Selective anisotropic reactive ion etching process for polysilicide composite structures

摘要: A reactive ion etching technique is disclosed for a gate electrode out of layers tungsten silicide (18) and polycrystalline silicon (16) without the underlying layer dioxide (14) which serves as dielectric covers source drain regions. The key feature invention, wherein gate, has been partially etched layers, coated with poly tetrafluoroethylene (teflon) (30) to protect sidewalls (24) from being excessively in lateral direction while continues at bottom on either side gate. process especially suitable formation structures since no subsequent thermal steps are required would otherwise cause delamination silicide. In addition eliminating undercutting, proess does not disturb oxide over areas. create leaky device unsuitable applications such dynamic RAMs. entire can be carried single pump down therefore contamination levels minimized.