Cell string and reading method for the cell string

Abstract

Provided are a cell string and a reading method for the cell string. The cell string includes a semiconductor body formed on a surface of an insulating layer, first and second semiconductor regions formed at respective ends of the semiconductor body and are formed by being doped with different types of impurities, two or more control electrodes which are separated from each other to be electrically isolated, and a gate insulating film stack which is formed between the semiconductor body and the control electrodes, wherein the semiconductor body is configured to include at least two layers, and adjacent layers of the semiconductor body have different energy band gaps, wherein the semiconductor body is formed by an intrinsic semiconductor or a semiconductor being doped with impurities, and wherein the first and second semiconductor regions are doped with impurities of which concentration is higher than that of the semiconductor body.

Dependencies are inferred from the claim text.