| 摘要 |
<p>A thin film transistor has gate electrode (41) formed on a surface of insulating layer (40). The gate electrode has its upper surface covered with gate insulating layer (42) and its side walls covered with sidewall oxide film (46) by a thermal oxidation. Dual sidewall conductive layers (47, 48) of a polycrystalline silicon are formed on side walls of the sidewall oxide film. Impurities of a higher concentration and of a lower concentration are introduced to each of the dual sidewall conductive layers. A polycrystalline silicon layer (43) is formed on surfaces of the gate electrode, the gate insulating layer and the like. Channel region (44) is formed in the polycrystalline silicon layer positioned above the gate electrode. Source/drain region (45) has source/drain regions (45a, 45b) having an LDD structure formed by a thermal diffusion from the dual sidewall conductive layers each having impurities of a higher concentration and a lower concentration. <IMAGE></p> |
