| 摘要 |
<p>A semiconductor device has a gate electrode (3) formed on a semiconductor substrate (11), and a source region (S) and a drain region (D) formed in the semiconductor substrate. The source and drain regions each comprise a first impurity region (15a), doped with impurity of opposite conductivity type to that of the semiconductor substrate and formed at a portion adjacent an edge (A) of the gate electrode. A second impurity region (15b) doped with impurity of opposite conductivity type to the semiconductor substrate is formed at a portion under the first impurity region, the impurity of the- second impurity region having a diffusion coefficient larger than that of the impurity of the first impurity region. A third impurity region (14) doped with impurity of opposite conductivity type to the semiconductor substrate, is formed at a portion spaced from the edge of the gate electrode, the third impurity region having a higher concentration than that of the first and second impurity regions, and the impurity of the third impurity region having a diffusion coefficient smaller than that of the second impurity region. By constructing the device in this manner, the channel hot-electron and avalanche hot-electron phenomena are reduced, and the mutual conductance is increased.</p> |
