Low-Energy Ion-Beam-Synthesis of Semiconductor Nanocrystals in Very Thin High-k Layers for Memory Applications

The fabrication of nanocrystals (NCs) into high-k dielectric matrices instead of SiO2 has retained particular attention for achieving NC memories with low programming voltages and improved charge retention. We present here an approach to face the challenge of NC formation into very thin (5–10 nm) high-k dielectrics related to the fabrication by low-energy ion-beam-synthesis of semiconductor (Si, Ge) NCs in thin oxide nitride oxide and Al2O3 films. The resulting structures were examined by coupling high resolution electron microscopy, energy filtered transmission electron microscopy and electron energy loss spectroscopy.