Charge trapping type SOI-FinFET flash memory

The charge trapping (CT) type tri-gate (TG) silicon on insulator (SOI) FinFET flash memories with different gate and blocking layer materials have successfully been fabricated, and their electrical characteristics including short-channel effect (SCE) immunity, threshold voltage (Vt) variability and memory property have comparatively been investigated. It was experimentally found that a large memory window is obtained in the physical vapor deposited (PVD) titanium nitride (TiN) metal gate flash memories than the n⁺-poly-Si gate ones owing to the higher work function of PVD-TiN metal gate, which is effective to suppress electron back tunneling during erase operation. It was also confirmed that the better SCE immunity and a significant improvement in memory window are observed by introducing a high-k Al²O³ blocking layer into the PVD-TiN metal gate flash memories. Moreover, it was found that the Vt variations before and after a program/erase (P/E) cycle are independent of the gate and blocking layer materials.