DUV EXCIMER LASER PROCESSING FOR THE MICRO VIA HOLE ON SEMICONDUCTOR PACKAGE: Paper Number Micro 803

摘要

The Moore's law has almost reached resolution limit on semiconductor die. The one of alternative solution is multi die packaging. The substrate materials are currently using the organic build-up film and the silicon substrate (Through Silicon Via: TSV) for these applications. Recently the organic film has faced resolution limit, also TSV is required expensive cost. In this situation, the non-alkali glass (glass) and fused silica (SiO_2) substrate will be expected high frequency signal transfer application like 5G tele-communication use. But the via holes are hard to process with less defect (tips and cracks) on the glass and SiO_2 substrates. DUV excimer laser ablation is expected for the finer (< 10 μm) resolution by shorter wavelength (248 ～ 193 nm) and hard material processing by higher photon energy (5 ～ 6.4 eV). We have explored to applying out DUV excimer laser ablation process for via hole on the hard materials like the glass and SiO_2 substrates. In this study, we investigated the via hole quality by DUV excimer laser ablation process. The results show the possibilities of micromachining on both the glass and SiO_2 substrates. We have succeeded < 50 μm through via holes grid aspect ratio 6 on glass substrate without any significant defects. As the ablation rate is quite affordable value, so DUV excimer lasers are expected on next generation manufacturing process for semiconductor package. We also are investigating SiO_2 substrate with DUV excimer lasers.