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

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...

Model sensitivity analysis of Monte-Carlo based SEM simulations

The sensitivity of simulated scanning electron microscopy (SEM) images to the various physical model ingredients is studied using an accurate, but slow simulator, to identify the most important ingredients to include in a reliable and fast SEM image simulator. The quantum mechanical transmission probability (QT) model and the electron...

Charge-induced pattern displacement in E-beam lithography

Electron beam lithography (EBL) requires conducting substrates to ensure pattern fidelity. However, there is an increasing interest in performing EBL on less well-conducting surfaces or even insulators, usually resulting in seriously distorted pattern formation. To understand the underlying charging phenomena, the authors use Monte Carlo...

Model improvements to simulate charging in scanning electron microscope

Background: Charging of insulators is a complex phenomenon to simulate since the accuracy of the simulations is very sensitive to the interaction of electrons with matter and electric fields. Aim: In this study, we report model improvements for a previously developed Monte-Carlo simulator to more accurately simulate samples that charge....

Estimating Step Heights from Top-Down SEM Images

Scanning electron microscopy (SEM) is one of the most common inspection methods in the semiconductor industry and in research labs. To extract the height of structures using SEM images, various techniques have been used, such as tilting a sample, or modifying the SEM tool with extra sources and/or detectors. However, none of these techniques...

Electron beam lithography on curved or tilted surfaces: Simulations and experiments

There is a growing interest for patterning on curved or tilted surfaces using electron beam lithography. Computational proximity correction techniques are well established for flat surfaces and perpendicular exposure, but for curved and tilted surfaces adjustments are needed as the dose distribution is no longer cylindrically symmetric with...

Model improvements to simulate charging in SEM

Charging of insulators is a complex phenomenon to simulate since the accuracy of the simulations is very sensitive to the interaction of electrons with matter and electric fields. In this study, we report model improvements for a previously developed Monte-Carlo simulator to more accurately simulate samples that charge. The improvements...

Challenges for scanning electron microscopy and inspection on the nanometer scale for non-IC application: And how to tackle them using computational techniques

In this paper key challenges posed on metrology by feature dimensions of 20nm and below are discussed. In detail, the need for software-based tools for SEM image acquisition and image analysis in environments where CD-SEMs are not available and/or not flexible enough to cover all inspection tasks is outlined. These environments include...