다공질 실리콘 산화막의 형성기구 및 계면특성

최복길 公州大學校工科大學生産技術硏究所 1993 論文集 Vol.1 No.-

HF용액내에서 양극 반응에 의해 형성된 다공질 실리콘층(PSL)의 특성을 조사하고 다공질 실리콘 산화막(OPS)의 형성 기구와 계면 특성을 규명하였다. SIMS분석을 통한 PSL의 밀도는 표면보다 PSL-Si 계면이 높으며 산화 반응이 PSL의 표면 및 내부의 세공 표면에서 균일하게 이루어진다. OPS막은 열산화 Sio₂에 비해 큰 프랫밴드 전압과 고정 전하 밀도를 나타내며 dlts법으로 측정한 OPS막의 포획 단면적과 계면 상태 밀도는 각각 10?㎠와 10?-10?eV?의 범위이다. The properties of porous silicon layer(PSL) formed by anodic reaction in hydroffluoric acid solution have been studied. Ferther, the formation mechanism and interface characteristics of oxidized porous silicon(OPS) film are reported. It is shown from SIMS analysis that the porous silicon nera the surface has a lower density than that near the PSL-substrate interface and that oxidation is performed uniformly through PSL. OPS film shows higher flat-band voltage and fixed charge density than thermally grown SiO₂ film. The capture cross-section and the interface states density of OPS film determined by DLTS method are of the order of 10?㎠ and 10??-10??cm?eV?? respectively.

LPCVD로 성장시킨 다결정 실리콘막의 전기적 특성에 미치는 열처리 효과

최복길,이규대 公州大學校工科大學生産技術硏究所 1996 論文集 Vol.5 No.-

Polycrystalline silicon films deposited by LPCVD have various applications and great importance as a base material to fabricate active elements in microelectronic technology. Recently, polycrystalline Si is widely used to obtain electrical and mechanical structures in surface micromachined microelectromechanical system(MEMS). For example, micro beam and cantilever made by polycrystalline silicon is needed to have low tensile strain and resistivity distribution. The variations of strain distribution and resistivity according to the process conditions such as deposition temperature, dopant concentration and annealing cycle will be studied in this paper. The aim of study is to determine process conditions able to meet the structural requirements for surface micromachined MEMS. The semi-amorphous Si films are first deposited by LPCVD and in-situ annealed at 600℃ for 1h to ensure the desired electrical and mechanical characteristics for doped and undoped sample. The best results have been obtained from post-implantation annealing at 850℃ for 30min which is used to activate the dopant. High doping concentration(1×10cm) reduced the stress.

다공질 실리콘 센서를 이용한 알코올 용액의 농도 측정

최복길,김성진 公州大學校工科大學生産技術硏究所 1999 論文集 Vol.7 No.-

A capacitance-type sensor using porous silicon layer was developed to measure aqueous alcohol concentration. Since alcohol, so called ethanol, is very permeable into the silicon wafer, it is often used to help chemical reaction when the silicon wafer is processed under some aqueous solution. In this work, the sensing property was measured for the alcohol concentration from zero to near 100 percent with two types of samples with porous silicon layer formed in 25 and 35% HF solution, respectively. Good reliability as well asw fast response time and good linearity were shown over 10㎑, and the measured capacitance was observed to be inverse to alcohol concentration due to the decrease of the whole dielectric constant in porous silicon layer.

α-Fe₂O₃ thermistor의 전기적 특징에 미치는 계면효과

최복길 공주대학교 기초과학연구소 1992 論文集 Vol.30 No.1

The dependence of capacitance on measuring temperature, I-V, C-V, and DLTS properties have been measured on polycrystalline samples of α-Fe2O3 containing small amounts of added titanium. The effects of grain boundary states on the electrical conduction mechanism in the ceramic semiconductor oxides have been investigated. The NTC mechanism of thermistor can be explained by the model of double Schottky barrier at the grain boundary with hopping conduction. It is found from DLTS measurement that interface states exist in the grain boundary and have an effect on electrical conduction. From these experiments we can suppose that trapping and detrapping of carier at the grain boundary states to temperature variation may be a major cause of NTC mechanism of α-Fe2O3 thermistor containing N-type impurities.

일측 자골신경의 절단 및 재연결 후 흰쥐 척수에서 신경세포 접착분자(NCAM)의 면역조직반응의 변화에 관한 형태학적 연구

황세진,전복관,안동춘,조원길,김승현 대한신경과학회 1999 대한신경과학회지 Vol.17 No.1

경북 지역의 지하수 수질에 관한 연구 2 : 깊이에 따른 지하수의 상태에 관한 연구 Study on he State of Ground Water by the Depth

한성욱,김복조,이길준 경운대학교 산업기술연구소 2000 産業技術硏究論文誌 Vol.3 No.1(B)

We investigated the contamination of ground water in Kyungbuk region about 87 points by the depth. The obtained results were as follows; 1. It was showed that nitrate nitrogen is highest and Cl^- is lowest for life used. 2. It was showed that nitrate nitrogen concentration is high in adjacent region of nightsoil treatment plant, COD is high in specific waste landfill and electric conductivity is high in golf field. 3. It showed that the relationship between depth and pH and nitrate nitrogen is good. pH is increased and nitrate nitrogen is decreased according to the depth.

바나듐 산화막을 활용한 습도센서의 제조에 관한 연구

이승철,최복길,김남철 公州大學校 工學硏究院 生産技術硏究所 2004 論文集 Vol.12 No.-

Vanadium oxides have been widely used in a variety of technological applications such electrochromic devices as infrared detectors and are expected as a material suitable for gas sensing applications. Thin films of Vanadium oxide (VOx) have been deposited by r.f magnetron sputtering under different oxygen partial pressure ratios(0%, 10%) and substrate temperatures(27℃, 400℃). Humidity-sensitive properties of resistive sensors having interdigitated electrode structure are characterized. Our sensors show good response to humidity over 20%RH to 80%RH Vanadium oxide films deposited with 0%O2 partial pressure at 400℃ exhibit greater sensitivity to humidity change than others.

Ellipticine과 그 이성질체들에 대한 분자궤도함수론적 연구

한성욱,이길준,김복조 경운대학교 산업기술연구소 2002 産業技術硏究論文誌 Vol.5 No.1(B)

Molecular orbital studies were carried out for the ellipticine and its isomers, known as having antitumor activity and cytotocity, by semiemperical PM3. Electrostatic potential studies have shown that the most reactive site of proton attacks was the nitrogen atom in carbazol ring. The net charge of the nitrogen was linearly correlated with the basicity of the isomers. We have predict the antitumor activity of the isomer by the basis of the dipole moment [suggested by Barone et.al. J. Mole. Stru.(Theochem) (1992), 253, 319]. And we have suggested that frontier orbital theory is valuable to explain for the formation of covalent adducts. These results may suggest clues that the method how to interpretate the mechanism of action for ellipticine and how to design new drugs.

스퍼터된 바나듐 산화막의 구조적, 광학적 특성에 미치는 기판 온도의 효과

이규대,최복길 公州大學校工科大學生産技術硏究所 1998 論文集 Vol.6 No.-

Thin films of vanadium pentoxide(V₂O5) have been deposited by r.f. magnetron sputtering from V₂O5 target in gas mixture of argon and oxygen. Crystal structure, surface morphology, surface composition and optical properties of films prepared under different substrates are characterized through XRD, SEM, AES, XPS and optical absorption measurements. The films prepared below 100℃ are amorphous, and those prepared above 200℃ are polycrystalline. Thermally Induced oxidation of films into higher oxide has been observed with increasing substrate temperature. Vanadium oxide films show two optical absorption bands indicating the presence of direct and indirect transitions.

비냉각 적외선 감지기용 비나듐 산화막의 전기전도기구

최용남,최복길,이규대 공주대학교 생산기술연구소 2001 論文集 Vol.9 No.-

Thin films of vanadium oxide(VO_(x)) have been deposited by r.f. magnetron sputtering from V_(2)O_(5) target in gas mixture of argon and oxygen. The oxygen/(oxygen+argon) partial pressure ratio is changed from 0% to 8%. Crystal structure, chemical composition and electrical properties of films sputter-deposited under different oxygen gas pressures have been characterized through XRD, AES, RBS and electrical conductivity measurements. All the films prepared below 8% O_(2) are amorphous, and those prepared without oxygen are gray indicating the presence of V_(2)O_(4) phase in the films. In order to measure the current-voltage characteristics and temperature dependence of conductance, devices of A1/VO_(x)/A1 sandwich structure have been fabricated. I-V characteristics are distinguished between linear and nonlinear region. In the low field region the conduction is due to Schottky emission, while at high field it changes to Fowler-Nordheim tunneling type conduction. The conductivity measurements have shown an Arrhenius dependence of the conductivity on the temperature.