AFM studies of the systems Hf/Si(100) and HfO2/Si(100)

The ongoing down-scaling of silicon based structures in the semiconductor industry leads to the demand of new gate dielectrics with high k values in order to replace the currently used SiO2. One of the most promising candidates is HfO2. In this work the thermal stability of thin films of Hf on Si(100) was studied with in situ (conductive)-AFM and LEED investigations. At temperatures above 700 C a (2 x 1) LEED pattern indicates large parts of the uncovered Si substrate surface. Further HfO2 was evaporated onto Si(100) substrates. The oxide films were stepwise heated from 400 C up to 900 C. After each annealing process the surface morphology and the growth of the HfSi2 islands was investigated by AFM and LEED