Evaluations of Mn-Ni-Co type thermistor thin film for thermal infrared sensing element

Mn-Ni-Co type thin films were prepared at various conditions by a rf magnetron sputtering system. At the condition. or substrate temperature of $300^{\circ}C$ and $Ar/O_2$= 10/0, a cubic spinel phase was obtained. When oxygen was included in process gas, a cubic spinel phase was not formed even after the thermal annealing at $900^{\circ}C$. The thermistor thin film had no other elements except Mn, Ni and Co. The infrared reflection spectra of the thermistor thin films showed that the films had somewhat high reflectance for incoming infrared ray with some angle. The etch rate of the thermistor thin films was about 63nm/min at a condition of DI water : $HNO_3$: HCl = 60 : 30 : 10 vol%. The B constant and temperature coefficient of resistance of the thermistor thin films were 3500 K and -3.95 %/K, respectively. The voltage responsivity of the thermistor thin film infrared sensor was 108.5 V/W and its noise equivalent power and specific detectivity were $5.1\times 10^{-7}$ W/$Hz^{-1/2}$ and $0.2\times 10^6$cm $Hz^{1/2}$/W, respectively.

열형 적외선 센싱소자용 Mn-Ni-Co계 써미스터 박막 특성 평가

rf magnetron sputtering법을 이용하여 Mn-Ni-Co계 써미스터 박막을 증착하였다. $300^{\circ}C$ 및 $Ar/O_2$ = 10/0에서, cubic spinel 상형성이 이루어졌으며 공정가스에 산소 첨가 시, cubic spinel 상은 열처리를 통해서도 형성되지 않았다. 써미스터 박막은 Mn, Ni, Co 성분 외 다른 이종 성분은 포함되어 있지 않았다. 써미스터 박막에 대한 적외선 반사 특성을 분석으로 증착된 박막은 일정 각도로 입사되는 적외선에 대해 비교적 높은 반사율을 가짐을 관찰할 수 있었다. DI water : $HNO_3$: HCI=60 : 30 : 10 vo1%에서 써미스터 박막의 식각 속도는 약 63 nm/min였다. 박막 써미스터의 B상수는 약 3500 K였으며 TCR은 약 -3.95%/K였다 전압감도는 약 108.5 V/W였으며 NEP와 specific detectivity는 각각 $5.1\times 10^{-7}$ W/$Hz^{-1/2}$ $0.2\times 10^6$cm $Hz^{1/2}$/W였다.