Optical design of refractive imaging spectrometer for semiconductor metrology

Wei-Jei Peng; Ming-Fu Chen; Tsung-Xian Lee

doi:10.1117/12.2672269

15 August 2023 Optical design of refractive imaging spectrometer for semiconductor metrology

Wei-Jei Peng, Ming-Fu Chen, Tsung-Xian Lee

Proceedings Volume 12618, Optical Measurement Systems for Industrial Inspection XIII; 1261821 (2023) https://doi.org/10.1117/12.2672269
Event: SPIE Optical Metrology, 2023, Munich, Germany

Conference Poster

Abstract

Critical dimension (CD) uniformity has recently become increasing essential with miniaturization in semiconductor production. For high-volume manufacturing, high-speed in-wafer uniformity inspection is inevitable. The conventional optical critical dimension (OCD) spectroscopy has low resolution issue because of the large spot size. Consequently, line-scan hyperspectral imaging (LSHI) is presented by Samsung Electronics in 2022. Compared with the OCD, the LSHI has advantages of high throughput, high spatial and spectral resolution, and large field of view. The LSHI can improve the throughput of OCD significantly and provide high-resolution spatial and spectral information. In this study, the optical design of the refractive imaging spectrometer based on the ruled reflection grating is presented. Most imaging spectrometers, such as Czerny-Turner or Ebert-Fastie setup, are off-axis reflective configuration. However, the performance is limited by serious astigmatism and smaller numerical aperture. The astigmatism leads to low spatial and spectral resolution, and the smaller numerical aperture requires more exposure time, which results in low throughput. Therefore, the refractive type using lens combinations for imaging spectrometers can eliminate aberrations effectively and increase numerical aperture significantly. In this study, the numerical aperture is designed as f/2.4, and the slit length is 14 mm for high throughput. The high spatial and spectral resolution is accomplished by optimizing lens combinations from 400 nm to 800 nm spectral region.

Citation Download Citation

Wei-Jei Peng, Ming-Fu Chen, and Tsung-Xian Lee "Optical design of refractive imaging spectrometer for semiconductor metrology", Proc. SPIE 12618, Optical Measurement Systems for Industrial Inspection XIII, 1261821 (15 August 2023); https://doi.org/10.1117/12.2672269

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available