Paper EM-WeM6
Boron Oxynitride as Gate Dielectric Films for Future CMOS Technology

Wednesday, October 22, 2008, 9:40 am, Room 210

Existing silicon oxynitride dielectric can only provide a very near term solution for the CMOS technology. The emerging high-k materials have a limited thermal stability and are prone to electrical behavior degradation which is associated with unwanted chemical reactions with silicon. We investigate here applicability of amorphous boron oxynitride (BO_xN_1-x) thin films as an emerging high temperature gate dielectric. (BO_xN_1-x) samples of thickness varying from 10 nm down to 1 nm were deposited in a high vacuum reactor using filamentless ion source assisted physical vapor deposition technique. The (BO_xN_1-x) dielectric structural and mechanical properties were investigated as a function of thickness and O/N composition. B10 implanted (BO_xN_1-x) /Si heterostructures and (BO_xN_1-x) layers deposited on B10 implanted Si substrates were post annealed at high temperatures up to 1000°C. Depth profiling of these layers were performed to evaluate the stability of the dielectric layers and their efficacy against B dopant diffusion simulating processes occurring in activated polySi-based devices. Elemental composition along with chemical and electronic states analysis of the layers were carried out using Secondary Ion Mass Spectrometry (SIMS), Glow Discharge Optical Emission Spectroscopy (GDOES), Glow Discharge Time of Flight Mass Spectrometry (GD-TOFMS) and X-ray Photo-Electron Spectroscopy techniques. Preliminary results show that (BO_xN_1-x) dielectric constant ranges from 4 – 6 and that capacitance change with temperature (25°C- 400°C) and frequency (10 KHz-2 MHz) is about 10% and 2%, respectively. Our conclusions on suitability of (BO_xN_1-x) for advanced energy storage devices and gate dielectric for future CMOS technology will be presented.

This research was supported in part by USDOE grant # DE-FG02-05ER84325 to Integrated Micro Sensors, Inc.