Nano-Scale Analysis Using Synchrotron-Radiation: Applications in the Semiconductor Industry

Abstract

In semiconductor industry, process control and physical failure analysis were dominated by light and electron microscopy as well as surface analysis techniques including X-ray photoelectron spectroscopy (XPS) until the end of the last century. During the past decade, X-ray diffraction (XRD) and X-ray reflectivity (XRR) have been successfully applied in out-of-fab analytical labs. In addition to XRF and TXRF, some additional X-ray techniques -e.g. XRD, XRR and XPS -have been moved or are in the process to be moved from lab-based studies to in-line applications, using cleanroom compatible thin film characterization tools in wafer fabs. Lab-based smallangle X-ray scattering (SAXS) tools are applicable for pore size characterization in porous thin films. Advanced transmission X-ray microscopy (TXM) and X-ray computed tomography (XCT) systems with sub-100 nm resolution are currently being evaluated for their use in out-of-fab analytical labs. Apart from the on-site use of laboratory X-ray sources, synchrotron-radiation sources have been used in all fields of X-ray techniques: diffraction (SR-XRD), spectroscopy (SR-XPS, XAFS) and microscopy (SR-TXM/XCT). The high brightness and collimation of SR beams provide unique possibilities, e.g. for in-situ X-ray microdiffraction, photoelectron emission microscopy (PEEM) and in-situ TXM/XCT.In this paper, we demonstrate the high potential of the X-ray techniques for semiconductor industry, we describe potential implementations of these techniques for current and future applications, particularly for advanced process development and process monitoring, and we provide an outlook showing that we are living in a decade which is characterized by a breakthrough in the industrial application of Xray techniques. The application focus of this review is on the study of two types of nanostructures with typical dimensions less than 100 nm: artificial nanolayers and nanostructures caused by thin film deposition and patterning (litho/etch) processes as well as nanostructured materials, i. e. thin film materials with a "sub-structure" on sub-100 nm length scale.

Quantification of a Single Aggregate Inner Porosity and Pore Accessibility Using Hard X-ray Phase-Contrast Nanotomography

“…This letter represents a pilot project for measuring the 3D internal structure of aggregates composed of polymer primary particles utilizing Zernike phase-contrast X-ray nanotomography. Even though Zernike phase-contrast X-ray imaging was applied to the acquisition of 2D images, − its application to determine the 3D internal structure of inorganic material such as zinc oxide particles and nanoporous gold or even cells is rather recent. The presented work represents the next step in the utilization of Zernike phase-contrast X-ray nanotomography toward the development of a high-throughput, high-resolution 3D technique for imaging very weakly absorbing materials.…”

Devices, Materials, and Processes for Nanoelectronics: Characterization with Advanced X‐Ray Techniques Using Lab‐Based and Synchrotron Radiation Sources

“…X‐ray texture and strain measurements on arrays of parallel copper interconnects using X‐ray micro‐diffraction (micro‐XRD) setups at lab and synchrotron radiation facilities have been reported in ref 9. To measure texture and strain averaged over a statistically significant number of copper crystallites, a collimated high‐intensity primary beam is directed to test structures with dimensions of typically a few 100 µm by a few 100 µm.…”

“…Synchrotron radiation has been used in all fields of X‐ray techniques: diffraction (SR‐XRD), spectroscopy (SR‐XPS, XAS), and transmission X‐ray microscopy (SR‐TXM). The high brightness and collimation of synchrotron radiation provide unique possibilities, e.g., TXRF with decreased detection limits, energy‐tuned photoelectron emission microscopy (PEEM), XAS including it's fine structure analysis, in situ X‐ray micro‐diffraction as well as in situ TXM, and X‐ray computer tomography (XCT) with high spatial resolution 9. Complementary to the X‐ray techniques, collimated neutron beams can be used to study the roughness of interfaces, oxide barrier thickness, and interdiffusion with ultra‐high resolution 5…”

Atomic spectrometry update. Industrial analysis: metals, chemicals and advanced materials

“…An overview by Zschech and co-workers discussed the rapidly increasing usage of nano-scale analysis using synchrotron-radiation-based techniques. 283 In addition to XRD and TXRF, an ever increasing number of other analytical techniques are being used both in analytical laboratories and also in-line, enabling increasingly rapid analyses to be performed. Such techniques include small angle X-ray scattering (SAXS), that may be used for pore size characterization, advanced transmission X-ray microscopy (TXM), X-ray computed tomography, SR-XRD, SR-XPS and XAFS.…”