| 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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