| 摘要 |
PURPOSE:To obtain a product which is capable of higher-scale integration and can be supplied to users in a short period by designing a semiconductor memory which stores two-value information corresponding to threshold voltages of a MOS transistor, in such a way that two-kind gate lengths of the transistor are provided according to the two-value information and two-kind threshold voltages are set according to the lengths. CONSTITUTION:A semiconductor memory which stores two-value information according to the threshold voltages of a MOS type transistor is so constituted that two-kind gate lengths of a transistor are provided according to the two- value information and two-kind threshold voltages are applied according to it. For example, the gate length of a memory cell to store '1' is made long and that of a memory cell to store '0' is made short by using the mask for program as a mask for gate pattern. And after LOCOS processing, a gate oxide film is formed and then by polysilicon or silicide, a gate layer is formed and using said mask, a word pattern as shown in the drawing is formed. Thereafter, diffusion layers 13-16 of source drain are formed by self alignment with the gate as a mask. |
