Publications in Scientific Journals:
V. Moraes, H. Riedl, R. Rachbauer, S. Kolozsvari, M. Ikeda, L. Prochaska, S. Paschen, P.H. Mayrhofer:
"Thermal conductivity and mechanical properties of AlN-based thin films";
Journal of Applied Physics,
While many research activities concentrate on mechanical properties and thermal stabilities of protective thin ﬁlms, only little is known about their thermal properties being essential for the thermal management in various industrial applications. Based on the 3x-method, we show the inﬂuence of Al and Cr on the temperature dependent thermal conductivity of single-phase cubic structured TiN and single-phase wurtzite structured AlN thin ﬁlms, respectively, and compare them with the results obtained for CrN thin ﬁlms. The dc sputtered AlN thin ﬁlms revealed a highly c-axis oriented growth for deposition temperatures of 250 to 700 C. Their thermal conductivity was found to increase strongly with the ﬁlm thickness, indicating progressing crystallization of the interface near amorphous regions during the sputtering process. For the 940 nm AlN ﬁlm, we found a lower boundary for the thermal conductivity of 55:3Wm1 K1. By the substitution of only 10 at. % Al with Cr, j signiﬁcantly reduces to 5:0Wm1 K1, although the single-phase wurtzite structure is maintained. The single-phase face centered cubic TiN and Ti0.36Al0.64N thin ﬁlms exhibit j values of 3:1Wm1 K1 and 2:5Wm1 K1, respectively, at room temperature. Hence, also here, the sub-stitutional alloying reduces the thermal conductivity, although at a signiﬁcantly lower level. Single-phase face centered cubic CrN thin ﬁlms show j values of 3:6Wm1 K1. For all nitride based thin ﬁlms investigated, the thermal conductivity slightly increases with increasing temperature between 200 and 330 K. This rather unusual behavior is based on the high defect density (especially point defects) within the thin ﬁlms prepared by physical vapor deposition.
"Official" electronic version of the publication (accessed through its Digital Object Identifier - DOI)
Electronic version of the publication:
Project Head Paul Heinz Mayrhofer:
Christian Doppler Labors für anwendungsorientierte Schichtentwicklung
Created from the Publication Database of the Vienna University of Technology.