Browsing by Author "Yang, TY"

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A study of boron diffusion from selectively grown epitaxial silicon-germanium into silicon during rapid thermal annealing
(2002)
Yang, TH
;
Chang, EY
;
Chen, KM
;
Chien, CH
;
Huang, HJ
Boron diffusion from selectively grown epitaxial Si1-xGex into Si during rapid thermal annealing (RTA) was investigated. Selective epitaxial growth (SEG) of in-situ boron-doped strained Si1-xGex epitaxial layers with different Ge percentages were selectively grown by ultra high vacuum chemical molecular epitaxy (UHVCME). The results show that the boron diffusion depth from SEG Si1-xGex into n-type Si depends on boron concentration, Ge profile in the SEG area, and the size of the SEG area. Higher boron concentrations in SEG Si1-xGex film increases the boron diffusion depth. However, the diffusion depth can be reduced by increasing Ge composition in SEG Si1-xGex. It was also found that the samples with graded Ge profiles have higher diffusion depths than those with uniform profiles. In addition, the boron diffusion depth increases with the size of the SEG Si1-xGex area. The strain in SEG Si1-xGex, the chemical potential of Ge in SEG Si1-xGex and the dislocations induced in the SEG Si1-xGex layers are the main reasons for the phenomena observed.
An innovative model of multi-project wafer service in the foundry industry
(2005)
Yang, TY
;
Tong, LI
;
Yuan, BJC
;
工業工程與管理學系
;
科技管理研究所
The cost of masks is rising rapidly as semiconductor manufacturing technology advances. This increase in cost is a major issue in the development of new products. This study focuses mainly on the business demands of semiconductor design companies who verify the prototypes and produce small-volume wafers, and analyses the constraints on the current Multi-Project Wafer (MPW) model. A new MPW model is proposed to reduce the mask cost and the unit die cost simultaneously. The proposed MPW model allows customers to find the optimal solution to the mask cost and unit die cost according to the chip size and the number of dice required. This study also compares the current model with the proposed MPW model using 0.13 um technology, as an example. For a purchased quantity of dice from a few thousand to less than a hundred thousand, the proposed MPW model yields the lowest sum of the mask cost and the dice cost. Since this ran-e of dice quantities covers more than half of the dice required for semiconductor products, the proposed MPW model can help the semiconductor industry to resolve the conflict between the mask cost and the unit die cost that is caused by the constraints on the current MPW model. When the technology advances to the 90 nm generation, and requested die quantities increased to more than 100,000, the small-volume MPW model proposed in this study will still yield the lowest mask cost and total dice cost.
Growth of ZnSe epilayer on Si using Ge/GexSi1-x buffer structure
(2004-06-15)
Yang, TH
;
Yang, CS
;
Luo, GL
;
Chou, WC
;
Yang, TY
The epitaxial growth of ZnSe layers on Si substrates utilizing a Ge/Ge0.95Si0.0.5/Ge0.9Si0.1 buffer structure is demonstrated. In this study, we examine the structure, optical characteristics and atomic interdiffusion of the ZnSe epilayer grown on Si. In a sample with a 2degrees off-cut Si substrate, the outdiffusion of Ge into the ZnSe epilayer is suppressed. The low-temperature PL measurements indicate that the sample with a 2degrees off-cut Si substrate improves its optical characteristic effectively. The X-ray diffraction analysis and transmission electron microscopy (TEM) results indicate that the use of a 2degrees off-cut Ge/Ge0.95Si0.05/ Ge0.9Si0.1/Si substrate markedly improves the crystallinity of and reduced the number of threading dislocations in ZnSe grown on Si.
Study of nickel silicide contact on Si/Si1-xGex
(2003-09-01)
Yang, TH
;
Luo, GL
;
Chang, EY
;
Yang, TY
;
Tseng, HC
The properties of nickel silicide formed by depositing nickel on Si/P+ - Si1-xGex layer are compared with that of nickel germanosilicide on P+ - Si1-xGex layer formed by depositing Ni directly on P+ - Si1-xGex layer without silicon consuming layer. After thermal annealing, nickel silicide on Si/P+ S Si1-xGex layer shows lower sheet resistance and specific contact resistivity than that of nickel germanosilicide on P+ - Si1-xGex layer. In addition, small junction leakage current is also observed for nickel silicide on Si/P+ - Si1-xGex/N - Si diode. In summary, witha Si consuming layer on top of the Si1-xGex, the nickel silicide contact formed demonstrated improved electrical and materials characteristics as compared with the nickel germanosilicide contact which was formed directly on Si1-xGex layer.