Browsing by Author "Hung, HY"

Now showing 1 - 3 of 3

Curing of polyimide and the effect of the TEOS SiO2 barrier layer on the electromigration of sputtered Cu with polyimide passivation
(2002-01-01)
Hung, HY
;
Chiou, BS
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
The curing process of polyimide and the electromigration of copper films with polyimide (PI) passivation are studied. Thermal analysis of polyimide suggests that imidization completes at similar to200degreesC with an endothermic reaction associated with the breaking of the C-OH and N-H bonds as revealed by Fourier transformation infrared spectroscopy (FTIR). Although there is 89.8% weight loss when PI is heated from 20 degreesC to 200 degreesC, outgassing of PI passivation is still observed at higher temperatures. Carbon, nitrogen, and oxygen atoms diffuse into Cu during thermal processing of PI/Cu films. The tetraethyl orthosilicate (TEOS) SiO2 films are used as the barrier layer between PI and Cu to retard the poisoning of Cu. The effect of TEOS SiO2 film on electromigration of Cu is investigated.
Electromigration in sputtered copper interconnection with polyimide as interlevel dielectric or passivation
(2000)
Chiou, BS
;
Jiang, JS
;
Wang, HW
;
Hung, HY
;
電子工程學系及電子研究所
Electromigration damage (EMD) is one of the major causes for the failures of interconnection. The use of copper and low dielectric constant dielectric has been proposed to reduce the RC time delay and to improve EMD. In this study, the Electromigration of Cu with polyimide is investigated with an empirical formula dR/dt.1/R-0 = AJ(n) exp(-Q/RT). Secondary ion mass spectrometry (SIMS) reveals the interdiffusion between Cu and polyimide during curing of the polyimide and/or annealing of Cu metallization. Thin layers of TiW is deposited between polyimide and Cu as a barrier to reduce the interdiffusion. The activation energy Q for the electromigration of Cu on polyimide is 0.77eV from 120 degrees C to 230 degrees C, while activation energies for samples with titanium tungsten as an interlayer are 0.79eV (140 degrees C to 190 degrees C) and 1.73eV (190 degrees C to 230"C). The presence of TiW barrier enhances the high temperature electromigration resistance and promotes the adhesion between Cu and polyimide interface. However, films with TiW are found to be more sensitive to current stressing than those without. Polyimide is also employed as a passivated layer on top of Cu metallization. Resistance of the passivated samples decrease in the initial stage of the electromigration experiment. Possible causes are discussed on the decrease in R. The geometry of the metallization also affects the electromigration, the current exponent (n), calculated from EMD data, are different for interconnection with different geometries.
Wavelet transform based digital watermarking for image authentication
(2005)
Tsai, MJ
;
Hung, HY
;
資訊管理與財務金融系註：原資管所+財金所
;
Department of Information Management and Finance
The rapid expansion of the Internet and the recent advance of digital technologies have sharply increased the availability of digital media. This paper is to investigate a wavelet based semi-fragile watermarking technique for image authentication. Image protection is achieved by the insertion of a secret wavelet tree based binary image signature (WTS) after wavelet decomposition followed by the quantization procedure. In addition, adaptive tuning steps are performed for the selected watermarked coefficients in order to increase the elasticity of watermark. During the verification, the original unmarked image is not needed for comparison. The detection of unauthorized tampering within the image is claimed by comparison with the possibly modified image's WTS and the authentic one.