The phase stability of hafnium aluminate films was analyzed for alternative gate dielectrics. The films of different compositions were deposited by jet vapor deposition at room temperature. The microstructure of the films was analyzed by high-resolution transmission electron microscopy, electron diffraction and electron energy loss spectroscopy (EELS) after annealing at 1100°C. The results show that with an increase in the Al content in the films, the amount of metastable HfO 2 with a tetragonal distorted fluorite structure increases, and no crystalline Al 2O 3 phase is detected in electron diffraction patterns in films with up to 30 mol% Al 2O 3.
ASJC Scopus subject areas
- Physics and Astronomy(all)