Novellus Systems, Inc., the productivity and technology leader in advanced deposition, surface preparation and chemical mechanical planarization (CMP) processes for the global semiconductor industry, today announced the introduction of ALTUS DirectFill-a single-system solution designed to meet contact and via-fill needs at 65 nm and below. Leveraging Novellus’ production-proven ALTUS platform, DirectFill eliminates the need for conventional titanium/titanium nitride (Ti/TiN) toolsets. This advanced plug-fill technique can reduce contact resistance (Rc) and lower overall cost of ownership (CoO) by 50 percent or more when compared to existing processes.
Novellus’ ALTUS DirectFill simplifies the tungsten deposition process by replacing the standard multi-tool, Ti/TiN/W approach with a single system. This system integrates an advanced preclean process in one process module, followed by Novellus’ proprietary, pulsed nucleation layer (PNL™) deposition of tungsten nitride (WN) in a second module, and then a combined PNL and chemical vapor deposition (CVD) tungsten (W) deposition in a third module. The multi-station sequential deposition process modules used for WN and W deliver high productivity and process reproducibility.
ALTUS DirectFill technology provides several key technical benefits. First, the tungsten nitride barrier exhibits atomic layer deposition (ALD) conformality and is substantially thinner than the Ti/TiN liner-barrier it replaces, allowing more of the contact to be filled with lower resistivity tungsten. The tungsten nitride/low resistivity tungsten DirectFill process can reduce contact plug resistance by as much as 50 percent at the 45-nm node. Additionally, PNL tungsten nitride provides excellent barrier characteristics for tungsten and adheres to a variety of dielectric materials. All process temperatures are below 400°C, providing compatibility with future process integration requirements. Unlike competitive systems, ALTUS DirectFill technology solves fill problems at advanced nodes without compromising resistivity.
“ALTUS DirectFill combines an innovative new model for advanced contact fill with the benefits of a proven Novellus platform,” said Karl Levy, vice president and general manager of Novellus’ Tungsten Business Unit. “Unlike the conventional PVD/MOCVD process sequence, our integrated single-architecture technology approach enhances current tungsten deposition applications, such as contact and bit line, while enabling future applications, such as capacitor electrode and metal gate electrode, where tungsten nitride and tungsten are currently being evaluated. It is a system that carries significant technical advantages without sacrificing productivity,” added Levy.
The new tool is available in both 200-mm (Concept Two ALTUS DirectFill) and 300-mm (Concept Three ALTUS DirectFill) configurations. Novellus is actively engaged in joint development projects and working with more than two dozen customers worldwide to develop processes for a wide range of applications and emerging technologies.
For more information on tungsten, click here.