| 摘要 |
The present invention provides a method of manufacturing on a substrate ( 50 ) a 2-transistor memory cell comprising a storage transistor ( 1 ) having a memory gate stack ( 1 ) and a selecting transistor, there being a tunnel dielectric layer ( 51 ) between the substrate ( 50 ) and the memory gate stack. ( 1 ). The method comprises forming the memory gate stack ( 1 ) by providing a first conductive layer ( 52 ) and a second conductive layer ( 54 ) and etching the second conductive layer ( 54 ) thus forming a control gate and etching the first conductive layer ( 52 ) thus forming a floating gate. The method is characterized in that it comprises, before etching the first conductive layer ( 52 ), forming spacers ( 81 ) against the control gate in the direction of a channel to be formed under the tunnel dielectric layer ( 51 ), and thereafter using the spacers ( 81 ) as a hard mask to etch the first conductive layer ( 52 ) thus forming the floating gate, thus making the floating gate self aligned with the control gate. The present invention also provides a memory cell wherein the control gate ( 54 ) is smaller than the floating gate ( 52 ), and spacers ( 81 ) are present next to the control gate ( 54 ).
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