A robust nitridation technique for fabrication of disordered superconducting TiN thin films featuring phase slip events

• Published in: Scientific reports 2021-04, Vol.11 (1), p.7888-7888, Article 7888
• Main Authors: Yadav, Sachin, Kaushik, Vinay, Saravanan, M. P., Aloysius, R. P., Ganesan, V., Sahoo, Sangeeta
• Format: Article
• Language: English
• Subjects: 639/766; 639/766/119; 639/766/119/1003; Fabrication; High temperature; Humanities and Social Sciences; multidisciplinary; Science; Science (multidisciplinary); Silicon nitride; Thin films
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-86819-6

Disorder induced phase slip (PS) events appearing in the current voltage characteristics (IVCs) are reported for two-dimensional TiN thin films produced by a robust substrate mediated nitridation technique. Here, high temperature annealing of Ti/Si 3 N 4 based metal/substrate assembly is the key to produce majority phase TiN accompanied by TiSi 2 & elemental Si as minority phases. The method itself introduces different level of disorder intrinsically by tuning the amount of the non-superconducting minority phases that are controlled by annealing temperature ( T a ) and the film thickness. The superconducting critical temperature ( T c ) strongly depends on T a and the maximum T c obtained from the demonstrated technique is about 4.8 K for the thickness range ~ 12 nm and above. Besides, the dynamics of IVCs get modulated by the appearance of intermediated resistive steps for decreased T a and the steps get more prominent for reduced thickness. Further, the deviation in the temperature dependent critical current ( I c ) from the Ginzburg–Landau theoretical limit varies strongly with the thickness. Finally, the T c , intermediate resistive steps in the IVCs and the depairing current are observed to alter in a similar fashion with T a and the thickness indicating the robustness of the synthesis process to fabricate disordered nitride-based superconductor.