Simplified bipolar technology and its application to systems

Base-diffusion isolation with a buried collector simplifies the fabrication of very-high-speed circuits. Base-diffusion isolation with a buried collector simplifies the fabrication of very-high-speed circuits. Base-diffusion isolation without a buried collector permits the fabrication of circuits with no more processing than is needed for a discrete planar transistor. Packing densities of these transistors are similar to those of IGFETs. Functional packing densities will depend upon the particular circuit used. The new structures should permit fabrication of many circuits with the performance advantages of bipolar devices at costs comparable to those of IGFETs. To exploit these devices to the best advantage low-voltage logic is required. Studies of an exploratory digital system using gates operated from a 2-V supply have shown the feasibility of such an approach.