A ICP Etching System created a 50μm diameter via hole on a SiC GaN-HEMT device from the back side of SiC substrate.
The top of the via hole was tapered for easy electrode formation.
SiC via hole etching requires a high etch rate, low damage, and low temperature.
The SiC substrate is glued onto a carrier wafer, using electron wax and is processed under a temperature suitable to the electron wax.
A via hole with vertical smooth sidewalls was obtained at an etch rate of 1.3μm/min while keeping the temperature below 150°C.
Processed by RIE-600iP ICP Etching System