Hyeongtag Jeon - Academia.edu (original) (raw)
Papers by Hyeongtag Jeon
![Research paper thumbnail of Erratum: “History of atomic layer deposition and its relationship with the American Vacuum Society” [J. Vac. Sci. Technol. A 31, 050818 (2013)]](https://attachments.academia-assets.com/120261695/thumbnails/1.jpg)
](Journal of vacuum science & technology, Mar 12, 2020
Biomedical Materials, 2009
ECS Journal of Solid State Science and Technology
Multiple patterning technology has become an essential process. In the commonly used self-aligned... more Multiple patterning technology has become an essential process. In the commonly used self-aligned multiple patterning process, the spacer should be dense at low temperatures and have a high elastic modulus. To meet these conditions, many thin-film deposition methods, such as plasma-enhanced atomic layer deposition, have been studied. We investigated remote plasma atomic layer deposition (RPALD) technology with a DC positive bias. After applying bias voltage to the plasma region, changes in the plasma properties, such as density and flux, were examined and applied to SiO2 deposition. When DC positive bias was applied, the sheath voltage decreased, causing an increase in the radical density, which contributed to the surface reaction. In an elastic recoil detection analysis, the application of 200 V reduced the hydrogen content of the film from 11.89% to 10.07% compared with no bias; an increase in SiO2 film density from 2.32 to 2.35 g cm−3 was also measured. The elastic modulus and ha...
Journal of the Korean Physical Society, 2002
Journal of the Korean Physical Society, 2002
Recently, many platinoid metals like platinum and ruthenium have been used as an electrode of mic... more Recently, many platinoid metals like platinum and ruthenium have been used as an electrode of microelectronic devices because of their low resistivity and high work-function. However the material cost of Ru is very expensive and it usually takes long initial nucleation time on SiO2 during chemical deposition. Therefore many researchers have focused on how to enhance the initial growth rate on SiO2 surface. There are two methods to deposit Ru film with atomic layer deposition (ALD); the one is thermal ALD using dilute oxygen gas as a reactant, and the other is plasma enhanced ALD (PEALD) using NH3 plasma as a reactant. Generally, the film roughness of Ru film deposited by PEALD is smoother than that deposited by thermal ALD. However, the plasma is not favorable in the application of high aspect ratio structure. In this study, we used a bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] as a metal organic precursor for both thermal and plasma enhanced ALDs. In order to reduce initial nuc...
Nanotechnology, 2020
Tin disulfide (SnS2) has emerged as a promising two-dimensional (2D) material due to its excellen... more Tin disulfide (SnS2) has emerged as a promising two-dimensional (2D) material due to its excellent electrical and optical properties. However, research into 2D SnS2 has mainly focused on its synthesis procedures and applications; its stability to humidity and temperature has yet to be studied. In this work, 2D SnS2 thin films were grown by atomic layer deposition (ALD) and characterized by various tools, such as X-ray diffraction, Raman analysis, and transmission electron spectroscopy. Characterization reveals that ALD-grown SnS2 thin films are a high-quality 2D material. After characterization, a four-inch-wafer-scale uniformity test was performed by Raman analysis. Owing to the quality, large-area growth enabled by the ALD process, 98.72% uniformity was obtained. Finally, we calculated the thermodynamic equations for possible reactions between SnS2 and H2O to theoretically presurmise the oxidation of SnS2 during accelerated humidity and temperature testing. After the accelerated humidity and temperature test, X-ray diffraction, Raman analysis, and Auger electron spectroscopy were performed to check whether SnS2 was oxidized or not. Our data revealed that 2D SnS2 thin films were stable at humid conditions.
Ceramics International, 2020
We used atomic layer deposition (ALD) to evaluate the effect of single Al 2 O 3 cycle insertion a... more We used atomic layer deposition (ALD) to evaluate the effect of single Al 2 O 3 cycle insertion at various locations on SnO 2 and Al-doped SnO 2 thin film transistors (TFTs). The ALD process was used to deposit the SnO 2 thin film in 67 cycles (5 nm thickness). The position of the Al doped layer of Al-doped SnO 2 was controlled by inserting a single Al 2 O 3 cycle into the 56th, 34th and 12th cycles out of 67 cycles. The inserted Al doping layer was analyzed by secondary ion mass spectrometry (SIMS). Crystallinity and thickness of SnO 2 and Al-doped SnO 2 were measured using transmission electron microscope (TEM). Al-doped SnO 2 thin films were prepared at different single Al 2 O 3 cyclic positions for use as channel layers. XPS analysis showed that the oxygen vacancies within the film ranged from 32.8% to 41.6%. Also, the carrier concentration varied from 1.44 x 10 16 to 2.80 x 10 20 cm −3 depending on the Al doping position based on Hall measurements. In addition, the field effect mobility and on/ off current ratios ranged from 1.4 to 8.1 cm 2 /Vsec and from 5.29 x 10 2 to 1.56 x 10 7 , respectively. Lastly, the threshold voltage varied from −6.56 to 11.60 V. Overall, SnO 2 and Al doped SnO 2 channel layers deposited using atomic layer deposition were adjusted to exhibit switching characteristics by inserting a single Al 2 O 3 cycle based on position.
physica status solidi (a), 2017
Tungsten‐nitrogen‐carbide (WNxCy) thin films were investigated as the metal gate of complementary... more Tungsten‐nitrogen‐carbide (WNxCy) thin films were investigated as the metal gate of complementary metal‐oxide‐semiconductor (CMOS) devices. WNxCy thin films were deposited by employing the remote plasma atomic layer deposition (RPALD) using a bis(tert‐butylimido) bis (dimethylamido) tungsten (BTBMW) precursor and hydrogen plasma as a reactant. The growth rate of the WNxCy films was about 0.12 nm/cycle. X‐ray diffraction (XRD) analysis indicated that the films consisted of a mixture of tungsten carbide and tungsten nitride phases. The atomic force microscope (AFM) analysis further confirmed that the WNxCy film surfaces deposited by RPALD were smooth. In addition, the chemical bonding state analysis showed that the WNxCy films consisted of WN, WC, and WO phases. To measure the work function of the WNxCy film, a MOSCAP (metal oxide semiconductor capacitor) stack was fabricated and the flat band voltage was measured by current–voltage (C–V) measurements. A WNxCy work function value of 4...
Current Applied Physics, 2017
We report the Schottky barrier height (SBH) at metaleinsulator interfaces in Pt/ZrO 2 eAl 2 O 3 e... more We report the Schottky barrier height (SBH) at metaleinsulator interfaces in Pt/ZrO 2 eAl 2 O 3 eZrO 2 (ZAZ)/ TiN dynamic random access memory capacitors by analyzing the photoconductivity yield and internal photoemission (IPE) yield using IPE spectroscopy. The SBH values at the Pt/ZAZ and ZAZ/TiN interfaces in the Pt/ZAZ/TiN stack were found to be 2.77 and 2.18 eV, respectively. The SBH difference between the top electrode/oxide and bottom electrode/oxide interfaces is related to the work function difference between Pt and TiN, and the subgap defect state features (density and energy) of the given dielectric. By combining experimental analysis using IPE at the device level and ultraviolet photoelectron spectroscopy and spectroscopic ellipsometry at the film level, a band structure model is proposed.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2016
The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposi... more The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposition (ALD) system for thin film encapsulation (TFE) of flexible organic light-emitting diode (OLED) displays at low temperatures (<100 °C). In this paper, the authors report the excellent moisture barrier properties of Al2O3 films deposited on 2G glass substrates of an industrially relevant size (370 × 470 mm2) using the newly developed ALD system. This new ALD system reduced the ALD cycle time to less than 1 s. A growth rate of 0.9 Å/cycle was achieved using trimethylaluminum as an Al source and O3 as an O reactant. The morphological features and step coverage of the Al2O3 films were investigated using field emission scanning electron microscopy. The chemical composition was analyzed using Auger electron spectroscopy. These deposited Al2O3 films demonstrated a good optical transmittance higher than 95% in the visible region based on the ultraviolet visible spectrometer measurements. ...
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2013
This article explores the history of atomic layer deposition(ALD) and its relationship with the A... more This article explores the history of atomic layer deposition(ALD) and its relationship with the American Vacuum Society (AVS). The authors describe the origin and history of ALD science in the 1960s and 1970s. They also report on how the science and technology of ALD progressed through the 1990s and 2000s and continues today. This article focuses on how ALD developed within the AVS and continues to evolve through interactions made possible by the AVS, in particular, the annual International AVS ALD Conference. This conference benefits students, academics, researchers, and industry practitioners alike who seek to understand the fundamentals of self-limiting, alternating binary surface reactions, and how they can be applied to form functional (and sometimes profitable) thin filmmaterials. The flexible structure of the AVS allowed the AVS to quickly organize the ALD community and create a primary conference home. Many new research areas have grown out of the original concepts of “Atomi...
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2020
Deposition of silicon oxycarbide (SiCOH) thin films by remote plasma atomic layer deposition was ... more Deposition of silicon oxycarbide (SiCOH) thin films by remote plasma atomic layer deposition was performed. In the experiment, the recipe was composed by adjusting the ratio of Ar and CH4 plasmas to control the carbon content in the SiCOH thin film. Octamethyl cyclotetrasiloxane was used as a precursor during the deposition process at 200, 300, and 400 °C. Ar plasma was used as an activant and CH4 plasma was used as a reactant. Plasma and deposition temperatures cause a significant impact on the physical and electrical properties of the film. When CH4 plasma was used during the deposition process, the film contained carbon and exhibited a low dielectric constant. In addition, when CH4 plasma is used as a reactant, Si–C bonds in the thin film form pores and lower ionic polarization to lower the dielectric constant. Fourier-transform infrared spectroscopy data indicate that the higher the ratio of CH4 plasma, the more the cage structure in the thin film. The cage structure contributes...
AIP Advances, 2017
Tin disulfide (SnS2) has attracted much attention as a two-dimensional (2D) material. A high-qual... more Tin disulfide (SnS2) has attracted much attention as a two-dimensional (2D) material. A high-quality, low-temperature process for producing 2D materials is required for future electronic devices. Here, we investigate tin disulfide (SnS2) layers deposited via atomic layer deposition (ALD) using tetrakis(dimethylamino)tin (TDMASn) as a Sn precursor and H2S gas as a sulfur source at low temperature (150° C). The crystallinity of SnS2 was improved by H2S gas annealing. We carried out H2S gas annealing at various conditions (250° C, 300° C, 350° C, and using a three-step method). Angle-resolved X-ray photoelectron spectroscopy (ARXPS) results revealed the valence state corresponding to Sn4+ and S2- in the SnS2 annealed with H2S gas. The SnS2 annealed with H2S gas had a hexagonal structure, as measured via X-ray diffraction (XRD) and the clearly out-of-plane (A1g) mode in Raman spectroscopy. The crystallinity of SnS2 was improved after H2S annealing and was confirmed using the XRD full-wi...
Proceedings, annual meeting, Electron Microscopy Society of America, 1992
Among the transition metal silicides, TiSi2 is considered to be a reasonable choice for VLSI appl... more Among the transition metal silicides, TiSi2 is considered to be a reasonable choice for VLSI applications because it exhibits low resistivity, high temperature stability and compatibility with current processing steps. Thin film reaction of Ti on Si results in the formation of two different forms of TiSi2 which have been identified as the C49 and the C54 crystal structures. The structures are base centered and face centered orthorhombic, respectively. The C49 phase is metastable (ie. it is not represented in the binary phase diagram), and forms at temperatures of 450 to 600°C. The stable C54 phase forms after high temperature annealing to > 650°C. In this paper the relation of the morphology and interface structures of epitaxial C49 TiSi2 on Si(l11) are described.The TiSi2/Si structures were prepared in a UHV system. The TiSi2 surface morphologies were examined by SEM and plan view TEM, and the interfaces were studied by TEM and HRTEM. The phase identification was obtained from t...
Japanese Journal of Applied Physics, 2008
... Ji-Young KIM, Cho-Rong KIM, Jaeyeop LEE, Won-Wook PARK, Jae-Young LEEM, Hyukhyun RYU Ã, Won-J... more ... Ji-Young KIM, Cho-Rong KIM, Jaeyeop LEE, Won-Wook PARK, Jae-Young LEEM, Hyukhyun RYU Ã, Won-Jae LEE 1, Ying-Ying ZHANG 1, Soon-Yen JUNG 1, Hi-Deok LEE 1, In-Kyum KIM 2, Suk-June KANG 2, Hyung-Sang YUK 2, Keunwoo LEE 3, Sunyeol JEON 3, and ...
Journal of Vacuum Science & Technology A
Molybdenum nitride thin films are deposited using a newly synthesized liquid Mo precursor [MoCl4(... more Molybdenum nitride thin films are deposited using a newly synthesized liquid Mo precursor [MoCl4(THD)(THF)] in an ALD super-cycle process. The new precursor is synthesized using MoCl5 and 2,2,6,6-tetramethyl-3,5-heptanedione, which is a bidentate ligand. The synthesized precursor exists in the liquid phase at room temperature and has a characteristic of evaporating 99% at 150–220 °C. Using this new precursor in an ALD super-cycle process results in a pure MoNx thin film with few impurities (C and O). In addition, such MoNx thin films have relatively low resistivity values due to excellent crystallinity and a low impurity concentration. The films' diffusion barrier characteristics confirm that they can perform the role of a barrier at over 600 °C.
Journal of Vacuum Science & Technology A
Sn-doped SiO2 thin films as a spacer for self-aligned patterning were deposited by plasma-enhance... more Sn-doped SiO2 thin films as a spacer for self-aligned patterning were deposited by plasma-enhanced atomic layer deposition and their characteristics were evaluated. This doping research was conducted to improve the mechanical properties of SiO2 films, which have been conventionally used as a spacer material. Because pure SiO2 films have a low Young's modulus, the pattern is stretchable and may collapse as the patterning size decreases. The ratio of the SnO2 and SiO2 deposition cycle was varied from 15(SiO2):1(SnO2) to 3(SiO2):1(SnO2) to modify the film characteristics. X-ray reflectivity (XRR) and time-of-flight secondary ion mass spectrometer analyses revealed whether Sn was doped in SiO2 or became a nanolaminate. The x-ray photoelectron spectroscopy analysis showed that a greater amount of Sn in the SiO2 thin film resulted in a binding energy shift toward the lower binding energy Si2p and Sn3d peaks, and more Si–O–Sn chemical bonding, which increased the number of stiffer ioni...
In this study, NH3 plasma treatment was utilized to enhance the resistive switching (RS) properti... more In this study, NH3 plasma treatment was utilized to enhance the resistive switching (RS) properties. Au/Ni/ TaOx/NiSi and Au/Ni/NH3 plasma-treated TaOx/NiSi resistance RAM (RRAM) devices were fabricated and the resistive switching (RS) properties of these devices were subsequently investigated. Both RRAM devices exhibited conventional electrochemical metallization memory (ECM) behaviors. However, the NH3 plasma-treated samples exhibited improved resistance distribution compared with that of nontreated samples due to the remaining Ni conductive filaments (CF), even following a RESET process. Additionally, superior retention properties longer than 10 s were observed due to the formation of stable Ni CFs. The formation of a defect-minimized TaON layer, observed via X-ray photoelectron spectroscopy (XPS), could be the source of stability for the Ni CFs, resulting in improved device behavior for the NH3 plasma-treated samples.
Journal of vacuum science & technology, Mar 12, 2020
Biomedical Materials, 2009
ECS Journal of Solid State Science and Technology
Multiple patterning technology has become an essential process. In the commonly used self-aligned... more Multiple patterning technology has become an essential process. In the commonly used self-aligned multiple patterning process, the spacer should be dense at low temperatures and have a high elastic modulus. To meet these conditions, many thin-film deposition methods, such as plasma-enhanced atomic layer deposition, have been studied. We investigated remote plasma atomic layer deposition (RPALD) technology with a DC positive bias. After applying bias voltage to the plasma region, changes in the plasma properties, such as density and flux, were examined and applied to SiO2 deposition. When DC positive bias was applied, the sheath voltage decreased, causing an increase in the radical density, which contributed to the surface reaction. In an elastic recoil detection analysis, the application of 200 V reduced the hydrogen content of the film from 11.89% to 10.07% compared with no bias; an increase in SiO2 film density from 2.32 to 2.35 g cm−3 was also measured. The elastic modulus and ha...
Journal of the Korean Physical Society, 2002
Journal of the Korean Physical Society, 2002
Recently, many platinoid metals like platinum and ruthenium have been used as an electrode of mic... more Recently, many platinoid metals like platinum and ruthenium have been used as an electrode of microelectronic devices because of their low resistivity and high work-function. However the material cost of Ru is very expensive and it usually takes long initial nucleation time on SiO2 during chemical deposition. Therefore many researchers have focused on how to enhance the initial growth rate on SiO2 surface. There are two methods to deposit Ru film with atomic layer deposition (ALD); the one is thermal ALD using dilute oxygen gas as a reactant, and the other is plasma enhanced ALD (PEALD) using NH3 plasma as a reactant. Generally, the film roughness of Ru film deposited by PEALD is smoother than that deposited by thermal ALD. However, the plasma is not favorable in the application of high aspect ratio structure. In this study, we used a bis(ethylcyclopentadienyl)ruthenium [Ru(EtCp)2] as a metal organic precursor for both thermal and plasma enhanced ALDs. In order to reduce initial nuc...
Nanotechnology, 2020
Tin disulfide (SnS2) has emerged as a promising two-dimensional (2D) material due to its excellen... more Tin disulfide (SnS2) has emerged as a promising two-dimensional (2D) material due to its excellent electrical and optical properties. However, research into 2D SnS2 has mainly focused on its synthesis procedures and applications; its stability to humidity and temperature has yet to be studied. In this work, 2D SnS2 thin films were grown by atomic layer deposition (ALD) and characterized by various tools, such as X-ray diffraction, Raman analysis, and transmission electron spectroscopy. Characterization reveals that ALD-grown SnS2 thin films are a high-quality 2D material. After characterization, a four-inch-wafer-scale uniformity test was performed by Raman analysis. Owing to the quality, large-area growth enabled by the ALD process, 98.72% uniformity was obtained. Finally, we calculated the thermodynamic equations for possible reactions between SnS2 and H2O to theoretically presurmise the oxidation of SnS2 during accelerated humidity and temperature testing. After the accelerated humidity and temperature test, X-ray diffraction, Raman analysis, and Auger electron spectroscopy were performed to check whether SnS2 was oxidized or not. Our data revealed that 2D SnS2 thin films were stable at humid conditions.
Ceramics International, 2020
We used atomic layer deposition (ALD) to evaluate the effect of single Al 2 O 3 cycle insertion a... more We used atomic layer deposition (ALD) to evaluate the effect of single Al 2 O 3 cycle insertion at various locations on SnO 2 and Al-doped SnO 2 thin film transistors (TFTs). The ALD process was used to deposit the SnO 2 thin film in 67 cycles (5 nm thickness). The position of the Al doped layer of Al-doped SnO 2 was controlled by inserting a single Al 2 O 3 cycle into the 56th, 34th and 12th cycles out of 67 cycles. The inserted Al doping layer was analyzed by secondary ion mass spectrometry (SIMS). Crystallinity and thickness of SnO 2 and Al-doped SnO 2 were measured using transmission electron microscope (TEM). Al-doped SnO 2 thin films were prepared at different single Al 2 O 3 cyclic positions for use as channel layers. XPS analysis showed that the oxygen vacancies within the film ranged from 32.8% to 41.6%. Also, the carrier concentration varied from 1.44 x 10 16 to 2.80 x 10 20 cm −3 depending on the Al doping position based on Hall measurements. In addition, the field effect mobility and on/ off current ratios ranged from 1.4 to 8.1 cm 2 /Vsec and from 5.29 x 10 2 to 1.56 x 10 7 , respectively. Lastly, the threshold voltage varied from −6.56 to 11.60 V. Overall, SnO 2 and Al doped SnO 2 channel layers deposited using atomic layer deposition were adjusted to exhibit switching characteristics by inserting a single Al 2 O 3 cycle based on position.
physica status solidi (a), 2017
Tungsten‐nitrogen‐carbide (WNxCy) thin films were investigated as the metal gate of complementary... more Tungsten‐nitrogen‐carbide (WNxCy) thin films were investigated as the metal gate of complementary metal‐oxide‐semiconductor (CMOS) devices. WNxCy thin films were deposited by employing the remote plasma atomic layer deposition (RPALD) using a bis(tert‐butylimido) bis (dimethylamido) tungsten (BTBMW) precursor and hydrogen plasma as a reactant. The growth rate of the WNxCy films was about 0.12 nm/cycle. X‐ray diffraction (XRD) analysis indicated that the films consisted of a mixture of tungsten carbide and tungsten nitride phases. The atomic force microscope (AFM) analysis further confirmed that the WNxCy film surfaces deposited by RPALD were smooth. In addition, the chemical bonding state analysis showed that the WNxCy films consisted of WN, WC, and WO phases. To measure the work function of the WNxCy film, a MOSCAP (metal oxide semiconductor capacitor) stack was fabricated and the flat band voltage was measured by current–voltage (C–V) measurements. A WNxCy work function value of 4...
Current Applied Physics, 2017
We report the Schottky barrier height (SBH) at metaleinsulator interfaces in Pt/ZrO 2 eAl 2 O 3 e... more We report the Schottky barrier height (SBH) at metaleinsulator interfaces in Pt/ZrO 2 eAl 2 O 3 eZrO 2 (ZAZ)/ TiN dynamic random access memory capacitors by analyzing the photoconductivity yield and internal photoemission (IPE) yield using IPE spectroscopy. The SBH values at the Pt/ZAZ and ZAZ/TiN interfaces in the Pt/ZAZ/TiN stack were found to be 2.77 and 2.18 eV, respectively. The SBH difference between the top electrode/oxide and bottom electrode/oxide interfaces is related to the work function difference between Pt and TiN, and the subgap defect state features (density and energy) of the given dielectric. By combining experimental analysis using IPE at the device level and ultraviolet photoelectron spectroscopy and spectroscopic ellipsometry at the film level, a band structure model is proposed.
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2016
The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposi... more The authors developed a high throughput (70 Å/min) and scalable space-divided atomic layer deposition (ALD) system for thin film encapsulation (TFE) of flexible organic light-emitting diode (OLED) displays at low temperatures (<100 °C). In this paper, the authors report the excellent moisture barrier properties of Al2O3 films deposited on 2G glass substrates of an industrially relevant size (370 × 470 mm2) using the newly developed ALD system. This new ALD system reduced the ALD cycle time to less than 1 s. A growth rate of 0.9 Å/cycle was achieved using trimethylaluminum as an Al source and O3 as an O reactant. The morphological features and step coverage of the Al2O3 films were investigated using field emission scanning electron microscopy. The chemical composition was analyzed using Auger electron spectroscopy. These deposited Al2O3 films demonstrated a good optical transmittance higher than 95% in the visible region based on the ultraviolet visible spectrometer measurements. ...
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2013
This article explores the history of atomic layer deposition(ALD) and its relationship with the A... more This article explores the history of atomic layer deposition(ALD) and its relationship with the American Vacuum Society (AVS). The authors describe the origin and history of ALD science in the 1960s and 1970s. They also report on how the science and technology of ALD progressed through the 1990s and 2000s and continues today. This article focuses on how ALD developed within the AVS and continues to evolve through interactions made possible by the AVS, in particular, the annual International AVS ALD Conference. This conference benefits students, academics, researchers, and industry practitioners alike who seek to understand the fundamentals of self-limiting, alternating binary surface reactions, and how they can be applied to form functional (and sometimes profitable) thin filmmaterials. The flexible structure of the AVS allowed the AVS to quickly organize the ALD community and create a primary conference home. Many new research areas have grown out of the original concepts of “Atomi...
Journal of Vacuum Science & Technology A: Vacuum, Surfaces, and Films, 2020
Deposition of silicon oxycarbide (SiCOH) thin films by remote plasma atomic layer deposition was ... more Deposition of silicon oxycarbide (SiCOH) thin films by remote plasma atomic layer deposition was performed. In the experiment, the recipe was composed by adjusting the ratio of Ar and CH4 plasmas to control the carbon content in the SiCOH thin film. Octamethyl cyclotetrasiloxane was used as a precursor during the deposition process at 200, 300, and 400 °C. Ar plasma was used as an activant and CH4 plasma was used as a reactant. Plasma and deposition temperatures cause a significant impact on the physical and electrical properties of the film. When CH4 plasma was used during the deposition process, the film contained carbon and exhibited a low dielectric constant. In addition, when CH4 plasma is used as a reactant, Si–C bonds in the thin film form pores and lower ionic polarization to lower the dielectric constant. Fourier-transform infrared spectroscopy data indicate that the higher the ratio of CH4 plasma, the more the cage structure in the thin film. The cage structure contributes...
AIP Advances, 2017
Tin disulfide (SnS2) has attracted much attention as a two-dimensional (2D) material. A high-qual... more Tin disulfide (SnS2) has attracted much attention as a two-dimensional (2D) material. A high-quality, low-temperature process for producing 2D materials is required for future electronic devices. Here, we investigate tin disulfide (SnS2) layers deposited via atomic layer deposition (ALD) using tetrakis(dimethylamino)tin (TDMASn) as a Sn precursor and H2S gas as a sulfur source at low temperature (150° C). The crystallinity of SnS2 was improved by H2S gas annealing. We carried out H2S gas annealing at various conditions (250° C, 300° C, 350° C, and using a three-step method). Angle-resolved X-ray photoelectron spectroscopy (ARXPS) results revealed the valence state corresponding to Sn4+ and S2- in the SnS2 annealed with H2S gas. The SnS2 annealed with H2S gas had a hexagonal structure, as measured via X-ray diffraction (XRD) and the clearly out-of-plane (A1g) mode in Raman spectroscopy. The crystallinity of SnS2 was improved after H2S annealing and was confirmed using the XRD full-wi...
Proceedings, annual meeting, Electron Microscopy Society of America, 1992
Among the transition metal silicides, TiSi2 is considered to be a reasonable choice for VLSI appl... more Among the transition metal silicides, TiSi2 is considered to be a reasonable choice for VLSI applications because it exhibits low resistivity, high temperature stability and compatibility with current processing steps. Thin film reaction of Ti on Si results in the formation of two different forms of TiSi2 which have been identified as the C49 and the C54 crystal structures. The structures are base centered and face centered orthorhombic, respectively. The C49 phase is metastable (ie. it is not represented in the binary phase diagram), and forms at temperatures of 450 to 600°C. The stable C54 phase forms after high temperature annealing to > 650°C. In this paper the relation of the morphology and interface structures of epitaxial C49 TiSi2 on Si(l11) are described.The TiSi2/Si structures were prepared in a UHV system. The TiSi2 surface morphologies were examined by SEM and plan view TEM, and the interfaces were studied by TEM and HRTEM. The phase identification was obtained from t...
Japanese Journal of Applied Physics, 2008
... Ji-Young KIM, Cho-Rong KIM, Jaeyeop LEE, Won-Wook PARK, Jae-Young LEEM, Hyukhyun RYU Ã, Won-J... more ... Ji-Young KIM, Cho-Rong KIM, Jaeyeop LEE, Won-Wook PARK, Jae-Young LEEM, Hyukhyun RYU Ã, Won-Jae LEE 1, Ying-Ying ZHANG 1, Soon-Yen JUNG 1, Hi-Deok LEE 1, In-Kyum KIM 2, Suk-June KANG 2, Hyung-Sang YUK 2, Keunwoo LEE 3, Sunyeol JEON 3, and ...
Journal of Vacuum Science & Technology A
Molybdenum nitride thin films are deposited using a newly synthesized liquid Mo precursor [MoCl4(... more Molybdenum nitride thin films are deposited using a newly synthesized liquid Mo precursor [MoCl4(THD)(THF)] in an ALD super-cycle process. The new precursor is synthesized using MoCl5 and 2,2,6,6-tetramethyl-3,5-heptanedione, which is a bidentate ligand. The synthesized precursor exists in the liquid phase at room temperature and has a characteristic of evaporating 99% at 150–220 °C. Using this new precursor in an ALD super-cycle process results in a pure MoNx thin film with few impurities (C and O). In addition, such MoNx thin films have relatively low resistivity values due to excellent crystallinity and a low impurity concentration. The films' diffusion barrier characteristics confirm that they can perform the role of a barrier at over 600 °C.
Journal of Vacuum Science & Technology A
Sn-doped SiO2 thin films as a spacer for self-aligned patterning were deposited by plasma-enhance... more Sn-doped SiO2 thin films as a spacer for self-aligned patterning were deposited by plasma-enhanced atomic layer deposition and their characteristics were evaluated. This doping research was conducted to improve the mechanical properties of SiO2 films, which have been conventionally used as a spacer material. Because pure SiO2 films have a low Young's modulus, the pattern is stretchable and may collapse as the patterning size decreases. The ratio of the SnO2 and SiO2 deposition cycle was varied from 15(SiO2):1(SnO2) to 3(SiO2):1(SnO2) to modify the film characteristics. X-ray reflectivity (XRR) and time-of-flight secondary ion mass spectrometer analyses revealed whether Sn was doped in SiO2 or became a nanolaminate. The x-ray photoelectron spectroscopy analysis showed that a greater amount of Sn in the SiO2 thin film resulted in a binding energy shift toward the lower binding energy Si2p and Sn3d peaks, and more Si–O–Sn chemical bonding, which increased the number of stiffer ioni...
In this study, NH3 plasma treatment was utilized to enhance the resistive switching (RS) properti... more In this study, NH3 plasma treatment was utilized to enhance the resistive switching (RS) properties. Au/Ni/ TaOx/NiSi and Au/Ni/NH3 plasma-treated TaOx/NiSi resistance RAM (RRAM) devices were fabricated and the resistive switching (RS) properties of these devices were subsequently investigated. Both RRAM devices exhibited conventional electrochemical metallization memory (ECM) behaviors. However, the NH3 plasma-treated samples exhibited improved resistance distribution compared with that of nontreated samples due to the remaining Ni conductive filaments (CF), even following a RESET process. Additionally, superior retention properties longer than 10 s were observed due to the formation of stable Ni CFs. The formation of a defect-minimized TaON layer, observed via X-ray photoelectron spectroscopy (XPS), could be the source of stability for the Ni CFs, resulting in improved device behavior for the NH3 plasma-treated samples.