Volume 41(1) - Winter 2025

The etching technique for high-aspect-ratio hole structures is one of the key technologies in modern semiconductor device manufacturing. Accurately evaluating hole shapes is crucial for developing and controlling the etching process. In order to create a precise evaluation system for deep hole shapes, Rigaku has developed a transmission small-angle X-ray scattering (T-SAXS) instrument. In this technical note, we describe the principles of a small-angle X-ray scattering (SAXS) technique for the determination of three-dimensional semiconductor device structures and its measurement sensitivity based on simulation results. We also demonstrate its performance for SAXS metrology by the measurement of deep holes on a 300 mm wafer. As a result of these measurements we were able to obtain the distribution of deep hole sizes and their tilt across the entire wafer.

Standardless FP analysis can easily calculate analytical values, but there is no established method for assessing them. Consequently, their reliability may decrease if appropriate sample models and corrections are not set. One approach to address this issue is by comparing the Compton scattering X-ray intensity, converted from the theoretical Compton scattering X-ray intensity (calculated from the analytical value), to the measurement intensity scale (hereinafter, “theoretical scattering intensity”) with the actual measured Compton scattering X-ray intensity (hereinafter, “measured scattering intensity”). In this paper, we introduce the method and show the effectiveness for the validity evaluation of SQX analyses.

The Compton scattering internal standard correction technique, which is a matrix correction method conventionally used for geological powder sample analysis, has been improved by integration of a matrix correction term. The matrix correction coefficients are theoretically calculated by the fundamental parameter (FP) method. The improved method accurately extends the applicable range of calibrations to high concentrations.

The improved correction method can be applied to mining samples, such as iron ores, copper ore / concentrate and nickel oxide and sulfide ores analyzed by the pressed pellet method.

The theoretical alpha coefficients obtained by the FP calculation are smaller than conventional theoretical alphas without internal standards. This means the method can reduce the influence of analytical errors from coexisting components. The method has applications in the analysis of powdered ore samples in mining.

TG-FTIR, which combines Simultaneous Thermal Analysis (STA) consisting of Thermogravimetry (TG) and Differential Thermal Analysis (DTA) with Fourier Transform Infrared Spectroscopy (FTIR), is an effective method for simultaneously obtaining information about the reactions occurring in a sample upon heating and the resulting reaction products. This paper presents several applications of TG-FTIR in the analysis of polymers, pharmaceuticals, foods, and inorganic materials. In fiber-reinforced plastics (FRPs), bisphenol A is evolved under thermal decomposition, while CO? is released during combustion. For other polymers, H?O and CO? were quantified during combustion. TG-FTIR was also applied to simulate the ceramic debinding process and identify polymer plasticizers. Additionally, TG-FTIR proved effective in analyzing dehydration in pharmaceuticals, thermal oxidation of edible oils, and reactions in inorganic materials such as gypsum dihydrate.

In X-ray diffraction measurements using a Cu source, transition metals in the sample—for example, batteries and steel materials—generate fluorescent X-rays. These fluorescent X-rays raise background intensities in the measured data, making it difficult to detect peaks derived from trace crystalline phases. The new “XSPA-200 ER” detector, which can be mounted on a benchtop X-ray diffractometer, has high energy resolution, enabling measurements with low background intensities.

This article explores the capabilities of X-ray Computed Tomography (CT) as a non-destructive 3D imaging tool for inspecting dense and complex materials. While not yet as widely adopted as Optical Microscopy (OM) and Scanning Electron Microscopy (SEM), X-ray CT is gaining recognition for its ability to provide detailed volumetric data nondestructively.

The CT Lab HV, developed by Rigaku, features a 225 kV X-ray source, a high-precision rotation stage, and a large detection area, enabling a broad variety of high-resolution imaging applications. Application examples, including additively manufactured superalloys and lithium-ion battery protection boards, highlight its effectiveness in defect detection, structural analysis, and product simulation. As demand for advanced imaging grows, the CT Lab HV offers an innovative solution for industry and research, enhancing the adoption of X-ray CT in critical applications.