Design and Optimization of MEMS-based Thermopile Detector Arrays for Infrared Sensing Applications

This research focuses on MEMS thermopile-based arrays. Thermopile-based detectors employ the Seebeck effect to generate electrical potential differences in response to temperature variations. The thermopiles are composed of polysilicon-based thermocouple elements interconnected in arrays to enhance sensitivity and output voltage.Expanding upon the prior work involving a double-layer structure and a single-layer circular structure, our research explores various thermocouple designs more comprehensively. This includes parametric variations of length and thickness and the development of stacked double-layer structure and its subsequent implementation in a circular array . In our study, we delve into crucial factors such as doping concentration, polysilicon layer thickness, and insulating silicon dioxide layer thickness to engineer specific Seebeck coefficients and achieve enhanced output voltage.Our findings reveal an important trend: increasing doping concentration reduces the Seebeck coefficient, while decreasing thermocouple strip thickness improves the output voltage. Minimizing the oxide layer thickness also proves instrumental in increasing the output voltage.Additionally, circular arrays are examined to analyze their performance in different thermoelectric structures. Through comparative analysis, the device performance in circular arrays for single-layer, double-layer, and stacked double-layer thermopile structures is demonstrated.