Laser drilling of via micro-holes in single-crystal semiconductor substrates using a 1070nm fibre laser with millisecond pulse widths

Abstract

. (2015) Laser drilling of via micro-holes in single-crystal semiconductor substrates using a 1070 nm fibre laser with millisecond pulse widths. Proceedings of SPIE. Industrial Laser Applications Symposium (ILAS 2015), 9657 (965701 A note on versions:The version presented here may differ from the published version or from the version of record. If you wish to cite this item you are advised to consult the publisher's version. Please see the repository url above for details on accessing the published version and note that access may require a subscription. ABSTRACTMicro-machining of semiconductors is relevant to fabrication challenges within the semiconductor industry. For via holes for solar cells, laser drilling potentially avoids deep plasma etching which requires sophisticated equipment and corrosive, high purity gases. Other applications include backside loading of cold atoms into atom chips and ion traps for quantum physics research, for which holes through the semiconductor substrate are needed. Laser drilling, exploiting the melt ejection material removal mechanism, is used industrially for drilling hard to machine materials such as superalloys. Lasers of the kind used in this work typically form holes with diameters of 100's of microns and depths of a few millimetres in metals. Laser drilling of semiconductors typically uses short pulses of UV or long wavelength IR to achieve holes as small as 50 microns. A combination of material processes occurs including laser absorption, heating, melting, vaporization with vapour and dust particle ejection and resolidification. An investigation using materials with different fundamental material parameters allows the suitability of any given laser for the processing of semiconductors to be determined. We report results on the characterization of via holes drilled using a 2000 W maximum power 1070 nm fibre laser with 1-20 ms pulses using single crystal silicon, gallium arsenide and sapphire. Holes were characterised in cross-section and plan view. Significantly, relatively long pulses were effective even for wide bandgap substrates which are nominally transparent at 1070 nm. Examination of drilled samples revealed holes had been successfully generated in all materials via melt ejection.

Laser Drilling of Small Holes in Different Kinds of Concrete

“…Concrete drilling technology using lasers to deal with reaction force [4]. But laser technology is rarely implemented in the construction field [5][6][7] however, it is being used in the manufacturing as drilling [8], cutting [9], welding [10], ablation and additive-manufacturing and microfabrication of medical devices, food industry, metal items, 767 in examinations and diagnostics for instance [11,12]. Nowadays, it has been started to research for civil engineering field [13][14][15].…”

All-solid anti-resonant single crystal fibers

“…First, the single crystal core can be obtained using the edge-defined film-fed growth method (EFG) [34] and laser heated pedestal method (LHPG) [21]. Then, the cladding ring structure is etched using femtosecond laser processing technology [35]. Finally, the low melting point and high refractive index glass material is injected into the ring structure to prepare the fiber.…”