric Energy Harvesters.

Area of Science:

• Materials Science
• Nanotechnology
• Electrical Engineering

Background:

• Piezoelectric energy harvesters (PEHs) are crucial for powering microelectronic devices.
• Aluminum nitride (AlN) thin films offer promising piezoelectric properties for PEH applications.
• Integration of PEHs with standard semiconductor manufacturing processes is highly desirable.

Purpose of the Study:

• To demonstrate a simple fabrication process for AlN-based PEHs.
• To achieve high piezoelectric coefficients in AlN thin films.
• To ensure compatibility with CMOS technology for scalable energy harvesting solutions.

Main Methods:

• Fabrication of AlN-based PEHs using multilayer ion beam-assisted deposition.
• Utilizing a simplified process with three lithography steps on a conventional silicon substrate.
• Characterization of cantilever deflection via laser interferometry and efficiency using a vibration shaker.

Main Results:

• Successfully fabricated AlN-based PEHs with a simple, three-step lithography process.
• Achieved highly (001) oriented AlN thin films with excellent piezoelectric coefficients (d33 = 7.33 ± 0.08 pC∙N−1).
• Demonstrated CMOS compatibility due to AlN deposition at ≈330 °C, suitable for wafer post-processing.

Conclusions:

• The developed fabrication method offers a straightforward route to AlN-based PEHs.
• The high piezoelectric performance and CMOS compatibility position this technology for widespread adoption.
• This work paves the way for integrated, CMOS-based energy harvesting systems.