Investigation of Boron Distribution at the SiO2/Si Interface of Monolayer Doping.

Monolayer doping is a possible method for achieving complex-geometry structures with different semiconductors. Understanding the dopant diffusion behavior of monolayer doping, especially under different heating sources, is essential for further improvement. We examine and compare the doping profile and dopant activation with two different heating sources (rapid thermal annealing and microwave annealing), especially focused on SiO2/Si interface. These heating sources are used for junction diode fabrication, to realize current switching behavior. Direct observations of monolayer doping profiles, especially inside the capping oxide, are discussed to provide quantitative information for dopant concentration. This can provide significant information for better tuning of surface chemistries and process protocols applied in monolayer doping methodologies.

Homogeneous barrier modulation of TaOx/TiO2 bilayers for ultra-high endurance three-dimensional storage-class memory.

Three-dimensional vertical resistive-switching random access memory (VRRAM) is the most anticipated candidate for fulfilling the strict requirements of the disruptive storage-class memory technology, including low bit cost, fast access time, low-power nonvolatile storage,and excellent endurance. However, an essential self-selecting resistive-switching cell that satisfies these requirements has yet to be developed. In this study, we developed a TaOx/TiO2 double-layer V-RRAM containing numerous highly desired features, including: (1) a self-rectifying ratio of up to 10³ with a sub-µA operating current, (2) little cycle-to-cycle and layer-to-layer variation, (3) a steep vertical sidewall profile for high-density integration, (4) forming-free and self-compliance characteristics for a simple peripheral circuit design, and (5) an extrapolated endurance of over 10¹5 cycles at 100 °C. Furthermore, the switching and self-rectifying mechanisms were successfully modeled using oxygen ion migration and homogeneous barrier modulation. We also suggest the new possibility of monolithically integrating working and storage memory by exploiting a unique tradeoff between retention time and endurance.