• JSTS:Journal of Semiconductor Technology and Science
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• v.9 no.1
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• pp.37-50
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• 2009

Evaluation results about area scaling capabilities of various SRAM margin-assist techniques for random $V_T$ variability issues are described. Various efforts to address these issues by not only the cell topology changes from 6T to 8T and 10T but also incorporating multiple voltage-supply for the cell terminal biasing and timing sequence controls of read and write are comprehensively compared in light of an impact on the required area overhead for each design solution given by ever increasing $V_T$ variation (${\sigma}_{VT}$). Two different scenarios which hinge upon the EOT (Effective Oxide Thickness) scaling trend of being pessimistic and optimistic, are assumed to compare the area scaling trends among various SRAM solutions for 32 nm process node and beyond. As a result, it has been shown that 6T SRAM will be allowed long reign even in 15 nm node if ${\sigma}_{VT}$ can be suppressed to < 70 mV thanks to EOT scaling for LSTP (Low Standby Power) process.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.448-451
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• 2003

This study describes a new maskless nano-fabrication technique of Si (100) using the combination of nanometer-scale mechanical forming by nano-indenter XP and KOH wet etching. First the surface of a Si (100) specimen was machined by using the nano-machining system, which utilizes the mechanism of the nano-indenter XP. Next, the specimen was etched by KOH solution. After the etching process, the convex structure or deeper hole is made because of masking or promotion effect of the affected layer generated by nano-machining. On the basis of this interesting fact, some sample structures were fabricated.

• Applied Microscopy
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• v.46 no.3
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• pp.127-133
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• 2016

Atom probe tomography is a time-of-flight mass spectrometry-based microanalysis technique based on the field evaporation of surface atoms of a tip-shaped specimen under an extremely high surface electric field. It enables three-dimensional characterization for deeper understanding of chemical nature in conductive materials at nanometer/atomic level, because of its high depth and spatial resolutions and ppm-level sensitivity. Indeed, the technique has been widely used to investigate the elemental partitioning in the complex microstructures, the segregation of solute atoms to the boundaries, interfaces, and dislocations as well as following of the evolution of precipitation staring from the early stage of cluster formation to the final stage of the equilibrium precipitates. The current review article aims at giving a comment to first atom probe users regarding the limitation of the techniques, providing a brief perspective on how we correctly interprets atom probe data for targeted applications.

• International Journal of Precision Engineering and Manufacturing
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• v.9 no.1
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• pp.25-29
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• 2008

We introduce a new fabrication process for antireflective structured surfaces. A 4-inch silicon wafer was dipped in a suspension of 300-nm-diameter silica particles dispersed in a toluene solution. When the wafer was drawn out of the suspension, a hexagonally packed monolayer structure of particles self-assembled on almost the complete wafer surface. Due to the simple process, this could be applied to micro- and nano-patterning. The self-assembled silica particles worked as a mask for the subsequent reactive ion etching. An array of nanometer-sized pits could be fabricated since the regions that correspond to the small gaps between particles were selectively etched off. As etching progressed, the pits became deeper and combined with neighboring pits due to side-etching to produce an array of cone-like structures. We investigated the effect of etching conditions on antireflection properties, and the optimum shape was a nano-cone with height and spacing of 500 nm and 300 nm, respectively. This nano-structured surface was prepared on a $30\;{\times}\;10-mm$ area. The reflectivity of the surface was reduced 97% for wavelengths in the range 400-700 nm.