The role of the TiN liner in forcefill

Forcefill is a process by which aluminum from a blanket film, covering a vi a hole, is driven into the via hole at elevated pressure and temperature. T he result of the forcefill process depends on the via wall material. A thin layer of TiN is applied to the wall and the bottom of the via prior to alu minum deposition. This layer is referred to as the wetting layer or liner. Via holes with a TiN liner are filled by the forcefill process, whereas via s without a TiN liner are not filled at all. The dependence of the filling on the presence of a liner is explained by the provision of a path for stre ss driven diffusion of aluminum atoms onto the via wall. (C) 1998 The Elect rochemical Society. S1099-0062(98)01-056-6. All rights reserved.