Browsing by Author "CHEN, YJ"

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COPPER CHEMICAL-VAPOR-DEPOSITION FROM CU(HEXAFLUOROACETYLACETONATE)TRIMETHYLVINYLSILANE
(1994-04-01)
CHIOU, JC
;
CHEN, YJ
;
CHEN, MC
;
電子工程學系及電子研究所
;
Department of Electronics Engineering and Institute of Electronics
Copper chemical vapor deposition using Cu-hexafluoroacetylacetonate (hfac) trimethylvinylsilane (TMVS) as precursor was performed in a cold-wall low pressure chemical vapor deposition (CVD) reactor. The design and operation of the reactor are described. Copper deposition on thermal SiO2, W, and CoSi2 substrate surfaces was investigated over the temperature range of 160-300-degrees-C and pressure range of 10-1000 mTorr. The activation energies of Cu CVD were determined to be 13.33 and 11.54 kcal/mole for the W and CoSi2 substrates, respectively. The dependence of film resistivity, grain size, and growth rate on deposition pressure and temperature were also investigated. The film uniformity was found to be better than ten percent over a 4-inch diameter substrate. Experimental results also show that selective deposition can be achieved at a pressure of 10 mTorr within the temperature range of 160-200-degrees-C. In addition, hydrofluoric acid dipping was found to modify the SiO2 surface and influence the copper deposition on it.
PERFORMANCE ANALYSIS OF AN OCR SYSTEM VIA AN ARTIFICIAL HANDWRITTEN CHINESE CHARACTER GENERATOR
(1994-02-01)
TUNG, CH
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CHEN, YJ
;
LEE, HJ
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資訊工程學系
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Department of Computer Science
A handwritten Chinese character generator that generates handwritten Chinese characters with different variations is proposed and used to evaluate the performance of an OCR system. The character generator first generates radicals of a character stroke by stroke and then combines the generated radicals to form a line-vector character. Next, the line-vector character is thickened to obtain a character image. Characters generated by this method will have great variance in shape but will still satisfy the structural constraints. The generated characters are then used to perform two types of evaluations. First, the stability of stroke extractors in terms of stroke number is evaluated. Two stroke extractors, one based on thinning and the other on vectorization, are analyzed. The vectorization-based stroke extractor we propose operates directly on the run length codes of line segments. From experimental results, we find that the thinning-based method is more time-consuming but more stable than the vectorization-based method. Second, the peak performance of a matching module is evaluated and the recognition error caused by stroke extractors is identified.
SOME PROPERTIES OF VECTORIAL ADDITION CHAINS
(1994)
CHEN, YJ
;
CHANG, CC
;
YANG, WP
;
資訊工程學系
;
Department of Computer Science
The concept of the shortest vectorial addition chains is considered to be an optimal approach for computing a monomial Pi(i=1)(p)x(i)(ni) with the minimum number of multiplications. In this paper, some properties of the shortest vectorial addition chain are presented. Furthermore, an approach to achieve the shortest chains in some special cases is proposed. The correctness of these properties and the optimality of this approach are also shown.