Fastest Thickness Measurements with a Terahertz Time-Domain System Based on Electronically Controlled Optical Sampling
Year: 2019
Type: article
Abstract: We apply a fast terahertz time-domain spectroscopy (TDS) system based on electronically controlled optical sampling (ECOPS) to contact-free thickness gauging. Our setup achieves a measurement speed of 1600 terahertz pulse traces per second, which—to our knowledge—represents the fastest thickness measurement performed with any terahertz system to-date. Using a silicon wafer as a test sample, we compare data of the ECOPS experiment to results obtained with a conventional terahertz TDS system and a mechanical micrometer gauge. We show that all systems provide consistent results within the measurement accuracy. Moreover, we perform thickness measurements of a rapidly moving sample and characterize the ECOPS setup with respect to time-domain dynamic range, signal-to-noise ratio, and spectral properties.
Source: Applied Sciences
DOI: 10.3390/app9071283
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,520
OpenAlex ID: W2935454897