Elemental distribution and oxygen deficiency of magnetron sputtered ITO films

TL;DR

This study investigates the atomic structure, composition, and oxygen deficiency in magnetron sputtered ITO films and their interfaces with silicon, revealing complex interfacial layers and nanoclusters affected by electron exposure.

Contribution

It provides detailed analysis of the ITO/Si interface structure, composition, and oxygen deficiency using TEM and XPS, highlighting effects of electron exposure on nanoclusters and interface layers.

Findings

Presence of SiO$_x$ layer at ITO/Si interface

Oxygen deficiency regions in ITO films

Electron exposure crystallizes In nanoclusters and thickens SiO$_x$ layer

Abstract

The atomic structure and composition of non-interfacial ITO and ITO-Si interfaces were studied with Transmission Electron Microscopy (TEM) and X-ray Photoelectron Spectroscopy (XPS). The films were deposited by DC magnetron sputtering on mono-crystalline p-type (100) Si wafers. Both as deposited and heat treated films consisted of crystalline ITO. The ITO/Si interface showed a more complicated composition. A thin layer of SiO$_x$ was found at the ITO/Si interface together with In and Sn nanoclusters, as well as highly oxygen deficient regions, as observed by XPS. High energy electron exposure of this area crystallized the In nanoclusters and at the same time increased the SiO$_x$ interface layer thickness.