| 摘要 |
PURPOSE:To improve the characteristics and reliability of a transistor by disposing rearward the periphery of the upper face of a gate electrode by isotropically etching in case of patterning, and then forming a gate by anisotropically etching to symmetrically implant ions near the gate without offset by the shade of the electrode. CONSTITUTION:After a gate oxide film 12 is formed on a single crystal silicon substrate 11, a polycrystalline silicon layer 13 is deposited. Thereafter, it is coated with a resist 14, exposed and developed. After the layer 13 is etched by isotropically etching, it is anisotropically etched to pattern a gate 13. Then, LDDN<-> ions are implanted at an angle of numeral 16, and N<+> ions or P<+> ions are implanted to form source and drain regions. Thus, the shadow effect of the gate in case of the ion implantation is reduced, and an offset is eliminated between the ion implanted region and a gate electrode. Further, the ion implantation is symmetrically conducted to improve the characteristics and reliability of a transistor and to reduce the irregularity in the characteristics.
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