Method for producing transistors in integrated semiconductor circuits

Abstract

Integrated semiconductor circuits have MOS transistors whose gate electrodes are provided with dopings in order to set the electrical potential of the channel area by changing the ionization energy (work function) of the electrons. Transistors in semiconductor circuits, which have both a memory area and a logic area, are produced either using different dopings for pMOS and NMOS transistors in the logic area (dual work function) or using common source/drain electrodes in the memory area (borderless contact), with all the transistors in the semiconductor circuit receiving the same gate doping in the latter case. A method is proposed by which a dual work function and a borderless contact can be produced at the same time. Furthermore, the method results without any additional effort in a trench between the gate layer stacks of the memory area and of the logic area, which prevents lateral ion diffusion.