| 摘要 |
PURPOSE: A floating electrode formation method of flash memories is provided to reduce a bridge between floating electrodes and to solve a field down problem in O/N/O(Oxide/Nitride/Oxide) etch processing by improve a structure. CONSTITUTION: The first poly spacers(21) are formed on both sides of oxides(3) filled in trenches after removing a CMP(Chemical Mechanical Polishing) stopping SiN on the first polysilicon. At this time, a C/R(Coupling Ratio) of a floating electrode is more secured. After partially removing the oxides(3), the second poly spacers(23) are formed at both sides of the first poly spacers(21) in each trench region. Then, a photoresist pattern(25) is completely removed and floating electrode structures are formed. At this time, the floating electrode structures solve a misalign problem between self-aligned trenches and floating electrodes.
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