发明名称 |
Stacked-gate flash EEPROM memory devices having mid-channel injection characteristics for high speed programming |
摘要 |
Flash EEPROM memory devices having mid-channel injection characteristics include a substrate having source and drain regions of first conductivity type therein extending adjacent a surface thereof. A stacked-gate electrode is also provided on the surface, between the source and drain regions. To provide improved mid-channel injection characteristics during programming, a preferred semiconductor channel region is provided in the substrate at a location extending opposite the stacked-gate electrode. This channel region comprises a first "source-side" region of second conductivity type (e.g., P+) and a second "drain-side" region of predetermined conductivity type (e.g., P-, N-). The second region has a lower first conductivity type dopant concentration therein than the drain region and a lower second conductivity type dopant concentration therein than said first region, and more preferably has a lower second conductivity type dopant concentration therein than said substrate. During programming, this EEPROM unit cell provides efficient mid-channel injection at high rates and at relatively low voltage levels and avoids many of the limitations associated with conventional stacked-gate EEPROM devices which typically provide less efficient drain-side injection and require relatively high voltage levels during programming. In particular, mid-channel injection of hot electrons from the channel region to the floating gate (within the stacked-gate electrode) is promoted by tailoring the conductivity of the channel region so that pinch-off occurs at a midpoint in the channel region during programming operations.
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申请公布号 |
US5912488(A) |
申请公布日期 |
1999.06.15 |
申请号 |
US19970881444 |
申请日期 |
1997.06.24 |
申请人 |
SAMSUNG ELECTRONICS CO., LTD;POSTECH FOUNDATION |
发明人 |
KIM, DAE MANN;CHO, MYOUNG-KWAN |
分类号 |
H01L21/8247;G11C16/04;H01L21/336;H01L27/115;H01L29/788;H01L29/792;(IPC1-7):H01L29/788 |
主分类号 |
H01L21/8247 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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