Phase-change memory device

A phase shift memory device is provided to prevent titanium of an upper electrode from penetrating into a phase changeable material pattern by using an improved diffusion barrier layer containing tellurium. A phase shift memory device includes a phase changeable material pattern(140), first and second electrodes, and a diffusion barrier layer. The first and second electrodes are used for supplying electric signals to the phase changeable material pattern. The diffusion barrier layer(150) contacts the first electrode. The diffusion barrier layer is used for the element contained in the first electrode from diffusing into the phase changeable material pattern. The first electrode contains titanium element. The diffusion barrier layer contacts one out of upper and lower surfaces of the first electrode. The diffusion barrier layer contains TiTe2.