Publikationsrepositorium - Helmholtz-Zentrum Dresden-Rossendorf

Semiconductor nanocrystals in dielectric matrices are of great interest for a broad range of applications, especially in the field of photon management in solar cells and for non-volatile memories. In this work we investigate the formation of crystalline Ge nanoparticles in superlattice stacks by flash lamp annealing. In detail, amorphous ZrO2/Ge and SiN/Ge superlattices confined by two SiO2 layers on Si were produced by magnetron-sputtering and plasma-enhanced chemical vapor deposition, respectively. Raman and TEM investigations reveal that, depending on the original Ge layer thickness, crystalline Ge nanoparticles with different aspect ratios will be formed under annealing. As shown by electrical measurements, these layers feature large charge trapping capabilities. We compare these two types of layer systems with regard to the formation process of the Ge nanoparticles, the trapped charge density, the memory window and the retention. Finally, the perspectives for non-volatile memories are discussed, if these layer stacks are downscaled to current device dimensions.