A New EEPROM with Side Floating Gates Having Different Work Function from Control Gate

A new flash EEPROM device with poly-Si control gate and poly-Si floating side gate was fabricated and characterized. The poly-Si gate is formed on both sides of the poly-Si gate, and controls the underneath channel conductivity depending on the number of electron in it. The cell was programmed by hot-carrier-injection at the drain extension, and erased by direct tunneling. The proposed EEPROM cell can be scaled down to 50 nm or less. Shown were measured programming and erasing characteristics. The channel resistance with the write operation was increased by at least 3 times.