Development of all-solution-processed nanocrystal memory

We developed an all-solution-processed nanocrystal memory containing high density (∼1 × 10¹²particles·cm⁻²) Au-SiO₂core-shell nanoparticles (NPs) within a uniform HfO₂matrix. High-quality HfO₂high-κ oxide composed of ultra-thin (<10 nm) tunnel and control oxide layers were prepared on a silicon substrate by the spin-on sol-gel process. The Au-SiO₂core-shell nanocomposite was also constructed by solution process using 3-aminopropyltrimethoxysilane (APTMS) as a functional mediator. This APTMS provides dual functions: (1) to serve as a binder for catching colloidal Au NPs onto the HfO₂substrate, and (2) to form a protective layer to cover up the Au NP core. The APTMS shell layer was well controlled through the self-assembly monolayer (SAM) layer-by-layer process with a self-limiting feature. It thermally decomposed into sub-nano thick SiO₂shell by post-deposition annealing, playing a key role in surmounting the deficiency of HfO₂for the use of both the tunnel oxide and the control oxide in the nanocrystal memory. This approach efficiently improved the application of a crystalline HfO₂nano-film for electronic device. By elaborately integrating the solution processes of the HfO₂oxide layer and the Au-SiO₂core-shell NPs, a high-performance nanocrystal memory was obtained. This study demonstrated the potential of chemical solution process for nanofabrication application.