Boron and Barium Incorporation at the 4H-SiC/SiO2 Interface using a Laser Multi-Charged Ion Source

TL;DR

This study employs a laser multicharged ion source to modify the 4H-SiC/SiO2 interface with boron and barium ions, significantly affecting the electrical properties of MOS capacitors.

Contribution

It introduces a novel laser-based method for interfacial treatment of 4H-SiC/SiO2 using multicharged ions of B and Ba, enabling controlled interface modification.

Findings

B interfacial layer drastically reduces flatband voltage

Ba layer has negligible effect on flatband voltage

Laser multicharged ion source effectively modifies the interface

Abstract

A laser multicharged ion source was used to perform interfacial treatment of the 4H-SiC/ SiO2 interface using B and Ba ions. A Q-switched Nd:YAG laser (wavelength {\lambda} = 1064 nm, pulse width {\tau} = 7 ns, and fluence F = 135 J/cm2) was used to ablate B and Ba targets to generate multicharged ions. The ions were deflected by an electrostatic field to separate them from the neutrals. The multicharged ions were used for nanometer layer growth and shallow ion implantation in 4H-SiC. Several metal-oxide-semiconductor capacitors (MOSCAP) were fabricated with a combination of B and Ba at the SiC/SiO2 interface. High-low C-V measurements were used to characterize the MOSCAPs. The B interfacial layer reduced the MOSCAP flatband voltage from 4.5 to 0.04 V, while the Ba layer had a negligible effect.