TY - BOOK

T1 - DC Magnetron Sputter Deposition of Molybdenum Oxide Thin Films from Metallic Mo and Ceramic MoOx Targets: Synthesis, Structure and Property Relations

AU - Pachlhofer, Julia

N1 - no embargo

PY - 2016

Y1 - 2016

N2 - Due to their unique optical, electrical and chemical properties, oxide based thin film materials are widely used in industrial applications ranging from hard coatings via diffusion barriers to thin films for opto-electronic applications. With changes in stoichiometry or by alloying or doping the base materials, it is possible to tune the material properties to the desired level. In the current work, the microstructure-property relationships in correlation with synthesis conditions of molybdenum oxide thin films deposited by dc magnetron sputter deposition were investigated. On the one hand, molybdenum oxide films were synthesised reactively in varying oxygen/argon atmosphere in a laboratory scale deposition system (equipped with circular planar Mo targets) as well as in an industrial scale deposition plant (equipped with a rotatable Mo target). The character of the films varied between non transparent electrically conductive and transparent insulating, depending on the used oxygen partial pressure during deposition. On the other hand, molybdenum oxide films were synthesised by non reactive dc magnetron sputter deposition from circular planar ceramic molybdenum oxide targets developed by powder metallurgical methods within this work with compositions ranging from MoO2.5 to MoO2.8 as an alternative synthesis process. These films exhibited a high optical absorbance and low reflectance character with a semi-conductive behaviour. All synthesised films were dominated by Mo4+ (MoO2), an intermediate oxidation state Mo5+, and Mo6+ (MoO3) depending on the synthesis conditions. In general, a successful upscaling for reactively sputtered molybdenum oxide films with tuneable properties depending on the used oxygen partial pressure during deposition from laboratory to industrial scale could be demonstrated. Moreover, the use of oxide targets in dc magnetron sputter deposition of molybdenum oxide films offers an efficient and reliable alternative to the use of metal targets and, hence, enables the usage of such films for a wide range of optical and electrical applications.

AB - Due to their unique optical, electrical and chemical properties, oxide based thin film materials are widely used in industrial applications ranging from hard coatings via diffusion barriers to thin films for opto-electronic applications. With changes in stoichiometry or by alloying or doping the base materials, it is possible to tune the material properties to the desired level. In the current work, the microstructure-property relationships in correlation with synthesis conditions of molybdenum oxide thin films deposited by dc magnetron sputter deposition were investigated. On the one hand, molybdenum oxide films were synthesised reactively in varying oxygen/argon atmosphere in a laboratory scale deposition system (equipped with circular planar Mo targets) as well as in an industrial scale deposition plant (equipped with a rotatable Mo target). The character of the films varied between non transparent electrically conductive and transparent insulating, depending on the used oxygen partial pressure during deposition. On the other hand, molybdenum oxide films were synthesised by non reactive dc magnetron sputter deposition from circular planar ceramic molybdenum oxide targets developed by powder metallurgical methods within this work with compositions ranging from MoO2.5 to MoO2.8 as an alternative synthesis process. These films exhibited a high optical absorbance and low reflectance character with a semi-conductive behaviour. All synthesised films were dominated by Mo4+ (MoO2), an intermediate oxidation state Mo5+, and Mo6+ (MoO3) depending on the synthesis conditions. In general, a successful upscaling for reactively sputtered molybdenum oxide films with tuneable properties depending on the used oxygen partial pressure during deposition from laboratory to industrial scale could be demonstrated. Moreover, the use of oxide targets in dc magnetron sputter deposition of molybdenum oxide films offers an efficient and reliable alternative to the use of metal targets and, hence, enables the usage of such films for a wide range of optical and electrical applications.

KW - molybdenum oxide

KW - MoO2

KW - MoO3

KW - thin film

KW - reactive sputtering

KW - non-reactive sputtering

KW - molybdenum oxide target

KW - powder metallurgy

KW - Molybdänoxid

KW - MoO2

KW - MoO3

KW - dünne Schichten

KW - reaktives Sputtern

KW - nicht-reaktives Sputtern

KW - Molybdänoxidtarget

KW - Pulvermetallurgie

M3 - Doctoral Thesis

ER -