Patent ID: 8372198

Claim:
A method of forming a dual damascene structure, the method comprising: forming a preliminary dual damascene structure comprising a first insulation member and a preliminary single crystal member, wherein the first insulation member is formed on a single crystal seed layer and comprises a first opening and a second opening, the first opening partially exposing the single crystal seed layer, the second opening being communicated with the first opening and being wider than the first opening, and wherein the preliminary single crystal member makes contact with the single crystal seed layer and fills up the first opening; forming a filling member on a side face of the second opening, the filling member partially filling up the second opening, wherein forming the filling member comprises forming a second insulation member in the second opening and etching the second insulation member to at least partially expose a floor of the second opening adjacent the preliminary single crystal member; forming a single crystal member by causing the preliminary single crystal member to grow epitaxially, the single crystal member continuously filling up the first opening and the second opening, the single crystal member making contact with the filling member; and planarizing the single crystal member, the filling member and the first insulation member.