| 摘要 |
PURPOSE:To improve the memory capacity by dividing a floating gate into two regions, first applying a high electric field between a source and a drain, and then inverting the source and the drain to implanting lectrons to the floating gates, thereby storing two bits. CONSTITUTION:The floating gate of a semiconductor memory made of EPROM is divided into two regions as th first and second floating gates 41, 42. First, the left side is used as a source 10, the right side is used as a drain 20, a high electric field is applied, and information is written in the second floating gate 42, to which the high electric field is applied. Then, the right side is used as the source 10 and the left side is used as the drain 20, and information is similarly written. Since the two bits can be stored by dividing the floating gate into two regions, the memory capacity can be improved in an EPROM. |
