Investigation of piezoelectric ZnO film deposited on diamond like carbon coated onto Si substrate under different sputtering conditions
2003; Elsevier BV; Volume: 252; Issue: 1-3 Linguagem: Inglês
10.1016/s0022-0248(02)02496-x
ISSN1873-5002
AutoresI‐Tseng Tang, Y.C Wang, Weng-Sing Hwang, Chien-Wen Hwang, Nan‐Chung Wu, Mau‐Phon Houng, Yeong‐Her Wang,
Tópico(s)ZnO doping and properties
ResumoThe applications of surface acoustic wave (SAW) devices aim directly at piezoelectric thin-films deposited onto amorphous diamond like carbon-coated on silicon substrates from target ZnO in this study. This study discusses the physics and electrics of the thin-films with the sputtering conditions of RF power, ambient pressure and mass flow ratios oxygen/argon (O2/Ar) under constant substrate temperature. This investigation analyses the thin-films of microstructure, grain size, micro-morphology, and O2/Ar ratio by XRD, SEM, TEM, AFM, and AES. The analytical results show increasing the deposition ratio of the thin-films increases power and decreases ambient pressure and O2 flow ratio. However, the RF power has a threshold limit value (TLV), and the growth ratio of thin-films decreases, if the RF power exceeds the TLV. The O2/Ar flow ratio not only affects the depositing ratio, but also the surface of the crystal type. A suitable O2/Ar flow ratio in the cavity, obtains a thin-film with a high-density structure and smooth surface. The optimal parameters for sputtering are RF power 200 W, ambient pressure 3×10−3 Torr, O2/Ar flow ratio of 1/8 and the distance between target and substrate of 35 mm. Finally, interdigital transducers were fabricated on the films to measure the characteristics of the SAW device. Consequently, the characteristics of SAW devices can be significantly enhanced by using diamond like carbon thin film as the inter-layer.
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