Monitoring of oxidation phases of copper thin films using long period fiber gratings

• Type: Article in International Scientific Journal
• Date: 2017

Authors

Coelho, L (Author) FCUP; Agostinho Moreira, JA (Author) FCUP; Tavares, PB (Author) Other; Santos, JL (Author) FCUP; Viegas, D (Author) FCUP; de Almeida, JMMM (Author) FCUP

Journal

Title: Sensors and Actuators, A: Physical

Vol. 253

Pages: 69-74

ISSN: 0924-4247

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 7 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-00M-760

DOI: 10.1016/j.sna.2016.11.024

Abstract (EN): Long period fiber gratings (LPFGs) were used to monitor the characteristics of copper (Cu) thin films when annealed in air atmosphere up to similar to 680 degrees C. The wavelength and the optical power shift of the resonant bands of the LPFGs when coated with the Cu thin films, were measured as a function of the annealing temperature, and were found to exhibit a different evolution comparing to a bare LPFGs. Thin films of Cu deposited on quartz (SiO2) substrates were annealed and analyzed by XRD, SEM/EDS and Raman spectroscopy, allowing to identify the formation of two distinct oxide phases at different temperatures, cuprous (Cu2O-cuprite) and cupric (CuO-tenorite) oxides, respectively. The observed features of the resonant bands of the LPFGs were found to be associated with the Cu oxide phase transitions, indicating the possibility of using LPFGs to monitor, in real time, the oxidation states of Cu thin films by following specific characteristics of the attenuation bands. In addition, LPFGs over coated with the two distinct oxidation phases of Cu were characterized for refractive index sensing in the range between 1.300 to 1.600, leading to the conclusion that the sensitivity to the refractive index of the surrounding medium of Cu coated LPFGs sensing systems can be temperature tuned.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6