Interface reactions between Pd thin films and SiC by thermal annealing and SHI irradiation

• DOI: 10.1016/j.nimb.2015.10.014
• Publication Date: 2015-10-25T05:24:18Z
• Authors: E.G. Njoroge; C.C. Theron; V.A. Skuratov; D. Wamwangi; T.T. Hlatshwayo; C.M. Comrie; J.B. Malherbe
• Keywords: Rutherford backscattering spectrometry; Swift heavy ion

Abstract The solid-state reactions between Pd thin films and 6H-SiC substrates induced by thermal annealing, room temperature swift heavy ion (SHI) irradiation and high temperature SHI irradiation have been investigated by in situ and real-time Rutherford backscattering spectrometry (RBS) and Grazing incidence X-ray diffraction (GIXRD). At room temperature, no silicides were detected to have formed in the Pd/SiC samples. Two reaction growth zones were observed in the samples annealed in situ and analysed by real time RBS. The initial reaction growth region led to formation of Pd 3 Si or (Pd 2 Si + Pd 4 Si) as the initial phase(s) to form at a temperature of about 450 °C. Thereafter, the reaction zone did not change until a temperature of 640 °C was attained where Pd 2 Si was observed to form in the reaction zone. Kinetic analysis of the initial reaction indicates very fast reaction rates of about 1.55 × 10 15 at cm −2 /s and the Pd silicide formed grew linear with time. SHI irradiation of the Pd/SiC samples was performed by 167 MeV Xe 26+ ions at room temperature at high fluences of 1.07 × 10 14 and 4 × 10 14 ions/cm 2 and at 400 °C at lower fluences of 5 × 10 13 ions/cm 2 . The Pd/SiC interface was analysed by RBS and no SHI induced diffusion was observed for room temperature irradiations. The sample irradiated at 400 °C, SHI induced diffusion was observed to occur accompanied with the formation of Pd 4 Si, Pd 9 Si 2 and Pd 5 Si phases which were identified by GIXRD analysis.