| 摘要 |
<p>PURPOSE: A bidirectional reading or programming non-volatile floating gate memory cell is provided to increase storage density by storing a single bit in each of two floating gates of a memory cell. CONSTITUTION: A substantially single crystalline semiconductor material is of the first conductivity type. The first region is formed on the semiconductor material, having the second conductivity type different from the first conductivity type. The second region is formed on the semiconductor material, having the second conductivity type and separated from the first region. A channel region including the first, second and third portions interconnects the first and second regions to conduct charges. A dielectric is formed on the channel region. The first floating gate(40a) is formed on the dielectric, separated from the first portion adjacent to the first region. The first floating gate stores at least one of a plurality of bits. The second floating gate(40b) is formed on the dielectric, separated from the second portion adjacent to the second region. The second floating gate stores at least on e of the plurality of bits. A gate electrode is formed on the dielectric, separated from the third portion located between the first and second portions. The first gate electrode is electrically connected to the first region, capacitively coupled to the first floating gate. The second gate electrode is electrically connected to the second region, capacitively coupled to the second floating gate.</p> |
