Invited Paper MS+AS-TuM5
Dynamics in SIMS Characterization for Advanced Nano-Technology: Challenges and Solutions for Novel Materials and 3-D Devices

Tuesday, November 8, 2016, 9:20 am, Room 103A

Over the last few decades, SIMS depth profiling techniques and instrumentation has tremendously evolved to keep up with developments in advanced CMOS technology. I will discuss the main technology drivers, their implications for SIMS characterization, and review some of the analytical challenges and solutions:

- Continued dimensional scaling (i.e. lower film thicknesses, ultra-shallow junctions USJ) demands for progressive improvement of depth resolution. This has been enabled by continuous instrumental developments to provide high-density, stable, and low-impact energy primary ions beams to enable sub-nm depth resolution (i.e. ‘Atomic layer’ SIMS). I will give various applications of high resolution SIMS analysis of thin-film stacks / USJ, routinely employing sub-500 eV ion beams

- Advanced IC development in a manufacturing context demands at-line SIMS metrology with high throughput and reproducibility, often requiring small area analysis on patterned wafers. Key enablers for advances in SIMS metrology are availability of high-density primary ion beams, high level of automation to allow for unattended operation, and instrumental stability / drift correction. I will discuss implications for high-throughput SIMS full wafer mapping and considerations for patterned device wafer

- Paradigm shift towards 3D device architectures (i.e. FinFET) poses one of the greatest challenges, and appears fundamentally incompatible with low-energy (i.e. ‘broad-beam’) SIMS. This can be partially circumvented by averaging over a large regular arrays of FinFET structures, in combination with backfill and planarization to delineate the Fin sidewall (‘SIMS through Fin technique; ), which we have successfully employed at realistic Fin dimensions and pitch, relevant for 14 nm node and beyond

- Integration of novel and dissimilar material stacks demands novel SIMS calibration methods and/or quantification protocols. Potential solutions to deal with the higher complexity are cross-calibration with absolute external techniques (ion scattering techniques, 3D-APT, advanced TEM-EDX / EELS, etc…) and multi-standard approaches for explicit correction of SIMS yield variations with matrix composition. I will give selected examples for quantification of in-situ doping in SiGe_x for wide variation in Ge% and different doping species in various III-V compounds