Share Email Print
cover

Proceedings Paper

Micromachining with femtosecond 250-nm laser pulses
Author(s): C. Li; Michael A. Argument; Ying Y. Tsui; Robert Fedosejevs
Format Member Price Non-Member Price
PDF $14.40 $18.00

Paper Abstract

Laser micromachining is a flexible technique for precision patterning of surfaces in microelectronics, microelectromechanical devices and integrated optical devices. Typical applications include drilling of holes, cutting of conducting lines or shaping of micro component surfaces. The resolution, edge finish and residual damage to the surrounding and underlying structures depend on a variety of parameters including laser energy, intensity, pulse width and wavelength. Femtosecond pulses are of particular interest because the limited time of interaction limits the lateral expansion of the plasma and the inward propagation of the heat front. Thus, very small spot size can be achieved and minimal heating and damage of underlying layers can be obtained. An additional advantage of femtosecond pulses is that multiphoton absorption leads to efficient coupling of energy to many materials independent of the linear reflectivity of the surface. Thus metals and transmitting dielectrics, which are difficult to micromachine, may be machined with such pulses. The coupling is improved further by employing ultraviolet wavelength laser pulses where the linear absorption typically is much higher than for visible and infrared laser pulses. To explore these advantages, we have initiated a study of the interaction of 250nm femtosecond laser pulses with metals. The laser pulses are obtained by generating the third harmonic from a femtosecond Ti:sapphire laser operating at 750nm. The pulses are focused to various intensities in the range of 1010Wcm2 to 1015 Wcm2 using reflective and refractive microscope objectives and ablation thresholds and ablation rates have been determined for a few metals. In addition the ability to control feature size and produce submicron holes and lines have been investigated. The results are presented and compared to results obtained using infrared and visible femtosecond laser pulses.

Paper Details

Date Published: 15 December 2000
PDF: 7 pages
Proc. SPIE 4087, Applications of Photonic Technology 4, (15 December 2000); doi: 10.1117/12.406367
Show Author Affiliations
C. Li, Univ. of Alberta (Canada)
Michael A. Argument, Univ. of Alberta (Canada)
Ying Y. Tsui, Univ. of Alberta (Canada)
Robert Fedosejevs, Univ. of Alberta (Canada)


Published in SPIE Proceedings Vol. 4087:
Applications of Photonic Technology 4
Roger A. Lessard; George A. Lampropoulos, Editor(s)

© SPIE. Terms of Use
Back to Top