Die-level patterning of parylene F by laser-ablation for further processing with ALD functional layers
Die-level patterning of a parylene F coated chip is achieved by short laser pulse ablation. Thus, the insulating polymer is removed selectively and local openings are achieved. Occurring melt-depositions at the cut edges are removed by applying an O2-flash which also thins the parylene layer from approximately 2 mm to 800 nm. Prepared dies are processed further by Atomic Layer Deposition (ALD). A transparent conductive In2O3-layer with a thickness of 45 nm is deposited three dimensionally onto the die so that Inter-Layer-Connections (ILC) with die metallisation are implemented through the opened parylene. Electrical connections through the patterned parylene, which demonstrate reasonable resistance values and non-ohmic behaviour, have been characterised by IV-measurements.