Titanium nitride (TiN) as a gate material in BiCMOS devices for biomedical implants

Titanium nitride (TiN) is a proven bio-compatible conductor and as such increasingly applied as an microelectrode material in novel biomedical devices. This paper reports the functioning of BiCMOS devices with titanium nitride as a gate electrode and interconnect material all fabricated in five photolithographic steps. This simple BiCMOS process allows the on-chip integration of a biomedical electrode arrays with electronics to reduce the electrode wiring density and hence reduce the electrodes footprint. This approach can be useful for medical devices like cochlear implants (CI's) where a high density electrode array is applied in a small volume.