탄화규소의 고온염소반응으로부터 생성된 탄소막의 제조 및 특성평가

최현주 고려대학교 대학원 2008 국내박사

Carbon is one of the most promising materials for nanotechnology applications. Various arrangements of carbon atoms result in amazingly different physical and chemical properties, offering a great flexibility in the design of new carbon-based materials. Silicon carbide-derived carbon is a new form of carbon which can be produced by etching silicon carbide in mixed gas environment containing chlorine and hydrogen at elevated temperatures much lower than those used for sintering or graphitization. Thus, a number of articles concerning carbide-derived carbon (CDC) have been published so far. This dissertation is divided in three parts: sliding wear of silicon carbide modified by etching with chlorine at various temperatures, effect of hydrogen on the mechanical and structural properties of SiC-derived carbon films, and tribology of carbon layers fabricated from SiC exposed to different H2/Cl2 gas mixtures. To begin with, the effect of reaction temperature on the formation of a carbon layer on the surface of SiC has been investigated. Subsequently, the tribological properties of the formed carbon layers were studied. The experimental procedure involved exposing reaction-bonded SiC balls to a flowing gas mixture of 5% Cl2, 2.5% H2, and Ar at a high temperature of 800 oC, 1000 oC, or 1200 oC. A ball-on disk tribometer was used to investigate the friction and wear behavior of the treated specimens. While partially unreacted SiC phases were observed in the layer modified at 800 oC, rhombohedral graphite crystals were formed in the layer modified at 1200 oC. Compared to untreated SiC, the treated SiC materials were found to have relatively low friction coefficients and better wear resistance. Increasing the treatment temperature was found to improve the tribological performance of the resulting surface-modified SiC balls. A possible reason for this tribological improvement has been discussed based on the observed carbon phases. In the second part of this dissertation, sintered SiC materials were treated with various compositions of chlorine-hydrogen gas mixtures at a temperature of 1000 oC for 20 hrs. Then, it focused on how the presence of hydrogen has key functions for structural and mechanical properties of modified carbon films on silicon carbide. Based on the structural analysis of carbon films produced, conversion from silicon carbide proceeded faster with increasing chlorine content at a high temperature, and besides, the chlorination reaction rate decreased with increasing hydrogen content of mixtures, as determined by XRD and SEM. The correlation between the degree of crystallinity and mechanical properties of carbon films produced depended obviously on the presence of hydrogen in terms of the kinetics of chlorination reaction. The action of chlorine on carbides led to a pore formation due to the physical transformations in the structure, not chemical transformation. Based on nanoindentation measurements, the hardness and elastic modulus of carbon films transformed by high-temperature chlorination of silicon carbide with varying hydrogen content of mixtures were determined. The hardness and elastic modulus of the carbon films treated with only Cl2 and Cl2-H2 of gas mixtures were related to the surface and structural properties as well as the film thickness of modified carbon films. Besides, an addition of hydrogen to a gas mixture led to an increase in plasticity (56.71 % in indentation deformation) of modified carbon films. Silicon carbide-based ceramics are some of the best materials for tribological applications. However, their tribological properties still need to be improved for certain uses under severe conditions. In the last part of this dissertation, carbon layers were produced by the exposure of ball and disc type SiCs to various compositions of chlorine-hydrogen gas mixtures at a temperature of 1000 oC for 20 hrs. After the chlorination of the silicon carbide materials, the modified layers were characterized by XRD, Raman, and FE-SEM. The effect of the hydrogen gas content on the carbide-derived carbon (CDC) layers and their resulting tribological properties have been investigated. The tribological behaviors of the CDC layers were studied using a ball-on-disk tribometer. Silicon nitride and chlorinated silicon carbide balls were selected as the counterpart material. The results showed that the wear resistance and frictional coefficients of the surface-modified ball and disk-type SiCs were significantly improved compared to those of untreated silicon carbide specimens. Increasing the hydrogen content of the gas mixture improved the tribological performance of the resulting carbon layers. The use of a higher applied load also improved the tribological performance. The possible mechanisms responsible for the tribological properties of the carbon layers have been discussed. 탄화규소의 고온염소반응으로부터 생성된 탄소막의 제조 및 특성평가 CVD, PVD 등과 같은 증착방법을 이용하여 제조된 세라믹이나 금속모재의 탄소막 코팅은 마찰특성을 향상시켜 재료의 내구성을 높여줌으로써 tribology 응용분야에 효과적으로 이용되고 있다. 그러나 이와 같은 코팅 방법은 코팅과 모재간의 접착력, 잔류응력의 문제를 갖고 있기 때문에 그 응용이 제한되어 왔다. 본 연구에 적용된 CDC (Carbide-Derived Carbon) 코팅방법은 실질적으로 탄화규소의 표면층에서부터 모든 깊이까지 고온 염소 처리함으로써 탄소로 상전이 되어 탄소층을 만드는 방법을 말한다. 그래서 요구되는 탄소막을 위해 실리콘 등 금속원자를 선택적으로 에칭시키는 본 방법을 이용하면, 생성 박막의 두께 및 표면조도를 자유롭게 조절할 수가 있게 된다. 그러므로 본 연구는 탄화규소볼을 이용하여 고온 염소처리시켜 탄소상으로 개질된 표면층을 얻었다. 이때 800℃-1200℃ 등의 온도 변화에 따른 탄소의 결정상태변화를 관찰하였고 이러한 변화가 tribology 특성에 미치는 영향을 평가하였다. 또한 반응가스로 사용된 염소와 수소 가스비를 달리하여 탄소층을 얻었으며 기계적 물성 및 마찰마모 특성을 평가하여 비교분석하였다. 이때, XRD, HRTEM, Raman 분석을 통해 생성된 탄소막이 나노결정질 및 비정질 흑연상임을 확인하였다. 나노인덴테이션법으로 생성 탄소막의 기계적 물성을 측정하였으며, 개질된 박막의 tribology 특성을 관찰하기 위하여 ball-on-disk 방식으로 마모실험을 실시하였다. 이렇게 고온에서 염소처리법으로 얻어진 박막의 tribology 특성평가 결과로는 표면개질 전과 비교해 볼 때 탄소로 표면개질된 탄화규소의 마모-마찰 특성이 현저히 향상되는 경향을 보여, 온도 및 가스조성비의 변화에 따른 탄소층의 결정상태와 그에 따른 tribology 특성과의 상관관계에 대해 비교 분석하였다.

Integrating Spin Defects With Thin-Film Silicon Carbide Devices

Dietz, Jonathan Richard Harvard University ProQuest Dissertations & Theses 2025 해외박사(DDOD)

Thin film silicon carbide (SiC) is a material used in commercial power electronics, and finding application in quantum information processing, microelectromechanical systems, photonics, and harsh environment sensors. Desirable in these applications is obtaining thin film-suspended device layers of undoped silicon carbide, which could be used as the basis of SiC-on-insulator (SiCOI) or for suspended photonics. It is an open challenge to obtain scalable thin films of single crystal silicon carbide, a challenge addressed in detail in this dissertation by implementing a dopant free photoelectrochemical (PEC) etching of SiC. In this dissertation we examine several incarnations of suspended SiC devices, and examine their potential for use in spin defect control, mechanical oscillators, and optical cavities.In initial experiments, the photoluminescence and spin properties of ensembles of color centers in silicon carbide are enhanced by fabricating optically isolated slab waveguide structures using a doped PEC process and carefully controlling annealing and cooling conditions. We find that the photoluminescence signal of an ensemble of implanted defects is enhanced in slab waveguides by an order of magnitude over identically implanted bulk defects. The slab waveguide-enhanced photoluminescence of several defect species is used to study recombination and diffusion in the presence of thermal annealing with both rapid quench cooling and a longer return to ambient conditions. The confined mechanical geometry of a thin film is exploited to measure the spin-strain coupling of the negatively charged silicon monovacancy. The methods in this work can be used to exercise greater control on near-surface emitters in silicon carbide and better understand and control the effects of strain on spin measurements of silicon carbide based color centers. On the basis of these results we conclude that the properties of defects and devices are likely strongly degraded by the use of heavily doped epilayers.Consequently, we reexamine in detail and then redesign the photoelectrochemical etching process used to suspend the devices to be compatible with a fully undoped device layer of SiC. PEC etching is a simple, rapid means of wet processing SiC, including the use of dopant selective etch stops that take advantage of mature SiC homoepitaxy. However, dopant selective photoelectrochemical etching typically relies on highly doped material, which poses challenges for device applications such as quantum defects and photonics that benefit from low doping to produce robust emitter properties and high optical transparency. In this work, we develop a selective photoelectrochemical etching process that relies not on high doping but on the electrical depletion of a fabricated diode structure, allowing the selective etching of an n-doped substrate wafer versus an undoped epitaxial (carrier density of 1(10)14cm−3) device layer. We characterize the photo-response and photoelectrochemical etching behavior of the diode under bias and use those insights to suspend large (100µm x 100µm) undoped membranes of SiC. We further characterize the compatibility of membranes with quantum emitters, performing comparative spin spectroscopy between undoped and highly doped membrane structures, finding the use of undoped material improves ensemble spin lifetime by > 5x. Furthermore, we examine these use of these films in the initial incarnations of photonic crystal cavities and mechanical "trampoline" type oscillators. This work enables the fabrication of high-purity suspended thin films suitable for scalable photonics, mechanics, and quantum technologies in SiC.Next, we consider electrically driven mechanical oscillators fabricated using a front-side back-side dry etch, known as Lateral Overtone Bulk Acoustic Resonators (LOBARs) and the coupling of their dynamic strain to defect centers in the SiC. Here we report acoustic spin control of naturally occurring negatively charged silicon monovacancies in a lateral overtone bulk acoustic resonator that is based on 4H silicon carbide. We show that acoustic driving can be used at room temperature to induce coherent population oscillations. Spin acoustic resonance is shown to be useful as a frequency-tuneable probe of bulk acoustic wave resonances, highlighting the dynamical strain distribution inside a bulk acoustic wave resonator at ambient operating conditions. Our approach could be applied to the characterization of other high quality-factor micro-electro-mechanical systems and has the potential to be used in mechanically addressable quantum memory.Finally, we consider an unconventional means of introducing defects into already suspended material through the process of energetic laser irradiation (referred to here as "laser-writing"). High-yield engineering and characterization of cavity-emitter coupling is an outstanding challenge in developing scalable quantum network nodes. Ex-situ defect formation systems prevent real-time analysis, and previous in-situ methods are limited to bulk substrates or require further processing to improve emitter properties. Here, we demonstrate direct laser-writing of cavity-integrated spin defects using a nanosecond-pulsed above-bandgap laser. Photonic crystal cavities in 4H-silicon carbide serve as a nanoscope monitoring silicon monovacancy defect formation within the approximately 200nm3 cavity mode volume. We observe spin resonance, cavity-integrated photoluminescence, and excited-state lifetimes consistent with conventional defect formation methods, without need for post-irradiation thermal annealing. We further find an exponential reduction in excited-state lifetime at fluences approaching the cavity amorphization threshold and show single-shot annealing of intrinsic background defects at silicon monovacancy formation sites. This real-time in-situ method of localized defect formation, paired with cavity-integrated defect spins, is necessary towards engineering cavity-emitter coupling for quantum networking.The proceeding work establishes a basis for the fabrication of integrated quantum systems using silicon carbide and the defects therein, from the incorporation of defects through laser writing, to the creating of nanofabricated geometries using PEC etching, to the control and read-out of their ground state spins using mechanical resonators. Though the experiments herein often investigate different devices, defects, and techniques, the underlying theme is same: improving the integration of spin defects in SiC with realistic devices that could lead to their use in quantum sensing and information processing.

Preparation of Tantalum Carbide and Silicon Nitride Powder by Magnesiothermic Reduction Process

황선민 (Hwang Seonmin) 부산대학교 대학원 2024 국내박사

In this study, the reduction of various metal oxides with magnesium was investigated under various conditions to optimize the reduction efficiency. The effects of metal oxide particle size, and the reaction temperature and the reduction mechanism were systematically investigated. These findings provide valuable insights into efficient high melting point materials manufacturing based on magnesium reduction from metal oxides. The following three aspects of manufacturing of high melting point materials were focused upon in this thesis. (1) Ta metal powder was successfully prepared by reduction of Mg gas with tantalum pentoxide. The reduction behavior was studied kinetically using Ta2O5 with different initial particle sizes. Reduction temperature varied in the range from 1073 to 1273 K. In the X-ray diffraction patterns of reduced powders, pure Ta peaks appear above 1123 K when using the 0.3 μm initial powder, and at 1173 K when using the 1.2 μm initial powder. With increasing reduction temperature, reduction rates were higher with the use of the 0.3 μm powder than with the coarser 1.2 μm powder. This behavior resulted in different activation energies for Mgreduction. In the powder reduced at 1273 K, the oxygen content was lowered to 0.66 and 0.88 wt% for the 1.2 and 0.3 μm powders, respectively; this is explained by differences in the specific surface area according to particle size. (2) In this section, we investigated the purification of hexane using titanium, copper, and aluminum powders and used the purified hexane for the gaseous carburization of tantalum. Ti exhibited lower activation energy for oxidation than Cu and Al and a significantly higher oxidation rate in hexane at room temperature than Cu and Al. The carbon content in tantalum carburized using the purified hexane was comparable to that carburized using unpurified hexane. However, its oxygen content was significantly lower, which indicates that the produced tantalum carbide has a higher purity. X-ray diffraction results revealed absence of oxidation products of tantalum carbide using purified hexane. Therefore, Ti powder can effectively remove oxygen-containing impurities from commercial hexane and facilitate its use as an effective carburizing medium for the synthesis of high-purity tantalum carbide. (3) The present chapter focused to prepare pure silicon powder from SiO2 by a magnesium thermal reduction process. A mixed-phase, Mg2Si + MgO, was obtained by the reduction of SiO2 powder by magnesium gas at 1223 K for 20 h. To extract pure silicon powder, Mg was separated by evaporation under vacuum through Mg2Si decomposition above 1073 K, leading to the formation of Si + MgO, and the MgO by-product was eliminated by dissolution in an aqueous hydrochloric acid solution. X-ray diffraction analysis confirmed the formation of pure Si powder. As a result, we tried to set the optimal reduction conditions according to the temperature through magnesium reduction using tantalum oxide and silicon oxide as the initial raw materials and investigated the reduction phase and kinetic behavior according to the conditions. In the case of tantalum, as a follow-up study, a process of removing impurities from hydrocarbons used before the carbonization process was additionally performed to produce higher-purity tantalum carbide, which is used as a technology that uses less energy and increases safety. 본 연구에서 제안하는 마그네슘열환원법은 나트륨, 알루미늄, 칼슘, 탄소환원법 등 의 상용공정에 비해 1)환원이 어려운 난환원성 산화물의 환원에 적용이 수월하며, 2) 반응온도가 1273 K 로 상대적으로 저온이고, 3) 환원 후 부산물인 산화마그네슘 제거 가 용이하다. 또한 4)시설비가 비교적 저렴하여 양산화가 용이한 장점등이 있다. 따라서, 본 연구에서는 마그네슘 환원법을 적용한 연구를 기초로 한 2가지 연구를 수행했다. 첫번째, 국방산업용 초합금 제조를 위한 합금원료인 탄탈륨을 추출하기 위해, 탄탈륨산화물을 초기원료로 하여 마그네슘 환원을 통해 온도에 따른 최적화된 환원 조건을 확립하였으며, 이후 최적화된 환원 조건에서 순수 탄탈륨 분말을 제조하였다. 이후 입자크기에 따른 환원 거동의 차이를 규명하기 위해 온도에 따른 마그네슘 환원 가능성과 산소 함량 및 상 거동, 그리고 초기 입자크기에 따른 환원 kinetic 거동을 조사하였다. 다음으로 후속 공정으로써 탄화탄탈륨을 합성하기 위한 효율적이고 경제적인 침탄 공정을 확립하고자 하였다. 탄화탄탈륨은 대부분의 경우 분말을 원료로 하여 소결공정을 통해 합성되며, 특히 소량으로도 내마모성과 가공성을 향상시켜 초경공구의 성능 향상을 위한 첨가제로의 활용가치가 높다. 따라서 탄화탄탈륨을 합성하기 위해서는 탄탈륨의 침탄시 탄화수소의 사용이 요구되었는데, 이때 재산화를 방지하고 양호한 침탄 반응을 유도하기 위해 종래의 탄화수소 대비 적은 비용이며, 다루기가 용이한 상용 헥산을 사용하고자하여 헥산을 정제하였으며 헥산 정제시의 kinetic을 조사하였고 정제된 헥산을 사용하여 탄화탄탈륨을 합성을 시도하여 침탄 매질로써의 가능성을 확인하였다. 마지막으로 전자기 부품, 태양전지 등 다양한 부품 제조를 위한 원료이며 고부가가치 재료인 질화규소 분말을 제조하기 위해 실리콘의 다양한 합성법이 개발되어 왔다. 그 중 직접질화법과 디이미드법이 산업적으로 상용화되고 있는데, 이들 합성법을 적용하기 위해서는 고순도 실리콘 실리콘 금속분말의 사용이 필수적인데 이를 위하여 실리콘 금속분말을 마그네슘 환원을 통해 추출하고자 하였으며, 이를 통해 마그네슘 환원 조건을 확립하고 이후 합성된 Mg2Si 에서 마그네슘만을 선택적으로 제거하는 진공 열처리 조건을 확립하여 고순도의 실리콘 금속분말을 얻었다. 이후 직접질화법을 적용해 질화규소를 얻었다.

Effect of Post-Annealing on the Microstructure and Properties of Low Temperature Chemical-Vapor-Deposited Carbides (TaC, HfC, SiC)

Jangwon Han 서울대학교 대학원 2023 국내박사

To investigate the effect of post-annealing on the microstructure and properties of low temperature chemical-vapor-deposited carbides (TaC, HfC, SiC), carbide films were deposited on graphite substrates by CVD and post-annealed at different conditions, and the relation between the deposition/post-annealing conditions and the microstructure/mechanical properties were studied. Tantalum carbide (TaC) coating layers were deposited on graphite substrates using the TaCl5-C3H6-H2 CVD system under various deposition conditions. The deposited TaC coating layers exhibited crystallographic preferred orientation, with (111) and (200) orientations being dominant. As the deposition temperature was increased, the preferred orientation changed to random orientations. Subsequent post-annealing significantly improved the crystallinity of the coating layers. When deposited at 1100oC to 1300oC, the microstructure exhibited columnar structures and columnar-equiaxed mixed structures. However, subsequent post-annealing resulted in grain growth, causing the transformation of the microstructure from columnar to equiaxed form. These findings highlight the ability of post-annealing to enhance crystallinity and induce mechanical property changes of up to 10% increase in TaC coating layers. Hafnium carbide (HfC) coating layers were deposited on graphite substrates using the HfCl4–C3H6–H2 CVD system at 1200°C. The as-deposited coating layers exhibited high crystallinity and dense microstructures (columnar-like structure). Post-annealing further affected the microstructures, transforming columnar structures into equiaxed structures and causing the coalescence of pores. The nano hardness of the coating layer was also improved during the post-annealing process. These results demonstrate that HfC coating layers deposited at 1200°C possess dense microstructures, and their crystallinity and nano hardness can be enhanced through post-annealing. Silicon carbide (SiC) coating layers were deposited on graphite substrates using the CVD method at various deposition temperatures. X-ray diffraction (XRD) analyses revealed changes in crystallinity depending on the deposition temperature. When layers were deposited at 900oCs, peaks of free silicon (Si) were observed, while they were absent at layers deposited at high temperatures due to the complete reaction of the precursor. The microstructure showed a tendency for increased thickness at higher deposition temperatures. Post-annealing improved the crystallinity of the deposited coating layers. The nano hardness of the coating layers also exhibited temperature-dependent variations. These findings suggest that post-annealing can modify the crystallinity, microstructure, and nano hardness of SiC coating layers. Furthermore, although TaC, HfC, and SiC are carbide-based coating layers, their growth mechanisms of the microstructure are slightly different. Therefore, the changes in the microstructure during the post-annealing process vary. In particular, TaC, HfC, and SiC exhibited partial differences after the post-annealing process, which were briefly discussed. This study provides comprehensive and detailed insights into the properties of high-temperature ceramic carbides (TaC, HfC, SiC) through the investigation of their crystallinity, microstructure, and the effects of post-annealing on the microstructure/mechanical properties. The findings contribute to a better understanding of the superior properties exhibited by these high-temperature ceramic carbides. 후열처리가 저온 화학기상증착법(CVD)으로 증착한 탄화물(TaC, HfC, SiC)의 미세구조와 특성에 미치는 영향을 조사하기 위해, 탄화물 코팅층을 CVD법을 사용하여 흑연 기판에 증착한 후 다양한 조건에서 후 열처리를 진행하였고, 증착-후열처리 조건과 미세구조-기계적 특성 간의 관계를 연구하였다. 탄탈륨 카바이드(TaC) 코팅층은 TaCl5-C3H6-H2 CVD 시스템을 사용하여 다양한 증착 조건아래 흑연 기판 위에 증착하였다. 증착된 TaC 코팅층은 결정학적 우선 방향성을 가지며, (111) 및 (200) 방향이 우세한 것으로 나타났다. 하지만, 증착 온도가 증가함에 따라 우선 방향이 무작위 방향성으로 변화하였다. 증착된 코팅층에 시행된 후 열처리공정은 코팅층의 결정성을 크게 향상시켰다. 증착온도를 1100℃부터 1300℃로 변화시키면서 증착하는 경우, 미세구조는 주상정형태의 구조와 주상정-등축 혼합 구조를 보였다. 코팅층에 행해진 후 열처리 공정은 입자 성장을 유발하여 미세구조가 주상정에서 등축형으로 변화하게 만들었다. 이러한 결과는 후 열처리가 저온에서 증착한 TaC 코팅층의 결정성을 향상시키고, 기계적 물성을 10%가량 증가시킬 수 있는 변화를 보여주고 있다. 하프늄 카바이드(HfC) 코팅층은 HfCl4–C3H6–H2 CVD 시스템을 사용하여 1200℃에서 흑연 기판에 증착하였다. 증착된 코팅층은 높은 결정성과 조밀한 미세구조(주상정 형태)를 보였다. 증착된 코팅층에 시행된 후 열처리 공정은 코팅층의 미세구조에 영향을 미쳐 주상정형태를 등축상 형태로 변화시키고, 기공구조가 드러나게 만들었다. 코팅층의 나노 경도도 후 열처리 과정에서 향상되었다. 이러한 결과는 1200℃에서 증착된 HfC 코팅층이 조밀한 미세구조를 가지고 있으며, 그 결정성과 나노 경도가 후 열처리를 통해 향상될 수 있다는 것을 보여주고 있다. 실리콘 카바이드(SiC) 코팅층은 다양한 증착 온도에서 CVD 방법을 사용하여 흑연 기판에 증착하였다. X선 회절(XRD) 분석 결과 증착 온도에 따라 코팅층의 결정성이 변화함을 보였다. 900℃에서 증착된 코팅층에서는 유리 실리콘(free Si)의 피크가 관찰되었지만, 전구체의 완전한 반응으로 인해 높은 증착 온도에서는 증착된 코팅층에서 실리콘 피크가 관찰되지 않았다. 높은 증착 온도에서 증착된 코팅층의 두께가 증가하는 경향을 보였다. 후 열처리는 증착된 코팅층의 결정성을 향상시켰다. 코팅층의 나노 경도도 또한 온도에 따라 변화하였다. 이러한 결과는 후 열처리가 SiC 코팅층의 결정성, 미세구조 및 나노 경도를 향상시킬 수 있다는 것을 보여준다. TaC, HfC, SiC는 탄화물 기반의 코팅층이지만, 그들의 미세구조의 성장 메커니즘은 유사하면서도 약간 다르다. 따라서, 후 열처리 과정에서 발생하는 미세구조의 변화도 다양하다. 특히, TaC, HfC와 SiC는 후 열처리 후에 부분적으로 차이를 보이며, 그 차이를 본 논문에서 간략히 논의하였다. 본 연구는 고온 세라믹 탄화물(TaC, HfC, SiC)의 결정성, 미세구조 및 후 열처리가 미세구조-기계적 특성에 미치는 영향을 조사함으로써 높은 온도에서 나타나는 이러한 세라믹 탄화물의 우수한 특성에 대한 포괄적이고 상세한 연구의 방향성을 제공한다. 이러한 연구 결과는 고온 세라믹 탄화물의 우수한 특성에 대한 이해를 높이는 데 기여할 수 있을 것으로 보인다.

Processing and Characterization of Silicon Carbide (6H-and 4H-SiC) Contacts for High Power and High Temperature Device Applications

이상권 KTH(Kungliga Tekniska Hogskolan) Royal Institute o 2002 해외박사

Silicon carbide is a promising wide bandgap semiconductor material for high-temperature, high-power, and high-frequency device applications. However, there are still a number of factors that are limiting the device performance. Among them, one of the most important and critical factors is the formation of low resistivity Ohmic contacts and high-temperature stable Schottky diodes on silicon carbide. In this thesis, different metals (TiW, Ti, TiC, Al, and Ni) and different deposition techniques (sputtering and evaporation) were suggested and investigated for this purpose. Both electrical and material characterizations were performed using various techniques, such as I-V, C-V, RBS, XRD, XPS, LEED, SEM, AFM, and SIMS. For the Schottky contacts to n- and p-type 4H-SiC, sputtered TiW Schottky contacts had excellent rectifying behavior after annealing at 500˚C in vacuum with a thermally stable ideality factor of 1.06 and 1.08 for n- and p-type, respectively. It was also observed that the SBH for p-type SiC (ΦBp) strongly depends on the choice the metal with a linear relationship ΦBp = 4.51 - 0.58Φm, indicating no strong Fermi-level pinning. Finally, the behavior of Schottky diodes was investigated by incorporation of size-selected Au nano-particles in Ti Schottky contacts on silicon carbide. The reduction of the SBH is explained by using a simple dipole layer approach, with enhanced electric field at the interface due to the small size of the circular patch (Au nano-particles) and large difference of the barrier height between two metals (Ti and Au) on both n- and p- SiC. For the Ohmic contacts, titanium carbide (TiC) was used as contacts to both n- and p-type 4H-SiC epilayers as well as on A1 implanted layers. The TiC contacts were epitaxially deposited using a co-evaporation method with an e-beam Ti source and a Knudsen cell for C60, in a UHV system at low substrate temperature (500˚C). In addition, we extensively investigated sputtered TiW (weight ratio 30:70) as well as evaporated Ni Ohmic contacts on both n- and p-type epilayers of SiC. The best Ohmic contacts to n-type SiC are annealed Ni (> 950˚C) with the specific contact resistance of = 8×10-6 Ωcm2 with doping concentration of 1.1×10-19 cm-3 while annealed TiW and TiC contacts are the preferred contacts to p-type SiC. From long-term reliability tests at high temperature (500˚C or 600˚C) in vacuum and oxidizing (20% O2/N2) ambient, TiW contacts with a platinum capping layer (Pt/Ti/TiW) had stable specific contact resistances for > 300 hours.

접촉 조건에 따른 실리콘 웨이퍼와 실리콘 카바이드의 프레팅 마찰 및 마모 거동 분석에 관한 연구

이명관 연세대학교 대학원 2026 국내석사

Silicon (Si) is widely used in advanced electronic industries and serves as a key material in semiconductor manufacturing, where numerous integrated circuits are fabricated in form of wafer, due to its high crystallinity and excellent micromachinability. Silicon carbide (SiC), a silicon-based ceramic, possesses a chemical composition similar to Si but exhibits high hardness, superior wear resistance, and outstanding chemical stability. Due to these properties, SiC is used as jigs that support, store and transport wafers under extreme conditions in semiconductor processes. During semiconductor manufacturing, vibrations generated by mechanical components and external factors induce micro-scale friction and wear at the contact interface between the Si wafers and the SiC jigs. Such repeated contact and relative motion result in fretting wear, which can contaminate or damage the wafer surface, thereby reducing process reliability and yield. Although numerous studies have been investigated the fretting behavior of Si-based materials, research focusing specifically on the fretting behavior between Si wafers and SiC, the core materials in semiconductor processes, remains limited. Accordingly, in this study, fretting tests between Si wafers and SiC were conducted using a custom-designed ball-on-flat test apparatus. To simulate semiconductor manufacturing conditions, the experiments were performed under dry conditions with fixed amplitude, frequency, and duration while varying the applied load to investigate the effect of contact pressure. After the test, fretting regimes were classified based on F-D curves and energy ratio analyses, and wear tracks were examined in detail using three-dimensional laser confocal microscope, SEM, and EDS. The results confirmed that fretting friction between the Si wafer and SiC was primarily governed by mechanical abrasion and oxidative wear mechanisms. Furthermore, fretting behavior was distinctly dependent on the applied normal load: the gross slip dominated at low loads (≤ 1 N), partial slip occurred at high loads (≥ 3 N), and mixed slip was observed in the intermediate range (1.5-2 N). Based on the identified wear mechanisms. Additional fretting tests were performed after applying a diamond-like carbon (DLC) coating to the SiC ball. The DLC coating reduced the coefficient of friction and wear rate of the Si wafer, which is attributed to the formation of a transferred DLC tribo-film on the wafer surface that suppresses direct contact between SiC and Si. These findings provide valuable insights into the fretting behavior at the Si wafer-SiC interface during semiconductor manufacturing and are expected to serve as fundamental knowledge for extending equipment lifetime and improving process yield 실리콘은 높은 결정성과 뛰어난 미세 가공성으로 인해 첨단 전자 산업에서 널리 활용되며, 특히 반도체 산업에서는 웨이퍼의 형태로 집적회로를 제작하는 핵심 소재로 사용된다. 실리콘 카바이드는 실리콘 기반의 세라믹 재료로, 실리콘과 유사한 화학적 성분을 가지면서도 고경도 및 우수한 내마모, 내화학적 안정성을 지니고 있다. 이러한 특성으로 인해 실리콘 카바이드는 극한 환경에서 안정성을 확보할 수 있어 반도체 제조 공정에서 웨이퍼를 지지, 보관, 운송하는 지그의 주 재료로 사용된다. 반도체 제조 공정 중 기계 부품의 움직임 및 외부 조건에 의해 발생하는 진동은 실리콘 웨이퍼와 실리콘 카바이드 지그의 접촉면에 미세한 마찰 및 마모를 유발한다. 이러한 반복적인 접촉과 상대 운동으로 인해 프레팅 마모가 발생하며, 이는 웨이퍼 표면 오염이나 손상으로 이어져 공정 신뢰성에 부정적인 영향을 미치고 수율을 저하시키는 원인이 된다. 실리콘 기반 재료의 프레팅에 관한 연구는 다수 수행되어 왔으나, 반도체 공정의 핵심 소재인 실리콘 웨이퍼와 실리콘 카바이드 간의 프레팅 거동에 대한 연구는 상대적으로 부족한 실정이다. 이에 따라 본 연구에서는 자체 제작한 ball-on-flat 방식의 실험 장치를 이용하여 실리콘 웨이퍼와 실리콘 카바이드 간의 프레팅 거동을 분석하였다. 본 실험에서는 반도체 제조 공정을 모사하여 건식 조건에서 진폭과 진동수, 실험 시간을 일정하게 고정하였으며, 접촉 압력 변화에 따른 프레팅 거동의 차이를 확인하기 위해 하중을 변경하며 실험을 진행하였다. 실험 후에는 마찰력 측정을 통한 F-D 곡선 및 에너지 비율 분석하였으며, 마모흔의 형상은 3 차원 레이저 공초점 현미경과, SEM, EDS 를 활용하여 정밀 분석하였다. 연구 결과, 실리콘 웨이퍼와 실리콘 카바이드의 프레팅 마찰은 주로 기계적 연삭 작용과 산화 마모 메커니즘에 의해 발생함을 확인하였다. 또한, 하중 조건에 따라 프레팅 거동이 뚜렷하게 구분되었다. 낮은 하중 조건에서는 gross slip 영역이 지배적이었으며, 하중이 증가함에 따라 미끄러짐이 억제되면서 mixed slip 그리고 partial slip 영역으로 전이되는 경향을 보였다. 규명된 마모 메커니즘을 바탕으로 실리콘 카바이드 볼 표면에 DLC(Diamond-like carbon) 코팅을 적용하여 실험을 수행한 결과 두 시편의 직접적인 접촉 감소 및 상대면에 tribo-film 전이를 통해 마찰 및 마모 저감 효과가 나타나는 것을 확인하였다. 본 연구 결과는 반도체 제조 공정에서 실리콘 웨이퍼와 실리콘 카바이드 접촉에 따른 프레팅 거동에 대한 이해를 제공하며, DLC 코팅을 활용한 마모 저감 방안을 제시함으로써, 장비 수명 연장 및 공정 수율 향상에 기여할 수 있는 기초적인 자료로 활용될 수 있을 것으로 기대된다.

Silicon Carbide based Devices for Power and Biomedical Applications : Silicon Carbide based Devices for Power and Biomedical Applications

이태섭 광운대학교 2016 국내석사

탄 화규소 (Silicon carbide, SiC)는 고에너 지갭 반 도체이 며, 규소 (Silicon, Si)와 다른 반도 체들에 비 해 높은 임계 전계 , 높은 열 전도율 을 가진 다. 이 로 인하 여 SiC는 고 온에서 동작가 능하고 전력 및 고주파 소 자에 적용 가능 하다 . 고전 압용 쇼트키 다이 오드 (Schottky diode, SBD) 제 작을 위해서 edge termination 구조 설 계가 필수 적이며 , 다이 오드 가장 자리 의 전계 집중 현상을 감 소시켜 높 은 항 복전 압을 얻을 수 있는 구조 이다 . 규 소 (Silicon, Si)는 생 명의학 분야 소자 에서 독 성을 가지고 있는 것으로 알 려져 있다 . 또 한, 규 소는 전해 질 용액 등 에서 독 성이 있는 silica, silicate를 형성한 다. 탄화 규소는 생 체 적 합성 ,무 독성 , 기계 적 강도 및 열 적·화 학적 안정 성과 같 은 특성으로 생 명의학 분야의 소자 에도 많 은 장점을 가지고 있 다. 3-aminopropyltriethoxisilane (APTES)는 SiC와 biotin 분자 의 연 결자 (linker)로 사용 되며 , DNA와 같은 생체 분자들 은 biotin streptavidin 시 스템에 쉽 게 결합 할 수 있 다. 생물의 학 소 자를 위한 Biotin-streptavidin 시 스템을 이용하 기 전 , SiC 표 면에 APTES층을 형성 하여 특성 을 분 석하는 연구 가 필요하 다. SiC-APTES 표면은 Fourier transform infrared spectroscopy (FTIR) 및 atomic force microscopy (AFM)을 이용 하여 분석하 였으며 , current-voltage (I-V) 분 석을 통하여 소자 를 평가하 였다 . APTES 자가 조립 단층 박막 (self-assembled monolayer, SAM)을 형성 한 경 우, 다이 오드 테스트 구조에서 는 순 방향 전류가 약 6 order 감소 하였다 . APTES SAM은 절 연체 와 같은 특성을 나타냈 으며 , APTES SAM 형성 후, 전도 도 (conductivity)는 감소 하였다 . SiC is a wide band gap semiconductor which has excellent properties compared with Si or other semiconductors such as high critical field, high thermal conductivity. For high-voltage Schottky diodes (SBDs), it is necessary to have an edge termination around the periphery of the diodes to reduce the electric field crowding at the diode edges. We have fabricated 1.2 kV SiC SBDs utilizing a double junction termination extension structure. This work presents the design considerations, the ion implantation process, and characterization results for 1.2 kV SiC SBDs. Si has been shown cytotoxicity in biomedical devices, mostly due to its instability in aqueous solutions with subsequent formation of silica and silicates, which are toxic. SiC is an attractive semiconductor for biomedical devices, due to its excellent biocompatibility, non-toxicity, mechanical robustness, thermal stability and chemical inertness. The 3- aminopropyltriethoxisilane (APTES) functionalized SiC surface can be used as a linker layer to bond biotin molecules to SiC. Biomolecules such as DNA can be easily biotinylated and bound to streptavidin. An understanding of how the APTES bind to the SiC surface is essential before employing the biotinstreptavidin system for biomedical device characterization. The SiC-APTES functionalized surface has been studied using Fourier transform infrared spectroscopy (FTIR) and atomic force microscopy (AFM), and the characterization study includes measurement of current-voltage (I-V). The current of the diode test structure was decreased by about 6 orders with the APTES. The dielectric behavior of the self-assembled monolayer (SAM) was further investigated from the I-V curves under forward bias, where a drop in conductivity was observed after the deposition of APTES SAM.

Atomic Force Microscopy-based Micro- / Nano-Scale Patterning and Analysis of Silicon Carbide

조영득 광운대학교 2010 국내석사

탄화규소 (SiC)는 높은 열전도성, 화학적 비반응성, 항복 전압을 갖는 고에너지밴드갭 반도체이다. 그뿐만이 아니라 탄화규소는 열산화가 성장가능한 유일한 화합물 반도체 중 하나이다. 그러므로 탄화규소는 고압, 고온, 고주파 등의 여러가지 중요한 응용분야에서 각광받고 있다. 최근 원자힘현미경 (atomic force microscopy)을 근간으로 하는 리쏘그래피 기술은 실리콘 표면의 국소산화 (local oxidation)에서 유용함을 보여주고 있다. 지금까지 딥-펜 나노 리쏘그래피 (dip-pen nano lithography), 국소양극산화 (local anodic oxidation)와 다른 기술들은 복합적인 나노구조물의 표면 변경을 위해 발전해왔다[1, 32]. 그러나 원자힘현미경으로 특히, 4H-탄화규소 표면패터닝을 조사한 연구는 보고되지 않았다. 탄화규소와 같은 고에너지밴드갭 물질의 원자힘현미경 국소산화 (AFM-LO)는 물리적 강성과 화학적 비반응성으로 인해 일반적으로 매우 어렵다. 여기서는 가열, 화학약품, 광조사 등이 필요없는 발전된 4H-탄화규소의 원자힘현미경 국소산화를 보고한다. 높게 도핑된 (~ 1019 cm-3) 탄화규소에 ~ 100 nN 정도 증가시킨 탐침의 인가하중 (loading force)은 음이온 (OH-) 이동을 위한 전계를 충분히 높게 생성시켜 (~ 107 V/cm) 4H-탄화규소에 산화생성 (~ 16 nm) 을 일으킨다. 2차원 시뮬레이션으로 탐침과 시료 구조물의 도핑농도와 전계분포를 분석했다. 또한 다양한 면방향 (a-, m-, and c-plane)과 스캔속도 (~ 1 ~ 8 μm/s) 조건에서 국소산화생성을 연구했다. 추가적으로 켈빈탐침력현미경 (Scanning Kelvin Probe Microscopy)을 이용하여 나노크기의 패턴된 탄화규소 구조물의 표면전위와 표면형태를 측정하였다. 측정된 결과는 백금 (Pt)으로 도금된 탐침을 사용했다. 표면에서 자동적으로 측정된 전위차이는 물질의 본질적인 (intrinsic) 일함수가 아닌 표면의 국소적인 전자밀도를 반영하는 것으로 가정되었다. 나노크기로 패턴된 탄화규소 산화 구조물의 일함수 는 본래의 탄화규소 표면의 일함수보다 낮은 것을 알 수 있었다. 이러한 결과로 산화물 / 탄화규소의 일함수와 장벽높이 차이를 확인할 수 있다. Silicon carbide (SiC) is a wide band gap semiconductor which reveals high thermal conductivity, chemical inertness and high breakdown. In addition, SiC is the only compound semiconductor on which thermal oxide can be grown. Therefore SiC has advantages for many important applications such as high power, high temperature, and high frequency applications. Recently, atomic force microscopy (AFM)-based lithography has been shown to be useful in local oxidation of Si surface. So far, dip-pen nano lithography, local anodic oxidation, and other techniques have been evolved to modify the surface of complex nanostructures [1, 32]. However, there has been no report which specifically examines the surface patterning of 4H-SiC by AFM. Atomic force microscopy-based local oxidation (AFM-LO) of wide bandgap semiconductors, such as SiC, is extremely difficult in general, mainly due to their physical hardness and chemical inactivity. Here, we report strongly enhanced AFM-LO of 4H-SiC at room temperature without the necessity of using heating, chemicals or photo-illuminations. It is demonstrated that the increased tip loading force (~100 nN) on a highly-doped (~ 1019 cm-3) SiC can produce a high enough electric field under the cathode tip (~ 107 V/cm) for transporting oxyanions (OH-) and thereby leading direct oxide growth (up to ~ 16 nm) on 4H-SiC. The doping concentration and the electric field profile of the tip-SiC sample structures have been further examined by 2-dimensional numerical simulations. Moreover, we investigated the local oxide growth on 4H-SiC for various plane orientations (a-, m-, and c-plane) and scan speeds (~ 1 ~ 8 μm/s). In addition, the surface potential and topography distributions of nano-scale patterned structures on SiC were measured at a nanometer-scale resolution using a scanning kelvin probe force microscopy (SKPM). The measured results were calibrated using a Pt-coated tip. It is assumed that the atomically resolved surface potential difference is not originated from the intrinsic work function of the materials but reflects the local electron density on the surface. It was found that the work function difference of the nano-scale patterned oxide structures on SiC is lower than that of original SiC surface. The results confirm the concept of the work function and the barrier heights of oxide structures / SiC structures.

Analysis and Control of Deep Level Defects in Ga2O3/4H-SiC Heterojunction Diodes

변동욱 광운대학교 일반대학원 2023 국내석사

전력 전자 장치는 재생 에너지 기술과 전기자동차, AI의 연구 개발로 인해 고전압, 고효율 전력이 필요시 되고 있다. 향후 10년 이내에 전기 에너지가 80% 까지 증가할 수 있다고 추측되고 있으며, 1세대 전력 반도체 재료 실리콘(Si)은 여전히 많은 곳에서 사용되고 있지만, 고전압, 고주파수 그리고 고온에서의 더 안정적인 작동을 위해서 차세대 재료의 개발이 필요하다. 이에 따라 넓은 밴드갭 시장에서 전력 반도체 재료로 탄화규소(SiC), 질화갈륨(GaN), 산화갈륨(Ga2O3)을 포함하는 신세대 광대역 갭 반도체 재료에 많은 연구가 되고 있다. 널은 밴드갭 물질 중 산화갈륨은 UWBG(Eg = ~4.8 eV)와 강한 방사선 경도, ~8 MV/cm의 높은 이론적인 전계 덕분에 심층 자외선(DUV) 광검출기와 고출력 무선 주파수(RF) 전자공학에 유망한 후보이다. 또한 산화갈륨 단결정은 대면적 웨이퍼를 사용하여 생산할 수 있는 능력이 있어 저비용 성장기술의 도움을 받아 상업적으로 가격 경쟁력이 있다고 보고되고 있다. 하지만 낮은 열전도율 (11~27 W/m³K)로 인해, 산화갈륨을 적용한 애플리케이션에서는 고출력의 열화와 고강도 빛에 의한 자기 발열 효과로 인해 소자의 성능 및 신뢰성이 저하될 수 있다. 이를 관리하기 위해 열관리가 필요한 영역에 높은 열전도성 물질을 접합시켜 열제거를 개선하는 방법이 있다. 예를 들어, SiC 및 Si과 Ga2O3의 이종접합구조는 특히 낮은 열전도성을 개선하기 위해 제안되었으며, Si 및 다이아몬드에 비해 격자 불일치(~1.3%)가 낮은 SiC 상의 Ga2O3는 낮은 전위의 밀도를 통해 더 높은 장치 성능을 초래하기 때문에 큰 관심을 끌고 있다. 산화갈륨에 대한 다양한 연구 노력으로 설계와 공정을 통한 고전압화가 실현되었지만, 그럼에도 불구하고 여전히 몇 가지 과제를 안고 있다. 심층 트랩은 전하 캐리어를 trapping 함으로써 장치의 성능에 부정적인 영향을 미칠 수 있으며, 결과적으로 소수 캐리어 수명이 감소하고 누출 전류가 증가할 수 있다. 따라서 결함의 본질과 내재적 빈 공간(VGa, VO), 불순물, 중간 또는 치환된 원자 및 이들의 복합체 등의 다른 특성을 이해하는 것이 필수적이다. Ga2O3와 같은 광대역 갭 반도체 물질을 자주 포함하는 고출력 애플리케이션에 사용되는 장치에서 심층 결함의 식별 및 제어가 특히 중요하다. 본 연구에서는 공정에서 발생하는 Ga2O3/4H-SiC 이종접합의 깊은 준위결함과 이들에 대한 특성을 측정 및 분석하였다. 또한 이러한 유형의 결점을 제어하는 방법을 연구했다. VO와 FeGa는 Ga2O3/4H-SiC의 대표적인 본질적 결함이다. 깊은 준위 결함은 공정에 부정적인 영향을 미치며 소자 성능의 주요 요인인다. 이 때문에 제조과정에서 깊은 준위 결함의 특징 변화 및 특성을 DLTS로 분석하여 소자 성능 개선을 위한 공정 조건을 연구하였다. Power electronics are playing an increasingly important role due to the rapid adoption of renewable energy technologies and the trend towards electrification of end-uses. More than 30% of electrical energy passes through power electronics today with speculation that in the next decade this could grow to 80%. The first-generation power semiconductor material silicon (Si) is still used in many places, but technological limitations require next-generation materials to substitute silicon. As a result, the wide bandgap market has the potential to grow. The use of Si as a power semiconductor material is giving way to a new generation of wide-bandgap semiconductor materials including silicon carbide (SiC), gallium nitride (GaN), and gallium oxide (Ga2O3). Among these materials, Ga2O3 is a promising candidate for deep-ultraviolet (DUV) photodetectors, and high power radio frequency (RF) electronics thanks to its UWBG (Eg = ~4.8 eV), strong radiation hardness, and high theoretical electrical breakdown field of ~8 MV/cm. The Ga2O3 single crystals have the abil-ity to be produced using large area wafers, making them commercially cost com-petitive with the help of low-cost growth techniques. However, Ga2O3 poses a challenge in low thermal conductivity conditions (range of 11–27 W/m‧K), potentially causing low performance and reliability in devices due to thermally accelerated degradation at high power and the self-heating effects with high-intensity light. To manage this, one approach is to place high thermal conductivity materials in close proximity to regions needing thermal management to improve heat removal by spreading it. For example, the hetero-structures of Ga2O3 on SiC and on Si have been proposed to improve their low thermal parameters in particular, Ga2O3 on SiC with its low lattice mismatch (~1.3 %) compared to Si and diamond has attracted keen interest because it re-sults in higher device performance by means of a low density of dislocations. Despite various efforts of researches in Ga2O3, withstanding high voltage and frequency application through design and process has been realized, it still has several challenges. Deep level traps can negatively affect the performance of de-vices by trapping charge carriers, resulting in a reduced minority carrier lifetime and increased leakage current. Consequently, it is essential to understand the na-ture of defects and others characteristics such as intrinsic vacancies (VGa, VO), impurities, interstitial or substituted atoms and their complexes. Identifying and controlling deep level defects is especially important in devices used for high-power applications, which frequently contain wide-bandgap semiconductor mate-rials such as Ga2O3. In this study, we measured the electrical and material properties of Ga2O3/4H-SiC heterojunction and defects occurring with the process. We also studied how to control these types of defects. VO and FeGa are the representative intrinsic de-fects of Ga2O3/4H-SiC. These defects have a significant effect at the fabrication process and are important factors in device performance. Therefore, we investi-gated the deep level defects that detected in the manufacturing process and sug-gest that the electrical properties and characteristics of the deep level defects in Ga2O3 can control with annealing process using by deep level transient spectros-copy (DLTS). In detail, the post-annealing process conditions with nitrogen could improve conductivity, and oxygen annealing could make insulating properties. This means that the annealing process in different atmospheres could affect the deep-level trap properties as well as conductance properties by influencing the morphology and crystallinity, suggesting that both may be closely related.

Three-dimensional architecture of graphene

박지훈 성균관대학교 일반대학원 2014 국내박사

육각형 모양의 탄소 원자들의 배열로 이루어진 2차원 단층 구조의 그래핀은 지난 세기동안 가장 영향을 준 발견 중의 하나가 되었다. 그래핀은 분수 양자홀 효과, 질량 없는 디락 페르미온, 선형 에너지 분산과 같은 독특한 성질을 가지고 있다. 그래핀에 대한 초기 연구의 대부분은 물리학, 화학, 재료 공학 분야에서 고유 성질에 대한 연구에 집중되었었고, 평면구조의 기판위에서 그래핀의 성장과 제조에만 한정 되어 왔었다. 하지만 실제 전자 장비에 그래핀을 응용되기 위해서는 그래핀 제작에 대한 다른 제어 방법이 요구 될 것이다. 그중의 한가지가 2차원 평면 구조를 가진 그래핀의 3차원 건축화이다. 이 논문에서는 화학 증기 증착 방법에 의한 그래핀의 3차원 건축화로써 (I) PMMA 제거의 일반적인 화학적 처리 과정없이 PMMA의 깨끗한 제거가 한 단계 열 처리 과정에 의해 성취되었다. 이 방법은 전처리 된 기판으로의 전이 과정에서 발생할 수 있는 그래핀의 표면으로부터의 찢어짐과 분리됨을 감소시킨다. (II) 그래핀-이산화 규소(SiO2) 라미네이트가 다양한 오목-볼록 구조의 이산화 규소를 사용하여 성공적으로 제작되었다. 볼록 구조의 이산화 규소 위에 있는 그래핀은 윗면 가장자리 근처에서 최대값을 가지는 변형을 받았고, 변형은 윗면의 가장자리와 비교했을 때 경사면에서 감소했다. 그래핀의 변형과 관련된 볼록구조에서의 그래핀의 면 저항은 구조에 의해 조절 되었다. 탄화규소(SiC) 위에서 에픽택셜 그래핀의 3차원 건축화로써, (III) 초탄성효과를 가진 독립적인 3차원 단결정의 그래핀이 탄화규소의 사용을 통한 설계 방법에 의해 성취되었다. 3차원으로 설계된 탄화규소 기판은 단순하고 명쾌한 한 단계 열적 과정에 의해 마이크로에서 나노 규모로 조절 될 수 있는 탄화규소 위에 구조를 유지한채, 독립적인 3차원 단결정의 그래핀으로 변환 되었다. 그것은 기판 규모로 크기를 증가할 수 있다. 독립적인 3차원 그래핀 구조는 매우 AFM에 의한 관측에 의해 외부에 의한 탄성 변형 후에도 기계적으로 지속가능하다. Graphene which is a single two-dimensional (2D) layer of carbon atoms arranged in a hexagonal lattice structure, has become one of the most influential discoveries of the last century. Graphene has unique property, such as half-integer quantum Hall effect, massless Dirac fermions, and linear energy dispersion. Most of the initial research has focused on the research for the intrinsic property of graphene in physics, chemistry, and materials science and growth methods and fabrications of graphene have limited on flat substrates. However, defferent controlled methods for its fabrication will be required to apply graphene in actual electronic devices. One of them is three-dimensional architecture of graphene which is two-dimensial planar structure. In this thesis, as the three-dimensional architecture of graphene by chemical vapor deposition, (I) The clean removal of PMMA was achieved by a single heat-treatment process without the chemical treatment that was adopted in other methods of PMMA removal. This method reduces to tear and separate from the surface of graphene which can be occurred in the transfer process onto prepatterned substrate. (II) 3D graphene-SiO2 laminates were successfully fabricated using various SiO2 concave-convex architectures. The graphene on the convex SiO2 architecture was strained, with a maximum value near the edge of the top face, and the strain was reduced at the inclined plane compared to that on the top face. The sheet resistivity of the graphene on the convex architecture, which is related to the strain of the graphene, was further controlled by its geometry. As the three-dimensional architecture of epitaxial graphene on SiC, (III) A freestanding 3D single-crytal graphene architecture with superelasticity was achieved in a designed manner using silicon carbide. 3D designed silicon carbide wafer was transfomed into a freestanding 3D single-crystal graphene architecture simply and brilliantly by a single-step thermal process, maintaing the overall silicon carbide structure that can be controlled from the mirco to nano scale, which can be scaled up to a wafer scale. The freestanding 3D graphene arcitechture was very mechanically sustainable even after external elastic (or plastic) deformations, as observed by atomic force mircroscopy.