High-k dielectrics by UV photo-assisted chemical vapour deposition

An overview of our recent work on thin films of metal oxides deposited on silicon by a novel excimer lamp-assisted ultraviolet injection liquid source CVD (UVILS-CVD) process for advanced high-k gate dielectrics applications will be presented. Recent results on TiO2, Ta2O5, ZrO2, HfO2, and TiO2-doped Ta2O5 will be demonstrated. The physical, structural, surface and interfacial properties and electrical characterisation of the as-deposited and UV-annealed new high dielectric constant (high-k) materials, determined using ellipsometry, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, LTV spectrophotometry, SEM, TEM and C-V, I-V measurements, showed that good quality layers could be produced. The investigation of high-k dielectrics grown by the UVILS-CVD process clearly demonstrates that low cost, high power density excimer lamp systems can provide an interesting alternative to conventional UV lamps and excimer lasers for industrial large-scale low temperature materials processing. UVILS-CVD is a promising technique for the controlled deposition of ultra-thin high-k metal-oxide dielectrics for deep sub-micron CMOS devices at temperatures as low as 350 degreesC. (C) 2002 Elsevier Science B.V. All rights reserved.