| 摘要 |
A square poly-spacer and making of the same are disclosed. The square poly-spacer is formed adjacent a floating poly-gate sharing a common source line with another floating poly-gate. The common source line comprises polysilicon and is separated from the floating poly-gate by an intervening oxide spacer. The square poly-spacer is also separated from the floating gate by an intergate oxide layer, and serves as a control gate and communicates with a salicided word line formed over the square top of the poly-spacer. It is shown that a square poly-spacer can be formed advantageously by first chemical mechanical polishing a poly spacer and then performing an etch back of the polysilicon, rather than just performing an etch back only. The square top, rather than the continuously contoured sloping wall, prevents the bridging that can occur over a curved poly spacer to the substrate when a portion of the poly spacer surface is salicided to obtain a well behaving word line.
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