Oxygen Incorporation in the MBE growth of ScxGa1-xN and ScxAl1-xN

TL;DR

This study uses SIMS to analyze impurity levels, especially oxygen, in scandium-containing nitride heterostructures grown by MBE, revealing a correlation between scandium content and impurity concentrations.

Contribution

It provides detailed impurity profiles in ScxGa1-xN and ScxAl1-xN heterostructures, highlighting how scandium incorporation affects oxygen and carbon levels during MBE growth.

Findings

Oxygen levels increase with scandium content in both heterostructures.

Impurity concentrations are influenced by growth conditions and substrate types.

Oxygen incorporation occurs during scandium alloyed layer deposition.

Abstract

Secondary-ion Mass Spectrometry (SIMS) is used to determine impurity concentrations of carbon and oxygen in two scandium containing nitride semiconductor multilayer heterostructures: ScxGa1-xN/GaN and ScxAl1-xN/AlN grown by molecular beam epitaxy (MBE). In the ScxGa1-xN/GaN heterostructure grown in metal rich conditions on GaN-SiC template substrates with Sc contents up to 28 atomic percent, the oxygen concentration is found to be below 1x1019/cm3, with an increase directly correlated with the Scandium content. In the ScxAl1-xN-AlN heterostructure grown in nitrogen rich conditions on AlN-Al2O3 template substrates with Sc contents up to 26 atomic percent, the oxygen concentration is found to be between 1019 to 1021/cm3, again directly correlated with the Sc content. The increased oxygen and carbon arises during the deposition of scandium alloyed layers.