In order to overcome shortcomings of residual stress relief incapability

low stiffness and span limits of planar micromechanical structures and unsmooth stepped edge occur in fabrication of dome-shaped structure using planar sacrificial layer that cause device failure or energy losses

to improve size limit

robustness and reliability of devices with dome shaped structure in existing methods

a new method for micro dome-shaped structure fabrication using selective chemical mechanical polishing（CMP） is proposed.In this method

selective slurry in CMP process is used

resulting in faster polish speed of Si substrate over the sacrificial layer

and utilizing physical and chemical effects in the process of sliding friction

dome-shaped structures which has continuous and smooth surface on the boundary of sacrificial layer and Si substrate are formed

and finally micro dome-shaped structure is fabricated on the top surface of Si substrate.Experimental results confirm that the micro dome-shaped structure has certain curvature

with a height of 3.5 μm and a span of over 100 μm

micro dome-shaped surface is smooth and continuous curvature.This method can give reference for fabrication of micro dome-shaped structure of MEMS transducers

micro piezoelectric actuators

film bulk acoustic resonators and filters.