Design of epitaxial Si punch-through diode based selector for high density bipolar RRAM

Bipolar Resistance RAM (RRAM) requires the selector device to have a symmetric IV characteristic to perform selection operation for a |V_set| (~ |V_reset|) range of 1V-5V and beyond as well as high currents. Recently, we have experimentally demonstrated a epitaxial Si punch-through diode based selector with an n+/p/n+ doping structure. In this paper, we present the selector performance engineering i.e. on-current density (J_on), on/off current ratio (J_on/J_off), and on-voltage Von designability based on TCAD simulations by modifying doping and p-layer thickness. High current density of 3MA/cm² is demonstrated for a J_on/J_off ratio of 10⁴ with a Von of 4V. Based on these simulations, we show the excellent designability of the selector in terms of Von (0-10V and beyond) and J_on (> few MA/cm² at high J_on/J_off of 10⁴). The main engineering controls are length and doping of p and n+ regions.