Molecular beam epitaxial growth of strained Si1-xGex layers on graded Si1-yGey for Pt silicide Schottky diodes

摘要

Low temperature growth of a high quality strained Si1-xGex film on graded Si1-yGey is demonstrated using MBE. In situ monitoring of reflection high electron energy diffraction (RHEED) patterns and intensity oscillations during different stages of the growth has shown two-dimensional pseudomorphic growth, The layers have been further characterized by x-ray photoelectron spectroscopy (XPS), x-ray diffraction (XRD), secondary ion mass spectroscopy (SIMS) and atomic force microscopy (AFM). The Schottky barrier height of platinum-silicide (PtSi) on p-type Si1-xGex has been found to vary between 0.19-0.57 eV in the temperature range 100-300 K. At 300 K, the ideality factor has been found to be 2.0 and 1.32 for PtSi/Si0.81Ge0.19 and PtSi/Si0.71Ge0.29 diodes, respectively. References: 14