Phase change memory (PCM) is a promising resistive non-volatile memory for its fast writing and reading speed, highly scalable properties, and long endurance. PCM formed by Ge₂Sb₂Te₅ (GST) on a vertical carbon nanotube- (CNT) filled contact plug is demonstrated in this work. The CNT electrode is developed from a CMOS compatible CNT vertical interconnect (via) technology.

In order to achieve CMOS compatibility, the CNTs are synthesized using a nickel catalyst at a low temperature. Then a dielectric filling and polishing process is carried out to enhance the strength of the electrode and fill the gap between the CNTs.

Reasonable contact characteristics between the CNTs and GST are achieved without a material compatibility problem. Due to the small contact size of the CNT to the p...[ Read more ]

Phase change memory (PCM) is a promising resistive non-volatile memory for its fast writing and reading speed, highly scalable properties, and long endurance. PCM formed by Ge₂Sb₂Te₅ (GST) on a vertical carbon nanotube- (CNT) filled contact plug is demonstrated in this work. The CNT electrode is developed from a CMOS compatible CNT vertical interconnect (via) technology.

In order to achieve CMOS compatibility, the CNTs are synthesized using a nickel catalyst at a low temperature. Then a dielectric filling and polishing process is carried out to enhance the strength of the electrode and fill the gap between the CNTs.

Reasonable contact characteristics between the CNTs and GST are achieved without a material compatibility problem. Due to the small contact size of the CNT to the phase change material, a significant reduction in programming power is achieved compared to metal contact at the same via size. The temperature simulation result shows that the CNT-filled via helps to reduce the programming area. The fabricated PCM on CNT-filled via is able to endure more than 104 SET/RESET cycles without observable degradation.

To meet the high demands for a high densely-packed cross-section array for the PCM, it is important is integrate the PCM cell with the selective driving devices. And PCM-CNT integrated on a silicon p-n diode is demonstrated in this thesis.