Microsystems Laboratory, Station 17, École Polytéchnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.
Nanotechnology. 2010 Dec 17;21(50):505501. doi: 10.1088/0957-4484/21/50/505501. Epub 2010 Nov 23.
Fast hydrogen sensors based on discontinuous palladium (Pd) films on supporting polyimide layers, fabricated by a cost-efficient and full-wafer compatible process, are presented. The films, deposited by electron-beam evaporation with a nominal thickness of 1.5 nm, consist of isolated Pd islands that are separated by nanoscopic gaps. On hydrogenation, the volume expansion of Pd brings initially separated islands into contact which leads to the creation of new electrical pathways through the film. The supporting polyimide layer provides both sufficient elasticity for the Pd nanoclusters to expand on hydrogenation and a sufficiently high surface energy for good adhesion of both film and contacting electrodes. The novel order of the fabrication processes involves a dicing step prior to the Pd deposition and stencil lithography for the patterning of microelectrodes. This allows us to preserve the as-deposited film properties. The devices work at room temperature, show response times of a few seconds and have a low power consumption of some tens of nW.
基于支撑聚酰亚胺层上不连续钯 (Pd) 薄膜的快速氢传感器，通过一种具有成本效益和全晶圆兼容的工艺制造。这些薄膜通过电子束蒸发沉积，名义厚度为 1.5nm，由孤立的 Pd 岛组成，这些岛由纳米级间隙隔开。在加氢过程中，Pd 的体积膨胀最初使分离的岛屿接触，从而导致通过薄膜形成新的电通路。支撑聚酰亚胺层为 Pd 纳米簇在加氢时膨胀提供了足够的弹性，并为薄膜和接触电极的良好附着提供了足够高的表面能。新颖的制造工艺顺序涉及在 Pd 沉积之前进行划片步骤和模板光刻以对微电极进行图案化。这使我们能够保留沉积后的薄膜特性。这些器件在室温下工作，响应时间为数秒，功耗仅几十纳瓦。
