Other materials

Ceramics crack, semiconductors chip and organic materials char, each under a different kind of thermal load. Femtosecond laser pulses are over before heat leaves the focal volume, so ceramic is milled, silicon and GaAs wafers are cut clean, organics are machined without burnt edges, and dielectric surfaces are activated for metallization.

Material processing
Material processing Glass Metal Polymer Other materials
Other materials

Femtosecond laser cutting of FZ-Si wafer

The production of customized optoelectronic devices often calls for silicon chips in specific shapes. Mechanical dicing is poorly suited to them: silicon cleaves along its crystallographic directions, which restricts the achievable shapes and leaves little control over the process. Femtosecond lasers cut smaller features with higher resolution and better processing efficiency than laser sources with longer pulses.

A float-zone silicon wafer (FZ-Si (100), 0.4 mm thick) was cut with a FemtoLux laser. Processing quality was high: a low heat-affected zone, no damage on the bottom surface, and curved contours that mechanical dicing cannot follow, as in the example below.

Manufacturing examples

Cutting of FZ-Si wafer.

Cutting of FZ-Si wafer.

Courtesy of FTMC.

Microscope image of processed FZ-Si wafer edge.

Microscope image of processed FZ-Si wafer edge.

Courtesy of FTMC.

Recommended products

FemtoLux
Industrial Femtosecond Lasers
  • 50 W / >300 µJ at 1030 nm
  • 20 W / >50 µJ at 515 nm
  • 10 W / >25 µJ at 343 nm
  • < 400 fs – 1 ps
  • Single shot to 4 MHz (AOM controlled)
  • MHz, GHz, MHz+GHz burst modes

Similar applications

50 µm depth groove formation in ceramic.
Femtosecond laser formation of grooves in ceramic

Ceramic is hard and brittle: mechanical processing presses on it with large forces and can crack the substrate. Femtosecond laser pulses form grooves without mechanical contact. Grooves 30, 50 and 70 µm deep were scribed at speeds up to 44.1 mm/s, and the 343 nm wavelength reduced the heat-affected zone from 8.23 µm to 4.88 µm.
Optical 3D profilometer image of milled alumina squares in different operational modes.
Ceramic processing with GHz burst

Femtosecond lasers mill ceramics precisely but slowly. GHz bursts raise the throughput: trains of pulses at GHz intra-burst repetition rates split one high-energy pulse into many smaller ones. With 92 pulses per burst, alumina milling throughput rose from 6.39 mm³/min in single-pulse mode to 10.38 mm³/min.
SEM image of a trench milled in GaAs under a layer of water.
Femtosecond processing of GaAs in air and water

Milling GaAs in ambient air leaves a band of debris redeposited along the trench walls. Under a layer of water the same process cuts deeper and cleaner: trench depth rose from 58 µm to 105 µm and the redeposition band shrank from 34 µm to 7.6 µm. Ablation efficiency was higher in all three regimes tested.
Copper circuit patterns on polyimide (PI).
Selective Surface Activation Induced by Laser (SSAIL)

SSAIL writes copper circuits directly onto dielectric surfaces: an ultra-short pulse laser draws the pattern, chemical activation follows it, and electroless plating deposits metal only on the lasered areas. Developed by FTMC and Akoneer, the process reaches trace widths down to 1 µm on PC/ABS, PMMA, PET, FR-4, Al2O3 ceramic, fused silica and silicon.
Cut edge of a heat-sensitive organic material.
Heat-sensitive organic material processing

Heat-sensitive organic materials warp and char when a cutting process leaves heat behind. Femtosecond pulses remove material before heat spreads into the lattice: thin organic sheets for medical applications were cut at 100 mm/s with 350 fs pulses, with kerf widths down to 14.38 µm and no charring on the cut edges.
All applications