Current conduction mechanism of Si/Ti-based Ohmic contacts to n-GaN
We have investigated the Ohmic contact formation mechanism of Si/Ti-based contacts to n-GaN. The Si/Ti contact system was selected because Ti silicides have a low work function and also Si has been used widely as an n-type dopant. Our experimental results show that the Ohmic behavior of Si/Ti-based contacts were attributed to the low barrier height of the Ti silicide/GaN interface. The contact resistance of Si/Ti-based Ohmic contacts decreased exponentially with the measuring temperature. It can be concluded that current flows over the low barrier height by thermionic emission. © 2000 American Institute of Physics.