Abstract
This study investigates the performance improvement of the polycrystalline silicon nanowires twin thin-film transistors nonvolatile memory (poly-Si NWs twin-TFT NVM) by NH 3 and H 2 plasma treatment. The NWs twin-TFT NVM exhibits superior gate control because its tri-gate structure provides a large memory window (V th ) and high program/erase (P/E) efficiency. Additionally, the proposed twin-TFT NVM scheme has effective NH 3 and H 2 plasma passivation efficiency due to its split nanowire channels structure. As for characteristics of transistors, passivation by both NH 3 and H 2 plasma increases the mobility and the I on /I off ratio. Moreover, as for characteristics of NVM, they increase δV th , P/E speed and improve the reliability of the devices. Comparing channel hot electron (CHE) injection and Fowler-Nordheim (FN) tunneling programming mechanisms reveals that the device with NH 3 plasma passivation can significantly enhance the program speed. This ability is attributed to passivation of the defects in both the grain boundaries of the poly-Si channel and the Si/SiO 2 interface by hydrogen and nitrogen radicals, respectively. As for reliability results, the NH 3 plasma-passivated NVM device has memory windows of 1.7 and 3.8 V after 10 3+ P/E cycles and for ten years of data storage, respectively. © 2011 The Electrochemical Society.