Browsing by Author "Cheng, JH"

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Anomalous electrical performance of nanoscaled interfacial oxides for bonded n-GaAs wafers
(2006-03-13)
Hao, OY
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Wu, YCS
;
Chiou, HH
;
Liu, CC
;
Cheng, JH
Electrical performance was found to be closely related to the variation of nanosized interface morphology in previous studies. This work investigated in detail the microstructural development of in- and anti-phase bonded interfaces for n-type (100) GaAs wafers treated at 500, 600, 700 and 850 degrees C. The interfacial energy of anti-phase bonding is higher than that of in-phase bonding based on the first-principles calculations. The higher interface energy tends to stabilize the interfacial oxide layer. The continuous interfacial oxide layer observed below 700 degrees C can deteriorate the electrical property due to its insulating property. However, the existence of nanoscaled oxide at anti-phase bonded interfaces can improve the electrical conductivity at 700 degrees C. This is due to the suppression of the evaporation of As atom by the interfacial nanoscaled oxides based on the analysis of autocorrelation function and energy dispersive x-ray spectroscopy. (c) 2006 American Institute of Physics.
Effects of annealing temperature on electrical resistance of bonded n-GaAs wafers
(2004-11-22)
Liu, PC
;
Lu, CL
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Wu, YCS
;
Cheng, JH
;
Ouyang, H
The electrical characteristics and microstructures of n-type (100) GaAs bonded interfaces were systematically investigated. Experimental results indicated that GaAs did not bond directly to itself, but via an amorphous oxide layer at 400 degreesC. When temperatures increased above 400 degreesC, the oxide bonded area declined and finally disappeared. Electrical resistance decreased with bonding temperature. However, the resistance increased with temperatures exceeding 850 degreesC. (C) 2004 American Institute of Physics.
Identification of Atractylodes plants in Chinese herbs and formulations by random amplified polymorphic DNA
(2001-06-01)
Chen, KT
;
Su, YC
;
Lin, JG
;
Hsin, LH
;
Su, YP
AIM: An efficient, precise, and sensitive method for identifying Atractylodes plants has been established and will contribute significantly to quality control and scientific analysis in Chinese traditional medicine. METHODS: Twenty primers were applied for setting up the RAPD (randomly amplified polymorphic DNA) markers of Atractylodes plants, Atractylodes lancea DC (A lancea MG:), Atractylodes japonica Koidz (A japonica K), and Atractylodes ovata DC (A ovata DC). The primer OPF03, OPF05, and OPF14 could discriminate them successfully. The results were also able to apply on the Chinese formulations with Atractylodes purchased from local markets. RESULTS: RAPD was used to investigate phylogenetic relationships among and within closely related species. RAPD analysis reflects heritable changes in the nucleotides sequence in both the coding and noncoding regions, because it is conducted directly from the DNA level. This work first conducted RAPD analysis of Atractylodes plants to establish their RAPD makers. CONCLUSION: The RAPD markers could be applied extensively in the Chinese herbal formulations.