NOVELTY - The ablation method involves ablating the dielectric (12) using a pulsed laser (14) with a wavelength in the mid- to far infrared having a pulse duration of less than 100 nanoseconds. The wavelength is selected so that the semiconductor substrate (10) will be substantially transparent and the dielectric will be substantially absorbing the radiation. The majority of the laser energy will be absorbed by the dielectric. The laser (14) has a wavelength in the range of 4-25 micrometers, and a pulse duration of 1-100 nanoseconds (ns).    USE - Ablation method for removing and/or destroying by cutting, abrading, or evaporating, a dielectric, such as an oxide layer, from a surface of a semiconductor substrate, i.e. a semiconductor substrate or wafer e.g. for a photovoltaic application, such as a solar cell application (claimed).    ADVANTAGE - Selection of an adequate wavelength ensures that the laser energy is absorbed in the dielectric and not in the underlying semiconductor substrate material and ensures that the semiconductor substrate remains transparent during the laser processing, thus dielectric can be removed without semiconductor substrate damage and without the need for an optical absorber layer, or any intermediate layer between the semiconductor substrate and the dielectric. By using a pulse duration of less than 100 ns, ablation of the dielectric can be achieved almost without heat transfer to the semiconductor substrate and consequently the semiconductor substrate will remain transparent during laser processing, ensuring that the semiconductor substrate will not be damaged by absorption of laser energy.    DETAILED DESCRIPTION - The substrate (10) comprises at least one of the following: silicon, crystalline silicon, monocrystalline silicon, amorphous silicon, gallium arsenide, germanium, gallium phosphide, indium phosphide. The dielectric (12) comprises at least one of the following: silicon oxide, silicon nitride, aluminum oxide, silicon carbide, silicon oxynitride. An INDEPENDENT CLAIM is also included for a dielectric ablation apparatus.    DESCRIPTION OF DRAWING(S) - The drawing shows the schematic views showing how a dielectric can be ablated from a substrate.    Semiconductor substrate (10)    Dielectric (12)    Pulsed laser (14)