IGFET Russian patent published in 1996 - IPC

FIELD: electronic engineering and in manufacture of insulated-gate field-effect transistors (IGFET). SUBSTANCE: the IGFET uses a gate with vertical walls and wall boundary dielectric regions made on the surface of the semiconductor substrate; in the semiconductor substrate on both sides of the gate the source-drain regions are formed by layers with an impurity conduction of the same type, but with a different concentration; the diffusion profile of the region with a lower concentration occurred at a lower depth is aligned with the gate edge, and the diffusion profile of the region with a higher concentration occurred at a higher depth is aligned with the external edge of the wall boundary region; an additional third layer with impurity of the same type of conduction as of the first two ones is made between the layers with lower and higher concentrations; the value of concentration of the third impurity is in the interval between the values of concentration of the first two ones, and its diffusion profile lies between the diffusion profiles of the first two regions. EFFECT: enhanced reliability. 1 dwg, 1 tbl