Plasma-damaged oxide reliability study correlating both hot-carrier injection and time-dependent dielectric breakdown

The oxide damage resulting from exposure to a plasma environment in four different dry-etch tools was investigated using both hot-carrier injection (HCI) and time-dependent dielectric breakdown (TDDB). A strong correlation was observed between hot-carrier injection results and time-dependent dielectric breakdown results. It was found that a damaged oxide has both a lower critical energy for HCI to create an interface trap, and a lower activation energy for Fowler-Nordheim injection to create a hole in the oxide. These results also suggest that in dry etching, possibly more damage occurs in the metal step than in the contact etch step.<>