Electrical and optical properties of TiO2 thin films prepared by plasma-enhanced atomic layer deposition

被引：47

作者：

Dang, Van-Son ^{[1
]}

Parala, Harish ^{[1
]}

Kim, Jin Hyun ^{[1
]}

Xu, Ke ^{[1
]}

Srinivasan, Nagendra B. ^{[1
]}

Edengeiser, Eugen ^{[1
]}

Havenith, Martina ^{[1
]}

Wieck, Andreas D. ^{[1
]}

de los Arcos, Teresa ^{[1
]}

Fischer, Roland. A. ^{[1
]}

Devi, Anjana ^{[1
]}

机构：

[1] Ruhr Univ Bochum, Bochum, Germany

来源：

PHYSICA STATUS SOLIDI A-APPLICATIONS AND MATERIALS SCIENCE | 2014年 / 211卷 / 02期

关键词：

dielectric properties; leakage current; plasma-enhanced atomic layer deposition; Raman spectroscopy; thin films; TiO2; CHEMICAL-VAPOR-DEPOSITION; DIELECTRIC-PROPERTIES; TEMPERATURE; TITANIUM; ANATASE; GROWTH; OXIDES; ALD;

D O I：

10.1002/pssa.201330115

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We report on the electrical and optical characterisation of the high-permittivity (high-) TiO2 thin films grown by plasma enhanced atomic layer deposition on Si (100) and glass substrates, respectively. TiO2 films were incorporated in metal-oxide semiconductor (MOS) capacitor structures with an Al metal gate electrode. The as-deposited films were amorphous; however upon annealing in the temperature range 500-900 degrees C, crystalline TiO2 in the anatase phase was formed. This was further confirmed by performing Raman measurements where the characteristic features corresponding to the anatase phase were observed. Transmittance and absorption spectra of the as-deposited and annealed films were performed by UV-Vis measurements showing more than 70% of transmittance. The formation of stoichiometric TiO2 was revealed by X-ray photoelectron spectroscopy (XPS) and Rutherford backscattering spectroscopy (RBS) analysis performed on annealed samples (500-900 degrees C). The dielectric constants were calculated from capacitance-voltage (C-V) curves of the MOS structure on the as-deposited film and annealed films revealing a significant improvement of the dielectric constants from 10 to 75 at AC frequencies of 100kHz for the 700 degrees C annealed TiO2 thin films. The increase in the dielectric constant for annealed films could be attributed to the transformation of film structure from amorphous to polycrystalline (anatase). However, the transformation of amorphous to crystalline phase, leads to an increase in the leakage current which was also found best fitted with Schottky emission mechanism at moderated electric fields.

引用

页码：416 / 424

页数：9

共 41 条

[1] Dielectric properties of TiO2-films reactively sputtered from Ti in an RF magnetron [J].