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Nonvolatile semiconductor memory device and manufacturing method thereof

  • US 20050199940A1
  • Filed: 12/17/2004
  • Published: 09/15/2005
  • Est. Priority Date: 03/10/2004
  • Status: Active Grant
First Claim
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1. A nonvolatile semiconductor memory device which has memory cells of a split structure, each memory cell comprising:

  • (a) a first semiconductor region and a second semiconductor region formed in a semiconductor substrate;

    (b) a select gate and a memory gate formed after the formation of said select gate, said gates being formed above the portion located between said first and second semiconductor regions of said semiconductor substrate;

    (c) a first insulator film formed between said select gate and said semiconductor substrate; and

    (d) a second insulator film formed between said memory gate and said semiconductor substrate and also on the sidewall of said select gate, said sidewall being located between said select gate and said memory gate, wherein said second insulator film formed between said memory gate and said semiconductor substrate includes a first potential barrier film on said semiconductor substrate, a silicon nitride film formed further thereon and a second potential barrier film formed yet further thereon, and one end of said silicon nitride film touches said first potential barrier film of said second insulator film formed on said select gate sidewall, and wherein said second insulator film formed on said select gate sidewall between said select gate and said memory gate includes said first and second potential barrier films but does not include said silicon nitride film.

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