SEMICONDUCTOR MEMORY ELEMENT, SEMICONDUCTOR MEMORY AND CONTROL METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To make suited to a high integration with a small area, by holding carriers in a carrier confining region and changing the threshold voltage of a semiconductor element to make a memory. SOLUTION: A p-type polycrystalline Si channel part 78 is formed on the side face of an SiO2 insulation film 82 and partitioned by a thin insulation film 87 to form a carrier confining region 79 of polycrystalline Si. When a fixed voltage is applied between a source and drain 77 to apply a gate voltage, electrons are induced in a polycrystalline Si film of a channel 78 to flow a current. When a high gate voltage is applied, the potential difference between the channel region 78 and carrier confining region 79 is high enough to finally inject electrons into a carrier confining region 79 after passing over a potential barrier of the insulation film 87 therebetween due to the tunneling or thermal excitation, resulting in that the threshold shifts to a higher value, and current value is reduced with the same gate voltage.