Preparation and characteristics of Nb-doped indium tin oxide thin films by RF magnetron sputtering

Abstract

Niobium-doped indium tin oxide (ITO:Nb) thin films are fabricated on glass substrates by radio frequency (RF) magnetron sputtering at different temperatures. Structural, electrical and optical properties of the films are investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), ultraviolet-visible (UV-VIS) spectroscopy and electrical measurements. XRD patterns show that the preferential orientation of polycrystalline structure changes from (400) to (222) crystal plane, and the crystallite size increases with the increase of substrate temperature. AFM analyses reveal that the film is very smooth at low temperature. The root mean square (RMS) roughness and the average roughness are 2.16 nm and 1.64 nm, respectively. The obtained lowest resistivity of the films is 1.2×10⁻⁴Ω·cm, and the resistivity decreases with the increase of substrate temperature. The highest Hall mobility and carrier concentration are 16.5 cm²/V·s and 1.88×10²¹cm⁻³, respectively. Band gap energy of the films depends on substrate temperature, which is varied from 3.49 eV to 3.63 eV.

Keywords

Atomic Force Microscopy / Substrate Temperature / Root Mean Square / Hall Mobility / Average Roughness

References

[1] DelahoyA. E., ChenL., AkhtarM., SangB., GuoS.. Solar Energy, 2004, 77: 785

[2] LiC. P., YangB. H., QianL. R., XuS., DaiW., LiM. J., LiX. W., GaoC. Y.. Optoelectronics Letters, 2011, 7: 431

[3] MaR. X.. Optoelectronics Letters, 2011, 7: 45

[4] TaharR. B. H., BanT., OhyaY., TakahashiY.. J. Appl. Phys., 1998, 81: 321

[5] AperathitisE., BenderM., CimallaV., EckeG., ModreanuM.. J. Appl. Phys., 2003, 94: 1258

[6] LanY. F., PengW. C., LoY. H., HeJ. L.. Materials Research Bulletin, 2009, 44: 1760

[7] MengL. J., GaoJ., SantosdM. P. d., WangX., WangT. T.. Thin Solid Films, 2008, 516: 1365

[8] ZhengJ. P., KwokH. S.. Applied Physics Letters, 1993, 63: 1

[9] TakahashiY., OkadaS., TaharR. B. H., NakanoK., BanT., OhyaY.. Journal of Non-Crystalline Solids, 1997, 218: 129

[10] SasabayashiaT., ItoaN., NishimuraaE., KonaM., SongaP. K., UtsumibK., KaijocA., ShigesatoY.. Thin Solid Films, 2003, 445: 219

[11] LuisA., CarvalhoC. N. d., LavaredaG., AmaralA., BrogueiraP., GodinhM. H.. Vacuum, 2002, 64: 475

[12] BeloG. S., SilvaB. J. P. d., VasconcelosE. A. d., AzevedoW. M. d., da SilvaE. F.Jr. Applied Surface Science, 2008, 255: 755

[13] AmaralA., BrogueiraP., CarvalhoC. N. d., LavaredaG.. Journal of Nanoscience and Nanotechnology, 2010, 10: 2713

[14] HestM. F. A. M. v., DabneyM. S., PerkinsJ. D., GinleyD. S.. Applied Physics Letters, 2005, 87: 2111

[15] PaengS. H., ParkM. W., SungY. M.. Surface and Coatings Technology, 2010, 205: 210

[16] GuptaR. K., GhoshK., PatelR., KaholP. K.. Applied Surface Science, 2009, 255: 6252

[17] YangM., FengJ. H., LiG. F., ZhangQ.. Journal of Crystal Growth, 2008, 310: 3474

[18] KangY. M., KwonS. H., ChoiJ. H., ChoY. J., SongP. K.. Thin Solid Films, 2010, 518: 3081

[19] ChungS. M., ShinJ. H., CheongW. S., HwangC. S., ChoaK. I., KimY. J.. Ceramics International, 2012, 38: s617

[20] YangC. H., LeeS. C., LinT. C., ZhuangW. Y.. Materials Science Engineering B, 2006, 134: 68

[21] YaoJ., ShaoJ., HeH., FanZ. X.. Applied Surface Science, 2007, 253: 8911

[22] KimH., HorwitzJ. S., KushtoG. P., QadriS. B., KafafiZ. H., ChriseyD. B.. Appl. Phys. Lett., 2001, 78: 1050

[23] SarkaraA., GhoshaS., ChaudhuriaS., PalA. K.. Thin Solid Films, 1991, 204: 255