Patent ID: 7759607

Claim:
A method for obtaining primarily non-thermal ablation of material from a semiconductor or dielectric structure, the method comprising the steps of: a) illuminating an area of a surface of the semiconductor or dielectric structure using a pulsed laser beam, wherein the laser pulse length of said laser beam is commensurate with, or less than, the time it takes for electrons in the semiconductor or dielectric structure to transfer their energy to the atomic lattice, known as the plasma relaxation time; b) illuminating said area of said surface of the semiconductor structure using said pulsed laser beam, wherein the wavelength of the pulsed laser beam is selected such that interband optical absorption provides a carrier production rate in excess of an avalanche photoionization rate in said semiconductor or dielectric structure; and c) illuminating said area of said surface of the semiconductor structure using said pulsed laser beam, wherein the intensity of said pulsed laser beam is selected such that electronic charge is sufficiently evacuated to induce Coulomb explosion of near-surface layers of said semiconductor or dielectric structure, wherein the ablation threshold for direct Coulomb explosion is less than the threshold for avalanche photoionization-induced Coulomb explosion; whereby ablation by Coulomb explosion occurs in the absence of avalanche photoionization.