플라즈마 채널링을 이용한 나노파티클 건식세정 연구

Laser dry cleaning by plasma channeling

The effective removal of nano particles from silicon wafer surface was demonstrated using the self-channeled plasma filament excited by a femtosecond (130fs) Ti:Sapphire laser (λρ=790 nm). This process has achieved successfully the removal of 100 nm sized polystyrene latex (PSL) particlesfrom the surface. The photoinduced self-channeled plasma filament in air reached a length of approximately 110-130 mm from the first focal spot with the diameters ranging from 40 to 50 ㎛ at the input intensities more than 1.0x10¹⁴W/㎠. By the scan of wafer using the X-Y-Z stage duringself-channeled plasm filament, the removal variation of nano particles on surface was observed in situ before and after plasma filament occurred. The cleaning efficiency was strongly dependent on the gap distance between the plasma filament and the surface. The removal efficiency of nano particles reached to 97% with no damage on the surface when the gap is 150 ㎛.