Optical shaping of a nano-scale tip by femtosecond laser assisted field evaporation

Enrico Di Russo (1) , Jonathan Houard (1) , V. Langolff (1) , Simona Moldovan (1) , Lorenzo Rigutti (1) , Bernard Deconihout (1) , D. Blavette (1) , J. Bogdanowicz (2) , Angela Vella (1)

1 GPM - Groupe de physique des matériaux
2 IMEC - IMEC

We have investigated the morphology of a nanotip under femtosecond laser pulse illumination and a high electric field. We show that both the symmetry and the local radius of the tip change with the direction of laser polarization as against the tip axis. The experiments were performed on the very same GaN nanotip by laser-assisted atom probe tomography and electron tomography. This allowed an accurate assessment of the tip features by following the order of evaporation of single atoms from the surface. A change of atom emission sites was observed when a change of the angle between the tip axis and the linearly polarized electric field of the laser was imposed. This enables an optical control of field-evaporation sites. A close optical control of the tip morphology on a scale below 10 nm is thus achievable. Calculations of the field at nanotip apex and absorption maps support the experimental observations. Based on the present study, methods can be developed for reshaping nanotips at the nanometer level. T...

Domaines: Physique [physics]

Enrico Di Russo, Jonathan Houard, V. Langolff, Simona Moldovan, Lorenzo Rigutti, et al.. Optical shaping of a nano-scale tip by femtosecond laser assisted field evaporation. Applied Physics Letters, 2018, 112 (14), pp.143103. ⟨10.1063/1.5022031⟩. ⟨hal-01928845⟩