접촉연소검지방식을 이용한 후막형 메탄가스센서의 제조 및 그 특성

박준식,이재석,홍성제,박효덕,신상모 경북대학교 센서기술연구소 1995 센서技術學術大會論文集 Vol.6 No.1

본 연구에서는 스크린 프린팅 기술을 이용한 병렬저항열원을 갖는 후막형 가연성 가스센서를 제조하고, 메탄가스에 대한 감도특성을 조사하였다 알루미나 기판의 양면 위에 제조된 병렬형 백금 후막발열체는 후막형 백금 저항체로 사용된 백금페이스트 온도 감지 특성과 표면 특성을 조사하여 paste A로 선정하였다. 제조된 백금 후막 발열체는 평균저항값이 1.8Ω이고, TCR값은 3685ppm/℃이었다. 제조된 백금 발열체상에 Pt과 Pd이 첨가된 촉매 페이스트를 제조하고 가지부는 Pt과 Pd가 첨가된 촉매를 스크린 프린팅하여 후막을 형성하고 열처리하여 제조하였다. 제조된 후막형 센서는 메탄가스에 대해 4.3mV/1009ppm의 감도를 보였으며, 소비전력은 2.12W이었다. We fabricated the sensors with parallel Pt heaters using screen printing process and investigated sensitivities to hydrocarbon gases. The paste A was selected as Pt paste for heater by investigated the properties of TCRs and thick film microstructures. The average resistance of parallel Pt heaters was 1.8Ω, and the best TCR obtained was 3685ppm/℃. On the top of the Pt heaters, a sensing layer added with Pt and Pd as catalyst paste was screen printed and heat treated. The sensitivity of fabricated the sensor was 4.3mV/1000ppm to methane. The power consumption of the sensors was 2.12watts

NO₂감지를 위한 SnO₂후막소자의 제조 및 그 특성

한종수,박효덕,손종락,이덕동 경북대학교 센서기술연구소 1992 센서技術學術大會論文集 Vol.3 No.1

박막형 습도센서

홍영호,박효덕,이덕동 경북대학교 센서기술연구소 1990 센서技術學術大會論文集 Vol.1 No.1

Recently there have been increasing demands for humidity-sensing elements applicable automatic humidity controlling system. There have been many reports about humidity sensors using materials such as electrolytes, organic polymers and metal oxides. Among them, those which utilize the conductivity change of metal oxides have been investigated actively. Thin film SnO_(2)/Al_(2)O_(3)/TiO_(2) devices were fabricated by evaporating the SnO_(2) powder mixed with 20.0wt% Al_(2)O_(3)and 10.0 wt% TiO_(2), and sintering them at the condition of 700℃-1hr in _(2). Analysis of FTIR indicates that water molecular act as an electron-donating gas and their chemisorption increases or decreases the electron conductivity depending on the n- or p- type. Sensing characteristics of thin film devices based on humidity-sensitive electrical properties have been investigated by response time and changes of resistance to relative humidity. Oxide filters, consisting mainly of Al_(2)O_(3) or SiO_(2) are formed on the sensors to cut off undesired sensitivity to common inflammable gases. Our experimental results suggest that metal oxide thin film can be used as humidity sensor and applicable to miniaturization and integration of sensors.

마이크로 압전 엑츄에이터용 Sol-Gel PZT 박막의 두께 변화에 따른 특성

장연태,박준식,김대식,박효덕,최승철 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

Pb가 10% 과잉되고 Zr : Ti = 52 : 48 조성을 갖는 PZT sol이Pt(3500A˚)/Ti(400A˚)/SiO2(3000A˚)/Si(525㎛)기판 위에 스핀 코팅법으로 반복 코팅된 후, 450℃에서 10분, 650℃에서 2분간 반복 열처리되었다.이와 같이 다양한 두께로 적층된 박막은 각 시편에 대해 최종적으로 650℃ 30분 동안 어닐링 처리되었다.제조된 PZT 박막의 두께는 4100A*에서 1.75㎛사이의 4종이었다.이어서 스퍼터링법으로 Pt전극이 PZT 막 위에 증착되었다.제조된 PZT 박막의 결정 구조 조사를 위해 XRD, 그리고 미세 구조 및 전기적 특성을 알아보기 위해 FESEM과 P-E 이력 곡선이 각각 관찰되었다.4100A˚에서 1.75㎛까지 두께 중가에 따른 장비상의 포화 이력 한계로 잔류 분극(Pr)값이 25A˚u C/㎠에서 다소 감소되었다.측정된 X선 회절 결과에서 최초 4회 코팅시 perovskite 결정 구조로 성장한 결정립은 (111)배향이 우세하였으나, 두께가 증가됨에 따라 (111)/(110)값이 감소되었으며, 이를 통해 두께 증가에 따른 (111)배향성이 다소 감소됨을 알 수 있었다.이상의 결과로부터 제조된 PZT 박막은 큰 힘과 높은 내전압 특성을 갖는 마이크로 압전 액츄에이터에 적용될 수 있을 것으로 생각되었다.

SnO₂/TiO₂후막형 습도센서의 제조 및 특성

이건동,이재현,박효덕,이덕동,최흥문 경북대학교 센서기술연구소 1991 센서技術學術大會論文集 Vol.2 No.1

SnO_(2) doped with TiO_(2) and other activating agents, is used as a raw material to prepare humidity sensors. SnO_(2) is an n-type semiconductor whose resistance is described as a function of relative humidity. SnO_(2)/TiO_(2) thick film humidity sensors have been fabricated by using typical silk screen printing techniques. The humidity sensitivity of SnO_(2)/TiO_(2) thick film has been investigated. And the sensing characteristics of the fabricated SnO_(2)/TiO_(2) sensors such as resistance change and response time, has been investigated from R.H.20 % to 90 %. Experimental results show that the impedance-humidity characteristics of the humidity sensors depend on the microstructure of surface roughness and pore size distribution.

집적화된 실리콘 압력센서의 출력전압 보상파라미터 추출 및 그 특성

이보나,김건년,박효덕,신상모,이경탁,김찬,권혁채,이상조,박현주 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

An integrated silicon pressure sensor has been designed, fabricated and tested. The signal conditioning circuits were designed to include calibration and temperature compensation of output voltage through trimming of diffusion and ion-implanted resistors. Before trimming of resistors, the compensation parameters such as pressure sensitivity, temperature coefficient of pressure sensitivity, temperature coefficient of piezoresistors and pressure sensitivity of piezoresistors were measured. Then offset voltage, span, and temperature coefficients of offset voltage and span were calibrated by trimming of resistors. The measured output voltage met our design specification and simulation value above room temperature. But, the measured output voltage at -30°C deviated from our design specification and simulation value because the offset voltages were found to vary randomly as a function of temperature.

바이폴라 공정으로 집적화된 압력센서 제작 및 평가

이유진,김건년,박효덕,이종홍 호서대학교 반도체제조장비국산화연구센터 2001 반도체장비학술심포지움 Vol.2001 No.-

실리콘 마이크로머시닝 기술과 바이폴라 공정으로 집적화된 압력센서를 제작하고 동작특성 평가를 수행하였다.센서부 보상파라미터를 추출하였고 트리밍 공정을 통하여 출력전압의 보상을 수행하였다.센서 특성은 압저항 위치, 마스크 정렬 오차, 다이어프램 정밀두께제어 정도, 보호막의 과도식각 정도 등에 의하여 민감하게 좌우됨을 알 수 있었다.웨이퍼별 샘플추출을 통하여 센서부 감도는 평균 0.653mV/kPa, 감도의 온도계수는 -2078.8ppm/℃, 옵셋전압은 30.78mV, 옵셋전압의 온도계수는 32.11uV/℃로 측정되었다.추출된 샘플의 다이어프램 두께오차는 27±2.5㎛였다.센서부 특성평가 결과를 통하여 신호처리회로의 옵셋 및 스팬보상, 온도보상을 위한 트리밍 공정을 수행한 결과 개발사양을 만족하는 결과를 얻을 수 있었다.

고두께 유리-실리콘의 대면적 양극접합에 관한 연구

김건년,이보나,박효덕,신상모,이근혁,권혁채 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

In this paper, we studied the anodic bonding of 5-inch silicon and #7740 Pyrex glass wafers with a thickness of 3mm by using the EV501 bonder and the Karl Suss SB6 bonder. The test conditions for anodic bonding of the EV501 bonder system with a full field electrode were temperature of 400 ℃ and voltage of 800V in a chamber pressure of 1X10^(3)mbar. The SB6 bonder with a star shaped electrode was tested at the temperature and voltage of 450 ℃ and 1300V in the atmosphere, respectively. As the results of test, we obtained the void free samples regardless of shape of substrates such as etched wafers with cavities and drilled glasses with holes.

Si Bulk Micromachining을 위한 Wafer Rolling Etching 및 그 특성

김건년,이보나,박효덕,신상모,공경준,장동근,김병철,권혁채,이봉희 경북대학교 센서기술연구소 1998 센서技術學術大會論文集 Vol.9 No.1

A wafer rolling etching system for the silicon bulk micromachining has been designed and fabricated. The silicon diaphragms were anisotropically etched in a 24.5 weight percent KOH solution. Compared to the conventional KOH etching systems, pyramidal hillocks, and wave-shaped structures on the etched surfaces were greatly reduced by using this system. After etching for time of 438 minutes, the average etched depth and the etch-rate were measured to be 537μm and 1.22μm/min, respectively. The average etching uniformity of etching depth was 0.87% in 5-inch wafer. Our results showed that the wafer rolling method enhanced etch uniformity and etch rate.

Fabrication of Piezoelectric Micro Bending Actuators Using Sol-Gel Thick PZT films

Park, Joon-Shik,Yang, Seong-Jun,Park, Kwang-Bum,Yoon, Dae-Won,Park, Hyo-Derk,Kang, Sung-Goon,Lee, Nak-Kyu,Na, Kyoung-Hoan The Korean Society Of Semiconductor Display Techno 2004 반도체디스플레이기술학회지 Vol.3 No.3

Fabrication and electrical and mechanical properties of piezoelectric micro bending actuators (PMBA) using sol-gel-multi-coated thick PZT films and MEMS processes were investigated. PMBA could be used for design and fabrication of micro fluidic devices, for example, micro-pumps, micro dispensers, and so on. PMBA were fabricated using 2 um thick PZT films on Pt (350 nm)/$SiO_2$ (500 nm)/Si ($300\mu\textrm{m}$) substrates and MEMS processes. 7 types of PMBA were fabricated with areas of silicon diaphragms, PZT films and top electrodes. When the sizes of silicon diaphragms, PZT films and Pt top electrodes were reduced from 3000$\times$$1389\mu\textrm{m}$, 4000$\times$$1000\mu\textrm{m}$ and 4000$\times$$900\mu\textrm{m}$ down to 14%, 14% and 11 % of them, respectively, the center displacements of PMBA were decreased from 0.68 um to 0.10 um at 5 Hz and 12 Vpp. So, PMBA with large areas showed larger displacements than PMBA with small areas and experimental results were also good agreement with the plate and shell theory.