Experimental observations of the thermal stability of high-k gate dielectric materials on silicon

TLDR: In this paper, high-k dielectric materials including zirconium oxide and hafnium oxide produced by atomic layer deposition have been evaluated for thermal stability using analyses derived from X-ray diffraction (XRD), Xray reflectometry (XRR), medium energy ion spectroscopy, high resolution transmission electron microscopy (HRTEM), tunneling atomic force microscopy, scanning electron microscopes, Auger electron spectroscope and secondary ion mass spectrography.

Abstract: High-k dielectric materials including zirconium oxide and hafnium oxide produced by atomic layer deposition have been evaluated for thermal stability. As-deposited samples have been compared with rapid thermal annealed samples over a range of source/drain dopant activation temperatures consistent with conventional complimentary metal oxide semiconductor polysilicon gate processes. Results of this initial investigation are presented utilizing analyses derived from X-ray diffraction (XRD), X-ray reflectometry (XRR), medium energy ion spectroscopy, high resolution transmission electron microscopy (HRTEM), tunneling atomic force microscopy, scanning electron microscopy, Auger electron spectroscopy and secondary ion mass spectroscopy. Changes in interface and surface roughness, percent crystallinity and phase identification for each material as a function of anneal temperature have been determined by XRD, XRR and HRTEM. Finally, high-k wet etch issues are presented relative to subsequent titanium silicide blanket film resistivity values.