Browsing by Author "Lee, C. K."

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Enhancement of InGaN-GaN indium-tin-oxide flip-chip light-emitting diodes with TiO2-SiO2 multilayer stack omnidirectional reflector
(2006-09-01)
Lin, C. H.
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Lai, C. F.
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Ko, T. S.
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Huang, H. W.
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Kuo, H. C.
Enhancement of light extraction of GaN-based flip-chip indium-tin-oxide light-emitting diodes (FC ITO LEDs) with an onmidirectional reflector (ODR) is presented. The ODR consisting of alternating layers of TiO2 and SiO2 is designed to possess a complete photonic bandgap within the blue region of interest, and it is fabricated by E-beam deposition. At a driving current of 300 mA and a chip size of 1 mm x 1 mm, the light output power of the FC ITO LEDs with the ODR reaches 156 mW. This is an enhancement of 31% when compared with the same device with an Al mirror instead. Furthermore, by examining the radiation patterns, the FC ITO LED with the ODR shows stronger enhancement around the vertical direction. Our work offers promising potential for enhancing output powers of commercial light-emitting devices.
Structural Design, Process, and Reliability of a Wafer-Level 3D Integration Scheme with Cu TSVs Based on Micro-bump/Adhesive Hybrid Wafer Bonding
(2012)
Ko, C. T.
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Hsiao, Z. C.
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Chang, Y. J.
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Chen, P. S.
;
Huang, J. H.
In this study, a wafer-level 3D integration scheme with Cu TSVs based on Cu/Sn micro-bump and BCB adhesive hybrid bonding is demonstrated. To realize the signal transmission effects in high speed digital signaling via Cu TSV and Cu/Sn micro-joint interconnection, the insertion loss was investigated by simulation analysis with variable TSV pitches, micro-bump diameters and chip thicknesses. Key technologies include TSV fabrication, micro-bumping, hybrid scheme making, hybrid bonding, wafer thinning and backside RDL formation were well developed and integrated to perform the 3D integration scheme. 5 mu m TSV, 10 mu m microbump, 20 mu m pitch, 40 mu m thin wafer, and 250 degrees C low temperature W2W hybrid bonding have been successfully integrated in the integration platform. The 3D scheme was characterized and assessed to have excellent electrical performance and reliability, and is potentially to be applied for 3D product applications.