• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.341-341
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• 2016

The discovery of light emission in nanostructured silicon has opened up new avenues of research in nano-silicon based devices. One such pathway is the application of silicon quantum dots in advanced photovoltaic and light emitting devices. Recently, there is increasing interest on the silicon quantum dots (c-Si QDs) films embedded in amorphous hydrogenated silicon-nitride dielectric matrix (a-SiNx: H), which are familiar as c-Si/a-SiNx:H QDs thin films. However, due to the limitation of the requirement of a very high deposition temperature along with post annealing and a low growth rate, extensive research are being undertaken to elevate these issues, for the point of view of applications, using plasma assisted deposition methods by using different plasma concepts. This work addresses about rapid growth and single step development of c-Si/a-SiNx:H QDs thin films deposited by RF (13.56 MHz) and ultra-high frequency (UHF ~ 320 MHz) low-pressure plasma processing of a mixture of silane (SiH4) and ammonia (NH3) gases diluted in hydrogen (H2) at a low growth temperature ($230^{\circ}C$). In the films the c-Si QDs of varying size, with an overall crystallinity of 60-80 %, are embedded in an a-SiNx: H matrix. The important result includes the formation of the tunable QD size of ~ 5-20 nm, having a thermodynamically favorable <220> crystallographic orientation, along with distinct signatures of the growth of ${\alpha}$-Si3N4 and ${\beta}$-Si3N4 components. Also, the roles of different plasma characteristics on the film properties are investigated using various plasma diagnostics and film analysis tools.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.75-88
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• 2005

Ameloblastoma is the most commonly occurring odontogenic tumor in oral cavity. Although most are benign epithelial neoplasm, they are generally considered to be locally aggressive and destructive, exhibiting a high rate of recurrence. The biological behavior of this neoplasm is a slowly growing, locally invasive tumor without metastasis, therefore malignant neoplasm, changed its histological appearance to carcinoma or showed distant metastasis, is only defined clinically. In this study, we identified the differentially expressed genes(DEGs) in stages under benign or malignant ameloblastoma compared with normal patient using ordered differential display(ODD) reverse transcription(RT)-PCR and $GeneFishing^{TM}$ technology. ODD RT-PCR is rather effective when the investigation of samples containing very small amounts of total RNA must be accomplished. ODD RT-PCR used the means of amplification with anchored T-primer and adaptor specific primer. bearing definite two bases at their 3' ends and so this method could display differential 3'-expressed sequence taqs(ESTs) patterns without using full-length cDNAs. Compared with standard differential display, ODD RT-PCR is more simple and have enough sensitivity to search for molecular markers by comparing gene expression profiles, However, this method required much effort and skill to perform. $GeneFishing^{TM}$ modified from DD-PCR is an improved method for detecting differentially expressed genes in two or more related samples. This two step RT-PCR method uses a constant reverse primer(anchor ACP-T) to prime the RT reaction and arbitrary primer pairs(annealing control primers, ACPs) during PCR. Because of high annealing specificity of ACPs than ODD RT-PCR, the application of $GeneFishing^{TM}$ to DEG discovery generates reproducible, authentic, and long(100bp to 2kb) PCR products that are detectable on agarose gels. Consequently, various DEGs observed differential expression levels on agarose gels were isolated from normal, benign, and malignant tissues using these methods. The expression patterns of the some isolated DEGs through ODD RT-PCR and $GeneFishing^{TM}$ were confirmed by Northern blot analysis and RT-PCR. The results showed that these identified DEGs were implicated in ameloblastoma neoplasm processes. Therefore, the identified DEGs will be further studied in order to be applied in candidate selection for marker as an early diagnosis during ameloblastoma neoplasm processes.

• Korean Journal of Materials Research
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• v.6 no.7
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• pp.700-708
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• 1996

Electroless plating technique was utilized to flip chip bonding to improve surface mount characteristics. Each step of plating procedure was studied in terms pf pH, plating temperature and plating time. Al patterned 4 inch Si wafers were used as substrstes and zincate was used as an activation solution. Heat treatment was carried out for all the specimens in the temperature range from room temperature to $400^{\circ}C$ for $30^{\circ}C$ minutes in a vacuum furnace. Homogeneous distribution of Zn particles of size was obtained by the zincate treatment with pH 13 ~ 13.5, solution concentration of 15 ~ 25% at room temperature. The plating rates for both Ni-P and Au electroless plating steps increased with increasing the plating temperature and pH. The main crystallization planes of the plated Au were found to be (111) a pH 7 and (200) and (111) at pH 9 independent of the annealing temperature.