| 摘要 |
The present invention provides a semiconductor memory which has sense amplifiers, each including a pair of MOSFETs having complete symmetry in regard to not only the shape but also to the impurity profile in a diffusion layer, and the present invention is also capable of reducing variations in electric characteristics, and provides a method of manufacturing the same. Annular gate electrodes 12 a, 12 b are formed on diffusion layer 11. Gate electrodes 13 are formed simultaneously with a sense amplifier along edges of diffusion layer 11 to bestride the boundary between diffusion layer 11 and r shallow trench isolation area 20. Contacts 16 are formed on diffusion layer 11; contacts 17 a, 17 b on diffusion layer 11 within annular gate electrodes 12 a, 12 b, respectively; and contacts 18 on gate electrodes 12 a, 12 b of the sense amplifier. All components are arranged in symmetry, and gate electrodes 13 running along the edges of diffusion layer 11 hold the same spacings 14, 15 between gate electrodes 12 a, 12 b and gate electrodes 13, so that an impurity profile in diffusion layer 11 is not affected by the edges of shallow trench isolation area 20. Consequently, the MOSFETs are arranged in complete symmetry and contribute to a reduction of variation in the characteristics.
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