Cell characteristics of FePt nano-dot memories with a high-k Al₂O₃ blocking oxide

Abstract

The cell characteristics of an alloy FePt nano-dot (ND) charge trapping memory with a high-k dielectric as a blocking oxide was investigated. Adoption of a high-k Al₂O₃ material as a blocking oxide for the metal nano-dot memory provided a superior scaling of the operation voltage compared to silicon oxide under a similar gate leakage level. For the 40-nm-thick high-k (Al₂O₃) blocking oxide, we confirmed an operation voltage reduction of ∼7 V under the same memory window on for silicon dioxide. Also, this device showed a large memory window of 7.8 V and a low leakage current under 10⁻¹⁰ A in an area of Φ 0.25 mm. From these results, the use of a dielectric (Al₂O₃) as a blocking oxide for a metal nano-dot device is essential, and a metal nano-dot memory with a high-k dielectric will be one of the candidates for a high-density non-volatile memory device.