Spin-dependent recombination at arsenic donors in ion-implanted silicon

TL;DR

This study investigates spin-dependent recombination processes in arsenic-doped silicon created by ion implantation, using sensitive magnetic resonance techniques to identify defect-related spin interactions at low magnetic fields.

Contribution

It demonstrates the use of SDR and EDMR techniques to detect and analyze spin-dependent processes in arsenic-implanted silicon, revealing defect interactions and recombination mechanisms.

Findings

Detection of As-related magnetic resonance at low fields

Identification of defect pairs involving oxygen-vacancy centers

Observation of spin-dependent recombination via electron double resonance

Abstract

Spin-dependent transport processes in thin near-surface doping regions created by low energy ion implantation of arsenic in silicon are detected by two methods, spin-dependent recombination (SDR) using microwave photoconductivity and electrically detected magnetic resonance (EDMR) monitoring the DC current through the sample. The high sensitivity of these techniques allows the observation of the magnetic resonance in particular of As in weak magnetic fields and at low resonance frequencies (40-1200 MHz), where high-field-forbidden transitions between the magnetic substates can be observed due to the mixing of electron and nuclear spin states. Several implantation-induced defects are present in the samples studied and act as spin readout partner. We explicitly demonstrate this by electrically detected electron double resonance experiments and identify a pair recombination of close pairs formed by As donors and oxygen-vacancy centers in an excited triplet state (SL1) as the dominant spin-dependent process in As-implanted Czochralski-grown Si.