Ablation of Submicrometer Holes Using an Extreme-Ultraviolet Laser

TY - JOUR

T1 - Ablation of Submicrometer Holes Using an Extreme-Ultraviolet Laser

AU - Rossall, Andrew K.

AU - Aslanyan, Valentin

AU - Tallents, Gregory John

AU - Kuznetsov, Ilya

AU - Rocca, Jorge

AU - Menoni, Carmen

PY - 2015/6/19

Y1 - 2015/6/19

N2 - Simulations and experiments are used to study extreme-ultraviolet (EUV) laser drilling of submicrometer holes. The ablation process is studied with a 2D Eulerian hydrodynamic code that includes bound-free absorption processes relevant to the interaction of EUV lasers with a solid material. Good agreement is observed between the simulated and measured ablated depths for on-target irradiances of up to 1×1010  W cm−2. An increase in the irradiance to 1×1012  W cm−2 is predicted to ablate material to a depth of 3.8  μm from a single pulse with a hole diameter 3 to 4 times larger than the focal spot size. The model allows for the simulation of the interaction of a laser pulse with the crater created by a previous shot. Multiple-pulse lower-fluence irradiation configurations under optimized focusing conditions, i.e., approaching the diffraction limit, are shown to be advantageous for applications requiring mesoscale [(100  nm)–(1  μm)] features and a high level of control over the ablation profile.

AB - Simulations and experiments are used to study extreme-ultraviolet (EUV) laser drilling of submicrometer holes. The ablation process is studied with a 2D Eulerian hydrodynamic code that includes bound-free absorption processes relevant to the interaction of EUV lasers with a solid material. Good agreement is observed between the simulated and measured ablated depths for on-target irradiances of up to 1×1010  W cm−2. An increase in the irradiance to 1×1012  W cm−2 is predicted to ablate material to a depth of 3.8  μm from a single pulse with a hole diameter 3 to 4 times larger than the focal spot size. The model allows for the simulation of the interaction of a laser pulse with the crater created by a previous shot. Multiple-pulse lower-fluence irradiation configurations under optimized focusing conditions, i.e., approaching the diffraction limit, are shown to be advantageous for applications requiring mesoscale [(100  nm)–(1  μm)] features and a high level of control over the ablation profile.

U2 - 10.1103/PhysRevApplied.3.064013

DO - 10.1103/PhysRevApplied.3.064013

M3 - Article

SN - 2331-7019

VL - 3

JO - Physical Review Applied

JF - Physical Review Applied

IS - 6

M1 - 064013

ER -