| 摘要 |
PURPOSE:To reduce the trap probability of carriers on a low-concentration drain layer even when forming LDD (Lightly Doped Drain) structure, and to set the length of the low-concentration drain layer with high precision by coating source-drain layers in low concentration with a gate electrode, holding a gate insulating film. CONSTITUTION:Source-drain layers 1 in low concentration are coated with a gate electrode 4, holding a gate oxide film 3. Even when hot carriers are generated in the low-concentration drain layer 1 and jump into the gate insulating film 3 just above the drain layer 1, hot carriers are collected to the gate electrode 4 in the structure, and probability in which carriers are trapped into the insulating film 3 is lowered in the same manner as an MIS-FET having normal structure. Since LDD structure is shaped basically, the generation of hot carriers is inhibited to a degree far lower than normal structure, thus suppressing the deterioration of device characteristics as a whole, then allowing control with high accuracy. Accordingly, LDD structure can be optimized at an extremely high level.
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