Low temperature PECVD of dielectric films for TSV applications

The effects of a novel, low-temperature (< 200 °C) PECVD TEOS SiO process on via step coverage and blanket film electrical performance are investigated and compared with a traditional PECVD SiH4 process at similar deposition temperatures. The PETEOS process provides > 2.5x via sidewall coverage than the PE-silane based process in medium-high aspect ratio vias and also exhibits superior electrical characteristics at these temperatures, with measured electrical leakage values < 1E-7 at 2 MV.cm⁻¹ and electrical breakdown electric field > 10 MV.cm⁻¹. Successful Cu plating results of via test structures are also shown.