Oh Jaesub, Song Hyeong-Sub, Park Jongcheol, Lee Jong-Kwon
Division of Nano Convergence Technology, National NanoFab Center, Daejeon-si 34141, Korea.
Foundry Business, Samsung Electronics Co., Suwon-si 18448, Korea.
Sensors (Basel). 2021 Oct 10;21(20):6722. doi: 10.3390/s21206722.
To realize high-resolution thermal images with high quality, it is essential to improve the noise characteristics of the widely adopted uncooled microbolometers. In this work, we applied the post-metal annealing (PMA) process under the condition of deuterium forming gas, at 10 atm and 300 °C for 30 min, to reduce the noise level of amorphous-Si microbolometers. Here, the DC and temperature coefficient of resistance (TCR) measurements of the devices as well as noise analysis were performed before and after the PMA treatment, while changing the width of the resistance layer of the microbolometers with 35 μm or 12 μm pixel. As a result, the microbolometers treated by the PMA process show the decrease in resistance by about 60% and the increase in TCR value up to 48.2% at 10 Hz, as compared to the reference device. Moreover, it is observed that the noise characteristics are improved in inverse proportion to the width of the resistance layer. This improvement is attributed to the cured poly-silicon grain boundary through the hydrogen passivation by heat and deuterium atoms applied during the PMA, which leads to the uniform current path inside the pixel.
为了实现高质量的高分辨率热图像，改善广泛采用的非制冷微测辐射热计的噪声特性至关重要。在这项工作中，我们在10个大气压和300°C的条件下，在氘形成气体环境中应用后金属退火（PMA）工艺30分钟，以降低非晶硅微测辐射热计的噪声水平。在此，在PMA处理前后对器件进行了直流和电阻温度系数（TCR）测量以及噪声分析，同时改变了像素为35μm或12μm的微测辐射热计电阻层的宽度。结果，与参考器件相比，经PMA工艺处理的微测辐射热计在10Hz时电阻降低约60%，TCR值增加高达48.2%。此外，观察到噪声特性与电阻层宽度成反比得到改善。这种改善归因于通过PMA过程中施加的热和氘原子进行氢钝化而固化的多晶硅晶界，这导致像素内部电流路径均匀。
