Multitechnique characterisation of Al₂O₃ thin layers deposited on SiO₂/Si surface by atomic layer chemical vapour deposition

Scaling-down of CMOS devices has driven the thickness of the gate SiO_2 film close to its physical limits. New high-k dielectric materials capable of providing the same capacitance with greater film thickness are considered as a replacement for SiO_2. Several candidate materials are currently under investigation. Different physical parameters of the layers such as thickness, composition, density, impurity depth distribution, etc. have to be determined. Since no single technique can provide all the information needed, the use of different complementary analytical techniques is essential. The results of such multitechnique approach, applied to Al_2O_3 layers deposited on 1 nm film are presented in this paper.