Low-Temperature Processing of Lead Zirconate Titanate Thin Films by 28 GHz Microwave Irradiation for MEMS Application

摘要

Pb(Zr_xTi_(1-x))O_3 (PZT) thin films were coated on Pt/Ti/SiO_2/Si substrates by a sol-gel method and then crystallized by 28 GHz microwave irradiation. The crystalline phases and microstructures as well as the electrical properties of the microwave-irradiated PZT films were investigated as a function of the elevated temperature generated by microwave irradiation. X-ray diffraction analysis indicated that the PZT films crystallized well into the perovskite phase at an elevated temperature of 480℃ by microwave irradiation. Scanning electron microscopy images showed that the films had a granular grain structure and most of the grains were approximately 1.5 μm in size. With increasing the elevated temperature from 480℃ to 600℃ by microwave irradiation, the breadth of grain boundaries of the films became narrow and the remanent polarization of the films increased lightly. It is clear that microwave irradiation is effective for obtaining well-crystallized PZT films with good properties at low temperatures in a short time.