Critical influence of target-to-substrate distance on conductive properties of LaGaO3/SrTiO3 interfaces deposited at 10-1 mbar oxygen pressure

TL;DR

This study shows that the target-to-substrate distance during pulsed laser deposition critically affects the electrical conductivity of LaGaO3/SrTiO3 interfaces, enabling control over their insulating or metallic states.

Contribution

It reveals the significant impact of target-to-substrate distance on interface conductivity at high oxygen pressure, highlighting plume dynamics as a key factor.

Findings

Decreasing target-to-substrate distance turns interface from insulating to metallic.

Plume propagation influences interface properties.

Conducting interfaces can be grown at high oxygen pressure.

Abstract

We investigate pulsed laser deposition of LaGaO3/SrTiO3 at 10-1 mbar oxygen background pressure, demonstrating the critical effect of the target-to-substrate distance, dTS, on the interface sheet resistance, Rs. The interface turns from insulating to metallic by progressively decreasing dTS. The analysis of the LaGaO3 plume evidences the important role of the plume propagation dynamics on the interface properties. These results demonstrate the growth of conducting interfaces at an oxygen pressure of 10-1 mbar, an experimental condition where a well-oxygenated heterostructures with a reduced content of oxygen defects is expected.