Photo-electrochemical (PEC) etching is a promising technique for fabricating GaN microelectromechanical systems devices. In this study, we demonstrate the fabrication of GaN cantilevers by the bandgap-selective PEC etching of an InGaN superlattice sacrificial layer. By using an InGaN superlattice as a sacrifice layer, we found the PEC etching rate became higher than using a normal InGaN layer. As a result, the InGaN superlattice was completely etched and we fabricated GaN-based cantilevers whose resonance characteristics were measured. The Young’s modulus of GaN was determined from the resonance characteristics of GaN cantilevers to be the same as the highest value reported previously.

光电化学（PEC）蚀刻是一种有前途的制造GaN微机电系统器件的技术。在这项研究中，我们证明了通过InGaN超晶格牺牲层的带隙选择性PEC蚀刻来制造GaN悬臂。通过使用InGaN超晶格作为牺牲层，我们发现PEC蚀刻速率变得比使用常规InGaN层更高。结果，InGaN超晶格被完全蚀刻，我们制造了测量共振特性的GaN基悬臂。GaN的杨氏模量由GaN悬臂梁的共振特性确定，与先前报道的最大值相同。