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 ( lambda =308 nm) pulsed excimer laser. High-quality ultrashallow (200-to-1500-AA) n/sup +//p and p/sup +//n junctions with concentrations of >4*10/sup 20/ cm/sup -3/ for n/sup +/ and >5*10/sup 21/ for p/sup +/ result from this process. In addition, ideal diode behavior for forward bias and low leakage currents (I/sub R/<10 nA-cm/sup -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 degrees C following formation of the source/drain region.<
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