In one aspect the invention provides a method for laser induced breakdown
of a material with a pulsed laser beam where the material is
characterized by a relationship of fluence breakdown threshold (Fth)
versus laser beam pulse width (T) that exhibits an abrupt, rapid, and
distinct change or at least a clearly detectable and distinct change in
slope at a predetermined laser pulse width value. The method comprises
generating a beam of laser pulses in which each pulse has a pulse width
equal to or less than the predetermined laser pulse width value. The beam
is focused above the surface of a material where laser induced breakdown
is desired. The region of least confusion (minimum beam waist or average
spot size) is above the surface of the material in which laser induced
breakdown is desired since the intensity of the beam falls off in the
forward direction, preferably the region of the beam at or within the
surface is between the region of least confusion and sufficient to remove
material and the minimum intensity necessary for laser induced breakdown
of the material to be removed, most preferably the region of minimum
intensity is disposed at the surface of the material to be removed. The
beam may be used in combination with a mask in the beam path. The beam or
mask may be moved in the x, y, and Z directions to produce desired
features. The technique can produce features smaller than the spot size
and Rayleigh range due to enhanced damage threshold accuracy in the short
pulse regime.