Effects of oxide isolation on propagation delay in integrated injection logic (I/sup 2/L)

Effects of oxide isolation on current gains, signal swing, and propagation delay time of an I/SUP 2/L gate at high dissipation levels are discussed in terms of the backward injection of the p-n-p transistor, the magnitude of which is reduced by the isolation. The reduction enhances the degree of saturation. On the other hand, it causes a larger collector current which enables a rapid discharge of the stored charge. These competing effects given an optimum condition for which the analytical expression is obtained.