CVD for aluminium deposition at 70nm
Existing DRAM circuit-wiring processes use physical vapour deposition (PVD), in which thin films are formed by turning solid-state materials into particles. However, “voids” in the metal from non-uniform deposition on the wafer surface causes problems in making reliable electric circuits. This has made PVD difficult to apply in 90nm-or-less processes.
The CVD aluminium process technology can solve both the void problem and dramatically improve the circuit properties. Samsung believes that it is an essential process technology for manufacturing 70nm DRAMs. Samsung’s analysis further suggests that it would reduce costs related to circuit-wiring processing by up to 20%, as it does not require the planarisation, etch-back or cleaning processes previously needed.
The company has applied for 15 international patents related to this technology. Samsung Electronics has already produced 90nm 512Mbit DRAM samples by applying aluminium CVD and plans to unveil 70nm DRAM that uses this process technology by the end of the year.
