Colloidal nanoparticles based non-volatile memory device: Role of wettability by nanoparticles solvents

Ethylene glycol and ortho-dichlorobenzene solvents are used for Nickel (Ni) and Cobalt (Co) nanoparticles (NPs) synthesis, respectively. The wettability by these colloidal nanoparticles samples over silicon oxide wafer substrate has been studied to get insight about distribution of nanoparticles over oxide wafer. It has been found that the samples having nanoparticles in ortho-dichlorobenzene and ethylene glycol solvents show average contact angles of 5.40° and 20.10° over silicon oxide wafer, respectively. Further, metal-oxide-semiconductor (MOS) non volatile memory (NVM) capacitors embedded with spin coated nanoparticles using above two nanoparticles solutions are fabricated. Tunnel oxide of SiO2 (∼3 nm) was thermally grown over p-type (100) Si-wafer followed by spin coating of nanoparticles layer (∼2–4 nm) over it. Finally, atomic layer deposition (ALD) of Al2O3(∼10 nm) layer as control dielectric followed by aluminum (Al) contact formations has been done. Our study concludes that NPs solvents severely affect the distribution of nanoparticles over silicon oxide and hence the memory device performance.