| 摘要 |
To increase the density of memory cells, a multibit memory cell (10, 50, 80, 110) can be manufactured by preventing the formation of at least one of the extension regions usually formed for the source or drain region. In one embodiment, a single mask (24) blocks the doping of the extension regions during ion implantation. If a tilt implantation process is used to form desired extension regions, two masks may be used. The process can also be integrated into a disposable spacer process. By blocking the extension region for a current electrode, a programmable region (32, 76, 102, 132) is formed adjacent a current electrode. The programmable region enables a two-bit memory cell to be formed.
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