Since the performance of micro-electro-mechanical system (MEMS)-based microphones is approaching fundamental physical, design, and material limits, it has become challenging to improve them. Several works have demonstrated graphene’s suitability as a microphone diaphragm. The potential for achieving smaller, more sensitive, and scalable on-chip MEMS microphones is yet to be determined. To address large graphene sizes, graphene-polymer heterostructures have been proposed, but they compromise performance due to added polymer mass and stiffness. This work demonstrates the first wafer-scale integrated MEMS condenser microphones with diameters of 2R = 220–320 μm, thickness of 7 nm multi-layer graphene, that is suspended over a back-plate with a residual gap of 5 μm. The microphones are manufactured with MEMS compatible wafer-scale technologies without any transfer steps or polymer layers that are more prone to contaminate and wrinkle the graphene. Different designs, all electrically integrated are fabricated and characterized allowing us to study the effects of the introduction of a back-plate for capacitive read-out. The devices show high mechanical compliances C_m = 0.081–1.07 μmPa⁻¹ (10–100 × higher than the silicon reported in the state-of-the-art diaphragms) and pull-in voltages in the range of 2–9.5 V. In addition, to validate the proof of concept, we have electrically characterized the graphene microphone when subjected to sound actuation. An estimated sensitivity of S_1kHz = 24.3–321 mV Pa⁻¹ for a V_bias = 1.5 V was determined, which is 1.9–25.5 × higher than of state-of-the-art microphone devices while having a ~9 × smaller area.

由于基于微机电系统 (MEMS) 的麦克风的性能正在接近基本的物理、设计和材料极限，因此改进它们已变得具有挑战性。几项工作已经证明了石墨烯作为麦克风隔膜的适用性。实现更小、更灵敏和可扩展的片上 MEMS 麦克风的潜力尚未确定。为了解决大石墨烯尺寸问题，人们提出了石墨烯-聚合物异质结构，但由于增加了聚合物质量和刚度，它们会损害性能。这项工作展示了第一个晶圆级集成 MEMS 电容式麦克风，直径为 2 R = 220–320 μm，厚度为 7 nm 多层石墨烯，悬挂在背板上，残余间隙为 5  μm。这些麦克风采用 MEMS 兼容的晶圆级技术制造，没有任何转移步骤或更容易污染石墨烯和使石墨烯起皱的聚合物层。不同的设计，所有的电气集成都被制造和表征，使我们能够研究引入电容读出背板的影响。该器件表现出较高的机械柔量C _m = 0.081–1.07 μ mPa ⁻¹（比最先进的隔膜中报告的硅高 10–100 倍）和 2–9.5 V 范围内的吸合电压此外，为了验证概念，我们对石墨烯麦克风在受到声音驱动时的电气特性进行了表征。确定了V _{b i a s} = 1.5 V时的估计灵敏度S _{1 k H z} = 24.3–321 mV Pa ⁻¹  ，比最先进的麦克风设备高 1.9–25.5 倍，同时具有约小 9 倍的面积。