Resistless Pattern Etching of SiC by Excimer Laser

Abstract

Resistless photo etching of the SiC was performed by using KrF excimer laser beams. In the present method, C1F3 was used for etchant gas. The C1F3 gas has the absorption band in the range between 200 and 400 nm. Therefore, C.1F3 gas is effectively decomposed by the XeF,KrF and ArF excimer lasers irradiation. It is found that absorption factor of SiC is about 50% in, the range of between 200 and 400 nm, and that the bonding energy of Si-C is lower than the photon energy of KrF laser beam. The above results indicate the direct decomposition of Si-C bond. On the other hand, KrF laser beams were simultaneously irradiated parallel and perpendicular to the substrate. The parallel beam induced decomposition of CIF: near the surface of a substrate to produce radicals and the perpendicular beam induced on the surface of the SiC substrate. Fluence of parallel beam was 50 mJ/cm2 , perpendicular beam on the substrate was 200 mJ/cm2 and a total flow rates through the cell were 0.05 1/min. The etched feature of reticle pattern can be fabricated by reductive projection. Line and space was 5 μm.