Vacuum ultraviolet referencing reflectometer and application method

Abstract

A spectroscopy system (500) is provided which operates in the vacuum ultra-violet spectrum. More particularly, a system utilizing reflectometry techniques in the vacuum ultraviolet spectrum is provided for use in metrology applications. To ensure accurate and repeatable measurement, the environment of the optical paths (506, 508) is controlled to limit absorption effects of gases that may be present in the optical path. To account for absorption effects that may still occur, the length of the optical path is minimized. To further account for absorption effects, the reflectance data may be referenced to a relative standard.

Description

Background technique [0001] The present invention relates generally to the instrumentation and application of vacuum ultraviolet reflectance spectroscopy. In one embodiment, the present invention can be used to provide semiconductor manufacturers with high throughput with non-contact metrology capabilities for process control during the manufacture of cutting-edge semiconductor devices. Furthermore, the invention is sufficiently compact to facilitate its use in integrated (in-line) process control applications. [0002] The semiconductor industry is currently developing processing technologies to enable the fabrication of devices composed of thinner layers and to handle smaller feature sizes than ever before. To enable these advances, supporting metrology techniques must be developed because current systems lack the sensitivity required to detect subtle changes in processing conditions. [0003] Optical metrology instruments have long been used in semiconductor processing ap...

AI Technical Summary

Problems solved by technology

While this system enables efficient measurements to be performed over multiple spectral subbands, it has no means of providing a reference for the collected data

Thus, while signal throughput may be high, system repeatability may be rather poor

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