Highly Scalable Phase Change Memory with CVD GeSbTe for Sub 50nm Generation

first present a PRAM with confinement of chemically vapor deposited GeSbTe (CVD GST) within high aspect ratio 50 nm contact for sub 50 nm generation PRAMs. By adopting confined GST, we were able to reduce the reset current below ~260 muA and thermally stable CVD Ge₂Sb₂Te₅ compound having hexagonal phase was uniformly filled in a contact while maintaining constant composition along with 150 nm depth. Our results indicate that the confined cell structure of 50 nm contact is applicable to PRAM device below 50 nm design rule due to small GST size based on small contact and direct top electrode contact, reduced reset current, minimized etch damage, and low thermal disturbance effect.