Bipolar type static memory cell

摘要

A bipolar type static memory cell comprising two cross connected circuits, each of the circuits including a transistor and a load element is disclosed. An N-type epitaxial layer, grown on an N+-type buried layer, is used as a collector region of the transistor, and a P-type layer formed in the N-type epitaxial layer and an N+-type layer formed in the P-type layer are used as a base region and an emitter region of the transistor. A P-type diffusion layer is formed in the N-type epitaxial layer from the surface of the epitaxial layer to reach and contact the buried layer. The structure results in the memory cell parasitic diodes being effectively eliminated from the cell together with the unwanted charge storage effects of the diodes.