Low-Power Crossbar Switch With Two-Varistor Selected Complementary Atom Switch (2V-1CAS; Via-Switch) for Nonvolatile FPGA

A nonvolatile and programmable routing switch featuring two-varistor selected complementary atom switch (2V-1CAS also known as via-switch) is evaluated. The a-Si/SiN/a-Si varistor as a selector for the atom switch shows superior nonlinear current–voltage characteristics with high selectivity of ~105, which originates from the staircase barrier height in the layers. The two control lines connected to the varistors realize multiple fan-outs of the crossbar switch without select transistors. The $50\,\,\sf \times20$ crossbar switch block is demonstrated, where the atom switch is placed at each cross point and programmed through the varistors. The developed via-switch crossbar switch is a strong candidate for achieving energy-efficient nonvolatile field-programmable gate array in the Internet-of-Things applications.