Scatterometry (OCD & Thin Film)

DUV-Vis-NIR (Wavelength Range: 190nm – 1000nm) Scatterometers/
Thin Film Metrology Systems:

The n&k LittleFoot-CD Series are DUV-Vis-NIR scatterometers/thin film metrology systems, based on polarized reflectance measurements (Rs and Rp) from 190nm to 1000nm, with microspot technology. The systems in the LittleFoot-CD Series determine thickness, n and k spectra from 190nm-1000nm of thin films, as well as depths, CDs, and profiles of trenches and contact holes.

Due to their ability to measure a large range of OCD and thin film structures that cover current and future applications, the tools belonging to the LittleFoot-CD Series are used extensively for power device and MEMS applications, as well as for the most challenging applications of today’s semiconductor industry.

The n&k LittleFoot-CD Series provides tools that are fully automated with approximately 40% reduction in footprint, resulting in a significant savings in the utilization of fab space. This reduction in footprint is achieved through an innovative and patented wafer handling mechanism.The tools belonging to the n&k LittleFoot-CD series are as reliable and fast as any robot-based handling system, but at a much reduced cost.

Please note that the optics of the n&k LittleFoot-CD Series are based on n&k’s new advance optical design. These tools have the same analytic capabilities as those of the OptiPrime-CD Series.

Due to their ability to measure a large range of OCD and thin film structures that cover current and future applications, the tools belonging to the LittleFoot Series are used extensively for the most challenging applications of today’s semiconductor industry.

• Standard films such as SiOx, SiNx, Poly-Si, a-Si:H, SiCx,
  SiGex, a-C:H, TiNx, AlOx
• Polyresists, polymers, polyimides
• Thin metal films (less than ~ 800Å in general)
  • – Al
  • – CrSi
  • – Ta
  • – Ti
  • – W
  • – Cu
  • – Fe
  • – Au
  • – Ag
• High-k films
• Low-k films
• Chalcogenide films
• SOI
• Graphene
• Inhomogeneous films
• A variety of complex film stacks, including
  • – Multi-Layer Film Stacks with Inhomogeneous Under-Layer
  • – Multi-Layer Film Stacks with Unknown Under-Layer
• Ultra-Thin Films (down to a few Å), e.g., a Monolayer of Graphene
• Ultra-Thin Residual Layers
• Films Deposited on Rough Surfaces
• Films on Substrates Besides Silicon:
  • – For example: GaAs, SiC, AlTiC
• Films on rough surfaces
• Surface and interface roughness of thin films
• Energy Band Gap
• Compositon (e.g., %Ge in SiGex; %N, %H, %O in SiOxNx:H,
  %N in TiNx, etc.)
• Crystallinity (e.g., degree of crystallinity of Poly-Si or GST)

• Small (<100nm) pitch and large (>3μm) pitch trenches and contact
  holes structures
• Complex 2-D (trenches) and 3-D (contact holes) structures
  • – Profile
  • – Sidewall Oxide Thickness
  • – Underlayer Thicknesses
• Etch Monitor for Power Devices at All Steps of the Process
  • – Si Trench
  • – Poly Recess
  • – Contact Trench
• FinFET Structures
  • – Gate Height
  • – Gate CD
  • – Fin Height
  • – Fin Top CD
  • – Fin Bottom CD
  • – Oxide Thickness
  • – Dielectric Top Thickness
  • – Dielectric Bottom Thickness
  • – Dielectric Side Wall Thickness
• Si Trench with Oxide Cutback
• Detection of trench and contact hole issues:
  • – Collapsed trenches
  • – Under-etch
  • – Over Etch

In addition, the tools belonging to the LittleFoot-CD Series measure films associated with OCD structures, including hard masks on trenches and contact holes and films at the bottom or lining of these structures.

Trench Array Capability Chart for the LittleFoot-CD Series

Contact Hole Array Capability Chart for the LittleFoot-CD Series