$p^+$-Si/nano-SiO$_2$/$n^+$-Si capacitor-based tunnel diode with negative differential resistance and a quartz resonator

To demonstrate the extending functionality of the simplest MOS (metal–oxide–semiconductor) capacitor, a structure with a $p^+$-Si/nano-SiO$_2$ heterojunction in which strongly degenerate $n^+$-Si is used instead of a metal electrode is considered. As a result, a tunnel diode with negative differential resistance and a quartz resonator is obtained. Its electrical characteristics are superior to those of the corresponding Esaki diode and are controlled not only by the Silicon doping level, but also by the SiO$_2$ thickness.