Design of Phase-Change Memory Using Apertureless Scanning Near-Field Optical Microscopy in the Near-Infrared Region

A novel optical secondary storage memory operated in the near-infrared (NIR) region is developed through the integration of an apertureless scanning near-field optical microscopy probe with the conventional Ge2Sb2Te5 storage stack. The probe composite and the optical coefficients of the storage media stack, particularly for the indium tin oxide capping layer, are optimized according to a previously developed electromagnetic wave model, and a newly established density functional theory model, respectively. The dielectric core and the metal coating medium of the probe are devised to be glass and barium, respectively, to provide high electric field in the NIR region, while the thickness of the ITO capping layer is chosen to be 3 nm here to provide high optical transmittance simultaneously with exemption of complex fabrication process. The recording operation of the aforementioned optimized device is subsequently simulated by a newly established thermo-optics model, and its feasibility of achieving >= Tbit in(-2), 10(8) bits per second, and picojoule energy consumption per bit is theoretically demonstrated.