• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.3-4
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• 2005

The Pseudo-MOSFET measurements technique has been used for the electrical characterization of the nano SOL Silicon islands for the Pseudo-MOS measurements were fabricated by selective etching of surface silicon film with dry or wet etching to examine the effects of the etching process on the device properties. The characteristics of the Pseudo-MOS was not changed greatly in the case of thick SOI film which was 205 nm. However the characteristics of the device was dependent on etching process in the case of less than 100 nm thick SOI film. The sub 100nm SOI was obtained by thinning the silicon film of standard thick SOI. The thickness of SOI film was varied from 88 nm to 44 nm by chemical etching. The etching process effects on the properties of pseudo-MOSFET characteristics, such as mobility, turn-on voltage, and drain current transient. The etching process dependency is greater in the thinner SOI and related to original SOI wafer quality.

• Korean Journal of Materials Research
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• v.15 no.3
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• pp.161-165
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• 2005

We investigated selective dry etching of GaAs over AlGaAs and InGaP in high density planar inductively coupled $BCl_3/SF_6$ plasmas. The process parameters were ICP source power (0-500 W), RE chuck power (0-30W) and gas composition $(60-100\%\;BCl_3\;in\;BCl_3/SF_6)$. The process results were characterized in terms of etch rate, selectivities of GaAs over AlGaAs and InGaP, surface morphology, surface roughness and residues after etching. $BCl_3/SF_6$ selective etching of GaAs showed quite good results in this study. Selectivities of GaAs $(GaAs:AlGaAs\~36:1,\;GaAs:InGaP\~45:1)$ were superior at $18BCl_3/2SF_6$, 20 W RF chuck power, 300 W ICP source power and 7.5 mTorr. Addition of $(5-15\%)SF_6\;to\;BCl_3$ produced relatively high selectivities of GaAs over AlGaAs and InGaP during etching due to decrease of etch rates of AlGaAs and InGaP (boiling points of etch products: $AlF_3\~1300^{\circ}C,\;InF_3>1200^{\circ}C$ at atmosphere) at the condition. SEM and AFM data showed slightly sloped sidewall and somewhat rough surface$(RMS\~9nm)$. XPS study on the surface of processed GaAs proved a very clean surface after dry etching. It shows that planar inductively coupled $BCl_3/SF_6$ plasmas could be a good candidate for selective dry etching of GaAs over AlGaAs and InGaP.

• ETRI Journal
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• v.27 no.5
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• pp.484-490
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• 2005

We fabricated 40 Gb/s front-end optical receivers using spot-size converter integrated waveguide photodiodes (SSC-WGPDs). The fabricated SSC-WGPD chips showed a high responsivity of approximately 0.8 A/W and a 3 dB bandwidth of approximately 40 GHz. A selective wet-etching method was first adopted to realize the required width and depth of a tapered waveguide. Two types of electrical pre-amplifier chips were used in our study. One has higher gain and the other has a broader bandwidth. The 3 dB bandwidths of the higher gain and broader bandwidth modules were about 32 and 42 GHz, respectively. Clear 40 Gb/s non-return-to-zero (NRZ) eye diagrams showed good system applicability of these modules.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.2 s.95
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• pp.60-67
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• 1999

Micro-fabrication techniques such as lithography and LIGA processes usually require large investment and are suitable for mass production. Therefore, there is a need for a new micro-fabrication technique that is flexible and more cost effective. In this paper a novel, economical and flexible method of producing micro-pattern on silicon wafer is presented. This method relies on selective removal of mask by mechanical cutting. Then micro-pattern is produced by chemical etching. V-shaped grooved of about 3 ${\mu}m$ wide and 2 ${\mu}m$ deep has been made on ${SiO_2}m$ coated silicon wafer with this method. This method may be utilized for making microstructures in MEMS application at low cost.

• Proceedings of the KIEE Conference
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• 2006.07c
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• pp.1430-1431
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• 2006

We investigated the formation of 2-dimension hologram grating by means of selective etching characteristic and photo-expansion effect according to photo irradiation on amorphous As-Ge-Se-S thin film. By method of phase holography, we made the 2-dimensional hologram grating by each (S:P) and ($+45^{\circ}:-45^{\circ}$) polarized beam with DPSS laser(532nm) and He-Ne laser(632nm). A recording property was observed at each polarized beam through 2-dimensional hologram surface relief grating. Chalcogenide thin film was etched selectively by NaOH solution after the formation of 1-dimensional diffraction grating. And then etched sample was rotated 90 degree to fabricate 2 dimensional hologram grating. We found that it was observed the formation of 2-dimensional hologram grating by AFM(Atomic Force Microscopy).

• Proceedings of the Korean Vacuum Society Conference
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• 1997.02a
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• pp.54-55
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• 1997

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.05a
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• pp.38.1-38.1
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• 2009

Plasma etching is an essential process for electronic device industries and the particulate contamination during plasma etching has been interested as a big issue for the yield of productivity. The oxynitride glasses have a merit to prevent particulate contamination due to their amorphous structure and plasma etching resistance. The YSiAlON oxynitride glasses with increasing nitrogen content were manufactured. Each oxynitride glasses were fluorine-plasma etched and their plasma etching rate and surface roughness were compared with reference materials such as sapphire, alumina and quartz. The reinforcement mechanism of plasma etching resistance of the YSiAlON glasses studied by depth profiling at plasma etched surface using electron spectroscopy for chemical analysis. The plasma etching rate decreased with nitrogen content and there was no selective etching at the plasma etched surface of the oxynitride glasses. The concentration of silicon was very low due to the generation of SiF4 very volatile byproduct and the concentration of aluminum and yttrium was relatively constant. The elimination of silicon atoms during plasma etching was reduced with increasing nitrogen content because the content of the nitrogen was constant. And besides, the concentration of oxygen was very low on the plasma etched surface. From the study, the plasma etching resistance of the glasses may be improved by the generation of nitrogen related structural groups and those are proved by chemical composition analysis at plasma etched surface of the YSiAlON oxynitride glasses.

• Proceedings of the Korean Vacuum Society Conference
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• 2005.02a
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• pp.78-78
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• 2005

• Applied Science and Convergence Technology
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• v.23 no.5
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• pp.284-288
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• 2014

We present tapered nanostructures fabricated on a selective area of gallium phosphide substrates for advanced optoelectronic device applications. A lithography-free fabrication process was accomplished by dry etching of metal nanoparticles. Thermal dewetting of micro-patterned metal thin films provides etch masks for tapered nanostructures. This simple process also allows the formation of plasmonic surfaces with corrugated shapes. Rigorous coupled-wave analysis calculations provide design guidelines for tapered nanostructures on gallium phosphide substrates.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.08a
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• pp.369-369
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• 2012

The present work deals with selective deposition of copper on fluoropolymers patterned silicon (111) surfaces. The pattern of fluoropolymer was fabricated by nanoimprint lithography (NIL) and plasma reactive ion etching (RIE) was used to remove the residuals layers. Copper was electrochemically deposited in bare Si regions which were not covered with fluoropolymers. The patterns of fluoropolymers and copper have been investigated by scanning electron microscopy (SEM). In this work, we used two deposition methods. One is galvanic displacement method and another is electrodeposition. Selective deposition works in both cases and it shows applicability to other materials. By optimization of the deposition conditions can be achieved therefore this process represents a simple approach for a direct high resolution patterning of silicon surfaces.