PHASE CHANGEABLE STRUCTURE AND METHOD OF FORMING THE SAME

摘要

A phase change structure and a method for forming the same are provided to implement a phase change pattern having a side and an upper surfaces hardly having defects by using a conductive etch stop layer pattern. A lower electrode(104) is formed on a substrate. A phase change pattern(106a) is formed on the lower electrode. A conductive etch stop layer pattern(108a) is formed on the phase changeable pattern. The conductive etch stop layer pattern has a first etching rate for an etching material including chlorine. An upper electrode(110a) is formed on the conductive etch stop layer pattern. The upper electrode has a second etching rate greater than the first etching rate for the etching material. The phase change pattern includes germanium, antimony, and tellurium. An adhesive layer is disposed between the phase change pattern and the conductive etch stop layer pattern and includes titanium. Further, the conductive etch stop layer pattern contains titanium nitride and tungsten nitride.