Carbon Nanotube Memory by the Self-Assembly of Silicon Nanocrystals as Charge Storage Nodes

A memory structure based on self-aligned silicon nanocrystals (Si NCs) grown over Al2O3-covered parallel-aligned carbon nanotubes (CNTs) by gas source molecular beam epitaxy is reported. Electrostatic force microscopy characterizations directly prove the charging and discharging of discrete NCs through the Al2O3 layer covering the CNTs. A CNT field effect transistor based on the NC/CNT structure is fabricated and characterized, demonstrating evident memory characteristics. Direct tunneling and Fowler–Nordheim tunneling phenomena are observed at different programming/erasing voltages. Retention is demonstrated to be on the order of 104 s. Although there is still plenty of room to enhance the performance, the results suggest that CNT-based NC memory with diminutive CNTs and NCs could be an alternative structure to replace traditional floating gate memory.