| 摘要 |
PURPOSE: To realize programming through a simple process by utilizing the difference of threshold voltage between first and second MOS transistors as the difference of storing state between first and second memory cells. CONSTITUTION: A first memory cell A forms a gate electrode 2 on a substrate 1 through a gate oxide 5 and a side wall insulation film 6 is formed on the opposite sides of the gate electrode 2. A pair of lightly doped diffusion layers 3 are formed while being aligned with the gate electrode 2 and a pair of heavily doped diffusion layers 4 are formed while being aligned with the side wall insulation film 6 thus constituting an MOS transistor. A second memory cell B has same structure as the first memory cell A except the pair of lightly doped diffusion layers 3 and constitute a MOS transistor. Difference of threshold voltage between the first and second MOS transistors is utilized as the difference of storing state between first and second memory cells A and B. |
