Self-isolated bipolar transistors in integrated circuits

The possibility of implementing bipolar transistors, and hence diodes, in integrated circuits in a self-isolated form has been proposed by one of the authors and independently by B. T. Murphy et al. The present paper is concerned with some of the experimental results of the proposed structures. A p-type epitaxial layer is grown on a p-type substrate where localized n⁺-layers are buried, and there is no need for additional isolation diffusion besides n⁺-collector contact diffusion. The higher packing density and the simlicity in processing resulting from the above structures are desirable features for LSI