Plug filling for dual-damascene process
A method of fabricating a dual-damascene structure comprising the following steps. A structure having a patterned low-k material layer formed thereover is provided. The patterned low-k material layer having an upper surface and at least one via hole formed therethrough. A plug material layer is formed over the patterned low-k material layer and filling the at least one via hole. The plug material layer being comprised of a material dissolvable in TMAH or deionized water. The plug material layer is developed to form a plug within the respective at least one via hole having a height below the upper surface of the patterned low-k material layer. The plug is baked to crosslink the plug material comprising the plug. A trench masking layer is formed and patterned to form a patterned trench masking layer having at least one trench substantially centered over the respective at least one via hole and exposing a portion of patterned low-k material layer adjacent the at least one via hole. Wherein the crosslinked plug material comprising the plug does not adversely interact with the trench masking layer. The patterned low-k material layer is etched at the exposed portion using the patterned trench masking layer as a mask to form a trench opening substantially centered over the via hole. The etching of the patterned low-k material layer also removing some of the plug to form a partially etched plug. The trench opening and the via hole comprising a dual-damascene opening. The partially etched plug is removed from the via hole. A planarized dual-damascene structure is formed within the dual-damascene opening.
Taiwan Semiconductor Manufacturing Company
H H
H01L H01L
inventional inventional
Jian-Hong Bang-Chein
Chen Ho