Coutu Ronald A, Medvedev Ivan R, Petkie Douglas T
Department of Electrical and Computer Engineering, Air Force Institute of Technology, 2950 Hobson Way, Wright-Patterson AFB, Dayton, OH 45433, USA.
Department of Physics, Wright State University, 3640 Colonel Glenn Highway, Dayton, OH 45435, USA.
Sensors (Basel). 2016 Feb 19;16(2):251. doi: 10.3390/s16020251.
In this paper, a microelectromechanical system (MEMS) cantilever sensor was designed, modeled and fabricated to measure the terahertz (THz) radiation induced photoacoustic (PA) response of gases under low vacuum conditions. This work vastly improves cantilever sensitivity over previous efforts, by reducing internal beam stresses, minimizing out of plane beam curvature and optimizing beam damping. In addition, fabrication yield was improved by approximately 50% by filleting the cantilever's anchor and free end to help reduce high stress areas that occurred during device fabrication and processing. All of the cantilever sensors were fabricated using silicon-on-insulator (SOI) wafers and tested in a custom built, low-volume, vacuum chamber. The resulting cantilever sensors exhibited improved signal to noise ratios, sensitivities and normalized noise equivalent absorption (NNEA) coefficients of approximately 4.28 × 10(-10) cm(-1)·WHz(-1/2). This reported NNEA represents approximately a 70% improvement over previously fabricated and tested SOI cantilever sensors for THz PA spectroscopy.
在本文中，设计、建模并制造了一种微机电系统（MEMS）悬臂梁传感器，用于测量低真空条件下太赫兹（THz）辐射诱导的气体光声（PA）响应。通过减少内部梁应力、最小化平面外梁曲率以及优化梁阻尼，这项工作极大地提高了悬臂梁的灵敏度，相较于之前的努力有了显著提升。此外，通过对悬臂梁的锚定端和自由端进行倒圆角处理，减少了器件制造和加工过程中出现的高应力区域，使制造良率提高了约50%。所有悬臂梁传感器均采用绝缘体上硅（SOI）晶圆制造，并在定制的小体积真空腔中进行测试。所得悬臂梁传感器的信噪比、灵敏度和归一化噪声等效吸收（NNEA）系数得到了改善，约为4.28×10⁻¹⁰ cm⁻¹·WHz⁻¹/²。该报道的NNEA相较于之前制造和测试的用于太赫兹光声光谱的SOI悬臂梁传感器有大约70%的提升。
