Nano-Floating Gate Memory Devices with Metal-Oxide Nanoparticles in Polyimide Dielectrics

Nano-Floating Gate Memory Devices with Metal-Oxide Nanoparticles in Polyimide Dielectrics

We fabricated nano-particles of ZnO, In₂O₃and SnO₂ by using the chemical reaction between metal thin films and polyamic acid. The average size and density of these ZnO, In₂O₃ and SnO₂ nano-particles was approximately 10, 7, and 15 nm, and 2 x 1011, 6 x 1011 , 2.4 x 1011 cm-2, respectively. Then, we fabricated nanofloating gate memory (NFGM) devices with ZnO and In₂O₃ nano-particles embedded in the devices’ polyimide dielectrics and silicon dioxide layers as control and tunnel oxides, respectively. We measured the current- ltage characteristics, endurance properties and retention times of the memory devices using a semiconductor parameter analyzer. In the In2O3 NFGM, the threshold voltage shift (ΔVT) was approximately 5 V at the initial state of programming and erasing operations. However, the memory window rapidly decreased after 1000 s from 5 to 1.5 V. The ΔVT of the NFGM containing ZnO was approximately 2 V at the initial state, but the memory window decreased after 1000 s from 2 to 0.4 V. These results mean that metal-oxide nano-particles have feasibility to apply NFGM devices.

We fabricated nano-particles of ZnO, In₂O₃and SnO₂ by using the chemical reaction between metal thin films and polyamic acid. The average size and density of these ZnO, In₂O₃ and SnO₂ nano-particles was approximately 10, 7, and 15 nm, and 2 x 1011, 6 x 1011 , 2.4 x 1011 cm-2, respectively. Then, we fabricated nanofloating gate memory (NFGM) devices with ZnO and In₂O₃ nano-particles embedded in the devices’ polyimide dielectrics and silicon dioxide layers as control and tunnel oxides, respectively. We measured the current- ltage characteristics, endurance properties and retention times of the memory devices using a semiconductor parameter analyzer. In the In2O3 NFGM, the threshold voltage shift (ΔVT) was approximately 5 V at the initial state of programming and erasing operations. However, the memory window rapidly decreased after 1000 s from 5 to 1.5 V. The ΔVT of the NFGM containing ZnO was approximately 2 V at the initial state, but the memory window decreased after 1000 s from 2 to 0.4 V. These results mean that metal-oxide nano-particles have feasibility to apply NFGM devices.