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With the development of information technology in Taiwan, night markets have improved their service performance by building information technology technologies, including Wi-Fi, cloud payment and mobile payment services, and QR codes. One of the most commonly used social networking sites among young people in Taiwan is Instagram (IG). In this study, we investigated whether users trust IG to provide sufficient security, and we found that the correctness of the trust information has a significant impact on their software use. This study focused on Taiwan’’s unique night market sightseeing experience and explored the use of Instagram by night market consumers. Questionnaire surveys and systematic sampling methods were used to survey consumers, and the number of valid questionnaires was 340. The results showed that the perceived usefulness and ease of use of IG Stories affected user attitudes, and user attitudes positively impacted behavioral intentions. Moreover, the attitude of night market consumers toward IG Stories was affected by trust, which in turn adjusted user behavior intentions. This research was the first to explore the experience of night market consumers using IG Stories. We concluded that night market vendors should strengthen their trust factor in order to have a positive attitude toward consumers and foster the higher behavioral intentions of consumers, which is essential for the successful promotion and marketing of night markets.

The little fire ant, Wasmannia auropunctata is an invasive species native to Central and South America. We report the establishment of this species in Taiwan, which is also the first confirmed population in the East Asian region. Little fire ants were found at two locations in central Taiwan, separated by approximately 30 km. Genetic and behavioral analyses indicated that the two populations both employ clonal reproduction and showed no aggression towards each other. Results of population genetic analyses indicate that the two populations are most likely derived from a common source population or genetically similar populations. Ministry of Science and Technology, Taiwan; Virginia Tech Faculty Start-up Research Fund; [MOST 111-2823-8-018-001] Published version Funding declaration This project was funded by the Ministry of Science and Technology, Taiwan (MOST 111-2823-8-018-001) and the Virginia Tech Faculty Start-up Research Fund.

The development of sports tourism is gaining momentum around the world, with many tourism industries combining sports events and programs to attract more domestic and overseas customers to promote economic and culture. Sustainability awareness has been gaining attention from many international organizations, resulting in the rise of sports tourism that incorporates sustainability. Therefore, the development of a valid and applicable sustainable sports tourism (SST) assessment model is an important task. In this study, a hybrid Multiple Attribute Decision-Making (MADM) model is proposed to measure the development performance of SST. The aims of this study include developing a SST assessment framework, identifying the mutual influential relationships among attributes, generating attribute influence weights, and calculating the performance of the evaluated items. The proposed model is divided into three stages. First, a cause-and-effect diagram is generated using the Grey Decision-Making Trial and Evaluation Laboratory (GDEMATEL) to describe the interactions and feedback among the attributes. Then, the GDEMATEL-based Analytic Network Process (GDANP) is applied to generate the influence weights of the attributes and their rankings. Finally, the expanded Probability-based Grey Relational Analysis (expanded PGRA) was applied to calculate the performance of the evaluated items and to determine the gap between evaluated items and the aspiration level. This study improves the original PGRA technique by introducing the concept of aspiration level into the PGRA calculation process, thereby replacing the traditional concept of “relative satisfaction” with “aspiration level”. In addition, the expanded PGRA can assess a single rated item without being limited to at least two items. We used the Sun Moon Lake Scenic Area in Taiwan as a model demonstration. The results show that the top three attributes that need to be strengthened are disease prevention and treatment, local social welfare and protection, and sports diversity. In the Sun Moon Lake, intersection control should be set up to ensure the health status of visitors and local residents. In addition to epidemic prevention, more measures and behaviors should be developed to deal with tourism diseases. We suggested that subsidies be provided to local residents to rebuild the fences around their homes to avoid disturbances caused by the influx of tourists. Moreover, the local government can create more sports events with special characteristics that can attract tourists to come again and again.

As the Coronavirus disease 2019 (COVID-19) epidemic spreads all over the world, governments of various countries are actively adopting epidemic prevention measures to curb the spread of the disease. However, colleges and universities are one of the most likely places for cluster infections. The main reason is that college students have frequent social activities, and many students come from different countries, which may very likely cause college campuses to be entry points of disease transmission. Therefore, this study proposes a framework of epidemic prevention work, and further explores the importance and priority of epidemic prevention works. First of all, 32 persons in charge of epidemic prevention from various universities in Taiwan were invited to jointly formulate a campus epidemic prevention framework and determined 5 dimensions and 36 epidemic prevention works/measures/criteria. Next, Bayesian best worst method (BWM) was used to generate a set of optimal group criteria weights. This method can not only integrate the opinions of multiple experts, but also effectively reduce the complexity of expert interviews to obtain more reliable results. The results show that the five most important measures for campus epidemic prevention are the establishment of a campus epidemic prevention organization, comprehensive disinfection of the campus environment, maintenance of indoor ventilation, proper isolation of contacts with confirmed cases, and management of immigration regulations for overseas students. This study provides colleges and universities around the world to formulate anti-epidemic measures to effectively reduce the probability of COVID-19 transmission on campuses to protect students’ right to education.

The purpose of this study is to explore the impact of the use motivation of Sports Intelligent Wearable Equipment on target orientation and Sports involvement. Taking the users of sports intelligent wearable equipment as the research object, the researchers were asked to send questionnaires and network questionnaires, total of 400 questionnaires were issued, 385 valid questionnaires were collected, the effective recovery rate was 96.25%. Data processing use descriptive statistics, independent sample t test, single factor variance analysis and multiple stepwise regression analysis. The research results are: first, male was mainly using the movement of intelligent wearable equipment: for the most age were 21 to 25 years old; most of the smart wear device price are below 1000. Second, different background variables in the use motivation, target orientation and sports involvement have significant differences exist. Third, the use motivations will positively affect the target orientation; the use motivation among the curiosity and epidemics will positively affect the sports involvement; target orientation will positively affect sports involvement.

In recent years, the awareness of sustainable tourism has risen around the world. Many tourism industries combine sports to attract more customers to facilitate the development of the economy and the promotion of local culture. However, it is an important task to establish a comprehensive tourism evaluation framework for sustainable sports tourism. This study proposes a Multi-Criteria Decision-Making (MCDM) model to discuss the above issues, using the Bayesian Best Worst Method (Bayesian BWM) to integrate multiple experts’ judgments to generate the group optimal criteria weights. Next, the modified Visekriterijumska Optimizacija i Kompromisno Resenje (VIKOR) technique is combined with the concept of aspiration level to determine the performance of sports attractions and their priority ranks. In addition, this study adds a perspective of institutional sustainability to emphasize the importance of government support and local marketing. The effectiveness and robustness of the proposed model is demonstrated through potential sports tourism attractions in Taiwan. A sensitivity analysis and models comparison were also performed in this study. The results show that the proposed model is feasible for practical applications and that it effectively provides some management implications to support decision-makers in formulating improvement strategies.

The purpose of this study was to explore the influencing factors of users using Nike + Run Club App by Theory of Reasoned Action (TRA) as the theoretical basis and add the perceived playfulness into the research framework. This study took the users of the Nike + Run Club App as the research subject and distributed 360 questionnaires by snowballing sampling, a total of 351 valid questionnaires. All data were analyzed by descriptive statistics, confirmatory factor analysis, and structural equation models. Overall, the results reveal that extending TRA could be a well-explained users’ behavior in the mobile application. The study found that the less the efforts spent in learning, the more positive the influence on attitude, thus affecting users’ behavior. Therefore, this study proposed the following suggestions: People are pursuing a clearer and simple interactive function, a simplistic design; or adding instructions next to the new features will make the Nike + Run Club App more perfect. Emphasize the user’s entertainment needs, develop interesting tasks, or games to make users feel interesting, and then be willing to continue to use the Nike + Run Club App.

The purpose of this research is to explore the correlation between leisure motivation, leisure attitude, perceived value and happiness of large heavy motorcycle riders. Taking knights in the central region of Taiwan as the research object, the questionnaire was distributed by intentional sampling. A total of 515 questionnaires were distributed, and 427 valid questionnaires (82.9%) were returned. The questionnaire was verified by descriptive statistics, confirmatory factor analysis, and structural equation modeling. The results found that leisure motivation, leisure attitude, and perceived value significantly positively affect happiness, and leisure attitude significantly positively affects perceived value. In addition, leisure attitude and perceived value also play an intermediary role between leisure motivation and happiness. Large heavy-duty riders choose to participate in self-preferred riding activities to obtain a pleasant experience of their self-demand, subtly improve overall life satisfaction, and effectively promote happiness.

The aim of this study was to understand the influence of youths on sports attitudes and sports behaviors after watching sports internet celebrity's on-line videos or articles. In this study, a network of questionnaires was used to survey 400 15-24 year-olds and a total of 360 valid questionnaires were collected. The results of this study found that: First, 78.6% of young people will actually participate in sports after viewing sports internet celebrity related videos or articles. Second, there is no significant difference in sports attitudes among adolescents of different genders; there are significant differences in sports behaviors, and men are higher than women. Third, the cognitive structure of sports attitudes has a positive effect on sports behavior. The sports internet celebrity has positively affected the youth's sports attitude and sports behavior, the government or related organizations can use the sports internet celebrity to increase young people's awareness of sports, then to promoting young people to participate in sports and achieve regular exercise.

This study proposed to construct a behaviour model for Pokemon Go user by consideration of Motivation, Sport Involvement, and Tourism Benefit. The subject of the study was the Pokemon Go users. The researcher used purposive sampling as the sampling method, a total of 500 surveys were issued, 426 valid samples and the effective response rate is 85.2%. The collected data were analyzed by descriptive statistics, confirmatory factor analysis, and structure equation model. The results are illustrated as follow. First, the behaviour model constructed in this study fitted well in statistics. Second, motivation has significant influence effect on sport involvement and tourism benefit. Third, sport involvement has no significant influence effect on the tourism benefit. In conclusion, the motivation has significant influence on sport involvement and tourism benefit, which represent that tourism industry should attach importance to their attraction with Pokemon related product and event to enhance the motivation of Pokemon Go users. Based on the above results, this study provided some practical suggestion for related tourism industry and directions for researcher in future.

The rice disease bakanae, caused by Fusarium fujikuroi Nirenberg, has been present in Taiwan for over a century. To better understand the genetic diversity and structure of F. fujikuroi, a set of 16 polymorphic simple sequence repeat (SSR) markers were newly developed and used to analyze 637 F. fujikuroi isolates collected in 14 cities or counties around Taiwan from 1996 to 2013. On the basis of Bayesian clustering, the isolates were classified into four highly differentiated clusters: cluster B likely derived from the more widespread and genetically diversified clusters A or C, and cluster D was restricted to four cities or counties and may have been introduced from unknown sources genetically distinct from clusters A, B, and C. The coexistence of both mating types (MAT1-1:MAT1-2 = 1:1.88) and the highly diversified vegetative compatibility groups (VCG) (16 VCG among the 21 assessed isolates) suggest the likelihood of sexual reproduction in the field. However, the biased mating type ratios and linkage disequilibrium in the population suggest nonrandom mating between individuals. A significant pattern of isolation by distance was also detected, which implies a geographical restricted gene flow and low dissemination ability of F. fujikuroi. Evaluation of 24 representative isolates on eight rice varieties revealed differential levels of virulence, however no clear pattern of specific variety x isolate interaction was observed. Investigations of the differences in virulence and fungicide sensitivity between 8 early isolates (1998 and 2002) and 52 recent isolates (2012) indicate the evolution of increased resistance to the fungicide prochloraz in F. fujikuroi in Taiwan.

We characterized patterns of genetic variation in populations of the fire ant Solenopsis invicta in China using mitochondrial DNA sequences and nuclear microsatellite loci to test predictions as to how propagule pressure and subsequent dispersal following establishment jointly shape the invasion success of this ant in this recently invaded area. Fire ants in Wuchuan (Guangdong Province) are genetically differentiated from those found in other large infested areas of China. The immediate source of ants in Wuchuan appears to be somewhere near Texas, which ranks first among the southern USA infested states in the exportation of goods to China. Most colonies from spatially distant, outlying areas in China are genetically similar to one another and appear to share a common source (Wuchuan, Guangdong Province), suggesting that long-distance jump dispersal has been a prevalent means of recent spread of fire ants in China. Furthermore, most colonies at outlier sites are of the polygyne social form (featuring multiple egg-laying queens per nest), reinforcing the important role of this social form in the successful invasion of new areas and subsequent range expansion following invasion. Several analyses consistently revealed characteristic signatures of genetic bottlenecks for S. invicta populations in China. The results of this study highlight the invasive potential of this pest ant, suggest that the magnitude of international trade may serve as a predictor of propagule pressure and indicate that rates and patterns of subsequent range expansion are partly determined by the interplay between species traits and the trade and transportation networks.

Ants have evolved very complex societies and are key ecosystem members. Some ants, such as the fire ant Solenopsis invicta , are also major pests. Here, we present a draft genome of S. invicta , assembled from Roche 454 and Illumina sequencing reads obtained from a focal haploid male and his brothers. We used comparative genomic methods to obtain insight into the unique features of the S. invicta genome. For example, we found that this genome harbors four adjacent copies of vitellogenin. A phylogenetic analysis revealed that an ancestral vitellogenin gene first underwent a duplication that was followed by possibly independent duplications of each of the daughter vitellogenins. The vitellogenin genes have undergone subfunctionalization with queen- and worker-specific expression, possibly reflecting differential selection acting on the queen and worker castes. Additionally, we identified more than 400 putative olfactory receptors of which at least 297 are intact. This represents the largest repertoire reported so far in insects. S. invicta also harbors an expansion of a specific family of lipid-processing genes, two putative orthologs to the transformer/feminizer sex differentiation gene, a functional DNA methylation system, and a single putative telomerase ortholog. EST data indicate that this S. invicta telomerase ortholog has at least four spliceforms that differ in their use of two sets of mutually exclusive exons. Some of these and other unique aspects of the fire ant genome are likely linked to the complex social behavior of this species.

Loss of natural enemies during colonization is a prominent hypothesis explaining enhanced performance of invasive species in introduced areas. Numerous studies have tested this enemy release hypothesis in a wide range of taxa but few studies have focused on invasive ants. We conducted extensive surveys for the presence of six microbes in recently established populations (California, Australia, New Zealand, Taiwan, and China) of the invasive fire ant Solenopsis invicta. These microbes include Wolbachia, two microsporidia (Kneallhaziasolenopsae and Vairimorpha invictae) and three RNA viruses (SINV-1, -2 and -3), all of which previously have been reported in native South American populations of S. invicta. These surveys showed that the total number of enemy species is lower in the recently invaded areas compared with both South American and US populations. Only two microbes were found in any of these recently invaded areas: SINV-1 was detected in all surveyed populations except Australia and New Zealand, and SINV-2 was detected in California and Taiwan only. These results support the general prediction that invasive species lose many of their natural enemies during invasion. Further, the conspicuous absence of some of these microbes in these areas may result from strong selection against founders due to fitness costs associated with harboring detrimental infections rather than the alternative hypothesis that they simply were absent among the original founders. While the successful invasion of S. invicta in these recently invaded areas may be explained partly by the absence of natural enemies, other factors likely have been important as well.

Solenopsis geminata (F.) was introduced into southern Taiwan decades ago and has continued to threaten the residents. Although the venom compositions of various fire ant species have been studied, the effects of environmental cues on the secretion pattern have received relatively little attention in an area with subtropical climate and high humidity, such as Taiwan. This study characterizes the effects of temperature and season on the venom compositions of S. geminata in Taiwan. Pure venom was sampled by using a microcapillary pipette and immersing the whole ant in hexane and subjected to gas chromatography-mass spectrometry analysis. The results showed that the ratio of cis C(11) to trans C(11) alkaloids in major workers was significantly higher than that in minor workers. No significant differences could be found in either the relative alkaloids content or the ratio of cis C(11) to trans C(11) alkaloids in venom of minor workers while rearing at four temperature conditions. Nevertheless, the ratio of cis C(11) to trans C(11) alkaloids in the venom of minor workers was the highest in spring and the lowest in winter. The results also showed that the body length, abdomen length, head length, head width, and venom volume differed significantly between major workers and minor workers of S. geminata. The venom volumes of these two castes were positively correlated with their body sizes.

The electrochemical oxidation of nitric oxide (NO) gas at a Pt/membrane electrode has been studied. The Pt/Nafion ® electrode was prepared by the impregnation–reduction (I–R) chemical plating method and was tested over the NO concentration range from 0 to 500 ppm. It is assumed that the electrooxidation of NO gas at the electrode can be considered as an irreversible process, from which a transcendental equation describing the I – E relationship can be derived. The derived I – E relationship fits the experimental data reasonably well. Several electrochemical parameters for the reaction, including the half-wave potential ( E 1/2 ), the standard apparent rate constant ( rak 0 ), the transfer coefficient ( α ), and the exchange current density ( i 0 ) can be extracted from the experimental data. Under the kinetic controlled regime, with the potential in the range of 0.7–0.9 V (versus Ag/AgCl/sat. KCl), the kinetic model predicts the electrooxidative behavior of NO at a Pt/Nafion ® electrode over a wide concentration range of 100–500 ppm. An amperometric NO gas sensor based on a Pt/Nafion ® electrode has been fabricated and tested over the NO concentration range from 0 to 500 ppm at 1.15 V (versus Ag/AgCl/sat. KCl) and a flow rate of 200 ml per min.

The fire ant Solenopsis invicta is a significant pest that was inadvertently introduced into the southern United States almost a century ago and more recently into California and other regions of the world. An assessment of genetic variation at a diverse set of molecular markers in 2144 fire ant colonies from 75 geographic sites worldwide revealed that at least nine separate introductions of S. invicta have occurred into newly invaded areas and that the main southern U.S. population is probably the source of all but one of these introductions. The sole exception involves a putative serial invasion from the southern United States to California to Taiwan. These results illustrate in stark fashion a severe negative consequence of an increasingly massive and interconnected global trade and travel system.

The novel radioactive tracer technique was applied to investigate the migration of cesium, manganese and zinc impuritiesfrom deep ultraviolet photoresist into underlying substrate. Two important process parameters, viz., baking temperaturesand substrate types (i.e., bare silicon, polysilicon, silicon oxide and silicon nitride), were evaluated. Our results indicatedthat the migration ratios were all below 6%, irrespective ofbaking temperatures and substrate types. The substrate types didnot appear to strongly affect the metallic impurity out-diffusion from deep ultraviolet photoresist. However, solvent and/orwater evaporation due to temperature change was found to have a significant effect on metal migration. The net drivingforce of impurity changes with temperature and the impurity diffusion can be classified into four types. Based on theproposed types, the obtained migration ratios can be realized. A new model, together with a new parameter, was proposed todescribe the out-diffusion behavior of impurities from deep ultraviolet photoresist. The diffusion profile of photoresist wasdepicted based on diffusion equations and the migration ratios. This model could explain the migration ratios of metallicimpurities in photoresist layers under various baking conditions.Key words: DUV photoresist, impurity out-diffusion, radioactive tracer, impurity diffusion model

We demonstrate an 8-layer 3D Vertical Gate NAND Flash with WL half pitch =37.5nm, BL half pitch=75nm, 64-WL NAND string with 63% array core efficiency. This is the first time that a 3D NAND Flash can be successfully scaled to below 3Xnm half pitch in one lateral dimension, thus an 8-layer stack device already provides a very cost effective technology with lower cost than the conventional sub-20nm 2D NAND. Our new VG architecture has two key features: (1) To improve the manufacturability a new layout that twists the even/odd BL's (and pages) in the opposite direction (split-page BL) is adopted. This allows the island-gate SSL devices [1] and metal interconnections be laid out in double pitch, creating much larger process window for BL pitch scaling; (2) A novel staircase BL contact formation method using binary sum of only M lithography and etching steps to achieve 2M contacts. This not only allows precise landing of the tight-pitch staircase contacts, but also minimizes the process steps and cost. We have successfully fabricated an 8-layer array using TFT BE-SONOS charge-trapping device. The array characteristics including reading, programming, inhibit, and block erase are demonstrated.

Since the 1990s, brown root rot caused by Phellinus noxius (Corner) Cunningham has become a major tree disease in Taiwan. This fungal pathogen can infect more than 200 hardwood and softwood tree species, causing gradual to fast decline of the trees. For effective control, we must determine how the pathogen is disseminated and how the new infection center of brown root rot is established. We performed Illumina sequencing and de novo assembly of a single basidiospore isolate Daxi42 and obtained a draft genome of ~40 Mb. By comparing the 12,217 simple sequence repeat (SSR) regions in Daxi42 with the low-coverage Illumina sequencing data for four additional P. noxius isolates, we identified 154 SSR regions with potential polymorphisms. A set of 13 polymorphic SSR markers were then developed and used to analyze 329 P. noxius isolates collected from 73 tree species from urban/agricultural areas in 14 cities/counties all around Taiwan from 1989 to 2012. The results revealed a high proportion (~98%) of distinct multilocus genotypes (MLGs) and that none of the 329 isolates were genome-wide homozygous, which supports a possible predominant outcrossing reproductive mode in P. noxius. The diverse MLGs exist as discrete patches, so brown root rot was most likely caused by multiple clones rather than a single predominant strain. The isolates collected from diseased trees near each other tend to have similar genotype(s), which indicates that P. noxius may spread to adjacent trees via root-to-root contact. Analyses based on Bayesian clustering, F ST statistics, analysis of molecular variance, and isolation by distance all suggest a low degree of population differentiation and little to no barrier to gene flow throughout the P. noxius population in Taiwan. We discuss the involvement of basidiospore dispersal in disease dissemination.

A novel wafer level chip scaled packaging (WLCSP) having the capability of the redistributing the electrical circuit is proposed herein to resolve the problem of assembling a fine pitched chip to a coarse pitched substrate. In the fan-out WLCSP, the chip is first attached to a specific 8" chip carrier, and then the trench between the chips are filled by the filler polymer. The solder bumps could be located on both the filler polymer and chip surface, but the fabrication of the fan-out WLCSP is similar to the conventional 8" WLCSP process. Because the packaging structure of the fan-out WLCSP differs from the conventional one, a series of coplanity and solder joint height experiment is conducted to verify the capability of mounting the said structure to the substrate. The experimental results indicated that the derivation of the fan-out WLCSP is approximated plusmn0.01 mm, which is acceptable in the surface mount technology of the substrate. Moreover, the nonlinear finite element (FE) method is applied to analyze the mechanical characteristics of the fan-out WLCSP. Moreover, both the solder joint reliability and the trace stress while the external thermal cycling loading is considered. The simulation result indicates that the distance between the solder joint and the edge of the chip and filler polymer was more sensitive than other the design parameters, and the said distance parameter would dominate the mechanical characteristic of the fan-out WLCSP

A novel solder on rubber (SOR) structure of the advanced wafer level chip scaled packaging (WLCSP), having the capability of releasing the deformation energy which is caused by the GTE mismatch between the silicon chip and the substrate, is proposed herein. In the SOR structure, a metallic trace and solder pad would be formed on the rubber-based polymer, and a solder is attached onto the said pad. Moreover, a delamination layer is designed and fabricated between the metallic trace and the stress buffer layer (SBL), and the metal trace is also designed as curved shape to prevent the over-stretching of the trace. By the failure of the designed delamination layer, the SOR structure could theoretically release more energy than the conventional WLCSP structure. In this paper, the design concept of the SOR structure, experimental measurement of the adhesion strength of the delamination layer and the finite element (FE) analysis of the SOR structure are discussed.

The radioactive tracer technique was applied to investigate the diffusion and adsorption behaviors of metallic impurities (i.e., Ba, Cs, Zn and Mn) from chemically amplified photoresist onto silicon-based underlying substrates. Two important process parameters, i.e., baking temperatures and substrate types (e.g., bare silicon, polysilicon, silicon dioxide, and silicon nitride) were evaluated. Our results indicated that the transition metals (Zn and Mn) could have lower diffusion ratios than alkali metal (Cs) and alkaline earth metal (Ba), irrespective of the substrate types and baking temperatures. It was found that the transition metals would form stable complex with the coexisting solvents and/or hydrolysis species in the photoresist layer. The size of metal complex, the drag force of solvent evaporation, and the baking process were found to have significant effects on impurity migration. In addition, a new diffusion-adsorption model was proposed to explain the effect of substrate types. Our model successfully explained the substrate effect for bare silicon with lower diffusion ratios as compared with silicon nitride. The coverage of substrate surface with silanol group could be attributed to the formation of native oxide. The effects, including the concentration of surface adsorption metal, the equilibrium constant, the surface concentration of silanol group, the concentration of metallic impurity and the pH value, played very important role on the diffusion ratios for Ba, Cs, Zn and Mn.

The novel radioactive tracer technique was applied to investigate the migration of cesium, manganese and zinc impurities from deep ultraviolet photoresist into underlying substrate. Two important process parameters, viz., baking temperatures and substrate types (i.e., bare silicon, polysilicon, silicon oxide and silicon nitride), were evaluated. Our results indicated that the migration ratios were all below 6%, irrespective of baking temperatures and substrate types. The substrate types did not appear to strongly affect the metallic impurity out-diffusion from deep ultraviolet photoresist. However, solvent and/or water evaporation due to temperature change was found to have a significant effect on metal migration. The net driving force of impurity changes with temperature and the impurity diffusion can be classified into four types. Based on the proposed types, the obtained migration ratios can be realized. A new model, together with a new parameter, was proposed to describe the out-diffusion behavior of impurities from deep ultraviolet photoresist. The diffusion profile of photoresist was depicted based on diffusion equations and the migration ratios. This model could explain the migration ratios of metallic impurities in photoresist layers under various baking conditions.

The modification of the i-line resist structure after spiking with various amount of poly(4-vinylphenol) polymer is characterized by the spectra of UV visible and gel permeation chromatography. The chemical structure of photoactive compound is found to be unchanged after modification, while slight change in the polymer chain is observed. The resist layer coated onto the wafer is characterized by various methods including n and k analyzer, Nanospec, Fourier transform IR red, thermogravimetric analysis, and differential scanning calorimetry to fully evaluate the film properties in terms of porosity, thickness, vibrational spectrum, and thermal stability. Our thermal analysis results show that the resists are mainly decomposed in three stages. The photoactive compound is found to decompose during the first stage, while the polymer decomposes during the latter stages. The resist exposure parameters, namely, A, B and C at 365 nm are determined by the absorbance measurement. The extracted parameters are further used in the resist profile simulation by PROLITH/2. It is shown that the spiking of poly(4-vinylphenol) polymer into the resist can improve the resolution and linearity for dense lines. In addition, the swing effects can be reduced by up to 35 and 31 percent for dense and isolated lines after resist modification, respectively.

The radioactive tracer technique was applied to investigate the migration and adsorption behaviors of metallic impurities ( i.e., Ba, Cs, Zn, and Mn) out of chemically amplified photoresist onto silicon-based underlying substrates. Two important process parameters, i.e., baking temperatures and substrate types ( e.g., bare silicon, polysilicon, oxide, and nitride) were evaluated. Our results indicated that the transition metals (Zn and Mn) have lower migration ratios than alkali metal (Cs) and alkaline earth metal (Ba), irrespective of the substrate types and baking temperatures. The transition metals form stable complexes with the coexisting solvents and/or hydrolysis species in the photoresist layer. The size of the metal complex, the drag force in solvent evaporation, and the baking process were found to have significant effects on impurity migration. A new model, together with the metal migration in the chemically amplified photoresist and the subsequent adsorption onto the underlying substrate, was proposed to explain the pathway of the metal migration. This model could explain the migration ratios of metallic impurities out of the photoresist layer onto the substrate surface.