Patent attributes
The invention relates to a method and apparatus for processing substrates, such as glass and semiconductor wafers. The method comprises directing to the substrate from a laser source a plurality of sequential focused laser pulses having a predetermined duration, pulsing frequency and focal spot diameter, the pulses being capable of locally melting the substrate, and moving the laser source and the substrate with respect to each other at a predetermined moving velocity so that a structurally modified zone is formed to the substrate. According to the invention, the pulse duration is in the range of 20-100 ps, pulsing frequency at least 1 MHz and moving velocity adjusted such that the distance between successive pulses is less than ⅕ of the diameter of the focal spot. The invention can be utilized, for example, for efficient dicing, scribing and welding of materials which are normally transparent.
