Quad Mass Gyroscope with 16 ppm Frequency Mismatch Trimmed by Focus Ion Beam

This paper reports a frequency trimming method of a quad-mass MEMS gyroscope using focus ion beam (FIB). A quad-mass gyroscope (QMG) using the standard SOI MEMS process was developed. The relationship between trimming geometry and resonant frequency was estimated by finite element analysis (FEA) and validated by experiment. The resonant frequency mismatch was initially about 2791 ppm. The proposed trimming method enables to reduce the frequency mismatch as small as 16 ppm with a small change of Q factor.