Title :
Stability of wafer level vacuum encapsulated single-crystal silicon resonators
Author :
Kaajakari, Ville ; Kiihamäki, Jyrki ; Oja, Aarne ; Seppä, Heikki ; Pietikäinen, Sami ; Kokkala, Ville ; Kuisma, Heikki
Author_Institution :
VTT Inf. Technol., Finland
Abstract :
The stability of wafer level vacuum encapsulated micromechanical resonators is characterized. The resonators are etched of silicon-on-insulator (SOI) wafers using deep reactive ion etching (DRIE) and encapsulated with anodic bonding. Bulk acoustic wave (BAW) resonators show drift better than 0.1 ppm/month demonstrating that the stability requirements for a reference oscillator can be met with MEMS. The drift of flexural resonators range from 4 ppm/month to over 500 ppm/month depending on resonator anchoring. The large drift exhibited by some flexural resonator types is attributed to packaging related stresses.
Keywords :
bulk acoustic wave devices; encapsulation; frequency stability; internal stresses; micromechanical resonators; silicon-on-insulator; sputter etching; wafer bonding; BAW resonator drift; DRIE; MEMS; SOI etched wafers; Si; anodic bonding; deep reactive ion etching; flexural resonator frequency drift; frequency references; frequency stability; micromechanical resonators; packaging related stresses; reference oscillator stability requirements; resonator anchoring; single-crystal silicon resonators; wafer level packaging; wafer level vacuum encapsulated resonators; Acoustic noise; Crystals; Etching; Frequency; Micromechanical devices; Oscillators; Packaging; Phase noise; Silicon on insulator technology; Stability;
Conference_Titel :
Solid-State Sensors, Actuators and Microsystems, 2005. Digest of Technical Papers. TRANSDUCERS '05. The 13th International Conference on
Print_ISBN :
0-7803-8994-8
DOI :
10.1109/SENSOR.2005.1496567
