Self-Aligned Nanotube–Nanowire Phase Change Memory

• Published in: Nano letters 2013-02, Vol.13 (2), p.464-469
• Main Authors: Xiong, Feng, Bae, Myung-Ho, Dai, Yuan, Liao, Albert D, Behnam, Ashkan, Carrion, Enrique A, Hong, Sungduk, Ielmini, Daniele, Pop, Eric
• Format: Article
• Language: English
• Subjects: Amorphous materials; Applied sciences; Confining; Cross-disciplinary physics: materials science; rheology; Data storage; Devices; Durability; Electrodes; Electronics; Exact sciences and technology; Materials science; Memory devices; Molecular electronics, nanoelectronics; Nanocrystalline materials; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Nanowires; Physics; Quantum wires; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl3038097

A central issue of nanoelectronics concerns their fundamental scaling limits, that is, the smallest and most energy-efficient devices that can function reliably. Unlike charge-based electronics that are prone to leakage at nanoscale dimensions, memory devices based on phase change materials (PCMs) are more scalable, storing digital information as the crystalline or amorphous state of a material. Here, we describe a novel approach to self-align PCM nanowires with individual carbon nanotube (CNT) electrodes for the first time. The highly scaled and spatially confined memory devices approach the ultimate scaling limits of PCM technology, achieving ultralow programming currents (∼0.1 μA set, ∼1.6 μA reset), outstanding on/off ratios (∼103), and improved endurance and stability at few-nanometer bit dimensions. In addition, the powerful yet simple nanofabrication approach described here can enable confining and probing many other nanoscale and molecular devices self-aligned with CNT electrodes.