DC 마그네트론 스퍼터링법에 의한 백금박막 증착과 온도센서에의 응용

정귀상,노상수,최영규 동서대학교 부설 연구소 1996 연구소 논문집 Vol.1 No.-

Platinum thin films were deposited on Al??O?? substrates by DC magnetron sputtering for RTD (resistance thermometer devices) temperature sensors. We investigated the physical and eletrical characteristics of these films under various conditions, the input power, working vacuum, temperature of substrate and also after annealing these films. At substrate temperature of 300℃, input power of 7 w/㎠, working vacuum of 4 mTorr and annealing conditions of 1000℃ and 240 min, we obtained resistivity of 10.65 μΩㆍcm closed to Pt bulk value. Pt-RTD temperature sensors were favricated by using Pt thin films which were formed under the best conditions. Al??O?? substrate, W-wire, silver epoxy and SOG(spin-on-glass). Resulted from investigating TCR(temperature coefficient of resistance) fo the Pt-RTD temperature sensors, we obtained TCR value of 3825 ppm/℃ at annealing temperature of 1000℃, time of 240 min and Pt thin films thickness of 1㎛.

SDB와 전기화학적 식각정지에 의한 마이크로 시스템용 매몰 cavity를 갖는 SOI구조의 제조

정귀상 東西大學校 2001 동서논문집 Vol.7 No.-

This paper describes a new process technique for batch fabrication of SOI(Si-on-insulator) structures with buried cavities for MEMS (micro electro mechanical system) applications by SDB (Si-wafe direct bonding) technology and electrochemical etch-stop. A low-cost electrochemical etch-stop method is used to control accurately the thickness of SOI. The cavities were maked on the upper handing wafer by Si anisotropic etching. Two wafers are bonded with an intermediate insulating oxide layer. After high-temperature annaling (1000℃, 60 min.), the SBB SOI structure with buried cavities was thinned by electrochemical etch-stop. The surface of the fabricated SDB SOI structure is more uniform that of gliding or polishing by mechanical method. This SBB SOI structure with buried cavities will provides a powerful and versatile substrate for novel microsensors and microactuators.

극한 환경 MEMS용 3C-SiC 박막의 결정 특성

정수용,정연식,류지구,정귀상,Shigehiro, Nishino 경북대학교 센서기술연구소 2002 센서技術學術大會論文集 Vol.13 No.1

수용성 TMAH 암모니아계를 이용한 실리콘 이방성 식각

정귀상,송승환,박진성,최영규 동서대학교 부설 연구소 1996 연구소 논문집 Vol.1 No.-

Si anistropic etching is a key technology for micromachining. The main advantages of teramethyl ammonium hydroxide (TMAH)-based solution are their full compatibility with IC process. In this paper, the anisotropic etching characteristics of single crystal Si in a TMAH ((CH??)??NOH) based solution was described. The influence of the adition of IPA to TMAH solution on their etching characteristics was also presented. The etching rate ratio of Si (111)/(100) is increased with increasing TMAH concentration. The addition of IPA to TMAH solution leads to smoother furfaces of sidewalls etched planes and reduce undercutting ratio by a factor of 2-3. Finally, the p?? Si anisotropic etching characteristics by means of heavily boron doping was investigated.

마그네트론 코스퍼터링에 의한 측온저항체 온도센서용 Pt-Co 합금박막의 증착과 그 특성

정귀상,김서연,노상수 東西大學校 1997 동서논문집 Vol.3 No.1

Plantinum-Cobalt alloy thin films were deposited on Al₂O₃ substrate by cosputtering for RTD(Resistance Thermometer Devices) temperature sensors. We made Pt-Co alloy resistance patterns on the Al₂O₃substrate by lift-off method and investigated the physical and electrical characteristics of these films under various conditions, the input power, working vacuum, annealing temperature and time, and also after annealing these films. The resistivity and sheet resistivity of these films were decreased with increasing the annealing temperature. After the annealing treatment at 800℃ for 60 min, the resistivity and sheet resistivity of Pt-Co thin films was 15μΩ·cm and 0.5Ω/□, respectively and the TCR value of Pt-Co alloy thin films with thickness of 3000Å was 3740 ppm/℃ in the temperature range of 25∼400℃. These results indicate that Pt-Co alloy thin films have potentiality for the RTD temperature sensors.

크롬질화박막형 스트레인 게이지의 제작

정귀상,서정환 東西大學校 1999 동서논문집 Vol.5 No.-

This paper presents characteristics of CrN thin-film strain gauges, which were deposited on glass by DC reactive magnetron sputtering in an argon-nitrogen atmosphere(Ar-(5-25 %)N₂). The physical and electrical characteristics of these films investigated with the thickness range 3500Å of CrN thin-films, annealing temperature (100∼300℃) and annealing time (24∼72 hr). The optimized condition of CrN thin-film strain gauges were thickness range of 3500Å and annealing condition(300℃, 48 hr) in Ar-10 % N₂ deposition atmosphere. Under optimum conditions, the CrN thin-films for strain gauge is obtained a high resistivity, ρ =1147.65 μΩcm, a low temperature coefficient of resistance, TCR=-186 ppm/℃ and a high temporal stability with a good longitudinal, 11.17. And change in resistance after annealing for the CrN thin-films were quitely linear and stable.

고속응답, 저소비전력형 마이크로 유량센서의 제작과 그 특성

정귀상,홍석우 東西大學校 2000 동서논문집 Vol.6 No.-

This paper describes on the fabrication and characteristics of hot-film type micro-flowsensors integrated with Pt-RTD's and micro-heaters on the Si substrate, in which MgO thin-films were used as medium lager in order to improve adhesion of Pt thin-films to SiO2 layer. The MgO layer improved adhesion of Pt thin-films to SiO2 layer without any chemical reactions to Pt thin-films under high annealing temperatures. In investigating output characteristics of the fabricated micro-flowsensors, the output voltages increased as gas flow rate and its conductivity increased due to increase of heat-loss from sensor to external. Output voltage was 82 mV at N2 flow rate of 2000 sccm/min, heating power of 1.2W.

수용성 암모니아 용약에서의 단결성 실리콘의 선택적 식각특성

정귀상,박진성 東西大學校 1998 동서논문집 Vol.4 No.-

This paper presents Si anisotropic ethcing characteristics in TMAH/JPA solution with addition of pyrazine Addition of IPA to TMAH solution, etching characteristics that the flatness of etching front was improved and undercutting was reduced were exhibited, but the etching rate of (100) Si was decreased. (100) Si etching rate of 0.747 ㎛/min which faster 52 % than pure TMAH 25 wt.% solution was obtained using TMAH 25 wt.%/IPA 17 vol.%/pyrazine 0.1 g and the etching rate of (100) Si was decreased with more additive quantity of pyrazine. Addition of pyrazine to TMAH 25 wt.% solution, the flatness variations of etching front was not observed and undercutting ratio was reduced about 30 ~ 50 %.

SOI기술을 이용한 고온용 고감도 홀 센서에 관한 연구

정귀상,최영규 東西大學校 1997 동서논문집 Vol.3 No.1

This paper describes the fabrication and characteristics of a Si Hall sensor fabricated on a SOI(Si-on-insulator) structure. The SOI structure was formed by SDB(Si-wafer direct bonding) technology and the insulator of the SOI structure was used as the dielectrical isolation layer of a Hall sensor. The Hall voltage and sensitivity of the implemented SDB SOI Hall sensors showed good linearity with respect to the applied magnetic flux density and supplied current. The product sensitivity of the SDB SOI Hall sensor was average 600V/A·T and its value has been increased up to 3 times compared to that of bulk Si with buried layer of 10㎛. In the temperature range of 25 to 300℃, the shifts of TCO and TCS were less than ±??/℃ and ±??/℃, respectively. These results indicate that the SDB SOI structure has potential for the development of Hall sensors with a high-sensitivity and high-temperature operation.

백금 미세발열체를 이용한 유량센서의 제작

정귀상,김순철,노상수 東西大學校 1998 동서논문집 Vol.4 No.-

This paper discribes the characteristics of Pt microheater using aluminum oxide films as medium layer and its application to flow sensors. Pt microheater have heating temperature of 390℃ at heating power of 1.2 W. Output voltages of flow sensors which were fabricated by integrating sensing-part with heating-part increase as gas flow rate adn its conductivity increase. At O₂flow rate of 2000 sccm, heating power of 0.8W, output voltge of flow sensor is 101 mV under bridge-applied voltage of 5 V.