کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1664521 | 1518013 | 2015 | 7 صفحه PDF | دانلود رایگان |
• W–O–N films of ~ 100 nm thick were sputter-deposited by varying nitrogen gas flow rate.
• Nitrogen incorporation into W-oxide is effective at or after 9 sccm flow rate of nitrogen.
• The band gap significantly decreases from ~ 3.0 eV to ~ 2.1 eV with progressive increase in nitrogen content.
• A composite oxide-semiconductor of W–O–N is proposed to explain the optical properties
Tungsten oxynitride (W–O–N) thin films were deposited onto silicon (100) and quartz substrates using direct current (DC) sputtering. Composition variations in the W–O–N films were obtained by varying the nitrogen gas flow rate from 0 to 20 sccm, while keeping the total gas flow constant at 40 sccm using 20 sccm of argon with the balance comprised of oxygen. The resulting crystallinity, optical properties, and chemical composition of the DC sputtered W–O–N films were evaluated. All the W–O–N films measured were shown to be amorphous using X-ray diffraction. Spectrophotometry results indicate that the optical parameters, namely, the transmission magnitude and band gap (Eg), are highly dependent on the nitrogen content in the reactive gas mixture. Within the W–O–N system, Eg was able to be precisely tailored between 2.9 eV and 1.9 eV, corresponding to fully stoichiometric WO3 and highly nitrided W–O–N, respectively. Rutherford backscattering spectrometry (RBS) coupled with X-ray photoelectron spectroscopy (XPS) measurements indicate that the composition of the films varies from WO3 to W–O–N composite oxynitride films.
Journal: Thin Solid Films - Volume 596, 1 December 2015, Pages 160–166