강자성체 박막(Fe-Ni, Co-Ni)의 자기-저항 효과에 관한 연구( I )

장충근,유중열,송재용,윤만영,박재형,손대락,Chang, C.G.,Yoo, J.Y.,Song, J.Y.,Yun, M.Y.,Park, J.H.,Son, D.R. 한국센서학회 1992 센서학회지 Vol.29 No.3

자기-저항 센서를 제작하기 위하여 Fe-Ni 합금과 Co-Ni 합금을 슬라이드 그라스와 Si wafer에 진공 증착하여 sensor element를 제작한 후 포화자속밀도($B_{s}$), 보자력($H_{c}$), 자기-저항 변화율 등을 조사하였다. 진공 증착된 Fe-Ni 합금 박막의 포화자속밀도는 0.65T이었으며 자화주파수 1 kHz에서 보자력은 0.379A/cm이었고 자냉처리 후 종방향 보자력은 0.370Acm(//), 횡방향 보자력은 0.390Acm(${\bot}$)로 변화되었다. 자기-저항 변화율은 박막의 산화로 인하여 매우 불안정하였다. 진공 증착된 Co-Ni 박막의 포화자속밀도는 0.66T이었으며 자냉처리 후의 종방향 보자력은 5.895Acm(//)이었고 횡방향 보자력은 5.898A/cm(${\bot}$)이었다. 한편 자기-저항 변화율(${\Delta}R/R$)은 $3.6{\sim}3.7%$로써 실온에서 매우 안정하였다. Fe-Ni 박막은 화학친화력이 강하여 자기-저항 센서 제조 공정에서 많은 문제점을 야기시키고 있으나, Co-Ni 박막은 화학친화력이 작고 자기-저항 효과가 뚜렷하여 고온용 자기-저항 소자 개발용 재료로 매우 적합할 것으로 사료된다. In order to fabricate magnetoresistive sensor, Fe-Ni and Co-Ni alleys were evaporated on the slide glass and the silicon wafers. Saturation magnetic induction($B_{s}$), coercive field strength($H_{c}$) and magnetoresistance were measured for fabricated samples. The evaporated Fe-Ni thin films show that the saturation magnetic induction was 0.65 T, and coercive field strength was 0.379 A/cm, and this value was changed to 0.370 A/cm(//), 0.390 A/cm(${\bot}$), respectively after magnetic annealing. For the measurement of coercive field strength, magnetizing frequency of 1 kHz was used. For the fabricated sensor element, the change of magnetoresistance (${\Delta}R/R$) was excessively unstable due to oxidation in the process of fabrication. The evaporated Co-Ni alloy thin films show that saturation magnetic induction was 0.66 T, and coercive field strengthes were 5.895 A/cm(//), 5.898 A/cm(${\bot}$), respectively, after magnetic annelaing. The change of magnetoresistance(${\Delta}R/R$) was $3.6{\sim}3.7%$ of which value was excessively stable to room temperature. Fe-Ni thin film could have many problems due to large affinity in the process of fabrication of magnetoresistance sensor, but Co-Ni thin film could be a suitable material for fabrication of magnetoresistance sensor, because of its small affinity and definite magnetoresistance effects.

강자성체 박막 ( Fe-Ni , Co-Ni ) 의 자기 - 저항 효과에 관한 연구 ( 1 )

장충근,유중열,송재용,윤만영,박재형,손대락 ( C . G . Chang,J . Y . Yoo,J . Y . Song,M . Y . Yun,J . H . Park,D . R . Son ) 한국센서학회 1992 센서학회지 Vol.1 No.1

In order tp fabricate magnetoresistive sensor, Fe-Ni and Co-Ni alloys were evaporated on the slide glass and the silicon wafers. Saturation magnetic induction(Bs), coercive field strength(H) and magnetoresistance were measured for fabricated samples. The evaporated Fe-Ni thin films show that the saturation magnetic induction was 0.65 T, and coercive field strength was 0.379 A/cm, and this value was changed to 0.370 A/cm(//), 0.390 A/cm(⊥), respectively after magnetic annealing. For the measurement of coercive field strength, magnetizing frequency of 1 kHz was used. For the fabricated sensor element, the change of magnetoresistance (△R/R) was excessively unstable due to oxidation in the process of fabrication. The evaporated Co-Ni alloy thin films show that saturation magnetic induction was 0.66 T, and coercive field strengthes were 5.895 A/cm(//), 5.898 A/cm(⊥), respectively, after magnetic annelaing. The change of magnetoresistance(△R/R) was 3.6∼3.7% of which value was excessively stable to room temperature. Fe-Ni thin film could have many problems due to large affinity in the process of fabrication of magnetoresistance sensor, but Co-Ni thin film could be a suitable material for fabrication of magnetoresistance sensor, because of its small affinity and definite magnetoresistance effects.

비접촉 토오크센서의 개발(Ⅰ)

손대락(De-Rac Son),임순재(Soon-Jae Lim),김창석(Chang-Suk Kim),남궁석(Suk Namgung) Korean Society for Precision Engineering 1992 한국정밀공학회지 Vol.9 No.1

비정질합금의 최대자기유도 변화를 이용한 힘센서

손대락(Derac Son),김창석(Chang Suk Kim) 한국자기학회 1991 한국자기학회 학술연구발표회 논문개요집 Vol.1 No.1

유한요소법과 투자율 텐서를 이용한 고조파 회전자계 계산

이창환(Chang-Hwan Lee),김홍규(Hong-Kyu Kim),정현교(Hyun-Kyo Jung),손대락(Derac Son) 한국자기학회 1997 韓國磁氣學會誌 Vol.7 No.3

Recently, many researchers are interested in the analysis of the magnetic fields considering the vector relation between the magnetic flux density and the magnetic field intensity.<br/> In this paper, Finite Element Method with two dimensional tensor permeability is adopted to calculate the magnetic field quantities in the system having the rotational magnetic field. In addition, the method of analyzing the magnetic field considering the harmonic components is introduced.<br/> The validity of the proposed method is proved compared with the experimental results.

강자성체 박막 ( Co-Ni ) 의 자기 - 저항 효과에 관한 연구 ( 3 )

장충근,윤만영,김영일,손대락 ( C . G . Chang,M . Y . Yoon,Y . I . Kim,K . R . Son ) 한국센서학회 1995 센서학회지 Vol.4 No.1

To fabricate low field magnetic sensors using magnetoresistance(MR) effects, we deposited thin layers of 600A in thickness of Ni-Co(0.7Ni-0.3Co) alloy on slide glasses. In the layers we ordered 4 anus of the fullbridge sensors in the shape of grid structure to be inclined at an angle of 45 to main axis and made the areal rate increase to 67%. While the response characteristics of the fabricated sensors had good linearity in the magnetic field of ±0.5 mT ranges, the white noise was 0.2 nV and the voltage sensitivity was 7.6 nV/μT.

강자성체 박막(Co-Ni)의 자기-저항 효과에 관한 연구(III)

장충근,윤만영,김영일,손대락,Chang, C.G.,Yoon, M.Y.,Kim, Y.I.,Son, D.R. 한국센서학회 1995 센서학회지 Vol.4 No.1

자기저항 효과를 이용한 저자장 자기센서를 제작하기 위하여 슬라이드 유리 기판위에 Ni-Co(0.7Ni-0.3Co) 합금을 $600\;{\AA}$ 두께로 진공증착 하였다. 증착된 박막을 bridge 구조의 격자무늬로 식각하는 과정에서 4개의 bridge arm을 주축과 $45^{\circ}$로 배열하고 그 면적율을 67%로 증대시켰다. 제작된 센서는 자장범위 ${\pm}0.5mT$에서 직선성이 양호하였으며 백색잡음은 0.2nV 이었고 전압감도는 7.6 $nV/{\mu}T$ 이었다. To fabricate low field magnetic sensors using magnetoresistance(MR) effects, we deposited thin layers of $600{\AA}$ in thickness of Ni-Co(0.7Ni-0.3Co) alloy on slide glasses. In the layers we ordered 4 arms of the fullbridge sensors in the shape of grid structure to be inclined at an angle of $45^{\circ}$ to main axis and made the areal rate increase to 67%. While the response characteristics of the fabricated sensors had good linearity in the magnetic field of ${\pm}0.5mT$ ranges, the white noise was 0.2 nV and the voltage sensitivity was 7.6 $nV/{\mu}T$.

강자성체 박막(Co-Ni)의 자기-저항효과에 관한 연구(II)

장충근,유중렬,남선우,손대락,Chang, C.J.,Yoo, J.Y.,Nam, S.W.,Son, D.R. 한국센서학회 1994 센서학회지 Vol.3 No.1

Grid type 70Ni-30Co thin films on slide glass at $250^{\circ}C$ has been fabricated to develope. From fabricated sensors using above process, we investigated the relation of temperature, resistivity, line width to magnetoresistance and we obtained the following results after observation of coercive force, saturated magnetization, maxium usable sensitivity, delay time, slew rate, white noise, resolution of the sensors. We confirmed that the $600{\AA}$ thin film at $250^{\circ}C$ formed crystalized magnetic anisotropy spontaneously and the sensor using the thin film had capability of detecting magnetic field with sensitivity of 230 nT. In these devices, the magnetoresistance change was increased linearly in ${\pm}10$ Oe range, and the magnetoresistance effect was increased when the ratio between line width and length was increased. When the devices was soldered using indium, the temperature-resistivity coefficient showed $8{\times}10^{-3}/deg$ and increased during the specific properties as magnetic field sensor were weakened. In this studies, the coercive forces of the films were about 5.1 A/cm and saturated magnetizations were 0.64 T, and the delay time in these devises was $5{\mu}s$ and slew rate showed 0.39 $Oe/{\mu}s$ and white noise was -120 dB. 강자성체 자기저항 센서를 개발하기 위하여 70Ni-30Co 합금을 $10^{-6}$ Torr의 진공중에서 $250^{\circ}C$ 의 슬라이드 그라스 위에 두께 $600{\AA}$ 으로 진공 증착한 후 박막을 격자형으로 식각하고 인출선을 연결하였다. 이와 같은 과정으로 제작된 센서의 자기저항 변화율에 미치는 온도, 저항, 선폭 등의 영향을 조사하고 보자력, 포화자화, 최대유효감도, 지연시간, 회전율, 백색잡음, 분해능 등을 조사 분석한 결과, (70Ni-30Co) 합금을 기판온도 $250^{\circ}C$ 에서 두께 $600{\AA}$ 으로 진공 증착하면 결정자기 이방성이 형성되어 자기저항 소자로써의 기능이 자발적으로 구비되면서 230 nT 의 최대유효감도가 구비됨을 확인하였다. ${\pm}10$ Oe 의 자장구간에서는 직선적인 자기저항변화를 보였으며, 센서소자를 형성하는 격자선의 폭에 대한 길이의 비가 클수록 자기저항 값이 증가함을 알 수 있었다. 한편 센서 소자와 인출선을 인듐으로 연결시키면 저항온도계수가 $8{\times}10^{-3}/deg$로 증가되어 센서 본연의 저항온도계수($1{\times}10^{4}/deg$)가 매우 심하게 열화된다는 것을 알 수 있었다. 이 실험에서 제작된 강자성박막(70Ni-30Co)의 특성은 보자력이 5.1 A/cm이고 포화자화가 0.64T 이었는데, 이 박막으로 제작한 자기저항 센서의 지연시간은 $5{\mu}s$이었고 회전율(slew rate)은 0.39 $Oe/{\mu}s$ 이었으며 백색잡음은 -120 dB 정도이었다.

강자성체 박막 ( Co-Ni ) 의 자기 - 저항효과에 관한 연구 ( 2 )

장충근,유중렬,남선우,손대락 ( C . J . chang,J . Y . Yoo,S . W . Nam,D . R . Son ) 한국센서학회 1994 센서학회지 Vol.3 No.1

Grid type 70Ni-30Co thin films on slide glass at 250℃ has been fabricated to develope. From fabricated sensors using above process, we investigated the relation of temperature, resistivity, line width to magnetoresistance and we obtained the following results after observation of coercive force, saturated magnetization, maxium usable sensitivity, duty time, slew rate, white noise, resolution of the sensors. We confirmed that the 600Å thin film at 250℃ formed crystalized magnetic anisotropy spontanernisly and the sensor using the thin film had capability of detecting magnetic field with sensitivity of 230 nT. In these devices, the magnetoresistance change was increased linearly in ±10 Oe range, and the magnetoresistance effect was increased when the ratio between line width and length was increased. When the devices was soldered using indium, the temperature-resistivity coefficient showed 8 X 10^(-3)/deg and increased during the specific properties as magnetic field sensor were weakened. In this studies, the coercive forces of the films were about 5.1 A/cm and saturated magnetizations were 0.64 T, and the delay time in these devises was 5 ㎲ and slew rate showed 0.39 Oe/us and white noise was -120 dB.