Rapid formation of deeply doped layer in crystalline silicon using KrF excimer laser-driven diffusion

Arsenic atoms implanted into a silicon substrate were activated by the sequential irradiation of two KrF excimer laser (λ=248 nm) pulses, each of which had a different pulse width. In the irradiation sequence, the 1st pulse having a width of 34 ns was irradiated to the heated sample followed by irradiating the 2nd laser pulse of 23 ns width after the time delay. The sequence was repeated in 20 cycles. In the case without the 2nd laser pulse irradiation, depth of the arsenic-doped layer increased monotonically with increasing the substrate temperature, but serious surface damage was observed. On the other hand, the surface roughness and crystalline damage was improved by irradiating the 2nd laser pulse after a time delay of 150 ns. The 2nd laser irradiation is considered to be effective to fabricate a high quality diffusion layers