Optimization of silicon nanocrystals growth process by low pressure chemical vapor deposition for non-volatile memory application

The processes of silicon nanocrystals (Si-NCs) growth on both SiO2 and Si3N4 substrates by low pressure chemical vapor deposition have been systematically investigated. A two-step process was adopted for Si-NCs growth: nucleation at a high temperature (580-600 °C) and growth at a low temperature (550 °C). By adjusting the pre-deposition waiting time and deposition time, the density, size and uniformity can be effectively controlled. Compared to the growth of Si-NCs on SiO2, the coalescence speed of Si-NCs on Si3N4 is faster. Uniform Si-NCs with a high density of 1.02 × 1012 cm− 2 and 1.14 × 1012 cm− 2 have been obtained on SiO2 and Si3N4, respectively. Finally, a Si-NCs-based memory structure with a 2.1 V memory window was demonstrated.