Nanoscale Phase Change Memory Arrays Patterned by Block Copolymer Directed Self-Assembly

Scaling the cell size of phase change memory (PCM) is crucial for reducing reset current and enabling energy-efficient switching. Because memory arrays have a regular pattern, block copolymer directed self-assembly (DSA) is uniquely suited for reducing patterning costs for future nanoscale PCM. Here, we realize the fabrication and electrical characterization of a PCM array with (GeSbTe5)-Sb-2-Te-2 phase change material featuring 20-nm cells patterned by DSA. Our confined cell PCM devices with similar to 20 nm bottom contact diameter switch at similar to 150-200 mu A, while maintaining a resistance on/off ratio of similar to 10. We also discuss some factors for further consideration for improving the limited endurance of such nanoscale confined cell PCM. Our demonstration would inspire further reduction of the PCM cell size below 10 nm using high-. block copolymers, thus paving the pathway towards ultrahigh density memory.