OPTICAL PATTERNING OF GAN FILMS

Patterned etching of GaN films was achieved with laser-induced thermal decomposition. High-energy laser pulses are used to locally heat the film above 900 degrees C, causing rapid nitrogen effusion. Excess gall ium is then removed by conventional etching. At exposures of 0.4 J/cm( 2) with 355 nm light, etch rates of 50-70 nm per pulse were obtained. Illumination with an interference grating was used to produce trenches as narrow as 100 nm. (C) 1996 American Institute of Physics.