Portal de Periódicos da CAPES

Wetting effect on gap filling submicron damascene by an electrolyte free of levelers

2002; American Institute of Physics; Volume: 20; Issue: 4 Linguagem: Inglês

10.1116/1.1486231

1520-8567

Shih-Chieh Chang, Jia‐Min Shieh, Kun-Cheng Lin, Bau‐Tong Dai, Ting-Chun Wang, Chia‐Fu Chen, Ming‐Shiann Feng, Ying-Hao Li, Chih-Peng Lu,

Semiconductor materials and devices

By using an acid–copper electrolyte without levelers and brighteners, we achieved defect-free filling of 0.13 μm vias with aspect ratio 8:1. This novel electrolyte consisted of copper sulfate (CuSO4⋅5H2O), sulfuric acid (H2SO4), chloride ions (Cl−), and two different average molecular weights of polyethylene glycols (PEG). The smaller-molecular-weight PEG200, with higher diffusion ability, was identified to enhance cupric ions transporting into deep features and was treated as a bottom-up filling promoter. The larger-molecular-weight PEG2000, with higher polarization resistance, provided enough inhibition effect on cupric ion reduction to obtain denser and small-grained deposits in a lower-current-density region, which benefits the filling capability in submicron features. In addition, adding PEG2000 could reduce the interfacial energy between the electrolyte and the opening of trenches/vias to enhance the filling capability.