High Performance of Fin-Shaped Tunnel Field-Effect Transistor SONOS Nonvolatile Memory With All Programming Mechanisms in Single Device

This paper demonstrates a silicon-oxide-nitrideoxide-silicon (SONOS) nonvolatile memory (NVM) with fin-shaped polycrystalline silicon channel tunnel field-effect transistor (TFET). It differs from other memory devices in that its programming mechanisms include Fowler-Nordheim (FN) tunneling, channel hot-electron (CHE) injection, and band-toband tunneling-induced hot electron (BBHE) in single memory cell. In FN programming, both the ON-state current and the program/erase (P/E) operations are based on quantum tunneling. For FN tunneling, when a VG of 17 V is applied for only 1 ms, this device has a large threshold voltage shift (ΔVTH) of 4.7 V. The fin-shaped TFET SONOS (T-SONOS) NVM exhibits superior endurance of 88% after 10⁴ P/E cycles. The memory window remains 65% of its original value after 10 years at a high temperature of 85 °C. On the other hand, the device exhibits better endurance of 74% for CHE programming and BBHE programming after 104 P/E cycles. The memory window retains 81% in CHE programming and 65% in BBHE programming after 10 years. The fin-shaped T-SONOS NVM exhibits high performance that can be achieved in polycrystalline silicon NVM.