Excimer-laser etching of diamond and hard carbon films by direct writing and optical projection

Excimer-laser patterning of monocrystalline diamond was performed in the direct writing and in the optical projection modes. The etching mechanism employs combined photochemical/thermal transformation of the initial crystal to graphite followed by sublimation or reaction of the transformed solid. In optical projection, linewidths as narrow as 0.13 μm were etched with patterning possible using single 0.193 μm (wavelength) laser pulses. Etch rates of 2000 Å/pulse were achieved. The morphology of the etched features was optimized by introducing gases which reacted chemically with the hot graphitic layer generated in the process of etching. Patterning of diamond-like carbon thin films was accomplished and the effectiveness of these films as resists for submicrometer-resolution lithography of semiconductors was demonstrated.