Application of atmospheric pressure micro-thermal-plasma-jet to ultra rapid thermal annealing for semiconductor device fabrication

We have developed a high-power-density micro-thermal-plasma-jet (μ-TPJ) to achieve ultra-rapid thermal annealing. Microsecond annealing was performed by μ-TPJ irradiation to an As-implanted Si wafer to form an ultra-shallow junction (USJ). The μ-TPJ could anneal the Si wafer surface at a temperature as high as 920 K for 340 μs. By reducing the annealing duration (ta) from 1.2 ms to 340 μs, the sheet resistance (R_S) of the As₂⁺-implanted Si wafer decreased from 1520 to 1287 Ω/sq. In addition, the chemical bond states of As at the very surface were measured by X-ray photoelectron spectroscopy (XPS) and the fraction of activated As was estimated to be ~15% larger than that in the case of millisecond annealing. Surface As atoms in Si wafers were more efficiently activated by a microsecond annealing than a millisecond annealing owing to the suppression of diffusion and clustering.