Diffusion at anodically bonded interfaces

Diffusion of gas molecules into cavities closed by anodic bonding has been quantified by annealing of specially designed test structures. Annealing has been performed at temperatures in the range 150-430oC for several days. An increased concentration of molecules within the closed cavities after heat treatments is veri-fied both electrically and optically. The diffusion of gas into the cavities is found to be substantial at tem-peratures above 300oC. A diffusion parameter, the diffusion coefficient times the height of the bonded interface, is found from curve fitting of experimental data with an analytic expression for diffusion.