Process for nanostructuring the surface of a material by laser

Patent metadata

Field	Value
Publication number	US-12005523-B2
Application number	US-201917257134-A
Country	US
Kind code	B2
Filing date	Jul 12, 2019
Priority date	Jul 13, 2018
Publication date	Jun 11, 2024
Grant date	Jun 11, 2024

Abstract

The invention relates to a process for nanostructuring the surface of a solid material in order to form a regular pattern of nanostructures on said surface, comprising:
irradiating the surface by a plurality of pulse trains ( 20 ) of a femtosecond laser beam:
each pulse train ( 20 ) comprises at least two pulses ( 21, 22 ), each pulse has a peak fluence, and a sum of the peak fluences of the pulses of a pulse train is between 10% and 70% of a threshold fluence corresponding to a material ablation threshold for one pulse for said material, two consecutive pulses of a pulse train are separated by a peak-to-peak duration ΔT between 500 fs and 150 ps, two consecutive pulse trains are separated by a duration greater than 10 ΔT,
obtaining a regular pattern of nanostructures on said portion of surface, having a spatial periodicity lower than 130 nm.

First claim

The invention claimed is:

1. Process for nanostructuring a surface of a solid material in order to form a regular pattern of nanostructures on said surface, said process comprising:
supplying the solid material, said material comprising the surface;
irradiating a portion of the surface by a femtosecond laser beam, comprising a plurality of pulse trains, wherein:
each pulse train comprises at least two pulses,
each pulse has a peak fluence, and a sum of the peak fluences of the pulses of a pulse train is between 10% and 70% of a threshold fluence corresponding to a material ablation threshold for one pulse for said material,
two consecutive pulses of a pulse train are temporally separated by a peak-to-peak duration ΔT between 500 fs and 150 ps,
two consecutive pulse trains are temporally separated by a duration greater than 10 ΔT,

obtaining of a regular pattern of nanostructures on said portion of the surface, having a spatial periodicity lower than 130 nm,
displacing the femtosecond laser beam on the surface in such a way as to irradiate other portions of said surface.

2. Process according to claim 1 , wherein each pulse has a peak fluence between 5% and 65% of a threshold fluence corresponding to a material ablation threshold for one pulse for said material.

3. Process according to claim 1 , wherein the irradiating by the plurality of pulse trains on a same surface portion represents a total dose less than 6 J/cm 2 .

4. Process according to claim 1 , wherein each portion of the surface is irradiated by at least 5 pulse trains.

5. Process according to claim 1 , wherein each portion of the surface is irradiated by a number of pulse trains less than 500.

6. Process according to claim 1 , wherein each pulse of a pulse train has a duration less than the duration ΔT between two consecutive pulses of the pulse train.

7. Process according to claim 1 , wherein the material has a crystalline structure, and in particular a face-centred cubic structure.

8. Process according to claim 1 , wherein the material contains diamond-like carbon.

9. Process according to claim 1 , wherein pulses of a pulse train have different linear polarisations when said pulses arrive on the surface.

10. Process according to claim 9 , wherein pulses of a pulse train have linear cross-polarisations.

11. Process according to claim 1 , wherein the nanostructures obtained are nano-pits or nano-holes and/or nano-bumps, forming a regular lattice on the surface.

12. Process according to claim 11 , wherein the nano-pits have a diameter between 10 nm and 40 nm, and preferably between 20 nm and 30 nm.

13. Process according to claim 1 , wherein the irradiated portions of the surface overlap partially.

14. Process according to claim 1 , wherein the material has a thickness less than 200 nm.

Assignees

• Univ Jean Monnet Saint Etienne
• Centre Nat Rech Scient

Inventors

• Pigeon Florent
• Abou Saleh Anthony
• Colombier-Cinquantin Jean-Philippe
• Garrelie Florence

Classifications

• B23K26/08

  Devices involving relative movement between laser beam and workpiece · CPC title

• B23K26/0006 Primary

  taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence) · CPC title

• B23K2103/52

  Ceramics · CPC title

• B23K26/0624

  using ultrashort pulses, i.e. pulses of 1 ns or less · CPC title

• B23K26/3568

  Modifying rugosity · CPC title