METHOD OF PRODUCING CROSS-COUPLINGS BETWEEN N AND P CHANNEL CMOS FIELD EFFECT TRANSISTORS OF READ-AND-WRITE MEMORIES, PARTICULARLY WITH 6-TRANSISTOR MEMORY DEVICES

摘要

Cross-couplings between n-channel and p-channel CMOS field effect transistors of static write-read memories (SRAMs) with buried contacts to the n+ and p+ regions in the substrate are obtained in accordance with known method steps and with a high packing density. A gate level thereof formed of a polycide double layer is used as an additional wiring level for the cross-coupling. The formation of the gate level occurs after the opening of regions for the buried contacts. A doping occurs simultaneously with the generation of source/drain regions of the n-channel and p-channel transistors by masked ion implantation and a subsequent high-temperature treatment. Accordingly, simple, mask-non-intensive method steps result which are especially useful in the manufacture of 6-transistor SRAMs.