In this work, we have successfully demonstrated SONOS memories with embedded Si-NCs in silicon nitride by In-situ deposition method. The self-assembly silicon nanocrystals were in-situ deposited within the Si 3N4 storage layer by dissociation of dichlorosilane (SiH2Cl2) gas to a high density of 9 × 10 11 cm-2. This new structure exhibits larger memory windows for up to 6 V, better program/erase characteristics, and excellent data retention properties as compared to control device. In addition, this novel process is simple, low cost, and compatible to the standard complementary metal-oxide-semiconductor (CMOS) processes. This technology seems to be very promising for the advanced flash memory devices.