Tailoring optical and electrical properties of thin-film coatings based on mixed Hf and Ti oxides for optoelectronic application

被引：26

作者：

Obstarczyk, A. ^{[1
]}

Kaczmarek, D. ^{[1
]}

Wojcieszak, D. ^{[1
]}

Mazur, M. ^{[1
]}

Domaradzki, J. ^{[1
]}

Kotwica, T. ^{[1
]}

Pastuszek, R. ^{[1
]}

Schmeisser, D. ^{[2
]}

Mazur, P. ^{[3
]}

Kot, M. ^{[2
]}

机构：

[1] Wroclaw Univ Sci & Technol, Fac Microsyst Elect & Photon, Janiszewskiego 11-17, PL-50372 Wroclaw, Poland

[2] Brandenburg Univ Technol Cottbus Senftenberg, Appl Phys & Sensors, Konrad Wachsmann Allee 17, D-03046 Cottbus, Germany

[3] Univ Wroclaw, Inst Expt Phys, Max Born 9, PL-50204 Wroclaw, Poland

来源：

MATERIALS & DESIGN | 2019年 / 175卷

关键词：

Magnetron sputtering; Optical coatings; Electrical properties; Mixed oxides; HfO2; TiO2; High-k oxides; Amorphous thin films; HIGH-K DIELECTRICS; ANNEALING-TEMPERATURE; HAFNIUM OXIDE; GATE DIELECTRICS; LEAKAGE CURRENT; BAND ALIGNMENT; MICROSTRUCTURE; DEPOSITION; MODULATION; CHEMISTRY;

D O I：

10.1016/j.matdes.2019.107822

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

In this work multi-magnetron sputtering stand was used for the deposition of the mixed oxides thin films based on HfO2 and TiO2. In order to obtain various material composition the power released to each magnetron (containing metallic hafnium and titanium targets) was precisely selected. Structural, surface, optical, electrical and mechanical properties of as-deposited coatings were analyzed. Depending on the hafnium content in the deposited thin films various types of the microstructure was obtained, i.e. HfO2-monoclinic, amorphous and TiO2-rutile. Increase of Ti content above 28 at. % in the as-prepared mixed oxides coatings caused their amorphization. It was found that with an increase of Ti content in prepared coatings their surface roughness and simultaneously water contact angle decreased. Performed measurements of electrical properties revealed that the lowest leakage current density in the range of 10(-7)-10(-8)A/cm(2) was obtained for amorphous coatings. Moreover, the tailoring of the dielectric constant was possible by a proper selection of material composition and microstructure of the deposited thin films. Average transparency in the visible wavelength region was in the range of ca. 79-86%. The influence of material composition and structure on shifting of the fundamental absorption edge and optical band gap energy was also observed. The refractive index increased with an increase of Ti content, while extinction coefficient was the lowest for amorphous coatings. Additionally, hardness values were dependent on the material composition and optical packing density and were in the range from 7.6 GPa to 10.1 GPa. (C) 2019 The Authors. Published by Elsevier Ltd.

引用

页数：15

共 64 条

[1] Growth, microstructure and electrical properties of sputter-deposited hafnium oxide (HfO2) thin films grown using a HfO2 ceramic target [J].