In Situ Rapid Thermal Nitridation of Collimated Titanium by Physical Vapor Deposition as a Blanket Tungsten Barrier

A very thin bilayered titanium nitride/titanium barrier was obtained from in situ rapid thermal nitridation (RTN) for collimated Ti by physical vapor deposition for blanket tungsten plug. Ti with in situ RTN results in fine barrier properties compared with those by RTN with exposure to air after Ti deposition. Furthermore, this thinner film without the re-entrant profile at the contact shoulder was effective for complete contact filling at 0.25 µm diameter with the aspect ratio of 4. This is one of the barrier technologies applicable to quarter-micron devices.