Research on Laser Trimming of Silicon MEMS Vibratory Gyroscopes

A method for frequency tuning of silicon MEMS vibratory gyroscopes by laser induced etching of silicon in chlorine atmosphere has been presented. The feasibility of this method is analyzed in theory and practice. An experimental apparatus is implemented to test and verify the scheme. A silicon chip of gyroscope has been etched in this apparatus for 30 seconds. The resonant frequency of the gyroscope is changed from 3200 Hz to 3209 Hz. This result shows laser induced etching is an effective way to realize frequency tuning.