Scatterfield microscopy is the union of a high-magnification imaging platform and the angular and/or wavelength control of scatterometry at the sample surface. Scatterfield microscopy uses Köhler illumination, where each point on the source translates to a particular angle of illumination yet also yields spatial illumination homogeneity. To apply scatterfield microscopy to quantitative metrology, several aspects of the optical column must be well understood. Characterizations are presented of the illumination intensity, angle, polarization, and measured glare as functions of the position of an aperture in the conjugate to the back focal plane (CBFP) of the objective lens. The characterization of a reference sample is shown to be as important as the inspection of other optical elements in the optical column. Reflectivity can be derived for line arrays lacking diffractive orders by measuring such a reference and deriving a 'tool function' to account for the current state of the optical platform. Examples from defect, critical dimension, and overlay metrologies are presented to demonstrate the necessity of characterization for scatterfield microscopy.

New techniques recently developed at the National Institute of Standards and Technology using bright-field optical tools are applied to signal-based defect analysis of features with dimensions well below the measurement wavelength. A key to this approach is engineering the illumination as a function of angle and analysis of the entire scattered field. In this paper we demonstrate advantages using this approach for die-to-die defect detection metrology. This methodology, scatterfield optical microscopy (SOM), is evaluated for defect inspection of several defect types defined by Sematech on the Defect Metrology Advisory Group (DMAG) intentional defect array (IDA) wafers. We also report the systematic evaluation of defect sensitivity as a function of illumination wavelength.Theoretical simulations are reported that were carried out using a fully three-dimensional finite difference time domain (FDTD) electromagnetic simulation package. Comprehensive modeling was completed investigating angle-resolved illumination to enhance the detection of several defect types from the IDA wafer designs. The defect types covered a variety of defects from the IDA designs. The simulations evaluate the SOM technique on defect sizes ranging from those currently measurable to those the industry considers difficult to measure. The simulations evaluated both the 65 nm IDA metal-1 M1 trench and the polysilicon stack and more recent 13 nm linewidth logic cells.

The refractive index of a y-cut SiO2 crystal surface is reconstructed from orientation-dependent soft X-ray reflectometry measurements in the energy range from 45 to 620 eV. Owing to the anisotropy of the crystal structure in the (100) and (001) directions, a significant deviation of the measured reflectance at the Si L 2,3 and O K absorption edges is observed. The anisotropy in the optical constants reconstructed from these data is also confirmed by ab initio Bethe–Salpeter equation calculations for the O K edge. This new experimental data set expands the existing literature data for quartz crystal optical constants significantly, particularly in the near-edge regions.

This paper focuses on the capability of the spectroscopic scatterometry method to determine holes features parameters from experimental 3D-target. Scatterometry uses optical tools for spectra recording as ellipsometer form KLA TENCOR and a MMFE (Modal Method of Fourier Expansion) software tool including an advanced electromagnetic simulator and an optimization loop for data extraction. This study reports on 3D-MMFE regression of different dense holes square and rectangular matrix structures on the simpliest structure -resist on silicon -to extract diameter, height of the holes. The holes diameter is from 90nm to 500nm, and the duty ratio is from 1:1 to 2:2 (CD/Space). To be close to real production stack the same matrices have been studied on more complex stack (close to via level with different dielectric material: FSG, dense SiOC). Finally this study is focused on an analysis on simulation and experiment of the relative sensitivity position of a hole inside the basic element of diffraction. That shows the possibility of scatterometry measurement in detecting via shift.

A scatterfield microscope using 193 nm laser light was developed that utilizes angle-resolved illumination for high resolution optical metrology. An angle scan module was implemented that scans the illumination beam in angle space at the sample by linearly scanning a fiber aperture at a conjugate back focal plane. The illumination light is delivered directly from a source laser via an optical fiber in order to achieve homogeneous angular illumination. A unique design element is that the conjugate back focal plane (CBFP) is telecentric allowing the optical axis of the fiber to be scanned linearly. Initial results from full field and angle-resolved illumination are presented and potential applications in semiconductor metrology are described.