Theoretical consideration of pits recording and etching processes in chalcogenide vitreous semiconductors

TL;DR

This paper presents a theoretical and computational study of laser recording and etching processes in chalcogenide semiconductors, providing models for pit formation and development based on optical and chemical parameters.

Contribution

It introduces a new theoretical framework and computer simulations for understanding and predicting pit shapes and sizes in chalcogenide photoresists during laser recording and etching.

Findings

Phototransformed region shapes depend on material and process parameters.

Derived analytical expressions relate pit dimensions to laser and etching conditions.

Simulations accurately describe pit characteristics in As40S60 chalcogenide layers.

Abstract

We propose theoretical consideration and computer modeling of information pit recording and etching processes in chalcogenide vitreous semiconductors. We demonstrate how to record and develop information pits with the necessary shape and sizes in chalcogenide photoresists using gaussian laser beam and selective etching. It has been shown that phototransformed region cross-section could be almost trapezoidal or parabolic depending on the photoresist material optical absorption, recording beam power, exposure, etchant selectivity and etching time. After illumination, the spatial distribution of photo-transformed material fraction was calculated using the Kolmogorov-Awrami equation. Analyzing obtained results, we derived a rather simple approximate analytical expression for the dependence of the photo-transformed region width and depth on the recording gaussian beam power, radius and exposure time. Then the selective etching process was simulated numerically. The obtained results quantitatively describes the characteristics of pits recorded by the gaussian laser beam in thin layers of As40S60 chalcogenide semiconductor.