Fabrication method for a flash memory device

摘要

In a fabrication method of a flash memory device, a first oxide layer is formed on the substrate in the memory cell region and in the peripheral circuit region. A first conductive layer is formed and defined to form a plurality of floating gates in the memory cell region. A second oxide layer and a silicon nitride layer are sequentially formed in the memory cell region and in the peripheral circuit region. The first conductive layer, the second oxide layer and the silicon nitride layer in the peripheral circuit region are removed. A doped region is formed in the peripheral circuit region. A third oxide layer is formed in the memory cell region and in the peripheral circuit region by wet rapid thermal oxidation. Thereafter, a second conductive layer is deposited to form concurrently a control gate in the memory cell region and a gate in the peripheral circuit region.