A new hollow-cathode magnetron source for 0.10 μm copper applications

A new design Hollow-Cathode Magnetron (HCM) source was evaluated for 0.10 μm copper (Cu) seed deposition applications. The new source included: (i) an external Dual Coil electromagnet for plasma confinement and metal ion flux control, and (ii) an optimized DC magnetron for high plasma density operation and improved target erosion. With the modified source, highly uniform deposition of copper seed(~2%, 1σ) was achieved on 200 mm wafers minimizing the center-to-edge variability in subsequent electrochemical copper fill (electrofill). In addition, the high plasma density operation significantly improved conformality of the seed deposition allowing reduction of the seed field thickness from 1500 Å to ~800 Å while achieving void free electrofill of 0.10-0.13 μm test structures