The very shallow junction of boron has been formed with the combination of ArF excimer laser and BF
3gas. Since BF
3gas is transparent at around 200 nm, boron atoms are obtained by pyrolysis of BF
3gas. Sheet resistance can be controlled by the number of pulses and BF
3 pressure under the condition of constant beam energy. From SEM analysis and Wright etching, any damages and defects are not observed on silicon surface at 1.2 J/cm
2. Junction depths depend on the number of pulses, and the shallowest junction of -360Ådepth is obtained by 5 pulses. From the results of SIMS and four-point probe measurements, it is confirmed that nearly all boron atoms doped are electrically activated up to the concentration of 10
20cm
-3. Spatial uniformity within the irradiated area is also confirmed. A diode fabricated by laser doping shows a good I-V characteristics.
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