Comparative Study of Non-Annealing and Annealing on Properties of ITO Deposited by RF Magnetron Sputtering

Abstract

A comparison of the properties for two ITO thin films was performed. The two films were as follows – as-deposited and annealed ITO films. The influence of annealing on the structural, morphological, electrical, and optical properties was studied. The post-annealing treatment was done at a temperature of 400 for 1 h in air. The ITO thin films were deposited onto glass substrates by RF magnetron sputtering of a ceramic In2O3: SnO2 target in pure argon atmosphere at a low base pressure of <10-6 mbar and a RF power of 50 W. The films were characterized by XRD, FTIR, contact angle measurements, FE-SEM combined with EDX, Hall-effect measurements and UV-Vis transmission spectroscopy. The ITO films showed a crystalline structure with a predominant orientation (400) and its intensity was increased after the film was annealed. The structure of the annealed film became reformed in more perfect columnar structure. The annealed film showed a decrease in contact angle and increase in FTIR spectra intensity. The annealing induced more tin incorporated into the film from 0.51 to 2.62 at%. The resistivity decreased from 2.7x10-3 to 1.1x10-3 Ω cm with increasing mobility from 7.5 to 27.5 cm2 V-1 s-1 but decreasing carrier concentration from 3.0x1020 to 2.0 x 1020 cm-3. The optical band gap increased from 3.43 to 3.50 eV. All films showed highly transparency (∼85%) in the visible light region. Compared with the non-annealed ITO film, the air-annealed ITO film revealed the better properties except for carrier concentration.

Realizing the Potential of RF-Sputtered Hydrogenated Fluorine-Doped Indium Oxide as an Electrode Material for Ultrathin SiOx/Poly-Si Passivating Contacts

“…sample, the S-parameter is 2.5% lower than that of the as-dep. sample, indicating elimination of the V In -nVo complex due to local oxidation, 53,55 which is also supported by a reported phenomenon 28 and the degraded electrical properties as shown in Hall measurements (Figure 2). S1.…”

“…We note that in our various annealing tests regarding the single TCO layer, our IFO:H films were stable up to 300 °C in N 2 , H 2 , and air ambiences, and annealing temperature above 400 °C facilitated considerable changes in electrical properties (a duration of 10 min was used in the annealing tests, “stable” means that the sheet resistance change upon annealing is within 5% compared to the as-deposited film). To avoid overheating of our poly-Si cell precursors, 400 °C was chosen to stimulate opto-electrical properties change in TCO and to maintain the passivation quality at the Si/SiO 2 interface. , …”

Effect of SnCl₄ Concentration on Transparent and Conducting Undoped Tin Oxide Thin Films

“…Indium tin oxide (ITO) is one of the most commonly known TCOs. ITO has a better optical transmission and a higher charge carrier concentration [3]. It is currently used as the industrial standard material for optoelectronic devices.…”