Papers by Author: Jong Min Lee

Abstract: Influence of steam, loading amounts of Pd (viz., 0.7, 2.1, 5.4 wt %) and other process parameters (viz. GHSV and temperature) on methane-based MCFC anodeeffluents over Pd-based La2O3-Al2O3 supported on honeycomb substrate have been investigated. TGA study reveals precise temperature of decomposition of Pd-O in catalytic combustion at high temperature. An increase in methane conversion at elevated temperature is attributable to decomposition of PdO to Pd active phase. The XRD analysis of spent catalysts suggests that the reflections corresponding to PdO gradually become weaker with increase in the Pd loading. The addition of 4% water in the feed decreases the methane conversion due to the reversible reaction of PdO with water adduct resulting in the formation of inactive Pd(OH)2 phase. However, the methane conversion remains unaffected and increases monotonously with 100% water concentration in the feed.

Abstract: A reliable fabrication method for providing close spacing between the emitter mesa and the base contact metal of InP-based heterojunction bipolar transistor is disclosed. The silicon nitride sidewall was formed on the emitter electrode and mesa periphery. It was used as a mask for emitter mesa etching and also as an overhang to self-align the base contact with respect to the emitter mesa. The self-aligned device fabricated by this technique exhibited better high-frequency performances with fT of 138 GHz and fmax of 143 GHz, respectively, superior to the re-aligned one on the same epitaxy wafer.