Sim Gi-Dong, Krogstad Jessica A, Reddy K Madhav, Xie Kelvin Y, Valentino Gianna M, Weihs Timothy P, Hemker Kevin J
Department of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218, USA.
Department of Materials Science and Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA.
Sci Adv. 2017 Jun 28;3(6):e1700685. doi: 10.1126/sciadv.1700685. eCollection 2017 Jun.
Silicon-based microelectromechanical systems (MEMS) sensors have become ubiquitous in consumer-based products, but realization of an interconnected network of MEMS devices that allows components to be remotely monitored and controlled, a concept often described as the "Internet of Things," will require a suite of MEMS materials and properties that are not currently available. We report on the synthesis of metallic nickel-molybdenum-tungsten films with direct current sputter deposition, which results in fully dense crystallographically textured films that are filled with nanotwins. These films exhibit linear elastic mechanical behavior and tensile strengths exceeding 3 GPa, which is unprecedented for materials that are compatible with wafer-level device fabrication processes. The ultrahigh strength is attributed to a combination of solid solution strengthening and the presence of dense nanotwins. These films also have excellent thermal and mechanical stability, high density, and electrical properties that are attractive for next-generation metal MEMS applications.
基于硅的微机电系统（MEMS）传感器在消费类产品中已无处不在，但要实现一个能对组件进行远程监测和控制的MEMS设备互联网络（这一概念常被称为“物联网”），将需要一套目前尚不存在的MEMS材料和特性。我们报道了通过直流溅射沉积合成金属镍 - 钼 - 钨薄膜的方法，该方法可得到完全致密的具有晶体织构的薄膜，且薄膜中充满纳米孪晶。这些薄膜表现出线性弹性力学行为，拉伸强度超过3 GPa，这对于与晶圆级器件制造工艺兼容的材料来说是前所未有的。超高强度归因于固溶强化和致密纳米孪晶的共同作用。这些薄膜还具有出色的热稳定性和机械稳定性、高密度以及电学特性，对下一代金属MEMS应用具有吸引力。
