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

Abstract

The processes of silicon nanocrystals (Si–NCs) growth on both SiO 2 and Si 3N 4 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 SiO 2, the coalescence speed of Si–NCs on Si 3N 4 is faster. Uniform Si–NCs with a high density of 1.02 × 10 12 cm − 2 and 1.14 × 10 12 cm − 2 have been obtained on SiO 2 and Si 3N 4, respectively. Finally, a Si–NCs-based memory structure with a 2.1 V memory window was demonstrated.