Simple and quick turnaround time fabrication process for deep submicrometer CMOS generation

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