Process simplification in deep submicron CMOS fabrication

Process simplification in deep submicron CMOS fabrication is discussed. Process step analysis is carried out for standard 1Poly/1Metal CMOS structure, and consequently, both isolation and gate formation process are extracted as items to simplify the process. A combination of shallow trench isolation and single mask step well/gate doping is proposed for deep submicron CMOS fabrication. This new process can achieve a reduction of 5 mask steps and eliminates both well drive-in annealing and field oxidation without performance deterioration. As a result, 10% process step reduction and 20% manufacturing turn-around-time reduction have been realized in comparison to the standard 1Poly/1Metal CMOS process with LOCOS isolation.