Triple boron doped silicon for selective epitaxial growth of 3D NAND flash memory

Lee Woong,노용한 한국물리학회 2022 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.80 No.12

Selective epitaxial growth (SEG) plays a critical role in vertical NAND (VNAND) fash memory because it serves as a ground select line (GSL) transistor, which is used to control the cell current in the vertical channel. In this study, diferent channel hole sizes between the adjacent hole and away hole from the common source line (CSL) were detected after vertical channel etch (VCE). This variance of channel hole sizes severely impacts the boron concentration of SEG applied through ex-situ boron implantation, and results in large GSL Vth variations. Novel in-situ boron-doping of triple-layered un-doped/ boron-doped/un-doped SEG was developed to solve the high variation of the boron concentration in SEG caused by diferent channel hole sizes. A series of experiments was designed and performed to determine the optimal height and concentration of the boron doped SEG. Finally, the optimized boron-doped SEG in the triple-layer SEG was shown to improve the distribution of the GSL Vth without deterioration of the SEG height uniformity

Effect of Ar dilution flow rate on LPCVD a boron-doped carbon coating from BCl3-C3H6-H2-Ar mixtures

Yongsheng Liu,Litong Zhang,Laifei Cheng,Wenbin Yang,Yongdong Xu 한양대학교 세라믹연구소 2009 Journal of Ceramic Processing Research Vol.10 No.3

A boron-doped carbon coating was deposited from a BCl3-C3H6-H2-Ar system by LPCVD. The effects of the Ar dilution flow rate on deposition rates, morphologies, compositions and bonding states were investigated. Deposition rates were almost the same, about 250 nm/h with different Ar dilution flow rate. Surface morphologies were also almost the same. The flat conchoidal aspect of the fracture surface transformed to a laminated structure with an increase in the Ar dilution flow rate. The carbon concentration was above 76.3 at.%, and the boron concentration was less than 17.9 at.%. The boron concentration increased with an increase in the Ar dilution flow rate, corresponding to a decreasing carbon concentration. The main bonding state of boron was B-sub-C and BC2O. The whole deposition process was dominated by a PyC formation reaction, which led to almost the same deposition rate with different Ar dilution flow rates. A boron-doped carbon coating was deposited from a BCl3-C3H6-H2-Ar system by LPCVD. The effects of the Ar dilution flow rate on deposition rates, morphologies, compositions and bonding states were investigated. Deposition rates were almost the same, about 250 nm/h with different Ar dilution flow rate. Surface morphologies were also almost the same. The flat conchoidal aspect of the fracture surface transformed to a laminated structure with an increase in the Ar dilution flow rate. The carbon concentration was above 76.3 at.%, and the boron concentration was less than 17.9 at.%. The boron concentration increased with an increase in the Ar dilution flow rate, corresponding to a decreasing carbon concentration. The main bonding state of boron was B-sub-C and BC2O. The whole deposition process was dominated by a PyC formation reaction, which led to almost the same deposition rate with different Ar dilution flow rates.

이종 원자 도핑 탄소 나노재료를 이용한 PEMFC Cathode용 촉매 합성 및 평가

조가영(G. Y. Jo),S. Shanmugam 한국태양에너지학회 2012 한국태양에너지학회 학술대회논문집 Vol.2012 No.3

Recently, enormous research efforts have been focused on the development of non-precious catalysts to replace Pt for electrocatalytic oxygen reduction reaction (ORR), and to reduce the cost of proton exchange membrane fuel cells (PEMFCs). In recent years, heteroatom (N, B, and P) doped carbon nanostructures have been received enormous importance as a non-precious electrode materials for oxygen reduction. Doping of foreign atom into carbon is able to modify electronic properties of carbon materials. In this study, nitrogen and boron doped carbon nanostructures were synthesized by using a facile and cost-effective thermal annealing route and prepared nanostructures were used as a non-precious for the ORR in alkaline electrolyte. The nitrogen doped carbon nanocapsules (NCNCs) exhibited higher activity than that of a commercial Pt/C catalyst, excellent stability and resistance to methanol oxidation. The boron-doped carbon nanostructure (BC) prepared at 900 ℃ showed higher ORR activity than BCs prepared lower temperature (800, 700 ℃). The heteroatom doped carbon nanomaterials could be promising candidates as a metal-free catalysts for ORR in the PEMFCs.

Doping Effect on the Metal-induced Lateral Crystallization Rate

Gui Fu Yang,Yong Woo Lee,Chang Woo Byun,Se Wan Son,주승기 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.2

The effects of phosphorus doping and boron doping on the metal-induced lateral crystallization (MILC) rate have been studied. In the case of phosphorus doping, the MILC rate is very sensitive to the sequence of nickel deposition and doping. Phosphorous doping before the nickel deposition reduced the MILC rate much more than the vice versa. When the nickel removal was between the nickel deposition and phosphorus doping,the doping effect on the MILC rate turned out to be in the between of the two cases which are phosphorus doping before nickel deposition and nickel deposition before phosphorus doping. Boron doping results in the crystallization of a-Si at a lower temperature (550°C) compared with that of the solid phase crystallization (SPC). The sheet resistance of boron doped Si remained high because the boron dopants were segregated at the grain boundaries during crystallization of a-Si.

Substitutional boron doping of carbon materials

Sumin Ha,Go Bong Choi,Seungki Hong,Doo Won Kim,Yoong Ahm Kim 한국탄소학회 2018 Carbon Letters Vol.27 No.-

A simple, but effective means of tailoring the physical and chemical properties of carbon materials should be secured. In this sense, chemical doping by incorporating boron or nitrogen into carbon materials has been examined as a powerful tool which provides distinctive advantages over exohedral doping. In this paper, we review recent results pertaining methods by which to introduce boron atoms into the sp2 carbon lattice by means of high-temperature thermal diffusion, the properties induced by boron doping, and promising applications of this type of doping. We envisage that intrinsic boron doping will accelerate both scientific and industrial developments in the area of carbon science and technology in the future.

Local Atomic and Electronic Structure of Boron Chemical Doping in Monolayer Graphene

Zhao, Liuyan,Levendorf, Mark,Goncher, Scott,Schiros, Theanne,Pá,lová,, Lucia,Zabet-Khosousi, Amir,Rim, Kwang Taeg,Gutié,rrez, Christopher,Nordlund, Dennis,Jaye, Cherno,Hybertsen, Mar American Chemical Society 2013 Nano letters Vol.13 No.10

<P>We use scanning tunneling microscopy and X-ray spectroscopy to characterize the atomic and electronic structure of boron-doped and nitrogen-doped graphene created by chemical vapor deposition on copper substrates. Microscopic measurements show that boron, like nitrogen, incorporates into the carbon lattice primarily in the graphitic form and contributes ∼0.5 carriers into the graphene sheet per dopant. Density functional theory calculations indicate that boron dopants interact strongly with the underlying copper substrate while nitrogen dopants do not. The local bonding differences between graphitic boron and nitrogen dopants lead to large scale differences in dopant distribution. The distribution of dopants is observed to be completely random in the case of boron, while nitrogen displays strong sublattice clustering. Structurally, nitrogen-doped graphene is relatively defect-free while boron-doped graphene films show a large number of Stone-Wales defects. These defects create local electronic resonances and cause electronic scattering, but do not electronically dope the graphene film.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2013/nalefd.2013.13.issue-10/nl401781d/production/images/medium/nl-2013-01781d_0005.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl401781d'>ACS Electronic Supporting Info</A></P>

Enhanced Field Emission Behavior from Boron-Doped Double-walled Carbon Nanotubes Synthesized by Catalytic Chemical Vapor Deposition

J.-H. Kang,H. C. Jang,S. C. Lyu,J. H. Sok 한국자기학회 2012 Journal of Magnetics Vol.17 No.1

Attempts to dope carbon nanotube (CNT) with impurities in order to control the electronic properties of the CNT is a natural course of action. Boron is known to improve both the structural and electronic properties. In this report, we study the field emission properties of Boron-doped double-walled CNT (DWCNT). Boron-doped DWCNT films were fabricated by catalytic decomposition of tetrahydrofuran and triisopropyl borate over a Fe-Mo/MgO catalyst at 900 oC. We measured the field emission current by varying the doping amount of Boron from 0.8 to 1.8 wt%. As the amount of doped boron in the DWCNT increases, the turn-on-field of the DWCNT decreases drastically from 6 V/μm to 2 V/μm. The current density of undoped CNT is 0.6 mA/cm2 at 9 V, but a doped-DWCNT sample with 1.8 wt% achieved the same current density only at only 3.8 V. This shows that boron doped DWCNTs are potentially useful in low voltage operative field emitting device such as large area flat panel displays.

Synergistic effect of metal-organic framework-derived boron and nitrogen heteroatom-doped three-dimensional porous carbons for precious-metal-free catalytic reduction of nitroarenes

Van Nguyen, Chi,Lee, Seulchan,Chung, Yongchul G.,Chiang, Wei-Hung,Wu, Kevin C.-W. Elsevier 2019 Applied Catalysis B Vol.257 No.-

<P><B>Abstract</B></P> <P>We report a scalable and controllable synthesis of metal-organic framework (MOF)-derived three-dimensional boron and nitrogen heteroatom-doped porous carbons (3D-BNPCs) and their synergistic effect for metal-free catalytic 4-nitrophenol (4-NP) reduction. The substitution of boron atoms into zeolitic imidazole framework-8 (ZIF-8)-derived nitrogen-doped porous carbon (B-NPC-1200) significantly improves the electrical conductivity and the catalytic 4-NP reduction. We propose the heteroatom-doping of boron, nitrogen and oxygen in the 3D- B-N PC catalysts creates synergistic effect on 4-NP reduction by creating more catalytically active sites. High-Resolution X-ray Photoelectron Spectroscopy (HR-XPS) and Density Functional Theory (DFT) calculations were carried out to confirm and investigate the role of active sites on adsorption of 4-NP molecules in B-NPC-1200. We find that the strongly active sites can only be created based on the synergistic effect between nitrogen, boron and oxygen atoms, and the increased density of the active sites are responsible for the lowering of the apparent activation energy in B-NPC-1200 structure. As synthesized B-NPC-1200 exhibits superior catalytic activities for 4-NP reduction with a low apparent activation energy of 27.0 kJ/mol and a high reaction rate constant of 2.3*10^<SUP>−3</SUP> (s<SUP>-1</SUP>). The catalyst can run five times without decreasing significant catalytic activity. The reduction reactions of various nitroarene compounds have been further tested using the B-N PC-1200 material as the precious-metal-free catalyst.</P> <P><B>Highlights</B></P> <P> <UL> <LI> ZIF-derived boron- and nitrogen-co-doped 3-dimensional porous carbon (3D-BNPC) is synthesized for the first time. </LI> <LI> The 3D-NPC shows uniform morphology and extremely high surface area. </LI> <LI> The 3D-NPC catalyst exhibits superior activity for 4-nitrophenol (4-NP) reduction into 4-aminophenol (4-AP). </LI> <LI> Density functional theory (DFT) calculation is studied. </LI> <LI> The co-doping of B with N in the 3D-BNPC catalysts provides the synergistic effect on 4-NP reduction. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Preparation and characteristic of platinum catalyst deposited on boron-doped carbon nanotubes

박수진,박정민 한국물리학회 2012 Current Applied Physics Vol.12 No.5

In this work, boron doped multi-walled carbon nanotubes (BMWNTs) were introduced as a Pt catalyst support due to their unique physicochemical properties. The effect of BMWNTs on methanol oxidation was investigated with different Pt loading contents. The surface and structural properties of the modified MWNT supports were characterized by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. The Pt loading contents in the catalysts were confirmed by inductive coupled plasma-mass spectrometer (ICP-MS) and the morphological structures of the catalysts were analyzed by transmission electron microscopy (TEM). The electrocatalytic activity of Pt/MWNTs was investigated by cyclic voltammetry measurement. As a result, the boron oxide vapor reacted with MWNTS to form BMWNTs, which led to enhancing the properties, such as graphitization and electrochemical behaviors. Moreover, Pt deposited on BMWNTs exhibited better electrocatalytic activity than on MWNTs for methanol oxidation. Consequently, it was found that partial boron doped MWNTs could influence on the properties of the MWNTs, resulting in enhancing the electrocatalytic activity of the catalysts for DMFCs. In this work, boron doped multi-walled carbon nanotubes (BMWNTs) were introduced as a Pt catalyst support due to their unique physicochemical properties. The effect of BMWNTs on methanol oxidation was investigated with different Pt loading contents. The surface and structural properties of the modified MWNT supports were characterized by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD), respectively. The Pt loading contents in the catalysts were confirmed by inductive coupled plasma-mass spectrometer (ICP-MS) and the morphological structures of the catalysts were analyzed by transmission electron microscopy (TEM). The electrocatalytic activity of Pt/MWNTs was investigated by cyclic voltammetry measurement. As a result, the boron oxide vapor reacted with MWNTS to form BMWNTs, which led to enhancing the properties, such as graphitization and electrochemical behaviors. Moreover, Pt deposited on BMWNTs exhibited better electrocatalytic activity than on MWNTs for methanol oxidation. Consequently, it was found that partial boron doped MWNTs could influence on the properties of the MWNTs, resulting in enhancing the electrocatalytic activity of the catalysts for DMFCs.

Industrial and environmental significance of photonic zirconia nanoflakes: Influence of boron doping on structure and band states

S.P. Ratnayake,C. Sandaruwan,M.M.M.G.P.G. Mantilaka,N. de Silva,D. Dahanayake,U.K Wanninayake,W.R.L.N. Bandara,S. Santhoshkumar,E. Murugan,G.A.J.Amaratunga,K.M. Nalin de Silva 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.95 No.-

A unique zirconia nanomorphology possessing an enhanced photocatalytic efficiency was developedutilizing a convenient single-sol synthesis process which involved in-situ doping of zirconia by boron. The boron-doped zirconia exhibited aflake morphology as opposed to the spherical pure form andsubsequent crystallographic investigations implied the phase conversion from binary to single-phasealong with the shape due to the doping. Optical characterization indicated a modified band structurewith newly generated isolated impurity states within the principle zirconia band edges. As per the X-rayspectroscopy data, boron was detected as chemically bound to oxygen while electron paramagneticresonance indicated the presence of an adsorbed oxygen lattice. During UV and simulated solarirradiation trials, respective removal capabilities of 90% and 93% of the model compound wereaccomplished, hence the effectiveness of the photocatalyst was confirmed. The enhanced photoactivityobserved in the UV region was attributed to combined effects of the boron-induced isolated impuritystates within principle band edges of zirconia, the defect-rich planer morphology, favorable interfacialinteractions and the greater availability of oxygen on the lattice. Developed nanoflakes are stable, inert,and efficient hence exhibiting compelling suitability in the remediation of harmful industrial organiccompounds.