• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.17-20
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• 2001

Nonvolatile semiconductor memory devices with reoxidized nitrided oxide(RONO) gate dielectrics were fabricated, and nitrogen distribution and bonding species which contribute to memory characteristics were analyzed. Also, memory characteristics of devices depending on the anneal temperatures were investigated. The devices were fabricated by retrograde twin well CMOS processes with $0.35{\mu}m$ Nonvolatile semiconductor memory devices with reoxidized nitrided oxide(RONO) gate dielectric were fabricated, and nitrogen distribution and bonding species which contributing memory characteristics were analyzed. Also, memory characteristics of devices according to anneal temperatures were investigated. The devices were fabricated by $0.35{\mu}m$ retrograde twin well CMOS processes. The processes could be simple by in-situ process of nitridation anneal and reoxidation. The nitrogen distribution and bonding state of gate dielectric were investigated by Dynamic Secondary Ion Mass Spectrometry(D-SIMS), Time-of-Flight Secondary Ion Mass Spectrometry(ToF-SIMS), and X-ray Photoelectron Spectroscopy(XPS). Nitrogen concentrations are proportional to nitridation anneal temperatures and the more time was required to form the same reoxidized layer thickness. ToF-SIMS results show that SiON species are detected at the initial oxide interface and $Si_{2}NO$ species near the new $Si-SiO_{2}$ interface that formed after reoxidation. As the anneal temperatures increased, the device showed worse retention and degradation properties. These could be said that nitrogen concentration near initial interface is limited to a certain quantity, so excess nitrogen are redistributed near the $Si-SiO_{2}$ interface and contributed to electron trap generation.

• Macromolecular Research
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• 제14권2호
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• pp.205-208
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• 2006

A polymeric film of a biodegradable poly(1,5-dioxepan-2-one) (PDXO) was formed on a gold surface by a combination of the formation of self-assembled monolayers (SAMs) presenting hydroxyl groups and the surface-initiated, ring-opening polymerization (SI-ROP) of 1,5-dioxepan-2-one (DXO). The SI-ROP of DXO was achieved by heating a mixture of $Sn(Oct)_2$, DXO, and the SAM-coated substrate in anhydrous toluene at $55^{\circ}C$. The resulting PDXO film was quite uniform. The PDXO film was characterized by polarized infrared external reflectance spectroscopy, X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, atomic force microscopy, ellipsometry, and contact angle goniometry.

• 한국광물학회:학술대회논문집
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• 한국광물학회.한국암석학회 2005년도 공동학술발표회 논문집
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• pp.50-57
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• 2005

Although the bulk composition of materials is one of the major considerations in extractive metallurgy and environmental science, surface composition and topography (edges and dislocations are preferred sites for physicochemical reactions) control surface reactivity, and consequently play a major role in determining metallurgical phenomena and pollution by heavy metals and organics. An understanding of interaction mechanisms of different chemical species with the mineral surface in an aqueous media is very important in natural environment and metallurgical processing. X-ray photoelectron spectroscopy (XPS) has been used as an ex-situ analytical technique, but the material to be analyzed can be any size from $100{\mu}m$ up to about 1 cm. It can also measure mixed solids powders, but it is impossible to ascertain the original source of resulting x-ray signals where they were emitted from, since it radiates and scans the macro sample surface area.

• 한국진공학회:학술대회논문집
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• 한국진공학회 1999년도 제17회 학술발표회 논문개요집
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• pp.203-203
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• 1999

Mass spectrometry technique provides the molecular weight distribution, data on the sequence of repeat units, polymer additives, and impurities, and structural information. time-of-Flight secondary Ion Mass Spectrometry (TOF-SIMS) has been used for structural characterization of various polymers1-2. the masses of repeat units and terminal groups and molecular weight distributions of polymers have been determined from their TOF-SIMS spectra. TOF-SMIS provides good sensitivity and structural specificity for high mass ions so that intact oligomers and large polymer fragments are observed. In this study, we investigated the detailed structural information on the oligomers and fragment ions of branched poly(1,3-butylene adipate) and branched poly[di(ethylene glycol) adipate] and the transesterification products of branched polyesters with trifluoroacetic acid or chloro difluoroacetic acid. Branched polyesters were chosen because they are important polymers but difficult to characterize; thus branched polyesters provide challanging test for TOF-SIMS. TOF-SIMS spectra of polyesters are obtained from thin polymer films cast from solution on a silver substrate. A good solvent for a polumer solution disrupts intermolecular forces between polymer chains but leaves the polumer intact. Transesterification reactions are potentially useful for characterization of high molecular weight and intractable polyesters. Transesterification products of polyesters and trifluoroacetic acid or an integral number of polyester repeat units and an additional diol. The progress of such reactions was monitored using peak intensities of reactants and products in TOF-SIMS spectra. The increasing abundance of tagged ions indicates that the reaction has progressed with time.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2000년도 제18회 학술발표회 논문개요집
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• pp.170-170
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• 2000

Synthetic polymers such as polyimide, polycarbonate, and poly(methyl methacrylate) are long chain molecules which consist of carbon, hydrogen, and heteroatom linked together chemically. Recently, polymer surface can be modified by using a high energy ion beam process. High energy ions are introduced into polymer structure with high velocity and provide a high degree of chemical bonding between molecular chains. In high energy beam process the modified polymers have the highly crosslinked three-dimensionally connected rigid network structure and they showed significant improvements in electrical conductivity, in hardness and in resistance to wear and chemicals. Polyimide films (Kapton, types HN) with thickness of 50~100${\mu}{\textrm}{m}$ were used for investigations. They were treated with two different surface modification techniques: Plasma Source Ion Implantation (PSII) and conventional Ion Implantation. Polyimide films were implanted with different ion species such as Ar+, N+, C+, He+, and O+ with dose from 1 x 1015 to 1 x 1017 ions/cm2. Ion energy was varied from 10keV to 60keV for PSII experiment. Polyimide samples were also implanted with 1 MeV hydrogen, oxygen, nitrogen ions with a dose of 1x1015ions/cm2. This work provides the possibility for inducing conductivity in polyimide films by ion beam bombardment in the keloelectronvolt to megaelectronvolt energy range. The electrical properties of implanted polyimide were determined by four-point probe measurement. Depending on ion energy, doses, and ion type, the surface resistivity of the film is reduced by several orders of magnitude. Ion bombarded layers were characterized by Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS), XPS, and SEM.

• 한국전기전자재료학회논문지
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• 제37권2호
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• pp.148-153
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• 2024

As complementary metal-oxide semiconductor (CMOS) is scaled down to achieve higher chip density, thin-film layers have been deposited iteratively. The poor film uniformity resulting from deposition or chemical mechanical planarization (CMP) significantly affects chip yield. Therefore, the development of novel fabrication processes to enhance film uniformity is required. In this context, high-pressure deuterium annealing (HPDA) is proposed to reduce the surface roughness resulting from the CMP. The HPDA is carried out in a diluted deuterium atmosphere to achieve cost-effectiveness while maintaining high pressure. To confirm the effectiveness of HPDA, time-of-flight secondary-ion mass spectrometry (ToF-SIMS) and atomic force microscopy (AFM) are employed. It is confirmed that the absorbed deuterium gas facilitates the diffusion of silicon atoms, thereby reducing surface roughness.

• 한국전기전자재료학회논문지
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• 제24권8호
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• pp.674-677
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• 2011

The dependency of sputtering power on the electrical performances in amorphous HIZO-TFT (hafnium-indium-zinc-oxide thin film transistors) has been investigated. The HIZO channel layers were prepared by using radio frequency (RF) magnetron sputtering method with different sputtering power at room temperature. TOF-SIMS (time of flight secondary ion mass spectrometry) was performed to confirm doping of hafnium atom in IZO film. The field effect mobility (${\mu}FE$) increased and threshold voltage ($V_{th}$) shifted to negative direction with increasing sputtering power. This result can be attributed to the high energy particles knocking-out oxygen atoms. As a result, oxygen vacancies generated in HIZO channel layer with increasing sputtering power resulted in negative shift in Vth and increase in on-current.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2002년도 추계학술대회 논문집 Vol.15
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• pp.240-243
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• 2002

반도체 소자의 고속화， 고접적화에 따라 집적회로의 최소 선폭이 감소할수록 device 의 신호지연, 잡음 및 전력소모 등이 증가하는 문제점이 있다. 이러한 문제점을 개선하기 위해서 저유전율의 층간 절연막이 절대적으로 필요하다. 본 실험에서는 KrF laser 조사를 이용한 표면개질 방법으로 다공성 절연막의 박막특성의 향상을 시도하였다. 다공성 절연막을 층간 절연막으로 응용할 경우 반도체 공정 적용성을 향상시키기 위하여 다공성 절연막의 표면개질이 필요하다. 표면개질 전후의 유전율 변화는 박막을 MIM구조로 측정하였고 화학 구조의 변화는 time-of flight secondary ion mass spectrometry(TOF-SIMS)를 이용하여 관찰하였다. 다공성 실록샌 물질의 pore로 인해서 생긴 누설전류 및 흡습 문제를 개선시키고 유전율을 감소시킬 수 있는 것을 알 수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.59.1-59.1
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• 2015

In the Linford group at Brigham Young University we have recently developed three new sets of materials for three different areas of separations science: thin layer chromatography (TLC), high performance liquid chromatography (HPLC), and solid phase microextraction (SPME). First, via microfabrication we have grown patterned carbon nanotube (CNT) forests on planar substrates that we have infiltrated with inorganic materials such as silicon nitride. The coatings on the CNTs are conformal and typically deposited in a process like low pressure chemical vapor deposition. The resulting materials have high surface areas, are porous, and function as effective separation devices, where separations on our new TLC plates are typically significantly faster than on conventional devices. Second, we used the layer-by-layer (electrostatically driven) deposition of poly (allylamine) and nanodiamond onto carbonized poly (divinylbenzene) microspheres to create superficially porous particles for HPLC. Many interesting classes of molecules have been separated with these particles, including various cannabinoids, pesticides, tricyclic antidepressants, etc. Third, we have developed new materials for SPME by sputtering silicon onto cylindrical fiber substrates in a way that creates shadowing of the incoming flux so that materials with high porosity are obtained. These materials are currently outperforming their commercial counterparts. Throughout this work, the new materials we have made have been characterized by X-ray photoelectron spectroscopy, time-of-flight secondary ion mass spectrometry, scanning electron microscopy, transmission electron microscopy, etc.

• 한국광물학회지
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• 제18권2호
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• pp.127-134
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• 2005

금속제련공학 및 환경과학 분야에 있어서 물질전체를 구성하고 있는 화학적 조성이 중요한 요소이나, 입자 표면의 화학조성과 미분화된 입자들의 표면 반응성을 제어함과 동시에, 입자 계면에서 일어나는 중금속과 유기물질등의 반응은 제련공정과 환경오염에 중요한 역할을 한다. 그러므로, 수용액상에 존재하는 여러 종류의 화학 물질과 광물입자 표면 사이에서 일어나는 계면반응 과정의 이해는 상당히 중요한 것이다. 일반적으로 입자 표면 분석에는 ex-situ 법을 사용하는 X-ray photo-electron spectroscopy (XPS) 분석 방법이 많이 적용되고 있으나, 이는 분석대상시료의 크기가 보통 100 마이크론에서 1 cm 정도의 범위 안에 혼재-혼합되어있는 고체 입자들을 분석하기 때문에 채취 분석된 X-ray의 원래 발산한 입자표면을 분석할 수는 없다. 그래서 본 연구에서는 Time-of-Flight Secondary-Ion Mass Spectroscopy (TOF-SIMS)를 응용하여 황화광물의 부유선광 공정 중 생성된 미세한 유화광물입자$(30\~75\;microns)$ 표면에 형성된 무기, 유기물의 반응 관찰을 통해 이들의 정성분석 및 상대적 정량분석법을 연구하고자 하였다.