Magnetic patterning of (Ga,Mn)As by hydrogen passivation

TL;DR

This paper introduces a novel hydrogen passivation technique to locally suppress ferromagnetism in (Ga,Mn)As layers, enabling magnetic patterning with minimal structure size of 200 nm and improved magnetic properties compared to traditional etching methods.

Contribution

The study demonstrates a new method for magnetic patterning of (Ga,Mn)As using hydrogen passivation, preserving surface continuity and achieving smaller feature sizes.

Findings

Hydrogen passivation effectively reduces hole density in targeted regions.

Patterned ferromagnetic dots show switching fields closer to continuous film coercivity.

The method allows for minimal feature sizes of about 200 nm.

Abstract

We present an original method to magnetically pattern thin layers of (Ga,Mn)As. It relies on local hydrogen passivation to significantly lower the hole density, and thereby locally suppress the carrier-mediated ferromagnetic phase. The sample surface is thus maintained continuous, and the minimal structure size is of about 200 nm. In micron-sized ferromagnetic dots fabricated by hydrogen passivation on perpendicularly magnetized layers, the switching fields can be maintained closer to the continuous film coercivity, compared to dots made by usual dry etch techniques.