纳米梁的金硅原电池腐蚀和无损释放技术研究

Study on the galvanic cell etching for Si-based nano beam with Au pad and release method without structure damage

采用金电极的硅纳米梁在通过HF湿法腐蚀S iO2牺牲层释放结构的时候会发生硅纳米梁被腐蚀现象,消除此效应对于纳米尺度梁制造非常重要。通过电化学工作站测量不同条件下金/硅在HF中的极化曲线和腐蚀电流,从定性和定量研究此腐蚀的原理和影响因素:金硅在HF中形成的原电池效应是此腐蚀的主要原因;改变金硅面积比和改变HF构成可以减缓此腐蚀。设计了一种简单可控的HF蒸气腐蚀装置彻底消除原电池腐蚀效应的影响,并实现了120 nm厚双端固支纳米梁的无损释放。

Hydrofluoric acid（HF） was widely used in wet etching operation to release Si-based micronano beams. However,corrosion of silicon may occur when silicon beam is electrically connected to Au Pad, which seriously damages the feature and performance of nano beams. According to the measurements of polarization curves of Au/ Si in HF, galvanic etching was suggested to play a major role in the etching of Si. Galvanic etching can be alleviated by changing the Au/Si area ratio and HF solution content based on the experiments. In the end, HF vapor phase etching devices was designed to totally eliminate the galvanic cell etching and 120 nm thickness two double-clamped nano beams was successfully fabricated by this method without structure damage.