METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for manufacturing EPROM tunnel oxide(ETOX) cell is provided to improve reliability of devices without variations in the volume of the ETOX cell by allowing an erase gate to pass through a floating gate within te ETOX cell. CONSTITUTION: An EPROM tunnel oxide(ETOX) cell includes a gate insulating film(24) on the second conductive type silicon substrate(21). The second conductive type silicon substrate(21) has an active region and a field region by a field oxide film(28) and also has a source/drain(23) region formed of the first conductive type impurity. A control gate(27), a floating gate(25) and an erase gate(255) are located on the insulating film(24). The control gate(27) is located on the surface and the side of the insulating film(24) formed on the floating gate(25). The floating gate(25) has the erase gate(255) protected by the insulating film along the channel width direction.