Nanoporous Pirani sensor based on anodic aluminum oxide

作者：Jeon Gwang Jae; Kim Woo Young; Shim Hyun Bin; Lee Hee Chul

来源：Applied Physics Letters, 2016, 109(12): 123505.

DOI：10.1063/1.4963183

A nanoporous Pirani sensor based on anodic aluminum oxide (AAO) is proposed, and the quantitative relationship between the performance of the sensor and the porosity of the AAO membrane is characterized with a theoretical model. The proposed Pirani sensor is composed of a metallic resistor on a suspended nanoporous membrane, which simultaneously serves as the sensing area and the supporting structure. The AAO membrane has numerous vertically-tufted nanopores, resulting in a lower measurable pressure limit due to both the increased effective sensing area and the decreased effective thermal loss through the supporting structure. Additionally, the suspended AAO membrane structure, with its outer periphery anchored to the substrate, known as a closed-type design, is demonstrated using nanopores of AAO as an etch hole without a bulk micromachining process used on the substrate. In a CMOS-compatible process, a 200 mu m x 200 mu m nanoporous Pirani sensor with porosity of 25% was capable of measuring the pressure from 0.1 mTorr to 760 Torr. With adjustment of the porosity of the AAO, the measurable range could be extended toward lower pressures of more than one decade compared to a nonporous membrane with an identical footprint. Published by AIP Publishing.

• 出版日期2016-9-19