Excimer Ablation of Soft Polymers

Dr. Charles Rohde and Dr. Bryon Wright are investigating the processing abilities of the PF excimer micro-machining system for ablating soft polymer films. Shown below are the results of a 1 cm² array of hexagonal close-packed (hcp) squares cut into a photosensitive epoxy.


Hexagonal close-packed array of 10µm x 10 µm squares, ablated in photosensitive epoxy.
10x image of an hcp array of 10µm x 10 µm squares, ablated in photosensitive epoxy.


60x-10umx10um-hcp-su8
60x image of hcp array of 10µm x 10 µm squares, ablated in photosensitive epoxy.

µMachining in New Zealand

JPSA Excimer laser at work, creating a mask for lithography.
JPSA Excimer laser at work, creating a mask for lithography.

Our first project! Here you can see the JPSA system cutting our first chrome on glass mask for Cosmin Laslua. The small blue spark is the 248nm light fluorescing as a thin layer of chrome is ablated from the surface of the glass microscope slide. This will produce a positive mask, though which light can expose a photoresit.

JPSA System Installed

JPSA µ-Machining platform installed and
JPSA µ-Machining platform installed and aligned

The JPSA system has been installed and is ready to start cutting! Well I should say that the UV excimer system is ready. The femtosecond system is currently causing some headaches. Primarily, the femtosecond system’s set power (3.3 mJ) and high repition rate (1 kHz) are causing some headaches. We are looking in to ultra-fast variable attenuators from Altechna to address the set output power of the Legend system. The trick here is to lower the power with out streching the pulse. This makes conventaional laser power adjustment with ND filters or polarizers unseable. The Altechna system uses thin film polarizers in combination with half waveplates to minimize the pulse stretching while allowing continuous pulse attenuation.

JPSA System Arrives

JPSA Inital System Placement
JPSA Inital System Placement

The inital placement of the JPSA µ-machining platform has been completed. With the arrival of the installation eningeers from JPSA and Coherent Scientific we can begin the final alignement of the Xantos Excimer laser (in the foreground on the labjack) and the Coherent Legend femtosecond laser beam paths. Just getting the system in the door proved to a challenge, but with the removal of a few (probably) insignificant handles we managed to JUST slip it in. We didn’t even need to remove the door frame (a speculation brought up serval times in the past. Thanks for the Peter!