Self-Organized Formation of Fractal and Regular Pores in Semiconductors

TL;DR

This paper investigates the self-organized formation of fractal and regular pores in semiconductors during electrochemical etching, using a dynamical model to explain the processes behind pore morphology.

Contribution

It introduces the Current-Burst-Model to describe the inhomogeneous, dynamic processes leading to pore formation in semiconductors.

Findings

Explains how pore structures depend on material and chemical interactions.

Provides a qualitative understanding of pore morphology formation.

Models the inhomogeneous dissolution processes during etching.

Abstract

Electrochemical etching of semiconductors, beside technical applications, provides an interesting experimental setup for self-organized structure formation capable of regular, diameter-modulated, and branching pores. The underlying dynamical processes governing current transfer and structure formation are described by the Current-Burst-Model: all dissolution processes are assumed to occur inhomogeneously in time and space as a Current Burst (CB); properties and interactions between CB's are described by a number of material- and chemistry- dependent ingredients, like passivation and aging of surfaces in different crystallographic orientations, giving a qualitative understanding of resulting pore morphologies.