Abstract
When packaging monolithic sensors by anodic bonding, protection of the
electronics is crucial. We have investigated two different methods for
protecting MOS capacitors from damage during anodic bonding. Our first
approach was to etch 50 µm deep cavities in the Pyrex glass, lowering
the electric field across the cavity during bonding. The second
protection method was to coat the inside of a 10 µm deep Pyrex cavity
with aluminium, forming a Faraday cage during anodic bonding. With both
methods, we obtained unchanged CV curves when measuring the capacitors
after bonding. In comparison, unprotected capacitors situated in a 10
µm deep Pyrex cavity exhibited increased leakage current after anodic
bonding.
electronics is crucial. We have investigated two different methods for
protecting MOS capacitors from damage during anodic bonding. Our first
approach was to etch 50 µm deep cavities in the Pyrex glass, lowering
the electric field across the cavity during bonding. The second
protection method was to coat the inside of a 10 µm deep Pyrex cavity
with aluminium, forming a Faraday cage during anodic bonding. With both
methods, we obtained unchanged CV curves when measuring the capacitors
after bonding. In comparison, unprotected capacitors situated in a 10
µm deep Pyrex cavity exhibited increased leakage current after anodic
bonding.
