Abstract
The electrical properties of a split-gate-type flash cell are investigated and optimized by junction engineering to obtain a high reliability. Phosphorus implantation is conducted to form a cell source junction, and the following three different anneal conditions change voltage coupling ratio between the source and the floating gate. As the ratio increases, it is observed that program characteristic is improved and endurance property is degraded, which matches well with simulation result. Therefore, cells in the pure N2 group are considered to be optimized cells. Optimized cells guarantee 105 cycle endurance, and show excellent program disturbance and bake retention properties.