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This paper shows how a computer can systematically remove non-essential chemical reactions from a large chemical kinetic mechanism. The computer removes the reactions based upon a single solution using a detailed mechanism. The resulting reduced chemical mechanism produces similar numerical predictions significantly faster than predictions that use the detailed mechanism. Specifically, a reduced chemical kinetics mechanism for iso-octane has been derived from a detailed mechanism by eliminating unimportant reaction steps and species. The reduced mechanism has been developed for the specific purpose of fast and accurate prediction of ignition timing in an HCCI engine. The reduced mechanism contains 199 species and 383 reactions, while the detailed mechanism contains 859 species and 3606 reactions. Both mechanisms have been used in numerical simulation of HCCI combustion.

A high-breakdown-voltage n+-GaAs/δ (p+)-GaInP/n-GaAs camel-gate field-effect transistor with the triple-step doped-channel has been successfully fabricated and demonstrated. Experimentally, the high gate turn-on voltage of 1.6 V at a gate current of 1 mA/mm and a very high breakdown voltage of 40 V with the low gate leakage current of 400 μA/mm are obtained. The measured transconductance is 145 mS/mm with the current gain cut-off frequency fT of 17 GHz and the maximum oscillation frequency fmax of 33 GHz for a 1×100 um2 device. Consequently, based on the remarkable experimental results, the studied device shows a promise for high-power circuit applications.

Due to the high bandgap (Eg =1.9eV) and etching selectively of In0.5 Ga0.5P material, the InGaP/GaAs material system has been proposed to replace the AlGaAs/GaAs. Undoped or lighted doped InGaP, with a relatively high resistance, was considered well as an “insulator”. The wide bandgap characteristics enhance the breakdown voltage and, thus, the power handling capabilities of the device for high power applications. From the device point of view, the high breakdown voltage is an important requirement for high power operations. The wide-gap InGaP was also used to increase the collector breakdown voltage in an NpN double heterojunction bipolar transistors (DHBT's). For InGaP/GaAs DHBT's, the electron blocking effect associated with the presented ΔEC between B-C heterojunction could cause a degraded current gain. Therefore, it is necessary to suppress the electron blocking effect which mainly resulting from the ΔEC at BC heterojunction.