Effects of post-annealing on texture evolution of sputtered ScAlN films

The piezoelectric response of the sputtered scandium aluminum nitride (ScAlN) film are highly dependent on its crystallinity. The film texture continues to develop during the post-annealing process at high temperatures. In this work, the annealing experiments at temperatures up to 1000 °C were conducted on the sputtered ScAlN/Mo film stacks. Temperature dependences of the crystal structure and the stress were evaluated and discussed. The interface between the ScAlN film and the bottom Mo electrode is also inspected to assess the thermal stability. Our results would contribute to the robust piezoelectric device development.