Accuracy and precision in x-ray reflectometry analyses of semiconductor materials
Abstract
Thin film thickness, density and interfacial roughness are parameters that are critical to the performance of conducting and dielectric layers in semiconductor devices. Sensitive and accurate measurements of these quantities are needed in the semiconductor industry in both the process development phase as well as in subsequent manufacturing practice. In contrast with optical probes, X-rays are characterized by short wavelengths (typically 0.8Åto 8.0Åversus 2000Åto 8000Åfor optical tools) and small refractive indices (|n- 1| << 0.0001 versus |n- 1| ∼ 0.3 to 0.8 for light), thus making the interaction of X-rays with solids nearly ideal for determining the geometry of thin film and multilayer structures. High resolution X-ray reflectometry has emerged as a particularly important analytical tool that is capable of providing quantitative information on thin films in either a laboratory setting or on the fab floor. However, there are several factors (both intrinsic to the interaction of X-rays with solids as well as extrinsic factors arising from limitations in experimental methods) that degrade the accuracy and precision of X-ray reflectometry analyses. This talk will review the physical origin of these limits to quantitative measurements and will discuss their effect on semiconductor materials characterization.
- Publication:
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APS March Meeting Abstracts
- Pub Date:
- March 2003
- Bibcode:
- 2003APS..MAR.G3005M