young hun seo - Academia.edu (original) (raw)
Papers by young hun seo
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1993
The mechanism of Si(100) etching reaction in HF-oxidizing agent-H 2 0 mixed solutions was investi... more The mechanism of Si(100) etching reaction in HF-oxidizing agent-H 2 0 mixed solutions was investigated using the redox potential of etching solution and th~ ban~ theory. of semiconductors. The experimental data of the etching reaction were taken m etchmg solutIOns of various compositions over the temperature range of 273-323 K. The etch rates were almost the same for both n-and p-type Si (100). The higher the energy difference between the valence band of Si and the solution potential of etchant, the lower the activation energy and the faster the etch rate of Si. In HeiNe laser-induced etching of Si with frequency of 632.8 nm, the etch rate for n-Si was drastically increased, while p-Si was not responsive to laser illumination. Experimental results showed that the rate determining step of the silicon etching reaction was the formation of holes at the surface.
Korean Journal of Chemical Engineering, 1996
We have used rapid thermal chemical vapor deposition (RTCVD) technique to grow epitaxial SiC thin... more We have used rapid thermal chemical vapor deposition (RTCVD) technique to grow epitaxial SiC thin films on Si wafers without carbonization process by pyrolyzing tetramethylsilane (TMS). The growth rate of SiC films increases with TMS flow rate and temperature, but it decreases with temperature at higher TMS flow rates. The XRD spectra of the films indicate that the growth direction
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2001
The dependency of void shape on Si surface orientation was investigated in the growth of silicon ... more The dependency of void shape on Si surface orientation was investigated in the growth of silicon carbide (SiC) films on Si substrates. The orientation of the SiC films followed that of the Si substrate. In the silicon side of the SiC/Si interface, reverse-triangle-shaped voids were observed for the growth of SiC(100) on Si(100), whereas trapezoid-shaped voids were observed for the growth of SiC(111) on Si(111). The origin of the voids seemed to be the oxygen-relative defects inherently existing in bulk Si wafers. The shape of the voids was determined by that of the etch pit initially formed during the hydrogen etching process, which depends on the orientation of the silicon substrate. The mechanism of the void formation in the growth of SiC films on Si substrates was proposed based on the experimental results.
Journal of Electronic Materials, 1999
The origin of the radiative recombination leading to yellow luminescence (YL) has been elucidated... more The origin of the radiative recombination leading to yellow luminescence (YL) has been elucidated by the study of luminescence properties of GaN films grown with two different gas feeding methods. GaN films were grown on a (0001) sapphire substrate in a rapid thermal chemical vapor deposition (RTCVD) reactor. GaN films emitted two different luminescence energies, 2.2 and 3.47 eV, depending on the introducing position of hydrogen gas in the growth reactor. The distribution of the TMGa flow and gas phase reactions in the reactor were investigated to understand the effect of the gas feeding methods on the optical properties of GaN films. The results suggest that YL is related to Ga vacancies in the grown films.
Journal of The Electrochemical Society, 1998
The effects of growth parameters have been examined for the epitaxial growth of a void‐free SiC f... more The effects of growth parameters have been examined for the epitaxial growth of a void‐free SiC film on a Si substrate. Experiments were performed under various growth conditions by pyrolyzing tetramethylsilane (TMS) in a rapid thermal chemical vapor deposition reactor. Void‐free ...
Journal of The Electrochemical Society, 1993
The chemical etching of silicon in mixed solution has been investigated experimentally. The etch ... more The chemical etching of silicon in mixed solution has been investigated experimentally. The etch rates were examined with varying and concentrations, agitation speed, and etching temperature. The etch rates were similar for both n‐ and p‐type Si(100). HF played an important role for accelerating the formation rate of holes at the silicon surface and the removal rate of formed on the wafer surface during the reaction. A comprehensive mechanism for the surface species formation and the silicon etching as a function of etchant concentration was developed. The holes formed at the silicon surface accelerated the etch rate and the formation of the layer. For high concentration, we suggest that the rate‐determining step of the reaction was the formation of holes at the silicon surface.
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 2001
KEE SUK NAHM1, KWANG CHUL KIM2, CHAN IL PARK2, KEE YOUNG LIM2,3, YEONG SEOK YANG4 AND YOUNG HUN S... more KEE SUK NAHM1, KWANG CHUL KIM2, CHAN IL PARK2, KEE YOUNG LIM2,3, YEONG SEOK YANG4 AND YOUNG HUN SEO5 1School of Chemical Engineering and Technology, Chonbuk National University, Chonju 561-756, Korea 2Department of Semiconductor Science and ...
Journal of Applied Physics, 1997
The mechanism of stain formation in the chemical etching reaction of silicon has been investigate... more The mechanism of stain formation in the chemical etching reaction of silicon has been investigated in HF–oxidizing agent–H2O solutions. The chemical formula of the stain formed during the silicon etching reaction is K2SiF6. The concentration of holes on silicon surface increases with the increase of redox potential and the concentration of oxidizing agent used in manufacturing the etching solution. The increase in the hole concentration accelerates not only the etch rate but also the formation rate of K2SiF6. The etched silicon surfaces are covered with a K2SiF6 layer when redox potential and concentration of oxidizing agent are great at low HF concentrations. This happens because the formation rate of K2SiF6 is much greater than its dissolution rate by HF. Sufficiently high HF concentration in the etching solution is apparently essential to increase the etch rate without the formation of K2SiF6.
Journal of Applied Physics, 1994
It has long been argued whether the luminescent mechanism of anodized porous silicon is mainly du... more It has long been argued whether the luminescent mechanism of anodized porous silicon is mainly due to the chemical compounds such as siloxene derivatives, or the quantum size effect. We performed a comprehensive study using atomic force microscope, infrared transmission, Raman scattering, and photoluminescence measurements in terms of various annealing temperatures. Low-temperature photoluminescence spectra have also been observed. This leads us to conclude that not only the siloxene derivatives but also the quantum size effect gives the luminescence in porous silicon. The previous pseudopotential calculations are used for the explanation of our experimental results.
Applied Physics Letters, 1997
Single crystal 3C-SiC epitaxial films are grown on Si(111) surfaces using tetramethylsilane by ra... more Single crystal 3C-SiC epitaxial films are grown on Si(111) surfaces using tetramethylsilane by rapid thermal chemical vapor deposition. Strong blue/green photoluminescence (PL) was observed at room temperature from the free films of SiC prepared by etching the Si substrate. The main PL peak energy varies from 2.1 to 2.4 eV with full widths at half-maximum between 450 and 500 meV, depending on the growth condition, excitation wavelength and excitation light intensity. A weak peak at 3.0 eV also appeared. The infrared (IR) spectra of free films of SiC exhibit modes associated with CH and OH groups. We also compared PL characteristics of free films of SiC with those from porous SiC produced by anodization of SiC/Si to determine the origin of the PL. Porous SiC shows a PL peak centered at 1.9 eV, different from those in SiC. From the analysis of the IR spectra and scanning electron microscopic images, we tentatively suggest that the origin of the PL from free films of SiC might be assoc...
Applied Physics Letters, 1993
Microscopic structures of light emitting porous silicon layers have been studied. The samples pre... more Microscopic structures of light emitting porous silicon layers have been studied. The samples prepared in an aqueous HF solution by anodizing p-type silicon substrates show a strong positional dependence of photoluminescence and Raman spectra. The photoluminescence peaks are broad around 1.8 eV, where the photoluminescence intensities are comparable to that of GaAs at 5 K. We have found from Raman studies showing two characteristic peaks at 500 and 520 cm−1 that microscopic structures reveal gradual changes from porous silicon to a mixture of polycrystalline and hydrogenated amorphous phases as the probing spot is moved to the edge of the sample. This is explained by the redeposition of silicon atoms on top of the porous silicon layers near the edge of the sample as a result of liquid flow caused by bubbles of hydrogen gas which was produced near the surface of the sample during the anodization process.
Applied Physics Letters, 1993
Porous silicon layers prepared by anodic dissolutions of silicon wafers in aqueous HF solutions r... more Porous silicon layers prepared by anodic dissolutions of silicon wafers in aqueous HF solutions reveal either crystalline phase or intermediate phase between microcrystalline and amorphous phases, depending on the anodization conditions. The configurations of hydrogen and oxygen atoms near the surface of microstructures are directly related to the light emitting characteristics of porous silicon layers. We observed that oxidation leads to the shifts of SiH, stretching modes to higher frequencies and enhanced photoluminescence intensity, which can be correlated with a charge transfer within O-Si-H bonds. We also observed that chemical treatments in trichloroethylene have similar effects as thermal oxidation.
Japanese Journal of Applied Physics, 1994
Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures, 1993
The mechanism of Si(100) etching reaction in HF-oxidizing agent-H 2 0 mixed solutions was investi... more The mechanism of Si(100) etching reaction in HF-oxidizing agent-H 2 0 mixed solutions was investigated using the redox potential of etching solution and th~ ban~ theory. of semiconductors. The experimental data of the etching reaction were taken m etchmg solutIOns of various compositions over the temperature range of 273-323 K. The etch rates were almost the same for both n-and p-type Si (100). The higher the energy difference between the valence band of Si and the solution potential of etchant, the lower the activation energy and the faster the etch rate of Si. In HeiNe laser-induced etching of Si with frequency of 632.8 nm, the etch rate for n-Si was drastically increased, while p-Si was not responsive to laser illumination. Experimental results showed that the rate determining step of the silicon etching reaction was the formation of holes at the surface.
Korean Journal of Chemical Engineering, 1996
We have used rapid thermal chemical vapor deposition (RTCVD) technique to grow epitaxial SiC thin... more We have used rapid thermal chemical vapor deposition (RTCVD) technique to grow epitaxial SiC thin films on Si wafers without carbonization process by pyrolyzing tetramethylsilane (TMS). The growth rate of SiC films increases with TMS flow rate and temperature, but it decreases with temperature at higher TMS flow rates. The XRD spectra of the films indicate that the growth direction
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2001
The dependency of void shape on Si surface orientation was investigated in the growth of silicon ... more The dependency of void shape on Si surface orientation was investigated in the growth of silicon carbide (SiC) films on Si substrates. The orientation of the SiC films followed that of the Si substrate. In the silicon side of the SiC/Si interface, reverse-triangle-shaped voids were observed for the growth of SiC(100) on Si(100), whereas trapezoid-shaped voids were observed for the growth of SiC(111) on Si(111). The origin of the voids seemed to be the oxygen-relative defects inherently existing in bulk Si wafers. The shape of the voids was determined by that of the etch pit initially formed during the hydrogen etching process, which depends on the orientation of the silicon substrate. The mechanism of the void formation in the growth of SiC films on Si substrates was proposed based on the experimental results.
Journal of Electronic Materials, 1999
The origin of the radiative recombination leading to yellow luminescence (YL) has been elucidated... more The origin of the radiative recombination leading to yellow luminescence (YL) has been elucidated by the study of luminescence properties of GaN films grown with two different gas feeding methods. GaN films were grown on a (0001) sapphire substrate in a rapid thermal chemical vapor deposition (RTCVD) reactor. GaN films emitted two different luminescence energies, 2.2 and 3.47 eV, depending on the introducing position of hydrogen gas in the growth reactor. The distribution of the TMGa flow and gas phase reactions in the reactor were investigated to understand the effect of the gas feeding methods on the optical properties of GaN films. The results suggest that YL is related to Ga vacancies in the grown films.
Journal of The Electrochemical Society, 1998
The effects of growth parameters have been examined for the epitaxial growth of a void‐free SiC f... more The effects of growth parameters have been examined for the epitaxial growth of a void‐free SiC film on a Si substrate. Experiments were performed under various growth conditions by pyrolyzing tetramethylsilane (TMS) in a rapid thermal chemical vapor deposition reactor. Void‐free ...
Journal of The Electrochemical Society, 1993
The chemical etching of silicon in mixed solution has been investigated experimentally. The etch ... more The chemical etching of silicon in mixed solution has been investigated experimentally. The etch rates were examined with varying and concentrations, agitation speed, and etching temperature. The etch rates were similar for both n‐ and p‐type Si(100). HF played an important role for accelerating the formation rate of holes at the silicon surface and the removal rate of formed on the wafer surface during the reaction. A comprehensive mechanism for the surface species formation and the silicon etching as a function of etchant concentration was developed. The holes formed at the silicon surface accelerated the etch rate and the formation of the layer. For high concentration, we suggest that the rate‐determining step of the reaction was the formation of holes at the silicon surface.
JOURNAL OF CHEMICAL ENGINEERING OF JAPAN, 2001
KEE SUK NAHM1, KWANG CHUL KIM2, CHAN IL PARK2, KEE YOUNG LIM2,3, YEONG SEOK YANG4 AND YOUNG HUN S... more KEE SUK NAHM1, KWANG CHUL KIM2, CHAN IL PARK2, KEE YOUNG LIM2,3, YEONG SEOK YANG4 AND YOUNG HUN SEO5 1School of Chemical Engineering and Technology, Chonbuk National University, Chonju 561-756, Korea 2Department of Semiconductor Science and ...
Journal of Applied Physics, 1997
The mechanism of stain formation in the chemical etching reaction of silicon has been investigate... more The mechanism of stain formation in the chemical etching reaction of silicon has been investigated in HF–oxidizing agent–H2O solutions. The chemical formula of the stain formed during the silicon etching reaction is K2SiF6. The concentration of holes on silicon surface increases with the increase of redox potential and the concentration of oxidizing agent used in manufacturing the etching solution. The increase in the hole concentration accelerates not only the etch rate but also the formation rate of K2SiF6. The etched silicon surfaces are covered with a K2SiF6 layer when redox potential and concentration of oxidizing agent are great at low HF concentrations. This happens because the formation rate of K2SiF6 is much greater than its dissolution rate by HF. Sufficiently high HF concentration in the etching solution is apparently essential to increase the etch rate without the formation of K2SiF6.
Journal of Applied Physics, 1994
It has long been argued whether the luminescent mechanism of anodized porous silicon is mainly du... more It has long been argued whether the luminescent mechanism of anodized porous silicon is mainly due to the chemical compounds such as siloxene derivatives, or the quantum size effect. We performed a comprehensive study using atomic force microscope, infrared transmission, Raman scattering, and photoluminescence measurements in terms of various annealing temperatures. Low-temperature photoluminescence spectra have also been observed. This leads us to conclude that not only the siloxene derivatives but also the quantum size effect gives the luminescence in porous silicon. The previous pseudopotential calculations are used for the explanation of our experimental results.
Applied Physics Letters, 1997
Single crystal 3C-SiC epitaxial films are grown on Si(111) surfaces using tetramethylsilane by ra... more Single crystal 3C-SiC epitaxial films are grown on Si(111) surfaces using tetramethylsilane by rapid thermal chemical vapor deposition. Strong blue/green photoluminescence (PL) was observed at room temperature from the free films of SiC prepared by etching the Si substrate. The main PL peak energy varies from 2.1 to 2.4 eV with full widths at half-maximum between 450 and 500 meV, depending on the growth condition, excitation wavelength and excitation light intensity. A weak peak at 3.0 eV also appeared. The infrared (IR) spectra of free films of SiC exhibit modes associated with CH and OH groups. We also compared PL characteristics of free films of SiC with those from porous SiC produced by anodization of SiC/Si to determine the origin of the PL. Porous SiC shows a PL peak centered at 1.9 eV, different from those in SiC. From the analysis of the IR spectra and scanning electron microscopic images, we tentatively suggest that the origin of the PL from free films of SiC might be assoc...
Applied Physics Letters, 1993
Microscopic structures of light emitting porous silicon layers have been studied. The samples pre... more Microscopic structures of light emitting porous silicon layers have been studied. The samples prepared in an aqueous HF solution by anodizing p-type silicon substrates show a strong positional dependence of photoluminescence and Raman spectra. The photoluminescence peaks are broad around 1.8 eV, where the photoluminescence intensities are comparable to that of GaAs at 5 K. We have found from Raman studies showing two characteristic peaks at 500 and 520 cm−1 that microscopic structures reveal gradual changes from porous silicon to a mixture of polycrystalline and hydrogenated amorphous phases as the probing spot is moved to the edge of the sample. This is explained by the redeposition of silicon atoms on top of the porous silicon layers near the edge of the sample as a result of liquid flow caused by bubbles of hydrogen gas which was produced near the surface of the sample during the anodization process.
Applied Physics Letters, 1993
Porous silicon layers prepared by anodic dissolutions of silicon wafers in aqueous HF solutions r... more Porous silicon layers prepared by anodic dissolutions of silicon wafers in aqueous HF solutions reveal either crystalline phase or intermediate phase between microcrystalline and amorphous phases, depending on the anodization conditions. The configurations of hydrogen and oxygen atoms near the surface of microstructures are directly related to the light emitting characteristics of porous silicon layers. We observed that oxidation leads to the shifts of SiH, stretching modes to higher frequencies and enhanced photoluminescence intensity, which can be correlated with a charge transfer within O-Si-H bonds. We also observed that chemical treatments in trichloroethylene have similar effects as thermal oxidation.
Japanese Journal of Applied Physics, 1994