PROCESS OF MANUFACTURE OF MIS LSI CIRCUITS Russian patent published in 1994 - IPC

FIELD: technology of manufacture of multithreshold LSI circuits on MIS transistors. SUBSTANCE: process involves operations of formation of active and field regions on silicon substrate, ion doping of region beneath gate, formation of polysilicon interconnection, deposition of interlayer insulation, formation of metallized wiring and subjecting of formed structure to X-ray radiation. X-ray radiation is conducted before formation of metallized wiring. After X-ray radiation adjustment of threshold voltages of each group of transistors with same values of thresholds is connected by radiation of their regions beneath gates with doses of ultra-violet radiation. On completion of adjustment structures are subjected to thermal annealing at temperature of 400-450 C for the course of 0.5-1.0 h. Radiation with ultra-violet beam is performed through contact quartz masks transparent for quanta within range 4.35-8.8 eV. Radiation process is conducted by pulses with pulse duration 2-10 μs and with pulse repetition frequency 0.1-20 Hz. X-ray radiation is conducted with saturation dose. Process of ultra-violet radiation of different groups is carried out by successive shading or opening of groups of transistors having same value of thresholds to beam. EFFECT: facilitated manufacturing process. 4 cl