Development of a Reliable Micro-Hotplate With Low Power Consumption

In this paper, a reliable micro-hotplate with low power consumption is demonstrated by optimizing its structure and materials. Its power consumption is successfully decreased by adopting a structure with two high length-to-width slender beams. High reliability is achieved by improving its mechanical strength and long-term stability. A stacked membrane with residual stress controlled and corner compensations improve its mechanical strength. Pt heater element and <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">Al₂ O ₃</tex></formula> adhesive layer deposited by atomic layer deposition (ALD) improve its long-term stability. Test results indicate that the micro-hotplate consumes only 18 mW when heated up to 400 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">∘</tex></formula> C with a heating response time <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$<$</tex></formula> 5 ms and cooling response time <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$<$</tex> </formula> 3 ms. It can sustain at least 842 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex Notation="TeX"></tex></formula> 400 circles pulsed-mode operation with ultra-low resistance drift and can continuously work stably at around 450 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">∘</tex></formula> C for at least 500 h.