Nonlinear coupling with silicon tunnel junctions in integrated logic

Most of the logic schemes that are amenable to integrated semiconductor construction utilize resistances to couple transistor stages to a power supply and to other stages. It is shown that the coupling functions ideally require nonlinear rather than linear current-voltage characteristics. Tunnel junctions can provide very attractive nonlinear characteristics for coupling purposes, and this is the main theme of the present paper. Performance advantages are investigated, particularly the improvement in delay-power product, or energy required to process a binary digit. Techniques for fabricating low-capacitance tunnel junctions in integrated fashion with silicon bipolar transistor regions are discussed.