4 / 2019-03-20 22:22:35

28nm Kelvin Via Rc Reduction in Metal Hard-mask based Cu/Ultra Low-K Interconnects by Special Gas Base Plasma Etching Development

28nm;,Kelvin Via Rc Reduction ;,Cu/Ultra Low-K Interconnects

Kelvin via Rc resistance reduction is a key challenge to advance device performance. In low k interconnect process, it’s usually to enlarge via critical dimension (CD) to reduce Rc resistance, but there has to be a trade off between via CD and bridge window. This paper meant to show how to enlarge via CD without sacrificing bridge window and CP yield. Higher ratio of special gas and lower ion bombardment of plasma etching recipe can reduce 15% of Kelvin via Rc resistance.