Unit cell structure and method of forming the unit cell structure, and non-volatile memory device having the unit cell structure and method of manufacturing the non-volatile memory device

摘要

A unit cell structure in a non-volatile semiconductor device includes a lower electrode. The variable resistor is formed on the lower electrode and includes a first insulation thin film, a third insulation thin film, and a second insulation thin film located between the first and third insulation thin films. A breakdown voltage of the second insulation thin film is lower than respective breakdown voltages of the first and third insulation thin films. An upper electrode is formed on the variable resistor.