Metal oxide semiconductor (MOS) transistors have a wall of P-type substrate sandwiched between two regions of N-type substrates. Capacitors used in MCUs and nanoscale in size, and fabricated on ICs. These are prepared by depositing oxide layers in sandwich patterns between semiconductor wafers. Diode used in Rabbit Semiconductor microcontroller has a dual-layered structure with a P-type semiconductor on one side, and N-type semiconductor on the other side, and a central PN junction.