The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 11, 2026
Filed:
Apr. 03, 2024
Kla Corporation, Milpitas, CA (US);
Qiang Zhao, Milpitas, CA (US);
Ming Di, Pleasanton, CA (US);
KLA Corporation, Milpitas, CA (US);
Abstract
Methods and systems for improved detection of defects of interest and measurement of structures buried within complex three dimensional semiconductor structures are described herein. Through-focus scanning optical microscopy (TSOM) using non-linear, second harmonic generation (SHG) light signals emitted from a sample provides interface-selective sensitivity for metrology and inspection of advanced semiconductor structures. A TSOM/SHG system includes a spectral filter to pass collected light at wavelengths corresponding to SHG emission. In some embodiments, a TSOM/SHG system includes an ultrafast, pulsed laser source emitting ultraviolet to near infrared wavelengths to efficiently induce SHG at surface interfaces. The halving of wavelength inherent to SHG enables a doubling of illumination wavelength without penalizing resolution. In a further aspect, a TSOM/SHG measurement system includes an exogenous illumination source, an external electric field source, or both, to induce a DC electric field at one or more interfaces of structures under illumination, thereby enhancing SHG emission.