Simulation of Electron-Matter Interaction in Electron Beam Lithography and Metrology

Abstract

Integrated circuit (IC) technology lies at the heart of today’s digital world. The immense amount of computational power that came along with the downscaling of circuits allowed us to place faster and smaller chips almost everywhere. However, with today’s requirements, even a one-nanometer error on those chips can drastically change the performance of the chip. Therefore, maintaining product quality is challenging, and more accurate techniques are needed to manufacture future generation chips. Electron beam based techniques are known to provide very high resolution both in production and testing of these chips. However, the ongoing trend is also challenging the established e-beam technologies. Two common problems in both imaging and lithography are addressed in the thesis. One of them is the emerging importance of the 3rd dimension (3D) in imaging and lithography. The other one is the notorious charging effect when the samples involved, such as gate oxides, are not sufficiently electrically conductive. The experimental trial and error approach to understand and solve these problems is too time-consuming and can also be very expensive. Therefore, tools such as Monte Carlo simulations are needed that aid in getting a better fundamental understanding of these issues. The development of a simulator that can help to find solutions for the problems above is one of the primary objectives of this thesis.