TiN Metal Hardmask Etch Residues Removal for Cu Dual Damascene Devices with TiN Mask Corner Rounding Scheme

Abstract

A novel wet cleaning non-fluoride formulation approach was developed with a TiN etch rate of more than 100 Aå/min at 55 ºC. The chemicals are compatible with Cu and low-k materials, and are suitable for Cu dual damascene interconnect 20 nm and smaller technology node applications. The chemicals offer a route to in situ controlled TiN pullback or even complete removal of the TiN mask during the cleaning process in single wafer tool applications. Additionally, development progress for recent formulations with greater than 250 Aå/min at 50 ºC TiN etch rates is reported.