Fine-tuning the etch depth profile via dynamic shielding of ion beam

TL;DR

This paper presents a novel dynamic shielding method for ion beam etching that enables precise control of etch depth profiles, validated through experiments and modeling, advancing ultra-precision fabrication of large optics.

Contribution

It introduces a parametric modeling approach for dynamic shielding effects in ion beam etching, demonstrating its effectiveness in fine-tuning etch depths.

Findings

Shielding rate profile is affected by leaf rotary angle.

The method achieves good agreement between experimental and simulated etch profiles.

Preliminary verification of the dynamic shielding approach for ultra-precision optics fabrication.

Abstract

We introduce a method for finely adjusting the etch depth profile by dynamic shielding in the course of ion beam etching (IBE), which is crucial for the ultra-precision fabrication of large optics. We study the physical process of dynamic shielding and propose a parametric modeling method to quantitatively analyze the shielding effect on etch depths, or rather the shielding rate, where a piecewise Gaussian model is adopted to fit the shielding rate profile. We have conducted two experiments. In the experiment on parametric modeling of shielding rate profiles, its result shows that the shielding rate profile is significantly influenced by the rotary angle of the leaf. And the experimental result of fine-tuning the etch depth profile shows good agreement with the simulated result, which preliminarily verifies the feasibility of our method.