Optimal performance of CMOS compatible IR thermoelectric sensors

This paper presents a theoretical and empirical study of the optimal perfor mance of CMOS compatible infrared thermoelectric sensors with varying pixel area and different aspect ratio of the pixels for two possible sensor stru ctures: cantilever and bridge types. Optimal performance is analyzed analyt ically, using simplifying assumptions. This analysis is verified by compari ng with the exact simulations as well as by comparing with measured results , The resistance of optimized sensors in the sense of minimal noise equival ent power (NEP) is shown to be independent of aspect ratio, but proportiona l to the third root of the pixel area. The product of the optimal NEP and t he square root of the time constant is shown to be constant with varying as pect ratios, while the same applies with the time constant to the power of 3/8 for varying areas. The measured sensors exhibit NEP's down to 13.5 nW i n a 300-Hz bandwidth and time constants up to 30 ms. [414].