Metal silicide as a barrier for MOM capacitors in CMOS technologies

摘要

The present invention provides a semiconductor device having a metal oxide metal (MOM) capacitor formed over a semiconductor wafer. In one embodiment, the device is a MOM capacitor that includes a first metal layer formed over the semiconductor wafer, a metal silicide layer, such as a tungsten silicide, silicide nitride or a refractory metal silicide, located on the first metal layer and an oxide layer located on the metal silicide layer. The metal silicide layer, which in an advantageous embodiment may be tungsten silicide nitride, resists the corrosive effects of deglazing that may be conducted on other portions of the wafer and is substantially unaffected by the deglazing process, unlike titanium nitride (TiN). Additionally, the metal silicide can act as an etch stop for the etching process. The MOM capacitor is completed by a second metal layer that is located on the oxide layer.