Semiconductor device including antireflective etch stop layer

摘要

A microelectronic device such as a Metal-Oxide-Semiconductor (MOS) transistor is formed on a semiconductor substrate. A tungsten damascene interconnect for the device is formed using an etch stop layer of silicon nitride, silicon oxynitride or silicon oxime having a high silicon content of approximately 40% to 50% by weight. The etch stop layer has high etch selectivity relative to overlying insulator materials such as silicon dioxide, tetraethylorthosilicate (TEOS) glass and borophosphosilicate glass (BPSG). The etch stop layer also has a high index of refraction and is anti-reflective, thereby improving critical dimension control during photolithographic imaging.