Analysis of hafnium containing powders and thin films for CMOS device applications

As the SiO₂ or Si(O, N) layer in complementary metal oxide semiconductor (CMOS) devices reaches its atomic limits it is necessary to find suitable materials that will allow further device scaling. Leading candidate materials include hafnia and hafnium silicate; however, issues remain regarding their stability which must be resolved. This paper highlights some of these issues in hafnium-containing gate stacks. Hafnium silicate bulk powders were investigated to gain a better understanding of the chemistry and crystallisation processes involved. This was done using x-ray diffraction, thermal analysis, transmission electron microscopy and electron energy-loss spectroscopy.