Fabrication of Hermetic Cell Using MEMS Technology

Small cavities with extremely high air tightness are used in many applications such as miniaturized magnetometers, atomic frequency references and spectroscopic reference cells. This paper presents a method to fabricate hermetic cell using MEMS technologies. Several processes are included such as cleaning, lithography, dry and wet etching and anodic bonding. Roughly the whole process covers two basic steps: a) a hole is etched out on the unit of silicon by wet processes and b). The hole is hermetic sealed with glasses by anodic bonding. This step also includes two bonding processes for the two sides bonding is performed respectively. After fabrication helium leak detection is performed, the result shows that a leakage rate of 2.68E-8 Pamiddotm ³/s is achieved