A simultaneous multichannel recording obtained from rat cortex using a plasma etched silicon depth probe

Combination of plasma and wet etching was done in developing a new silicon depth-probe type microelectrode array. The plasma etch uses low temperature oxide (LTO) mask instead of thick photoresist mask, and enables the thickness of the probe shank to be defined more freely and in wider range. The entire probe shaping process was performed only at low temperature, and is CMOS compatible. A probe with 30 μm shank thickness was successfully used in recording from rat´s somatosensory cortex. A four-channel simultaneous neural recording shows signal-to-noise ratio performance comparable with that obtained using conventional microprobes