PHASE CHANGE RANDOM ACCESS MEMORY INCLUDING WORD LINE OF METAL MATERIALS AND METHOD OF FORMING THEREOF

摘要

A phase change memory including a cell diode in direct contact with a wordline of a metal material is provided to improve an electrical characteristic while reducing the layout area of a phase change memory by forming a wordline in direct contact with a cell diode on a semiconductor substrate wherein the wordline is made of a metal material like tungsten and a metal contact is not included. A wordline(WL) is positioned on a semiconductor substrate(ACT) of a first conductivity type. A cell diode(SEG) comes in contact with the semiconductor substrate and a corresponding wordline physically. The cell diode can include a semiconductor region of a second conductivity type different from the first conductivity type and a semiconductor region of the first conductivity type formed on the semiconductor region of the second conductivity type. The semiconductor region of the second conductivity type is of a low density, and the semiconductor region of the first conductivity type is of a high density.