Angular dependence of Ion Beam etching rates for acoustic resonator fabrication

In this project, we will explore the etching rate of Nickel (Ni) and Titanium (Ti) using the Ion Beam etching (IBE) method. The substrate holder is rotated in different directions to enable different etching angles. By manipulating the etch angle from -10 degrees to -60 degrees, the etching rate and surface characteristics are modified. Different characteristic methods are used to detect the etching rate, secondary ion mass spectroscopy is used to track the real-time weight of atoms in the chamber and to characterize the end-point, and the sheet resistance measurement method is used to characterize conductive material thickness. With the standard recipe Medium_IBE.prc in CMi, the obtained minimum SIMS etching rate is 43.8 nm/min for evaporated Ti and 39.2 nm/min for sputtered Ti. This project offers valuable resources for further acoustic resonator fabrication which requires accurate etching speed control, and low etching rate material for the stop layer and hard mask applications.