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Introduction
Micro-electro-mechanical systems (MEMS) technology-based acceleration sensors have received enormous attention in day to day applications such as consumer electronics, gaming console, smart screen rotation in hand-held electronics, airbag deployment, inertial navigation, and guidance systems, etc. This is due to their wide dynamic range, higher sensitivity, and smaller size (Park et al. 2017). Most of MEMS acceleration sensors use capacitive sensing, piezoelectric sensing, or piezoresistive sensing (Zou et al. 2008; Martins et al. 2014; Mahmood et al. 2017; Hadi Said et al. 2018). The capacitive acceleration sensor offers a DC response and reduced noise performance but is affected by the various parasitic capacitance and electromagnetic interference and also requires complex signal conditioning to process the output (Tez et al. 2015). The piezoelectric based acceleration sensors have higher bandwidth and relatively long-term stability with reduced dependence on temperature variation; however, the output is highly dependent on the piezoelectric material and its coefficients. The piezoelectric materials are also not compatible with the standard IC fabrication steps (Zou et al. 2008; Schulze et al. 2014). Compared to these techniques, piezoresistive acceleration sensors are attractive due to the structural simplicity, the fabrication compatibility with the existing Integrated read-out circuitry, and immune to parasitic capacitance and electromagnetic interference (Thaysen et al. 2002). Though, the piezoresistive behavior is influenced by the variation in temperature, the net effect of temperature change can be reduced by using multiple piezoresistors in the Wheatstone bridge-type arrangement (Roy and Bhattacharyya 2015; Hari et al. 2018).
Recent research and development are undergone to enhance the sensitivity to reduce the overall cost and to make the fabrication simpler. In most of the commercial acceleration sensors, silicon is chosen as a preferred substrate material due to its mechanical rigidity, high Young’s modulus, lower thermal expansion coefficient, and fabrication compatibility at higher process temperatures. However, the fabrication process to make silicon-based acceleration sensor involves a lot of complicated steps such as diffusion/ion implantation, deep reactive ion etching (DRIE), wet etching (KOH or TMAH), which not only increases the overall production cost but also results in higher residual stresses.
In several daily-life applications such as children’s toys, practical demonstration for educational purposes where the accuracy requirement is not very critical, there is a need to develop a simple, cost-effective MEMS acceleration...