Derrick Shaughnessy

Enhancing scatterometry CD signal-to-noise ratio for 1x logic and memory challenges

The ongoing transition from 2D to 3D structures in logic and memory has led to an increased adoption of scatterometry CD (SCD) for inline metrology. However, shrinking device dimensions in logic and high aspect ratios in memory represent primary challenges for SCD and require a significant breakthrough in improving signal-to-noise performance. We present a report on the new generation of SCD technology, enabled by a new laser-driven plasma source. The developed light source provides several key advantages over conventional arc lamps typically used in SCD applications. The plasma color temperature of the laser driven source is considerably higher than available with arc lamps resulting in >5X increase in radiance in the visible and >10X increase in radiance in the DUV when compared to sources on previous generation SCD tools while maintaining or improving source intensity noise. This high radiance across such a broad spectrum allows for the use of a single light source from 190-1700nm. When combined with other optical design changes, the higher source radiance enables reduction of measurement box size of our spectroscopic ellipsometer from 45×45um box to 25×25um box without compromising signal to noise ratio. The benefits for 1×nm SCD metrology of the additional photons across the DUV to IR spectrum have been found to be greater than the increase in source signal to noise ratio would suggest. Better light penetration in Si and poly-Si has resulted in improved sensitivity and correlation breaking for critical parameters in 1xnm FinFET and HAR flash memory structures.

Advanced Dopant Metrology for 45 nm and Beyond

An overview of the advanced (45 nm and beyond) ion implant and USJ metrology applications using the modulated optical reflectance (MOR) technology is provided.

High Resolution Monitoring of Implant and Anneal Uniformity Using Therma-Probe Technology

A new advanced application of the therma-probe systems for high-resolution mapping of implant and anneal non-uniformities is described.

Dynamics of Carrier Plasma and Thermal Waves in Ion Implanted Si with Varying Pump and Probe Wavelengths

Dynamics of the carrier plasma‐ and thermal‐waves in ion implanted Si is studied using the Modulated Optical Reflectance (MOR) technique with varying pump and probe beam wavelengths. It is shown that selection of the pump and probe beam wavelengths allows control of the MOR signal behavior on Si samples implanted with a wide range of implantation energies and doses.