• Journal of IKEEE
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• v.26 no.2
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• pp.306-312
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• 2022

We investigated electrical properties and deep level traps in 4H-SiC merged PiN Schottky (MPS) diodes with different barrier heights by different PN ratios and metallization annealing temperatures. The barrier heights of MPS diodes were obtained in IV and CV characteristics. The leakage current increased with the lowering barrier height, resulting in 10 times larger current. Additionally, the deep level traps (Z_1/2 and RD_1/2) were revealed by deep level transient spectroscopy (DLTS) measurement in four MPS diodes. Based on DLTS results, the trap energy levels were found to be shallow level by 22~28% with lower barrier height It could confirm the dependence of the defect level and concentration determined by DLTS on the Schottky barrier height and may lead to incorrect results regarding deep level trap parameters with small barrier heights.

• Journal of Korean Society of Forest Science
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• v.89 no.1
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• pp.135-140
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• 2000

Matsucoccus thunbergianae is a major insect pest of Pinus thunbergiana in southern Korean peninsula. To study the flight behavior of M. thunbergianae males responding to the synthetic pheromone, five sticky traps were placed on a bamboo pole at various heights, between 0.1m and 2.0m above ground. A bait impregnated with the synthetic pheromone was placed at 0.1m, 1.0m or 2.0m above ground and the number of male catches on each trap was counted. In an open area, numbers of males caught per trap were not different between heights when the bait was placed at 2m or 1m above ground ; when the bait was placed at 0.1m height, male flight was aggregated near the ground. In a forest with low crown closure, trap catches on five traps on the same bamboo pole were not different one another when the bait was placed at 2m height, but most males were flying near the bait when it was placed at 1m height. In a dense pine forest, most males were flying around the bait regardless of the bait position. In all three places, most males were caught on the trap near the ground when the baits were placed 0.1m above ground. Thus, for monitoring the frontal zone of infestation of the scale, placing the pheromone trap near the ground was considered the most efficient. When the males perceived pheromone, they tended to fly in the air with low wind speed.

• Korean journal of applied entomology
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• v.49 no.4
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• pp.325-331
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• 2010

Attractiveness of stink bugs to various colors, heights and locations of fish-net traps incorporated with aggregation pheromones was determined. Bean bug, Riptortus pedestris Fabricius, was most attracted to yellow color trap, followed by white, black, green, blue and brown. R. pedestris and one-banded stink bug, Piezodorus hybneri Gmelin, were most attracted to fish-net traps placed 80 cm above the ground regardless of sexes of two species of stink bugs. Between the sexes, however, R. pedestris females were more attracted to 40 and 80 cm above the ground than the males at those heights although the attraction was not significantly different at 120 and 160 cm heights. P. hybneri females tended to be attracted to 40 and 80 cm height traps but the attraction was the opposite at 120 and 160 cm heights. The highest attraction of R. pedestris was observed in a perilla field with no significant difference in the soybean field and border area in which no crop were cultivated between the perilla and soybean fields. R. pedestris was also more attracted to the sweet persimmon orchard than the soybean and medicinal crops fields, which was a significant difference between the two fields.

• Journal of Korean Tunnelling and Underground Space Association
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• v.4 no.1
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• pp.71-78
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• 2002

In this study, the influence of the presence of discontinuity planes on the load transfer mechanism and the pattern of loosening zone was studied based on the laboratory test. The trap-door and the reaction plates are installed as the bottom plane of the model box. The vertical discontinuity plane is installed in the dry sand. Various overburden heights and locations of discontinuity planes are applied as major factors in this study. The results show that at higher overburden heights over about 1.5 times the excavation width, the ratio of the transferred stress to the insitu stress converges to a certain value even if the overburden height increases further. The results also show that the discontinuity plane gives relatively larger influence on the load transfer mechanism, that produces the unsymmetrical load concentration, when the discontinuity plane locates within the tunnel width. When the discontinuity plane locates outside the tunnel width, the unsymmetrical load concentration is reduced considerably.

• Korean journal of applied entomology
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• v.39 no.3
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• pp.153-156
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• 2000

Spatial activities of Liriomyza trifolii (Burgess) were investigated weekly using yellow sticky trap which were placed at three different height and monitored during four time periods. Yellow sticky trap placed at plant height caught significantly more L. trifolii (Burgess) than did traps placed at 30 and 60cm above plant height. Diel activities of L. trifolii (Burgess) were monitored with yellow sticky traps at 1- and 2-h intervals during three time periods. Leafminer flight activity in May, July and October peaked from 1400 to 1800 hours, 0800 hours and from 1200 to 1400 hours, respectively. 2nd peak of flight activity only occurred in May. Attraction of L. trifolii (Burgess) for yellow sticky traps was affected by temperature as well as solar intensity. Male of L. trifolii (Burgess) appeared more responsive to yellow sticky traps than female regardless of trap height or time of day.

• Korean Journal of Materials Research
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• v.27 no.1
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• pp.48-52
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• 2017

In this study, we used I-V spectroscopy, photoconductivity (PC) yield and internal photoemission (IPE) yield using IPE spectroscopy to characterize the Schottky barrier heights (SBH) at insulator-semiconductor interfaces of Pt/$HfO_2$/p-type Si metal-insulator-semiconductor (MIS) capacitors. The leakage current characteristics of the MIS capacitor were analyzed according to the J-V and C-V curves. The leakage current behavior of the capacitors, which depends on the applied electric field, can be described using the Poole-Frenkel (P-F) emission, trap assisted tunneling (TAT), and direct tunneling (DT) models. The leakage current transport mechanism is controlled by the trap level energy depth of $HfO_2$. In order to further study the SBH and the electronic tunneling mechanism, the internal photoemission (IPE) yield was measured and analyzed. We obtained the SBH values of the Pt/$HfO_2$/p-type Si for use in Fowler plots in the square and cubic root IPE yield spectra curves. At the Pt/$HfO_2$/p-type Si interface, the SBH difference, which depends on the electrical potential, is related to (1) the work function (WF) difference and between the Pt and p-type Si and (2) the sub-gap defect state features (density and energy) in the given dielectric.

• Journal of the Korean Vacuum Society
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• v.16 no.3
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• pp.197-204
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• 2007

Ultra thin Er-silicide layers formed by Er deposition on the clean p-silicon and in situ post annealing technique were investigated with respect to change of the Schottky barrier height. The formation of Er silicides was confirmed by XPS results. UPS measurements revealed that the workfunction of the silicide decreased and was saturated as the deposited Er thickness increased up to $10{\AA}$. We found that the silicides were mainly composed of Er5Si3 phase through the XRD experiments. After Schottky diodes were fabricated with the Er silicide/p-Si junctions, the Schottky barrier heights were calculated $0.44{\sim}0.78eV$ from the I-V measurements of the Schottky diodes. There was large discrepancy in the Schottky barrier heights deduced from the UPS with the ideal junction condition and the real I-V measurements, so that we attributed the discrepancy to the $Er_5Si_3$ phase in the Er-silicides and the large interfacial density of trap state of it.

• Journal of Korean Tunnelling and Underground Space Association
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• v.5 no.3
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• pp.217-226
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• 2003

This study is focused on the finding out load transfer mechanism in the ground near the tunnel during tunnel excavation in the jointed sandy ground. Laboratory model tests were performed on various cases of the overburden heights above tunnel crown, location, and degree of discontinuity planes. For model tests, a movable plate was installed in the midst of the bottom of sandy ground. This plate, moving downwards, was intended to model the stress relaxation during tunnel excavation. The load transfer was measured at the fixed separated bottom plates adjacent to the movable plate. As the result, the loosening zone and the load-transfer form around the tunnelling site were affected by the overburden height and the characteristics of discontinuous planes. And large loosening zone was developed along the discontinuous planes which were close to the tunnel.

• Korean journal of applied entomology
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• v.45 no.1 s.142
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• pp.37-43
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• 2006

Catch of garden thrips, Frankliniella intonsa, on sticky traps was assessed by color and height in commercial plastic vinyl house strawberry crops grown on 40-cm-high trellises. Yellow, blue and white sticky cards were tested for color attractiveness, and upper (50 cm), lower (10 cm above the floor) and ground were for height. At each height, trapped thrips on yellow, blue and white were significantly different. Blue sticky cards were significantly greater than traps on yellow and white. The trapped thrips were also significantly greatest at 50 cm above the floor, less at lower and ground. However, there is no significantly different the population of garden thrips on the flower in each tested site.