| 摘要 |
PURPOSE:To reduce the dispersion of the threshold voltage of a transistor, and to increase the density of a memory cell by using a semiconductor substrate having single structure, forming first and second trenches having different width into the substrate and shaping a capacitor and the transistor to the side sections of the trenches. CONSTITUTION:First and second trenches 21, 22 being formed to a semiconductor substrate 20 and having different width facilitates the uniform formation of a capacitor C and a transistor to the side sections of the trenches while simplifying the electrode isolation of both the capacitor and the transistor. First and second semiconductor regions 32, 33 in the transistor are formed into the single semiconductor substrate 20. Accordingly, the impurity concentration of a channel region is controlled easily and the control concentration of threshold voltage is increased, and a peripheral circuit can be constituted of a CMOS. |
