Excimer Laser Induced Etching of Silicon-Carbide

ABSTRACTResistless photoetching of SiC was performed by using XeF and KrF excimer laser beams. In this method, ClF3 gas was used for etchant. C1F3 gas has a unique absorption band in the range of 300- 430 nm. The strongest absorption band corresponds to the wavelength of the XeF laser (350 nm). So C1F3 gas is decomposed effectively. On the other hand, the absorption factor of SiC is about 30% in the range of 200-400 nm, and the bonding energy of SiC is lower than the photon energy of the KrF laser beam. For these reasons, it is possible to cut the bond of SiC directly. Thus, two laser beams were used. Fluence of the KrF laser beam was 200 mJ/cm2, of the XeF, 50 mJ/cm2. Total flow rates through the cell were 0.05 1/min. We can fabricated the etched feature of reticle pattern by reductive projection. Line and space was 10 μm and etching rate was 50Å/pulse.