A NOVEL STRUCTURE FOR PZT-BASED PIEZOELECTRIC MICROPHONE
H.J. Zhao, T.L. Ren, J.S. Liu, L.T. Liu, Z.J. Li
Institute of Microelectronics, Tsinghua University, CN
Keywords: MEMS, PZT, piezoelectric, microphone
Microphone is one of the most challenging and developing areas and markets in the field of microsensor technology. Piezoelectric microphones have the advantages of simple fabrication process and easy to be integrated into semiconductor devices and are paid more and more attention. The use of PZT materials to replace the other materials as the piezoelectric layers of the microphone structure was proven to be a simple and effective way to improve the sensitivity of the microphone.
In this paper, a PZT-based structure used for the integrated microphone is proposed. The performance of the PZT thin films and the devices were improved due to adoption of the PT layer as the seeding layer. The acoustic outputs of the fabricated microphones have been measured with a standard microphone as a reference and a high sensitivity of 38 mV/Pa can be obtained. This quality is prominent in the existed microphones. The frequency response of the microphone is very flat in the audio frequency range. The novel piezoelectric microphone should be very promising for acoustic applications.
NSTI Nanotech 2003 Conference Technical Program Abstract