Role of the substrate and the temperature of deposition on the properties of the TaxN thin films

We present an interim report on the investigations of the Ta
_x
N thin films deposited on the (100) Si wafers coated with a 140-nm thermal SiO
₂
layer. Our conclusions are based on the room temperature sheet resistance measurements, transport properties measurements from helium up to room temperature and on the Raman spectra analysis of the investigated series. In particular, we discuss a nonmonotonous concentration dependence of transport properties. This behaviour we attribute to a local minimum in the density of electronic states at the Fermi level calculated for the intermetallic Ta
₄
N
₅
[1]. Such behaviour was not observed in other investigations on the transport properties of Ta
_x
N found in literature. Also our Raman spectra show some differences compared to other Raman investigations on Ta
_x
N. We ascribe these and other differences discussed to the substrate properties which were used in the preparation of these thin films. The overall properties of the Ta
_x
N deposited on the oxidized Si wafers are compared to the properties of the Ta
_x
N thin films deposited on sapphire.