Techniques for single trench damascene interconnect formation using TiN HMO are provided. In one aspect, a method for forming interconnects on a substrate includes: forming an underlayer on the substrate; forming a hardmask on the underlayer; patterning trenches in the hardmask that extend down to the underlayer; forming the interconnects in the trenches; removing the hardmask; and burying the interconnects in an ILD. The trenches can be patterned in the hardmask using a process such as sidewall image transfer. An interconnect structure is also provided.