Submicrometer CMOS device fabrication using gas immersion laser doping (GILD)

The first successful fabrication of submicrometer CMOS devices using the gas immersion laser doping (GILD) process. It consists of placing a suitably masked silicon wafer in a gas cell containing the desired dopant gas and then incorporating the dopant species in one or more melt/regrowth steps initiated by a XeCl (λ=308 nm) pulsed excimer laser. High-quality ultrashallow (200-to-1500-Å) n⁺ /p and p⁺/n junctions with concentrations of >4×10²⁰ cm^-3 for n⁺ and >5×10²¹ for p⁺ result from this process. In addition, ideal diode behavior for forward bias and low leakage currents (I_R<10 nA-cm^-2 at -5 V) for reverse bias are observed for unannealed junctions formed by the GILD process, a result with potential advantages for future ULSI processing. The first implementation of laser doping in a CMOS process is also reported. Excellent device characteristics are obtained on devices that have not received any thermal processing about 380°C following formation of the source/drain region