4M Knowledge base - papers

A CAD/CAM Approach for Layer-Based FIB Processing

Georgi Lalev(a), Stefan Dimov(a), Jeff Kettle(a), Falco van Delft(b) and Roussi Minev(a)
a: Manufacturing Engineering Centre, Cardiff University, Queen's Buildings, The Parade, Newport Road, Cardiff, CF24 3AA, UK
b: Philips Research Europe, MiPlaza, High Tech Campus 4, 5656 AE Eindhoven, The Netherlands

Abstract

The realization of complex three-dimensional structures at micro- and nano-meter scale in various materials is of great importance for a number of micromechanical, microoptical and microelectronic applications. Focused Ion Beam (FIB)patterning is one of the promising technologies for producing such 3D structures utilizing layer-by-layer fabrication methods. A novel and efficient data preparation approach is proposed in this paper for layer-based FIB processing. By applying it, complex surfaces can be designed easily in any 3D CAD package and then converted into GDSII streams for FIB sputtering or deposition. To validate the proposed CAD/CAM approach an experimental study was conducted.

The factors that can affect the accuracy of the structures produced by layer-based FIB processing are also discussed. By assessing all stages of the proposed approach and the results of its experimental validation, conclusions are drawn about its applicability.

Submitted on November 12, 2007 - 16:23.

FIB Milling and Characterization of CrC Coatings on Tool Steel Substrate

R.M. Minev(a), M. Ilieva(b), J. Kettle(a), G. Lalev(a), S.S. Dimov(a), I. Dermendjiev(b), R. Shishkov(b)
a: Manufacturing Engineering Center, Cardiff University, Cardiff, CF24 3AA, UK
b: Department of Materials Science and Technology, Rousse University, Bulgaria

Abstract

In microtools, the base of a die should be ductile, and its working surface should be hard, having low roughness, low wettability and high erosion resistance. To ensure this diverse range of properties, nano-crystalline CrC coatings were deposited onto 12% Cr tool steel with DC magnetron sputtering in a vacuum furnace with electrical graphite heating. Subsequently, these properties were studied by application of different metallographic techniques. Corrosion resistance as studied by means of potentiodynamic anodic polarization. A STEM analysis of the structure was performed on samples repared with Focused Ion Beam (FIB) using nano-manipulator. The mechanical properties and grain size were determined and statistically analyzed. Studies using X-ray diffraction and scanning electron microscopy were also performed. Rectangular trenches were produced in the coating using FIB XB1540 Carl Zeiss SEM/FIB system to study the effects of the target ion beam current, exposure time and ion fluence on the sputtering yield and roughness of the samples profile. Some essential parameter’ windows for productive milling with speed >1 μm/min and for best surface integrity were determined during the experiments.

Submitted on November 12, 2007 - 16:23.

Micromachining of amorphous and crystalline Ni78B14Si8 alloys using micro-second and pico-second lasers

I. Quintana (1), T. Dobrev (3), A. Aranzabe (2), G. Lalev (3), S. Dimov (3)

(1) CIC marGUNE. Pol. Ibaitarte 5, 20870; Elgoibar; Guipúzcoa, Spain
(2) Manufacturing Processes Department, Fundación Tekniker, Av. Otaola 20, 2060, Eibar, Guipúzcoa, Spain
(3) Manufacturing Engineering Centre, Cardiff University, Cardiff, CF24 3AA

Abstract

The machining response of amorphous and polycrystalline Ni-based alloys (Ni78B14Si8) to micro-second and pico-second laser processing was investigated. The shape and topography of craters created with single pulses as a function of laser energy together with holes drilled in both materials were studied. The carried out FIB analysis of craters in amorphous and polycrystalline samples revealed that processing both with micro-second and pico-second lasers does not lead to materials crystallization and the short-range atomic ordering of metallic glasses can be retained. When processing the amorphous sample the material laser interactions resulted in a significant ejection of molten material from the bulk that was then followed by its partial re-deposition around the craters. Additionally, there were no signs of crack formation that indicate a higher surface integrity after laser machining. A conclusion is made that laser processing both with short and long pulses is a promising technique for micromachining metallic glasses because does not lead to material crystallisation.

Submitted on July 30, 2008 - 13:22.

Template fabrication incorporating different length scale features

G. Lalev (1), P. Petkov (1), N. Sykes (2), V. Velkova (1), S. Dimov (1), D. Barrow (2)

(1) Manufacturing Engineering Centre, Cardiff University, Newport Road,Cardiff, CF24 3AA, UK
(2) metaFAB, Cardiff University, Newport Road, Cardiff, CF24 3AA, UK

Abstract

A cost effective methodology for pattering of Nano Imprint Lithography (NIL) templates with different length scale features is proposed. The approach relies on selecting the optimum processing window of different technologies for cost effective micro and nano patterning. Very promising results were obtained when first fused silica templates were structured by F2 laser ablation at 157 nm without inducing phase transformation of the material. It was demonstrated that nanoscale features and complex 3D microscale features could be machined with a Focused Ion Beam (FIB) over the existing topography produced by laser ablation. Thus, a large area (up to several square centimetres) of the NIL templates is easily patterned with micro- and even meso-scale features by laser ablation while nano- and micro-scale features could be introduced by FIB machining.

Submitted on August 4, 2008 - 14:32.

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