Patent ID: 7494849

Claim:
A method for fabricating a multi-terminal PCD (phase-change device) following CMOS processing, comprising: patterning a first via in an etch stop layer disposed over a metal layer comprising metal portions disposed in a first dielectric material, the first via communicating with a first of said metal portions; depositing a first diffusion barrier metal in the first via; disposing a second dielectric material over the etch stop layer; providing one or more metal-filled vias in the second dielectric material in communication with corresponding metal portions of the metal layer; providing a heating element over the second dielectric material; disposing a third dielectric material over the heating element; forming a second via in the second and third dielectric materials and the heating element, the second via being in registry with the first via; depositing a phase change material (PCM) in the second via, the phase change material establishing electrical contact with the first metal portion of the metal layer by way of the diffusion barrier; disposing a second diffusion barrier over the phase change material; and disposing a fourth dielectric material over the second diffusion barrier.