Optical profilometer at nanometer scales for semiconductor chip

• Main Author: Wei, Haoran
• Other Authors: Cuong Dang
• Format: Thesis-Master by Coursework
• Language: English
• Published: Nanyang Technological University 2022
• Subjects: Engineering::Electrical and electronic engineering::Optics, optoelectronics, photonics
• Online Access: https://hdl.handle.net/10356/159268
• Institution: Nanyang Technological University

With the development of the semiconductor industry, the feature size of semiconductor chips has been gradually reduced and has reached the nanometer level. Whether it is scientific research or actual production, it is necessary for the detection of such small-sized structural contours. The conventional light wave detection scheme has certain inoperability due to the wavelength of light up to several hundreds of nanometers. Considering that most of the structures in the chip are periodic, this project approximates the optical properties of the unit structure as a diffraction grating model of nanostructures, and uses powerful simulation tools and computers to solve the inverse problem and find the structure profile from the reflection spectrum. The project uses coupled wave analysis to perform mathematical calculations on such approximate diffraction grating models, and systematically studies the operation process of the simulation platform COMSOL Multiphysics. After the systematic learning, operations such as model building and physical field settings are performed in COMSOL Multiphysics. The output is visualized and data statistics are constructed to construct a relevant reflectance spectrum library. The matching of the reflectance spectrum of the chip profile of the unknown structure with the content in the data set is realized, and the operation of inferring the structure to be tested and its related size parameters is based on this.