标题：Large piezoelectricity on Si from highly (001)-oriented PZT thick films via a CMOS-compatible sputtering/RTP process
作者：Wang Y.; Cheng H.; Yan J.; Chen N.; Yan P.; Yang F.; Ouyang J.
作者机构：[Wang, Y] Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials (Ministry of Education), School of Materials Science and Eng 更多
通讯作者地址：[Ouyang, J] Key Laboratory for Liquid-Solid Structure Evolution and Processing of Materials (Ministry of Education), School of Materials Science and E 更多
关键词：CMOS-Si; Lead zirconate titanate (PZT) ferroelectric film; Magnetron sputtering; Micro-electro-mechanical systems (MEMS); Piezoelectric; Rapid thermal processing (RTP)
摘要：Integration of lead zirconate titanate (PZT) ferroelectrics into CMOS-Si technology has become a perennial challenge due to the continuously shrinking thermal budget in semiconductor processing. In this work, Pb(Zr 0.53 Ti 0.47 )O 3 (PZT) thick films (∼1 µm) were prepared on LaNiO 3 buffered (111)Pt/Ti/SiO 2 /(100) Si substrates via a low temperature (350 °C) sputtering deposition followed by a rapid thermal process (RTP). This two-step fabrication process resulted in a highly (001)-oriented perovskite PZT film with a dense, fine-grain morphology and reduced strains, hence an optimal electrical performance intrinsic to the chemical composition was achieved. EDS and XPS analyses verified a desirable evolution of the chemical stoichiometry in the RTP, as well as the expected chemical bonding states of the elements in the annealed films. Moreover, prototypical piezoelectric thin film cantilevers fabricated from the PZT/LaNiO 3 /Pt/Ti/SiO 2 /(100)Si heterostructure yielded a large transverse piezoelectric coefficient (e 31, f ) up to 15.7 C/m 2 , together with a high coupling coefficient k 2 ∼0.23 for energy conversion efficiency. The PZT films showed high e 31, f coefficients (∼10 C/m 2 ) even when the RTP annealing time was reduced down to 2 min. Such a piezoelectric performance is close to the highest ones reported in the literature from epitaxial or highly-oriented PZT films, which require a much higher thermal budget for processing. These high quality PZT films open up many possibilities for the integration of piezoelectricity into Si-based micro-electro-mechanical systems (MEMS). © 2019