Structure and electrical property of platinum film biased dc-sputter-deposited on silicon

A study is made by Cross-sectional transmission electron microscopy (X-TEM) and by measuring electrical resistivity rho as a function of temperature ( less than or equal to 300 K), of structure and electrical property of Pt fi lms equal to or thinner than 35 nm which are deposited on Si(0 0 1) at 200 degreesC by de-sputtering at -2.7 kV in Ar gas. A bias voltage V-s of 0 or -90 V is applied to the substrate during deposition. As deposited Pt films retain polycrystalline structure with PtSi compound f ormation and inter-atomic diffusion at the Pt/Si interface both of which ar e suppressed with application of V, and the rho values of them decrease wit h an increase in temperature T from 50-150 to 300 K depending on both V, an d thickness. After annealed at 450 degreesC for 30 min in 10(-5) Pa, the fi lms consist mainly of PtSi at V-s = 0 V and still mainly of Pt at V-s = -90 V while the T range where negative T coefficient of rho (n-TCR) is observe d is localized between 100 and 140 K for the 33 nm thick film prepared at V -s = 0 V but diffused away from 70 to 220 K for the 35 nm thick film prepar ed at V-s = -90V. The application of V-s is effective to determine the stru ctural and electrical properties of Pt films de-plasma-sputter deposited on Si(0 0 1) through controlling compound formation and inter-atomic diffusio n at the interface. (C) 2001 Elsevier Science B.V. All rights reserved.