Browsing by Author "Chang, DF"

Now showing 1 - 3 of 3

Diamond growth onCoSi(2)/Si by bias-enhanced microwave plasma chemical vapor deposition method
(2001-11-01)
Chen, MR
;
Chang, L
;
Chang, DF
;
Chen, HG
;
材料科學與工程學系
Diamond was grown on polycrystalline CoSi2/Si substrates by bias-enhanced microwave plasma chemical vapor deposition. Both of the positive and negative biasing effects were investigated by microstructural characterization. It has been found that nucleation density can reach similar to 10(9) cm(-2) with positive biasing, much higher than with negative biasing. Cross-sectional transmission electron microscopy shows that diamond deposited by positive biasing grows on a relatively smooth CoSi2 surface, while the etching effect of ion bombardment during negative biasing results in a rough CoSi2 surface. The diamond morphology obtained with negative bias has a flat surface with a strong (1 0 0) texture. (C) 2001 Elsevier Science B.V. All rights reserved.
iSMS: An integration platform for Short Message Service and IP networks
(2001-03-01)
Rao, HCH
;
Chang, DF
;
Lin, YB
;
交大名義發表
;
National Chiao Tung University
This article describes iSMS, a platform that integrates IP networks with the Short Message Service in mobile telephone systems. iSMS provides a generic gateway for creating and hosting wireless data services for mobile stations. Our approach does not require any modification to the mobile telephone system architecture. The iSMS system can be quickly developed and operated by a third party or end user without involvement of mobile equipment manufacturers and telecom operators. Based on the iSMS platform, we illustrate services such as e-mail delivery/forwarding, Web access (e.g., stock and train schedule query) and handset music services. The iSMS platform and the services have been implemented for GSM networks With iSMS, users are able to use standard GSM handsets to access wireless Internet services, while other approaches like Wireless Application Protocol and SIM Toolkit services require function-enabled MSs.
Thermal stability of Cu/Ta/GaAs multilayers
(2000-11-20)
Chen, CY
;
Chang, L
;
Chang, EY
;
Chen, SH
;
Chang, DF
Copper metallization for GaAs was evaluated by using Cu/Ta/GaAs multilayers for its thermal stability. A thin Ta layer of 40 nm was sputtered on the GaAs substrate as the diffusion barrier before copper film metallization. As judged from sheet resistance, x-ray diffraction, Auger electron spectroscopy and transmission electron microscopy, the Cu/Ta films with GaAs were very stable up to 500 degreesC without migration into GaAs. After 550 degreesC annealing, the interfacial mixing of Ta with GaAs substrate occurred, resulting in the formation of TaAs2. At 600 degreesC annealing, the reaction GaAs with Ta and Cu formed TaAs, TaAs2, and Cu3Ga, resulting from Cu migration and interfacial instability. (C) 2000 American Institute of Physics. [S0003-6951(00)03047-3].