Fabrication of Lithium Phosphorus Oxynitride (LiPON) Thin Films by r.f. Sputtering Coupled with Electron Cyclotron Resonance

Lithium Phosphorus Oxynitride (LiPON) thin films were successfully deposited by r.f. sputtering of Li3PO4 target coupled with electron cyclotron resonance (ECR) in N2 ambient. The effects of ECR powers on the composition, surface morphology, and structures of the as-deposited thin films were examined by X-ray photoelectron spectra (XPS), scanning electron microscope (SEM), and UV-Vis spectra measurements. The results indicated that ECR power had an influence on the growth of LiPON thin films. The optimization condition was found to be at ECR power of 200W to assist r.f. sputtering deposition of LiPON thin films, and Li ionic conductivity was obtained to be 8.0×10~6S/cm. Too high ECR power may be proven to destroy the structure of the thin film, and go against the effective insertion of N into Li3PO4. The mechanism of N inserted into Li3PO4 was discussed during r.f. sputtering process with ECR plasma assisting for the fabrication of LiPON film.