Interfacial strain-induced self-organization in semiconductor dielectric gate stacks. II. Strain-relief at internal dielectric interfaces between SiO ₂ and alternative gate dielectrics

The strain-relief at internal dielectric interfaces between interfaces between SiO ₂ and alternative dielectrics was investigated. A scaling relationship for the density of bond-strain induced defects at internal dielectric interfaces was developed using bond constraint theory. It was observed that the interfaces between SiO ₂ and ZrO ₂, HfO ₂ and Zr and Hf silicate alloys showed a strain-induced self-organization after annealing to temperature of ∼600-800 °C, producing a diphasic interfacial transition region . On the other hand, strain-induced self-organization did not occur at interfaces between SiO ₂ and Al ₂O ₃ alloys for temperature up to 1000 °C.