Titanium nitride barrier layers

摘要

An improved titanium nitride barrier layer that prevents spiking between an overlying aluminum layer and a silicon substrate is formed by first sputter depositing a titanium layer onto the substrate, forming an oxygen-containing titanium layer thereover, and sputter depositing a titanium nitride layer over the oxygen-containing layer. The oxygen-containing layer can be formed in an oxygen-containing plasma, or titanium can be sputtered in the presence of oxygen. The titanium nitride layer can also be treated with an oxygen-containing plasma. Robust titanium nitride barrier layers are formed that can prevent spiking by an overlying aluminum contact layer, even after heat treatment up to 550 DEG C.