ABSTRACT
Analysis of the energy loss near edge structure present on the ionisation edges recorded using spectrum imaging is a powerful tool for the investigation of the physical and chemical changes that occur during the deposition and processing of high-k gate stacks. The replacement of SiO2 as the gate oxide in CMOS by materials with higher permittivity such as HfD2/HfSiO has encountered problems from physical and chemical changes that occur during processing of the gate stack. Spectrum imaging is a powerful technique with which to investigate the structure and chemistry of such gate stacks. Spectrum imaging was performed using Gatan Digital Micrograph and Digiscan software. Line spectrum images were recorded across the oxide regions of the stack. The endeavour to replace SiO2 as the gate oxide in CMOS devices by a dielectric with higher permittivity is one of the grand challenges in the International Technology Roadmap for Semiconductors.
