X-ray photoelectron spectroscopy and diffraction investigation of a metal–oxide-semiconductor heterostructure: Pt/Gd2O3/Si(111)

Abstract Platinum thin films deposited by physical vapor deposition (PVD) on Gd 2 O 3 /Si(111) templates are investigated by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and X-ray photoelectron diffraction (XPD). Both XRD and XPD give clear evidence that Gd 2 O 3 grows (111)-oriented and single-domain on Si(111) with mirror epitaxial relationship viz., [1¯10] Gd 2 O 3 (111)//[11¯0] Si(111). On Gd 2 O 3 /Si(111), Pt is partially crystallized with (111) orientation. There are two epitaxial domains and a slightly visible (111) fiber texture. The in-plane relationships of these Pt(111) domains with Gd 2 O 3 (111) are a direct one: [11¯0] Pt(111)//[11¯0] Gd 2 O 3 (111) and a mirror one: [1¯10] Pt(111)//[11¯0] Gd 2 O 3 (111). XPS reveals that Pt4f exhibits a metallic behavior even for small amounts of Pt but very small chemical shifts suggest that Pt environment is different at the interface with Gd 2 O 3 . These XPS chemical shifts have been correlated with features in XPD azimuth curves, which could be related with the existence of hexagonal α -PtO 2 (0001)layer.