| 摘要 |
PURPOSE: A method for fabricating a flash memory cell is provided to erase the cell with a high speed and a low voltage by depositing the first and second sub oxide and tungsten silicide. CONSTITUTION: The first sub oxide(2), undoped polysilicon layer(3), the first tungsten silicide(4), the second sub oxide(5), and nitride are sequentially deposited on a surface of a silicon substrate(1). A nitride etching process is carried out by using a gate mask. Then, a nitride spacer is formed by etching the nitride layer. The second sub oxide(5) is etched by using the nitride layer and the nitride spacer as a mask. After removing the nitride layer and the nitride spacer, a doped sub polysilicon is deposited. Then, ISO etching process is carried out by using ISO mask. After depositing a tunnel oxide(12) and the first polysilicon(13), the first polysilicon(13) is etched. Then, an ONO film(14), the second polysilicon(15), the second tungsten silicide(16) and an insulating film are sequentially etched. Then, a junction(10A) is formed on the doped sub polysilicon layer so as to form a cell gate.
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